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Udder surgery in ewes
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Udder surgery in ewes ⁎
V. Tsioli , G.C. Fthenakis Veterinary Faculty, University of Thessaly, 43100, Karditsa, Greece
A R T I C LE I N FO
A B S T R A C T
Keywords: Ewe Mastitis Udder Teat Surgery
Objective of this review is to present relevant information about udder surgery in ewes and to discuss its applications within the frame of sheep health management. The indications, diagnostic procedures, techniques, possible complications, post-operative care and prognosis of surgical conditions of the ovine udder are reviewed. Mammary surgery may help in decision-taking for the management of various udder and teat conditions providing alternative therapeutic solutions.
1. Introduction Surgical conditions of the udder of sheep are infrequently reported in the literature, in contrast to similar disorders in dairy cattle. Surgical conditions of the udder can affect the overall health status of affected animals and might lead to death or culling of ewes. In sheep, mammary surgery is not applied frequently, although indications for surgical treatment of udder disorders exist and surgical techniques are available and may be employed to improve recovery of affected animals and improvement of their welfare. Objective of this review is to present relevant information regarding surgical management of udder problems in sheep and to discuss indications, techniques, post-operative care and complications within the frame of sheep health management. It is noteworthy that there is little literature related to mammary surgery specifically in ewes and for the present review relevant publications in does and cows have been used, appropriately adopted for application to ewes. 2. Indications for udder surgery In sheep, various conditions of the udder require surgical intervention. Surgical management of udder wounds is the most frequently needed procedure in sheep and occur often in that species. Sheep graze upon a variety of environments and territories, that way exposing their mammary glands to adverse conditions and predisposing to wounds. Further, teat injuries are common and significant and affect milkability of ewes and reduce animal welfare (Couture and Mulon, 2005; Mulon, 2016). They can be the consequences of traumas, infections, inappropriate husbandry practices (e.g., inappropriate regulated milking routine) and adverse environmental factors. Teat injuries predispose
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ewes to mastitis (Mavrogianni et al., 2006; Mavrogianni and Fthenakis, 2007). Although they have been commonly reported in cows (Bristol, 1989a,b; Nichols, 2008), there are few reports on their impact and management in ewes. Mammary biopsy can be performed for diagnostic purposes or in research situations, for histological evaluation of tissue samples. Thelotomy or thelectomy are indicated in cases of presence of supernumerary teats, traumatic injuries or fistulas (Bristol, 1989a; Anderson and Hull, 2002; Couture and Mulon, 2005; Nichols, 2008; Mulon, 2016). Indications for mastectomy include large abscesses, pendulous udder, irreparable udder injuries and neoplasias (Wooldridge et al., 1999; El-Maghraby, 2001; Anderson and Hull, 2002; Fubini et al., 2004; Monsang et al., 2014; Sabuncu et al., 2015). Mastectomy can be unilateral or radical (Yeshwantkumar and Nirmala, 2008; Sabuncu et al., 2015). Unilateral mastectomy, although considered technically more demanding, offers the advantage of a shorter operating time. Moreover, ewes can continue to lactate (El-Maghraby, 2001; Sabuncu et al., 2015), thus maintained in the reproductive process. Mammary neoplasms in sheep are rare (Löhr, 2012; Mihevc and Dovc, 2013) and reports on management of relevant disorders are sparse (Ali, 1986; Gulbahar et al., 2007; McElroy and Bassett, 2010; Dezfoulian et al., 2011). The differential diagnosis for masses palpated within the udder includes chronic mastitis, abscess, fibrosis and haematoma (Mihevc and Dovc, 2013). 3. Surgical anatomy The udder of ewes consists of the two semi-spherical mammary glands, each of which has one teat 2.0–3.5 cm in length in an angle of 40–45 ° to the body of the ipsilateral mammary gland (May, 1970;
Corresponding author. E-mail address: [email protected] (V. Tsioli).
https://doi.org/10.1016/j.smallrumres.2019.06.019 Received 2 April 2019; Received in revised form 19 June 2019; Accepted 19 June 2019 0921-4488/ © 2019 Elsevier B.V. All rights reserved.
Please cite this article as: V. Tsioli and G.C. Fthenakis, Small Ruminant Research, https://doi.org/10.1016/j.smallrumres.2019.06.019
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aseptically, as detailed before (Vasileiou et al., 2018). The results will reveal potential presence of mastitis, which needs to be taken into account, for correct management of the animal pre- and post-operatively. Ultrasonographic examination by using B-mode, Doppler and/or contrast-enhanced technologies can be of particular value in identifying possible lesions within the organ. Their detailed description is beyond the scope of this review, as relevant papers have been published recently (Barbagianni et al., 2017; Petridis et al., 2017; Mantziaras et al., 2018). Teat endoscopy (‘theloscopy’) is a diagnostic procedure that has recently been described in ewes (Kiossis et al., 2009). It is a non-invasive technique that allows direct observation of the internal side of the teat and thus can provide a precise diagnosis of pathological conditions in there. There is also the possibility to employ the technique for surgical management of teat lesions (‘theloresectoscopy’), through use of high-frequency surgical cutting unit (Geishauser et al., 2005).
Schummer et al., 1981; Pasquini and Spurgeon, 1989; Hofmeyer, 1990). Immediately after the teat orifice (ostium papillae), located at the distal end of the teat, follows the teat duct (ductus papillaris), with a total length of 0.3 to 0.8 cm. The teat duct is followed by the teat cistern (sinus papillaris), which is demarcated from the gland cistern by an annular ring, which contains a large vein that encircles the base of the teat (Schummer et al., 1981). Each teat is lined with five layers: mucosa, submucosa, a layer of connective tissue, a layer of muscular tissue, composed of circular and longitudinal fibers and the skin, covered by stratified squamous epithelium. Presence of supernumerary teats occurs often, occasionally, some of them being fully functional and allowing expression of milk through them. The mammary parenchyma has a typical tubulo-alveolar structure. The gland cistern (sinus lactiferous), with a capacity of 20 to 80 mL, which drains to the teat cistern, receives the 10 to 15 lactiferous ducts (ducti lactiferi), which further divide in smaller, 2nd and 3rd class, ducts and ductules, which receive the mammary secretion from the lobes and lobules of the parenchyma. The udder is supported by the medial and lateral suspensory ligaments, which play an important role in supporting the udder and maintaining it tightly attached to the ventral abdominal wall. The medial lamina is comprised of two sheets, which divide the udder in two halves, thus permitting unilateral mastectomy. The lateral suspensory ligament arises from the pelvic symphysis, subpubic and prepubic tendon. Blood supply to each mammary gland is provided mainly by the external pudendal artery that emerges from the inguinal ring, branches to the udder and continues cranially as the cranial superficial epigastric artery. Udders are drained by the external pudendal veins, the caudal superficial epigastric and the perineal veins (Fig. 1). The iliohypogastric, the ilioinguinal, the genitofemoral and branches of the pudendal nerves innervate the udder. The superficial inguinal lymph nodes provide lymph drainage and are located at the caudoproximal aspect of the udder.
5. Surgical techniques The surgical principles must be applied in all cases of udder surgery. These include haemostasis, application of aseptic conditions and delicate tissue handling. Appropriate sedation, anaesthesia and analgesia should also be administered as needed (Galatos, 2011). Sedation is done by administration of a-2 adrenoceptor agonists (xylazine, romifidine, detomidine, medetomidine, dexmedetomidine) or benzodiazepines (diazepam, midazolam). Cranial epidural anaesthesia can be performed. Further, local anaesthesia can be provided by ring block, inverted ‘V’ block, teat cistern infusion or intravenous regional anaesthesia. For full thickness biopsies, extended parenchyma wounds and mastectomies, general injectable or inhalation anaesthesia might be required. Injectable anaesthetics can be used for short-term anaesthesia (ketamine, propofol, thiopental). Inhalation anaesthesia is preferred for longer operating periods (isoflurane, sevoflurane) (Anderson and Hull, 2002; Skarda and Tranquilli, 2007; Nichols, 2008; Galatos, 2011; Mulon, 2016). Pre-operative administration of antibiotics and nonsteroidal anti-inflammatory drugs is indicated.
4. Diagnostic approaches in surgical conditions of the udder 5.1. Management of mammary parenchyma wounds Initially, a complete history should be taken, to be followed by a detailed clinical examination (Fthenakis, 1994; Mavrogianni et al., 2005). Standard laboratory examinations include bacteriological and cytological examination of milk samples, which need to be collected
Planning treatment of udder wounds should take into consideration: time that has elapsed since injury, size of the wound, degree of contamination, extent of tissue damage, extent of necessary debridement, wound blood supply, animal’s general condition, wound location and presence of tension or dead space (MacPhail, 2013b). Immediate primary closure, delayed primary closure (3–5 days after wounding) or second intention healing should be considered and undertaken appropriately. Mammary parenchyma wounds should be thoroughly cleaned before surgical management would be attempted. Initially, copious irrigation of wounds can be performed with tap water, in order to reduce gross contamination. Subsequently, lavage with antiseptic solution should follow. Chlorhexidine 0.05 to 0.1% solution or povidone iodine 0.1 to 0.01% solution is recommended. High pressure irrigation (5–8 psi) is ideal and can be applied by the use of an 18- to 19 – gauge needle. Application of cold hydrotherapy pre- and post-operatively can reduce wound contamination and oedema. Wound debridement is indicated to remove necrotic, contaminated or devitalised tissues (Anderson and Hull, 2002; Fubini et al., 2004; Nichols, 2008; Mulon, 2016). Management of mammary parenchyma wounds can be usually undertaken on site and only in a few cases an operating room would be needed (e.g., when excessive debridement would be required). Primary closure in partial thickness wounds of the udder is performed by suturing skin with absorbable or non-absorbable, monofilament or multifilament sutures by using a continuous or simple interrupted pattern. In full thickness wounds, a three-layer closure technique needs to be performed (described in 5.2., 5.3). Delayed primary closure
Fig. 1. Diagram of arterial supply to ewes’ udder. a. external pudendal artery, b. branch to lymph nodes, c. papillary arteries, d1., d2., d3. cranial, middle and caudal mammary artery. 2
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5.3. Management of teat injuries, thelotomy, thelectomy
can be employed in contaminated wounds, wounds with substantial oedema and in wounds when staged debridement would be required. With this technique, daily open wound management is performed, until granulation tissue formation, thus, wound closure is delayed for 3–5 days after injury (Hosgood, 2012). Second intention healing is more appropriate for dirty wounds with gross inflammation, presence of necrotic tissues and extensive soft tissue trauma, these wounds being unsuitable for primary or delayed primary closure. In second intention healing wounds are treated as open and closure is achieved by contraction and epithelialisation. Local application of antimicrobial agents is indicated to be performed early in wound management. This includes ointments and silver-based or hyperosmotic dressings (MacPhail, 2013b). Wound protection with a bandage is important, particularly during second intention healing.
Teat injuries, thelotomy and thelectomy can be performed after administration of local or epidural anaesthesia, with the animal in standing position or in recumbency. These procedures can be undertaken in the field, whilst an operating room might be needed only in selected cases, in which would be scheduled. Teat injuries are initially debrided and lavaged and then sutured. If the mucosa of the teat cistern has been torn, a three-layer closure is performed. The mucosa (incorporating the submucosa) is sutured initially, followed by the muscular layer and then by the skin. It is noteworthy that sutures should not penetrate the mucosa. Suturing of the mucosa, submucosa and muscular layer is performed by using monofilament synthetic absorbable material (polyglycolic acid, polydioxanone) with a taper point swagedon needle of size 4-0. Skin can be closed with metallic staples or monofilament sutures with a reverse cutting swaged-on needle of size 20 to 4-0. In severe injuries in which teat reconstruction may not be possible, a thelectomy can possibly be performed. Teat fistulas do not occur often in ewes. Fistulas and their tracks are dissected en bloc from surrounding normal tissues, with a three-layer closure performed at the end (Bristol, 1989a; b; Anderson and Hull, 2002; Fubini et al., 2004; Couture and Mulon, 2005; Nichols, 2008; Tsioli et al., 2019). During thelotomy, a longitudinal full-thickness incision is made through the wall of the teat (Fig. 3a). The teat cistern is examined and lesions are removed. A three-layer closure is performed; subsequent steps are as previously described (Fig. 3b, c). Small supernumerary teats or teats in young animals can be removed with scissors. Larger formations can be removed with a scalpel, with simultaneous control of haemorrhage. An elliptical incision is performed in a craniocaudal direction at the teat base. In cases in which these communicate with the teat canal or cistern, a thelectomy at the base of the teat can be performed, followed by a three-layer closure (Bristol, 1989a, 1989b; Anderson and Hull, 2002; Fubini et al., 2004; Couture and Mulon, 2005; Mulon, 2016; Tsioli et al., 2019). In ewes with small size teats, development of granulation tissue during healing after injuries can lead in teat stenosis or obstruction, thus leading in reduced milk flow. In such cases, increase of the diametre of teat duct can be affected through use of a ‘teat knife’. After insertion of the knife into the teat canal, this would be angled at 45° and a cut can be made at the area of the border between teat duct - teat cistern to the proximal part of the teat duct (Bristol, 1989a,b; Anderson and Hull, 2002; Fubini et al., 2004; Couture and Mulon, 2005; Mulon, 2016). In ewes with floating scar tissue or lactoliths therein, extraction can be initially attempted by mosquito or alligator forceps; if this is not successful, a thelotomy can be performed. For thelectomy, atraumatic crushing forceps are placed at the base of the teat to provide haemostasis (Fig. 4a). The teat is sharply amputated, distal to the forceps and a three-layer closure is performed, as previously described for thelotomy (Fig. 4b, c).
5.2. Udder biopsy Udder biopsy can be performed by needle biopsy procedures or by performing a full thickness technique. Needle biopsy can be undertaken on site, whereas full thickness biopsy should be preferably performed in an operating room. Needle biopsies can be performed by local or epidural anaesthesia, with the animal in standing position or in recumbency. A large biopsy needle (14-gauge) is inserted, ideally under ultrasound guidance, in the area where lesions are located and tissue samples are collected. A purse string suture can be applied at the site to avoid milk seepage (Anderson and Hull, 2002). If larger samples would be needed, a small incision might be made at the skin and the underlying fascia until the mammary capsule would be identified and samples would be collected by using reusable core biopsy instruments (with disposable needles of 12 gauge × 10 cm). The incision is then closed as previously mentioned for partial thickness wounds (Toral et al., 2015). Minor haemorrhage caused by needle biopsy procedures can be controlled by pressure, local application of vasoconstrictors (epinephrine, adrenaline or ephedrine) or haemostatic agents (Anderson, 2012; MacPhail, 2013a). For biopsy by using the full thickness technique, the animal is positioned in lateral or dorsal recumbency with the hind legs tied, to allow a good exposure of the udder region. The skin is initially incised with a 3–5 cm length section, preferably in the caudal part of the mammary gland. Then, the subcutaneous tissues and the mammary ligaments are carefully dissected to expose the mammary parenchyma. Holding of ligaments with Alice tissue forceps or stay sutures is recommended, as that helps in obtaining easier the tissue samples, whilst the surgeon would in better control of potential haemorrhage (Fig. 2a). Tissue samples, usually in the shape of a cube 1 × 1 × 1 cm are excised, unless a larger sample is specifically required (Fig. 2b). Haemorrhage should be controlled by monopolar or bipolar electrosurgery and suture ligation. Various haemostatic agents (e.g., gelatins, collagens, cellulosebased materials) and sealants alone or combined with procoagulants (eaminocaproic acid, tranexamic acid, ethamsylate) might be used for haemostasis. To note that administration of haemostatic agents is contraindicated in the presence of infection or when used in confined spaces (Anderson, 2012; MacPhail, 2013a).The mammary ligaments and subcutaneous tissues are closed with a simple continuous suture pattern using absorbable monofilament or multifilament sutures, size 20 to 4-0, with a taper point swaged-on needle (Fig. 2c). The udder skin can be sutured with absorbable or non-absorbable sutures by using a continuous or simple interrupted pattern (Fig. 2d). The aforementioned three-layer closure technique results in tight sealing of the incisions and thus no milk leakage would take place. However, small amount of blood can be expressed in secretion samples collected subsequently to the operation.
5.4. Mastectomy Mastectomy can be performed by local and epidural or general anaesthesia in an operating room. For mastectomy, the animal is placed in dorsal recumbency, with the hind legs tied, to allow a good exposure of the inguinal region and the udder. However, prolonged dorsal recumbency in sheep is not recommended, as it may possibly lead in respiratory distress, decreased cardiac output and tympany (Galatos, 2011). In order to avoid these adverse effects, feed and water must be withheld for at least 8 h prior to the operation, a tilt table should be used, the ewe’s head should be positioned in a way that the larynx would be elevated relatively to the thoracic inlet and mouth, the trachea might be intubated and a stomach tube is to be inserted to the rumen for gas relief (Galatos, 2011; Sabuncu et al., 2015). In cases of unilateral mastectomy, ewes can be placed in lateral recumbency, with the affected udder side uppermost and the respective hind limb safely 3
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Fig. 2. Udder biopsy: (a) use of Alice tissue forceps helping in collecting tissue samples and controlling haemorrhage, (b) mammary parenchyma being incised for tissue sample collection, (c) suturing of udder ligaments with a simple continuous suture pattern, (d) suturing of udder skin with a simple interrupted pattern with non-absorbable sutures.
or ultrasonic energy and harmonic device systems can be employed for haemostasis (MacPhail, 2013a; Benitez, 2018). The medial suspensory ligament is incised, leaving 1.0 to 2.0 cm attached to the abdomen wall, in order to facilitate closure. The regional mammary lymph nodes are dissected en bloc with the gland. Specifically, in unilateral mastectomy, the right and left tunics of the medial suspensory ligament are separated, with only the ipsilateral ligament removed. In these cases, dissection is performed from the lateral side of the incision to the medial lamina of the suspensory ligament of the udder, until the udder would be removed. Smaller vessels between the two glands should be ligated. In all cases, closure begins with obliteration of dead space, by placing tension-relieving sutures (walking sutures, vertical mattress or near-far-far-near), apposing the deep subcutaneous tissues (Fig. 5d). Sutures should include the remnant of the medial suspensory ligament. Skin and subcutaneous tissues are routinely closed in a double layer pattern, by using multifilament or monofilament suture material of size 4-0 to 0 (Fig. 5e). Placement of drains would not normally be needed, but if the surgeon chooses to place one closed systems are preferred, in order to avoid ascending infections (MacPhail, 2013b; Sabuncu et al., 2015); however, if placed, drains should be removed 3–5 days post-
secured. An elliptical skin incision around the udder is created (Fig. 5a). When tension of the surgical wound might be anticipated, initial skin incision should be performed a few centimetres of the way up the side of the udder and the skin dissected to the base of the organ. That way, sufficient skin is preserved for wound closure. Subcutaneous tissues are dissected by using a combination of sharp and blunt dissection. Haemorrhage is controlled and the lateral suspensory ligament is incised cautiously, as the external pudendal artery and vein lie beneath it. Haemorrhage control can be improved by pre- and/or post-operative administration, intramuscularly or intravenously, of systemic haemostatic drugs (e-aminocaproic acid, tranexamic acid, ethamsylate) Mechanical and active haemostatic agents can also be used locally to prevent haematoma formation. The external pudendal vessels should be double ligated bilaterally at their exit point from the inguinal rings (Fig. 5b). It is recommended that the external pudendal artery should be ligated first, before the vein, to reduce blood losses (Anderson and Hull, 2002; Cable et al., 2004). The subcutaneous abdominal veins and their branches (Figs. 5c and 6 ), running laterally on each side of the udder, and the perineal veins caudally, are then double ligated. Ligations are performed by using multifilament absorbable material (polyglactin 910) of size 2-0 to 2. Alternatively, bipolar vessel sealing devices 4
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Fig. 3. Thelotomy: (a) longitudinal full-thickness incision made through the wall of the teat, (b) suturing with a three-layer closure, with mucosa sutured first, (c) followed by the muscular layer and then the skin.
therapy is mandatory in all surgical conditions, in which haemorrhage would be anticipated, administration of crystalloids during mastectomies can be initiated before receiving anaesthesia.
operatively (MacPhail, 2013b). 6. Potential complications
7. Post-operative care
Complications following thelotomy and thelectomy include haemorrhage, damage to the muscular layer at the border between teat duct - teat cistern, infection, mastitis, dehiscence, stenosis and fistula formation (Bristol, 1989a,b; Anderson and Hull, 2002; Fubini et al., 2004; Nichols, 2008). Complications following mastectomy include incisional seroma, haemorrhage, necrotising cellulitis, infection and, specifically after unilateral mastectomy, decreased milk production (El-Maghraby, 2001; Anderson and Hull, 2002; Cable et al., 2004; Fubini et al., 2004; Nichols, 2008). Seroma formation is the most common complication after mastectomy (Phiri et al., 2010). Tight closure of subcutaneous tissues along with meticulous haemostasis precludes seroma or haematoma, thus rendering placement of drains unnecessary. Closed systems are preferred, as they decrease the risk of environmental contamination compared with open drains and prevent skin excoriation around the exit point (Campbell, 2012; MacPhail, 2013b). As fluid
Following mammary surgery, ewes should be penned separately, in order to avoid post-operative infections and injuries and to apply appropriate hygiene conditions. Hospitalisation might be required only in selected cases (e.g., mastectomy, poor body condition). Usually, skin sutures can be removed 8–14 days after the surgery. Fly control is necessary in all surgically treated animals. Depending on the severity of the disorder and the situation, milking machine may or may not be applied post-operatively. If machine milking would be applied, a larger teat cup is recommended. If it is not applied, a teat cannula should be inserted at every milking for 2–3 days. In general, hand-milking should be avoided for up to 1 week post-operatively, especially after teat surgery, as it stresses the incision focally; machine milking can apply pressure evenly to the teat, avoiding focal tension on the incision line (Couture and Mulon, 2005; Mulon, 2016). 5
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Fig. 4. Thelectomy: (a) atraumatic crushing forceps placed at the base of the teat for haemostasis; (b) amputation of the teat distally to the forceps and (c) suturing with a three-layer closure.
be followed, but for a longer period (antimicrobial agents for up to 10 days, non-steroidal anti-inflammatory drugs for up to 3 days). Exercise needs to be restricted for up to 10 days, in order to prevent seroma formation. In all cases of mammary surgery, following drug administration, relevant withdrawal periods should be maintained.
After completing surgery in teat injuries, thelotomy or thelectomy, antmicrobial agents should be administered systematically and also possibly with intramammary infusion for a period of 3 days post-operatively. The principles of administration of antimicrobial agents in mammary disorders have been reviewed by Mavrogianni et al. (2011). More recent findings regarding potential resistance of staphylococci from ewes’ udder samples (i.e., the most frequently recovered bacteria) and relevant literature references have been presented by Vasileiou et al. (2019). Administration (for up to 48 h) of non-steroidal anti-inflammatory drugs contributes to pain management and improves animal welfare (Fthenakis and Vasileiou, 2017). Wounds should be bandaged. The contact layer of the bandage should be a sterile, low adherent, semi-occlusive pad, which can be held in place by using stirrups on the pad and the adjacent skin. A tie over bandage can be also applied. Bandages should be changed as needed until total wound healing or suture removal (Campbell, 2012). Development of mastitis following surgery is possible, hence operated ewes must be closely monitored; if mastitis develops, it should be addressed appropriately. Following mastectomy, the pharmaceutical regime as above should
8. Prognosis In case of teat injuries, prognosis would depend on exact location of the wound on the teat, its size, depth and orientation, as well as possible contamination of the wound or presence of mastitis (Steiner, 2004). Prognosis is considered to be good in teat injuries sutured primarily (Turner and McIlwraith, 1989). Injuries perpendicular to the long axis of the teat have been found to have greater risk for fistula formation, because of the orientation of blood supply to the general region; injuries to the distal part of the teat have a poorer prognosis compared to proximal ones, due to better blood perfusion proximally (Bristol, 1989a,b; Anderson and Hull, 2002; Couture and Mulon, 2005; Nichols, 6
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Fig. 5. Unilateral mastectomy: (a) creation of an elliptical skin incision around the udder, (b) double ligation of the external pudendal vessels at their exit point from the inguinal rings (white arrow) and of the perineal veins caudally (black arrow), (c) double ligation of the subcutaneous abdominal veins (white arrow) and of smaller vessels between the udder halves (black arrow), (d) closure by apposing the deep subcutaneous tissues with walking sutures, including the remnant of the medial suspensory ligament, (e) routine double layer closure of skin and subcutaneous tissues.
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Clinical, bacteriological, Cytological and pathological features of teat disorders in ewes. J. Vet. Med. A 54, 219–223. Mavrogianni, V.S., Menzies, P.I., Fragkou, I.A., Fthenakis, G.C., 2011. Principles of mastitis treatment in sheep and goats. Vet. Clin. N. Am. Farm Anim. Pract. 27, 115–120. May, N.D.S., 1970. The Anatomy of the Sheep. University of Queensland Press, Melbourne. McElroy, M.C., Bassett, H.F., 2010. Mammary carcinoma in a ewe. J. Vet. Diagn. Invest. 22, 1006–1007. Mulon, P.Y., 2016. Surgical management of the teat and the udder. Vet. Clin. N. Am. Food Anim. Pract. 32, 813–832. Mihevc, S.P., Dovc, P., 2013. Mammary tumors in ruminants. Acta argic. Sloven. 102, 83–86. Monsang, S.W., Pal, S.K., Kumar, M., Roy, J., Sharma, C.S., Singh, M.N., 2014. Bilateral mastectomy for successful management of chronic suppurative mastitis in a Black Bengal doe (Capra hircus). J. Anim. Health and Prod. 2, 2–30. Nichols, S., 2008. Teat laceration repair in cattle. Vet. Clin. N. Am. Food Anim. Pract. 24, 295–305. Pasquini, C., Spurgeon, T., 1989. Anatomy of Domestic Animals, 5th edn. Sudz Publishing, Pilot Point. Petridis, I.G., Barbagianni, M.S., Ioannidi, K.S., Samaras, E., Fthenakis, G.C., Vloumidi, E.I., 2017. Doppler ultrasonographic examination in sheep. Small Rumin. Res. 152, 22–32. Phiri, A.M., Muleya, W., Mwape, K.E., 2010. Management of chronic gangrenous mastitis in a 3-year-old cow using partial (quarter) mastectomy. Trop. Anim. Health Prod. 42, 1057–1061. Sabuncu, A., Ozlem, Enginler, S., Yildar, E., Karacam, E., Dal, G.E., Kahraman, B.B., 2015. Unilateral mastectomy as an alternative treatment for gangrenous mastitis in a Saanen goat. Int. J. Vet. Sci. Med. 3, 9–12.
Fig. 6. Diagram showing sites of ligation of vascular supply of the sheep’s udder during mastectomy. a. medial suspensory ligament, b. lateral suspensory ligament, c., c’. external pudendal vessels at the inguinal ring, d., d’. perineal vessels (between the base of the udder and the vulva), e., e’. subcutaneous abdominal veins.
2008). Teat injuries extending in the teat duct or cistern have a poorer prognosis than partial-thickness lacerations. Time of attendance to injuries is also important: prognosis is poorer for injuries that had taken place over 4 h earlier; moreover, in injuries that had taken place 12 h prior to dealing with them, prognosis is considered to be extremely poor. Certainly, if animals with wounds would be presented for suturing, even after 48 h post-trauma, wounds can be attended and sutured. However, in cases that a period of 96 h has elapsed, it would be preferable to allow the wounds to heal by second intention (Anderson and Hull, 2002; Couture and Mulon, 2005; Nichols, 2008). Mastectomy is considered as a high-risk procedure, due to the potential of blood loss, potentially general toxaemia and ensuing shock and potential adverse effects of general anaesthesia (Anderson and Hull, 2002; Cable et al., 2004). Nevertheless, prognosis regarding the surgical procedure is considered to be good, especially taking into consideration that it is a salvage procedure. Histopathological examination of tissue samples must be performed, if surgery is performed as part of therapeutic management regime in cases of neoplasia, hyperplasia or in the presence of masses to aid in diagnosis and prognosis. Removal of the superficial inguinal lymph nodes in ewes, in which neoplasia had been diagnosed or suspected, should always be performed, in order to improve prognosis and be more accurate in staging (Cable et al., 2004). References Ali, A.O., 1986. An ovine mammary adenoma. Vet. Pathol. 23, 217–218. Anderson, D.M., 2012. Surgical hemostasis. In: Tobias, K.M., Johnston, S.A. (Eds.), Veterinary Surgery: Small Animal, 2nd edn. Elsevier, Missouri, pp. 214–220. Anderson, D.E., Hull, B.L., Pugh, D.G., 2002. Diseases of the mammary gland. In: Pugh, D.G. (Ed.), Sheep and Goat Medicine. Saunders, Philadelphia, pp. 341–358.
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sheep. N. Z. Vet. J. https://doi.org/10.1080/00480169.2019.1618222. Turner, A.S., McIlwraith, C.W., 1989. Techniques in Large Animal Surgery, 2nd edn. Lea & Febiger, Philadelphia, pp. 351–352. Vasileiou, N.G.C., Cripps, P.J., Ioannidi, K.S., Chatzopoulos, D.C., Gougoulis, D.A., Sarrou, S., Orfanou, D.C., Politis, A.P., Gonzalez-Valerio, T.C., Argyros, S., Mavrogianni, V.S., Petinaki, E., Fthenakis, G.C., 2018. Extensive countrywide field investigation of subclinical mastitis in sheep in Greece. J. Dairy Sci. 101, 7297–7310. Vasileiou, N.G.C., Sarrou, S., Papagiannitsis, C., Chatzopoulos, D.C., Malli, E., Mavrogianni, V.S., Petinaki, E., Fthenakis, G.C., 2019. Antimicrobial agent susceptibility and typing of staphylococcal isolates from subclinical mastitis in ewes. Microb. Drug Resist. https://doi.org/10.1089/mdr.2019.0009. Wooldridge, A.A., Gill, M.J., Lemarchand, T., Eilts, B., Taylor, H.W., Otterson, T., 1999. Gynecomastia and mammary gland adenocarcinoma in a Nubian buck. Can. Vet. J. 40, 663–665. Yeshwantkumar, C., Nirmala, G.C., 2008. Surgical management of gangrenous mastitis in a pregnant goat. Vet. World 1, 250.
Schummer, A., Wilkens, H., Volmerhaus, B., Habermehl, K.H., 1981. The circulatory system, the skin, and the cutaneous organs of the domestic mammals. In: In: Nickel, R., Schummer, A., Seiferle, E. (Eds.), The Anatomy of the Domestic Animals, vol. 3 Verlag Paul Parey, Berlin. Skarda, R.T., Tranquilli, W.J., 2007. Local and regional anesthetic and analgesic techniques: ruminants and swine. In: Tranquilli, W.J., Thurmon, J.C., Grimm, K.A. (Eds.), Lumb & Jones’ Veterinary Anesthesia and Analgesia, 4th edn. pp. 643–681 Ames: Blackwell, Ames, Iowa. Steiner, A., 2004. Teat surgery. In: Fubini, S.L., Ducharme, N.G. (Eds.), Farm Animal Surgery. Saunders, Philadelphia, pp. 408–419. Toral, P.G., Hervás, G., Frutos, P., 2015. Reductions in milk Δ9-desaturation ratios to oral dosing of cobalt-acetate are accompanied by the downregulation of SCD1 in lactating ewes. J. Dairy Sci. 98, 1961–1971. Tsioli, V., Spanos, S.A., Bikiaris, D., Grigoriadou, I., Barbagianni, M.S., Fthenakis, G.C., Papazoglou, L.G., Sideri, A.I., Galatos, A.D., 2019. Comparative evaluation of metallic skin staples or polypropylene sutures for primary closure of teat wounds in
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Contents lists available at ScienceDirect
Small Ruminant Research journal homepage: www.elsevier.com/locate/smallrumres
Udder surgery in ewes ⁎
V. Tsioli , G.C. Fthenakis Veterinary Faculty, University of Thessaly, 43100, Karditsa, Greece
A R T I C LE I N FO
A B S T R A C T
Keywords: Ewe Mastitis Udder Teat Surgery
Objective of this review is to present relevant information about udder surgery in ewes and to discuss its applications within the frame of sheep health management. The indications, diagnostic procedures, techniques, possible complications, post-operative care and prognosis of surgical conditions of the ovine udder are reviewed. Mammary surgery may help in decision-taking for the management of various udder and teat conditions providing alternative therapeutic solutions.
1. Introduction Surgical conditions of the udder of sheep are infrequently reported in the literature, in contrast to similar disorders in dairy cattle. Surgical conditions of the udder can affect the overall health status of affected animals and might lead to death or culling of ewes. In sheep, mammary surgery is not applied frequently, although indications for surgical treatment of udder disorders exist and surgical techniques are available and may be employed to improve recovery of affected animals and improvement of their welfare. Objective of this review is to present relevant information regarding surgical management of udder problems in sheep and to discuss indications, techniques, post-operative care and complications within the frame of sheep health management. It is noteworthy that there is little literature related to mammary surgery specifically in ewes and for the present review relevant publications in does and cows have been used, appropriately adopted for application to ewes. 2. Indications for udder surgery In sheep, various conditions of the udder require surgical intervention. Surgical management of udder wounds is the most frequently needed procedure in sheep and occur often in that species. Sheep graze upon a variety of environments and territories, that way exposing their mammary glands to adverse conditions and predisposing to wounds. Further, teat injuries are common and significant and affect milkability of ewes and reduce animal welfare (Couture and Mulon, 2005; Mulon, 2016). They can be the consequences of traumas, infections, inappropriate husbandry practices (e.g., inappropriate regulated milking routine) and adverse environmental factors. Teat injuries predispose
⁎
ewes to mastitis (Mavrogianni et al., 2006; Mavrogianni and Fthenakis, 2007). Although they have been commonly reported in cows (Bristol, 1989a,b; Nichols, 2008), there are few reports on their impact and management in ewes. Mammary biopsy can be performed for diagnostic purposes or in research situations, for histological evaluation of tissue samples. Thelotomy or thelectomy are indicated in cases of presence of supernumerary teats, traumatic injuries or fistulas (Bristol, 1989a; Anderson and Hull, 2002; Couture and Mulon, 2005; Nichols, 2008; Mulon, 2016). Indications for mastectomy include large abscesses, pendulous udder, irreparable udder injuries and neoplasias (Wooldridge et al., 1999; El-Maghraby, 2001; Anderson and Hull, 2002; Fubini et al., 2004; Monsang et al., 2014; Sabuncu et al., 2015). Mastectomy can be unilateral or radical (Yeshwantkumar and Nirmala, 2008; Sabuncu et al., 2015). Unilateral mastectomy, although considered technically more demanding, offers the advantage of a shorter operating time. Moreover, ewes can continue to lactate (El-Maghraby, 2001; Sabuncu et al., 2015), thus maintained in the reproductive process. Mammary neoplasms in sheep are rare (Löhr, 2012; Mihevc and Dovc, 2013) and reports on management of relevant disorders are sparse (Ali, 1986; Gulbahar et al., 2007; McElroy and Bassett, 2010; Dezfoulian et al., 2011). The differential diagnosis for masses palpated within the udder includes chronic mastitis, abscess, fibrosis and haematoma (Mihevc and Dovc, 2013). 3. Surgical anatomy The udder of ewes consists of the two semi-spherical mammary glands, each of which has one teat 2.0–3.5 cm in length in an angle of 40–45 ° to the body of the ipsilateral mammary gland (May, 1970;
Corresponding author. E-mail address: [email protected] (V. Tsioli).
https://doi.org/10.1016/j.smallrumres.2019.06.019 Received 2 April 2019; Received in revised form 19 June 2019; Accepted 19 June 2019 0921-4488/ © 2019 Elsevier B.V. All rights reserved.
Please cite this article as: V. Tsioli and G.C. Fthenakis, Small Ruminant Research, https://doi.org/10.1016/j.smallrumres.2019.06.019
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aseptically, as detailed before (Vasileiou et al., 2018). The results will reveal potential presence of mastitis, which needs to be taken into account, for correct management of the animal pre- and post-operatively. Ultrasonographic examination by using B-mode, Doppler and/or contrast-enhanced technologies can be of particular value in identifying possible lesions within the organ. Their detailed description is beyond the scope of this review, as relevant papers have been published recently (Barbagianni et al., 2017; Petridis et al., 2017; Mantziaras et al., 2018). Teat endoscopy (‘theloscopy’) is a diagnostic procedure that has recently been described in ewes (Kiossis et al., 2009). It is a non-invasive technique that allows direct observation of the internal side of the teat and thus can provide a precise diagnosis of pathological conditions in there. There is also the possibility to employ the technique for surgical management of teat lesions (‘theloresectoscopy’), through use of high-frequency surgical cutting unit (Geishauser et al., 2005).
Schummer et al., 1981; Pasquini and Spurgeon, 1989; Hofmeyer, 1990). Immediately after the teat orifice (ostium papillae), located at the distal end of the teat, follows the teat duct (ductus papillaris), with a total length of 0.3 to 0.8 cm. The teat duct is followed by the teat cistern (sinus papillaris), which is demarcated from the gland cistern by an annular ring, which contains a large vein that encircles the base of the teat (Schummer et al., 1981). Each teat is lined with five layers: mucosa, submucosa, a layer of connective tissue, a layer of muscular tissue, composed of circular and longitudinal fibers and the skin, covered by stratified squamous epithelium. Presence of supernumerary teats occurs often, occasionally, some of them being fully functional and allowing expression of milk through them. The mammary parenchyma has a typical tubulo-alveolar structure. The gland cistern (sinus lactiferous), with a capacity of 20 to 80 mL, which drains to the teat cistern, receives the 10 to 15 lactiferous ducts (ducti lactiferi), which further divide in smaller, 2nd and 3rd class, ducts and ductules, which receive the mammary secretion from the lobes and lobules of the parenchyma. The udder is supported by the medial and lateral suspensory ligaments, which play an important role in supporting the udder and maintaining it tightly attached to the ventral abdominal wall. The medial lamina is comprised of two sheets, which divide the udder in two halves, thus permitting unilateral mastectomy. The lateral suspensory ligament arises from the pelvic symphysis, subpubic and prepubic tendon. Blood supply to each mammary gland is provided mainly by the external pudendal artery that emerges from the inguinal ring, branches to the udder and continues cranially as the cranial superficial epigastric artery. Udders are drained by the external pudendal veins, the caudal superficial epigastric and the perineal veins (Fig. 1). The iliohypogastric, the ilioinguinal, the genitofemoral and branches of the pudendal nerves innervate the udder. The superficial inguinal lymph nodes provide lymph drainage and are located at the caudoproximal aspect of the udder.
5. Surgical techniques The surgical principles must be applied in all cases of udder surgery. These include haemostasis, application of aseptic conditions and delicate tissue handling. Appropriate sedation, anaesthesia and analgesia should also be administered as needed (Galatos, 2011). Sedation is done by administration of a-2 adrenoceptor agonists (xylazine, romifidine, detomidine, medetomidine, dexmedetomidine) or benzodiazepines (diazepam, midazolam). Cranial epidural anaesthesia can be performed. Further, local anaesthesia can be provided by ring block, inverted ‘V’ block, teat cistern infusion or intravenous regional anaesthesia. For full thickness biopsies, extended parenchyma wounds and mastectomies, general injectable or inhalation anaesthesia might be required. Injectable anaesthetics can be used for short-term anaesthesia (ketamine, propofol, thiopental). Inhalation anaesthesia is preferred for longer operating periods (isoflurane, sevoflurane) (Anderson and Hull, 2002; Skarda and Tranquilli, 2007; Nichols, 2008; Galatos, 2011; Mulon, 2016). Pre-operative administration of antibiotics and nonsteroidal anti-inflammatory drugs is indicated.
4. Diagnostic approaches in surgical conditions of the udder 5.1. Management of mammary parenchyma wounds Initially, a complete history should be taken, to be followed by a detailed clinical examination (Fthenakis, 1994; Mavrogianni et al., 2005). Standard laboratory examinations include bacteriological and cytological examination of milk samples, which need to be collected
Planning treatment of udder wounds should take into consideration: time that has elapsed since injury, size of the wound, degree of contamination, extent of tissue damage, extent of necessary debridement, wound blood supply, animal’s general condition, wound location and presence of tension or dead space (MacPhail, 2013b). Immediate primary closure, delayed primary closure (3–5 days after wounding) or second intention healing should be considered and undertaken appropriately. Mammary parenchyma wounds should be thoroughly cleaned before surgical management would be attempted. Initially, copious irrigation of wounds can be performed with tap water, in order to reduce gross contamination. Subsequently, lavage with antiseptic solution should follow. Chlorhexidine 0.05 to 0.1% solution or povidone iodine 0.1 to 0.01% solution is recommended. High pressure irrigation (5–8 psi) is ideal and can be applied by the use of an 18- to 19 – gauge needle. Application of cold hydrotherapy pre- and post-operatively can reduce wound contamination and oedema. Wound debridement is indicated to remove necrotic, contaminated or devitalised tissues (Anderson and Hull, 2002; Fubini et al., 2004; Nichols, 2008; Mulon, 2016). Management of mammary parenchyma wounds can be usually undertaken on site and only in a few cases an operating room would be needed (e.g., when excessive debridement would be required). Primary closure in partial thickness wounds of the udder is performed by suturing skin with absorbable or non-absorbable, monofilament or multifilament sutures by using a continuous or simple interrupted pattern. In full thickness wounds, a three-layer closure technique needs to be performed (described in 5.2., 5.3). Delayed primary closure
Fig. 1. Diagram of arterial supply to ewes’ udder. a. external pudendal artery, b. branch to lymph nodes, c. papillary arteries, d1., d2., d3. cranial, middle and caudal mammary artery. 2
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5.3. Management of teat injuries, thelotomy, thelectomy
can be employed in contaminated wounds, wounds with substantial oedema and in wounds when staged debridement would be required. With this technique, daily open wound management is performed, until granulation tissue formation, thus, wound closure is delayed for 3–5 days after injury (Hosgood, 2012). Second intention healing is more appropriate for dirty wounds with gross inflammation, presence of necrotic tissues and extensive soft tissue trauma, these wounds being unsuitable for primary or delayed primary closure. In second intention healing wounds are treated as open and closure is achieved by contraction and epithelialisation. Local application of antimicrobial agents is indicated to be performed early in wound management. This includes ointments and silver-based or hyperosmotic dressings (MacPhail, 2013b). Wound protection with a bandage is important, particularly during second intention healing.
Teat injuries, thelotomy and thelectomy can be performed after administration of local or epidural anaesthesia, with the animal in standing position or in recumbency. These procedures can be undertaken in the field, whilst an operating room might be needed only in selected cases, in which would be scheduled. Teat injuries are initially debrided and lavaged and then sutured. If the mucosa of the teat cistern has been torn, a three-layer closure is performed. The mucosa (incorporating the submucosa) is sutured initially, followed by the muscular layer and then by the skin. It is noteworthy that sutures should not penetrate the mucosa. Suturing of the mucosa, submucosa and muscular layer is performed by using monofilament synthetic absorbable material (polyglycolic acid, polydioxanone) with a taper point swagedon needle of size 4-0. Skin can be closed with metallic staples or monofilament sutures with a reverse cutting swaged-on needle of size 20 to 4-0. In severe injuries in which teat reconstruction may not be possible, a thelectomy can possibly be performed. Teat fistulas do not occur often in ewes. Fistulas and their tracks are dissected en bloc from surrounding normal tissues, with a three-layer closure performed at the end (Bristol, 1989a; b; Anderson and Hull, 2002; Fubini et al., 2004; Couture and Mulon, 2005; Nichols, 2008; Tsioli et al., 2019). During thelotomy, a longitudinal full-thickness incision is made through the wall of the teat (Fig. 3a). The teat cistern is examined and lesions are removed. A three-layer closure is performed; subsequent steps are as previously described (Fig. 3b, c). Small supernumerary teats or teats in young animals can be removed with scissors. Larger formations can be removed with a scalpel, with simultaneous control of haemorrhage. An elliptical incision is performed in a craniocaudal direction at the teat base. In cases in which these communicate with the teat canal or cistern, a thelectomy at the base of the teat can be performed, followed by a three-layer closure (Bristol, 1989a, 1989b; Anderson and Hull, 2002; Fubini et al., 2004; Couture and Mulon, 2005; Mulon, 2016; Tsioli et al., 2019). In ewes with small size teats, development of granulation tissue during healing after injuries can lead in teat stenosis or obstruction, thus leading in reduced milk flow. In such cases, increase of the diametre of teat duct can be affected through use of a ‘teat knife’. After insertion of the knife into the teat canal, this would be angled at 45° and a cut can be made at the area of the border between teat duct - teat cistern to the proximal part of the teat duct (Bristol, 1989a,b; Anderson and Hull, 2002; Fubini et al., 2004; Couture and Mulon, 2005; Mulon, 2016). In ewes with floating scar tissue or lactoliths therein, extraction can be initially attempted by mosquito or alligator forceps; if this is not successful, a thelotomy can be performed. For thelectomy, atraumatic crushing forceps are placed at the base of the teat to provide haemostasis (Fig. 4a). The teat is sharply amputated, distal to the forceps and a three-layer closure is performed, as previously described for thelotomy (Fig. 4b, c).
5.2. Udder biopsy Udder biopsy can be performed by needle biopsy procedures or by performing a full thickness technique. Needle biopsy can be undertaken on site, whereas full thickness biopsy should be preferably performed in an operating room. Needle biopsies can be performed by local or epidural anaesthesia, with the animal in standing position or in recumbency. A large biopsy needle (14-gauge) is inserted, ideally under ultrasound guidance, in the area where lesions are located and tissue samples are collected. A purse string suture can be applied at the site to avoid milk seepage (Anderson and Hull, 2002). If larger samples would be needed, a small incision might be made at the skin and the underlying fascia until the mammary capsule would be identified and samples would be collected by using reusable core biopsy instruments (with disposable needles of 12 gauge × 10 cm). The incision is then closed as previously mentioned for partial thickness wounds (Toral et al., 2015). Minor haemorrhage caused by needle biopsy procedures can be controlled by pressure, local application of vasoconstrictors (epinephrine, adrenaline or ephedrine) or haemostatic agents (Anderson, 2012; MacPhail, 2013a). For biopsy by using the full thickness technique, the animal is positioned in lateral or dorsal recumbency with the hind legs tied, to allow a good exposure of the udder region. The skin is initially incised with a 3–5 cm length section, preferably in the caudal part of the mammary gland. Then, the subcutaneous tissues and the mammary ligaments are carefully dissected to expose the mammary parenchyma. Holding of ligaments with Alice tissue forceps or stay sutures is recommended, as that helps in obtaining easier the tissue samples, whilst the surgeon would in better control of potential haemorrhage (Fig. 2a). Tissue samples, usually in the shape of a cube 1 × 1 × 1 cm are excised, unless a larger sample is specifically required (Fig. 2b). Haemorrhage should be controlled by monopolar or bipolar electrosurgery and suture ligation. Various haemostatic agents (e.g., gelatins, collagens, cellulosebased materials) and sealants alone or combined with procoagulants (eaminocaproic acid, tranexamic acid, ethamsylate) might be used for haemostasis. To note that administration of haemostatic agents is contraindicated in the presence of infection or when used in confined spaces (Anderson, 2012; MacPhail, 2013a).The mammary ligaments and subcutaneous tissues are closed with a simple continuous suture pattern using absorbable monofilament or multifilament sutures, size 20 to 4-0, with a taper point swaged-on needle (Fig. 2c). The udder skin can be sutured with absorbable or non-absorbable sutures by using a continuous or simple interrupted pattern (Fig. 2d). The aforementioned three-layer closure technique results in tight sealing of the incisions and thus no milk leakage would take place. However, small amount of blood can be expressed in secretion samples collected subsequently to the operation.
5.4. Mastectomy Mastectomy can be performed by local and epidural or general anaesthesia in an operating room. For mastectomy, the animal is placed in dorsal recumbency, with the hind legs tied, to allow a good exposure of the inguinal region and the udder. However, prolonged dorsal recumbency in sheep is not recommended, as it may possibly lead in respiratory distress, decreased cardiac output and tympany (Galatos, 2011). In order to avoid these adverse effects, feed and water must be withheld for at least 8 h prior to the operation, a tilt table should be used, the ewe’s head should be positioned in a way that the larynx would be elevated relatively to the thoracic inlet and mouth, the trachea might be intubated and a stomach tube is to be inserted to the rumen for gas relief (Galatos, 2011; Sabuncu et al., 2015). In cases of unilateral mastectomy, ewes can be placed in lateral recumbency, with the affected udder side uppermost and the respective hind limb safely 3
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Fig. 2. Udder biopsy: (a) use of Alice tissue forceps helping in collecting tissue samples and controlling haemorrhage, (b) mammary parenchyma being incised for tissue sample collection, (c) suturing of udder ligaments with a simple continuous suture pattern, (d) suturing of udder skin with a simple interrupted pattern with non-absorbable sutures.
or ultrasonic energy and harmonic device systems can be employed for haemostasis (MacPhail, 2013a; Benitez, 2018). The medial suspensory ligament is incised, leaving 1.0 to 2.0 cm attached to the abdomen wall, in order to facilitate closure. The regional mammary lymph nodes are dissected en bloc with the gland. Specifically, in unilateral mastectomy, the right and left tunics of the medial suspensory ligament are separated, with only the ipsilateral ligament removed. In these cases, dissection is performed from the lateral side of the incision to the medial lamina of the suspensory ligament of the udder, until the udder would be removed. Smaller vessels between the two glands should be ligated. In all cases, closure begins with obliteration of dead space, by placing tension-relieving sutures (walking sutures, vertical mattress or near-far-far-near), apposing the deep subcutaneous tissues (Fig. 5d). Sutures should include the remnant of the medial suspensory ligament. Skin and subcutaneous tissues are routinely closed in a double layer pattern, by using multifilament or monofilament suture material of size 4-0 to 0 (Fig. 5e). Placement of drains would not normally be needed, but if the surgeon chooses to place one closed systems are preferred, in order to avoid ascending infections (MacPhail, 2013b; Sabuncu et al., 2015); however, if placed, drains should be removed 3–5 days post-
secured. An elliptical skin incision around the udder is created (Fig. 5a). When tension of the surgical wound might be anticipated, initial skin incision should be performed a few centimetres of the way up the side of the udder and the skin dissected to the base of the organ. That way, sufficient skin is preserved for wound closure. Subcutaneous tissues are dissected by using a combination of sharp and blunt dissection. Haemorrhage is controlled and the lateral suspensory ligament is incised cautiously, as the external pudendal artery and vein lie beneath it. Haemorrhage control can be improved by pre- and/or post-operative administration, intramuscularly or intravenously, of systemic haemostatic drugs (e-aminocaproic acid, tranexamic acid, ethamsylate) Mechanical and active haemostatic agents can also be used locally to prevent haematoma formation. The external pudendal vessels should be double ligated bilaterally at their exit point from the inguinal rings (Fig. 5b). It is recommended that the external pudendal artery should be ligated first, before the vein, to reduce blood losses (Anderson and Hull, 2002; Cable et al., 2004). The subcutaneous abdominal veins and their branches (Figs. 5c and 6 ), running laterally on each side of the udder, and the perineal veins caudally, are then double ligated. Ligations are performed by using multifilament absorbable material (polyglactin 910) of size 2-0 to 2. Alternatively, bipolar vessel sealing devices 4
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Fig. 3. Thelotomy: (a) longitudinal full-thickness incision made through the wall of the teat, (b) suturing with a three-layer closure, with mucosa sutured first, (c) followed by the muscular layer and then the skin.
therapy is mandatory in all surgical conditions, in which haemorrhage would be anticipated, administration of crystalloids during mastectomies can be initiated before receiving anaesthesia.
operatively (MacPhail, 2013b). 6. Potential complications
7. Post-operative care
Complications following thelotomy and thelectomy include haemorrhage, damage to the muscular layer at the border between teat duct - teat cistern, infection, mastitis, dehiscence, stenosis and fistula formation (Bristol, 1989a,b; Anderson and Hull, 2002; Fubini et al., 2004; Nichols, 2008). Complications following mastectomy include incisional seroma, haemorrhage, necrotising cellulitis, infection and, specifically after unilateral mastectomy, decreased milk production (El-Maghraby, 2001; Anderson and Hull, 2002; Cable et al., 2004; Fubini et al., 2004; Nichols, 2008). Seroma formation is the most common complication after mastectomy (Phiri et al., 2010). Tight closure of subcutaneous tissues along with meticulous haemostasis precludes seroma or haematoma, thus rendering placement of drains unnecessary. Closed systems are preferred, as they decrease the risk of environmental contamination compared with open drains and prevent skin excoriation around the exit point (Campbell, 2012; MacPhail, 2013b). As fluid
Following mammary surgery, ewes should be penned separately, in order to avoid post-operative infections and injuries and to apply appropriate hygiene conditions. Hospitalisation might be required only in selected cases (e.g., mastectomy, poor body condition). Usually, skin sutures can be removed 8–14 days after the surgery. Fly control is necessary in all surgically treated animals. Depending on the severity of the disorder and the situation, milking machine may or may not be applied post-operatively. If machine milking would be applied, a larger teat cup is recommended. If it is not applied, a teat cannula should be inserted at every milking for 2–3 days. In general, hand-milking should be avoided for up to 1 week post-operatively, especially after teat surgery, as it stresses the incision focally; machine milking can apply pressure evenly to the teat, avoiding focal tension on the incision line (Couture and Mulon, 2005; Mulon, 2016). 5
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Fig. 4. Thelectomy: (a) atraumatic crushing forceps placed at the base of the teat for haemostasis; (b) amputation of the teat distally to the forceps and (c) suturing with a three-layer closure.
be followed, but for a longer period (antimicrobial agents for up to 10 days, non-steroidal anti-inflammatory drugs for up to 3 days). Exercise needs to be restricted for up to 10 days, in order to prevent seroma formation. In all cases of mammary surgery, following drug administration, relevant withdrawal periods should be maintained.
After completing surgery in teat injuries, thelotomy or thelectomy, antmicrobial agents should be administered systematically and also possibly with intramammary infusion for a period of 3 days post-operatively. The principles of administration of antimicrobial agents in mammary disorders have been reviewed by Mavrogianni et al. (2011). More recent findings regarding potential resistance of staphylococci from ewes’ udder samples (i.e., the most frequently recovered bacteria) and relevant literature references have been presented by Vasileiou et al. (2019). Administration (for up to 48 h) of non-steroidal anti-inflammatory drugs contributes to pain management and improves animal welfare (Fthenakis and Vasileiou, 2017). Wounds should be bandaged. The contact layer of the bandage should be a sterile, low adherent, semi-occlusive pad, which can be held in place by using stirrups on the pad and the adjacent skin. A tie over bandage can be also applied. Bandages should be changed as needed until total wound healing or suture removal (Campbell, 2012). Development of mastitis following surgery is possible, hence operated ewes must be closely monitored; if mastitis develops, it should be addressed appropriately. Following mastectomy, the pharmaceutical regime as above should
8. Prognosis In case of teat injuries, prognosis would depend on exact location of the wound on the teat, its size, depth and orientation, as well as possible contamination of the wound or presence of mastitis (Steiner, 2004). Prognosis is considered to be good in teat injuries sutured primarily (Turner and McIlwraith, 1989). Injuries perpendicular to the long axis of the teat have been found to have greater risk for fistula formation, because of the orientation of blood supply to the general region; injuries to the distal part of the teat have a poorer prognosis compared to proximal ones, due to better blood perfusion proximally (Bristol, 1989a,b; Anderson and Hull, 2002; Couture and Mulon, 2005; Nichols, 6
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Fig. 5. Unilateral mastectomy: (a) creation of an elliptical skin incision around the udder, (b) double ligation of the external pudendal vessels at their exit point from the inguinal rings (white arrow) and of the perineal veins caudally (black arrow), (c) double ligation of the subcutaneous abdominal veins (white arrow) and of smaller vessels between the udder halves (black arrow), (d) closure by apposing the deep subcutaneous tissues with walking sutures, including the remnant of the medial suspensory ligament, (e) routine double layer closure of skin and subcutaneous tissues.
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Barbagianni, M.S., Mavrogianni, V.S., Vasileiou, N.G.C., Fthenakis, G.C., Petridis, I.G., 2017. Ultrasonographic examination of the udder in sheep. Small Rumin. Res. 152, 86–99. Benitez, M.E., 2018. Principles and use of energy sources in small animal surgery. In: Tobias, K.M., Johnston, S.A. (Eds.), Veterinary Surgery: Small Animal, 2nd edn. Elsevier, Missouri, pp. 200–209. Bristol, D.G., 1989a. Teat and udder surgery in dairy cattle-part I. Compend. Contin. Educ. Pract. Vet. 11, 868–872. Bristol, D.G., 1989b. Teat and udder surgery in dairy cattle-part II. Compend. Contin. Educ. Pract. Vet. 11, 983–988. Cable, C.S., Peery, K., Fubini, S.L., 2004. Radical mastectomy in 20 ruminants. Vet. Surg. 33, 263–266. Campbell, B.G., 2012. Bandages and drains. In: Tobias, K.M., Johnston, S.A. (Eds.), Veterinary Surgery: Small Animal, 2nd edn. Elsevier, Missouri, pp. 221–230. Couture, Y., Mulon, P.Y., 2005. Procedures and surgeries of the teat. Vet. Clin. N. Am. Food Anim. Pract. 21, 173–204. Dezfoulian, O., Asedian, P., Sookhtehzari, A., Kheradmand, A., 2011. Estrogen-induced mammary fibroadenoma in a lamb: hormonal and immunohistochemical aspects. Iran. J. Vet. Res. 12, 163–166. El-Maghraby, H.M., 2001. Comparison of two surgical techniques for mastectomy of goats. Small Rumin. Res. 40, 215–221. Fthenakis, G.C., 1994. Prevalence and aetiology of subclinical mastitis in ewes in Southern Greece. Small Rumin. Res. 13, 293–300. Fthenakis, G.C., Vasileiou, N.G.C., 2017. Review of published reports and author’s work assessing the use of non-steroidal anti-inflammatory drugs in sheep diseases. Proceedings of 9th International Sheep Veterinary Congress (Harrogate, United Kingdom). pp. 20. Fubini, S.L., 2004. Surgery of the mammary gland. In: Fubini, S.L., Ducharme, N.G. (Eds.), Farm Animal Surgery. Saunders, Saint Louis, pp. 403–407. Galatos, A.D., 2011. Anesthesia and analgesia in sheep and goats. Vet. Clin. N. Am. Food Anim. Pract. 27, 47–59. Geishauser, T., Querengässer, K., Querengässer, J., 2005. Teat endoscopy (theloscopy) for diagnosis and therapy of milk flow disorders in dairy cows. Vet. Clin. N. Am. Food Anim. Pract. 21, 205–225. Gulbahar, M.Y., Guvenc, T., Yarim, M., Kabak, Y.B., Sozgen, Y., 2007. Mammary fibroadenoma in a lamb. J. Vet. Sci. 8, 423–425. Hofmeyer, C.V., 1990. Ruminant Urogenital Surgery. Iowa State University Press, Ames. Hosgood, G., 2012. Open wounds. In: Tobias, K.M., Johnston, S.A. (Eds.), Veterinary Surgery: Small Animal. Elsevier, Missouri, pp. 1210–1220. Kiossis, E., Brozos, C.N., Papaioannou, N., Tzanidakis, N., Boscos, C., 2009. Endoscopic and histopathological findings of teats in dairy ewes. Small Rumin. Res. 87, 70–75. Löhr, C.V., 2012. One hundred two tumors in 100 goats (1987–2011). Vet. Pathol. 50, 668–675. MacPhail, C.M., 2013a. Biomaterials, suturing and hemostasis. In: Fossum, T.W. (Ed.), Small Animal Surgery, 4th edn. Mosby, St. Louis, pp. 64–83. MacPhail, C.M., 2013b. Surgery of the reproductive and genital systems. In: Fossum, T.W. (Ed.), Small Animal Surgery, 4th edn. Mosby, St. Louis, pp. 780–855. Mantziaras, G., Vasileiou, N.G., Ioannidi, K.S., Mavrogianni, V.S., Gougoulis, D.A., Fthenakis, G.C., Petridis, I.G., Barbagianni, M.S., 2018. Use of contrast-enhanced ultrasonographic examination to evaluate health status of mammary glands of ewes at the end of a lactation period. J. Dairy Res. 85, 39–43. Mavrogianni, V.S., Fthenakis, G.C., Brooks, H., Papaioannou, N., Cripps, P.J., Taitzoglou, I., Brellou, G., Saratsis, P., 2005. The effects of inoculation of Mannheimia haemolytica into the teat of lactating ewes. Vet. Res. 36, 13–25. Mavrogianni, V.S., Cripps, P.J., Papaioannou, N., Taitzoglou, I., Fthenakis, G.C., 2006. Teat disorders predispose ewes to clinical mastitis after challenge with Mannheimia haemolytica. Vet. Res. 37, 89–105. Mavrogianni, V.S., Fthenakis, G.C., 2007. Clinical, bacteriological, Cytological and pathological features of teat disorders in ewes. J. Vet. Med. A 54, 219–223. Mavrogianni, V.S., Menzies, P.I., Fragkou, I.A., Fthenakis, G.C., 2011. Principles of mastitis treatment in sheep and goats. Vet. Clin. N. Am. Farm Anim. Pract. 27, 115–120. May, N.D.S., 1970. The Anatomy of the Sheep. University of Queensland Press, Melbourne. McElroy, M.C., Bassett, H.F., 2010. Mammary carcinoma in a ewe. J. Vet. Diagn. Invest. 22, 1006–1007. Mulon, P.Y., 2016. Surgical management of the teat and the udder. Vet. Clin. N. Am. Food Anim. Pract. 32, 813–832. Mihevc, S.P., Dovc, P., 2013. Mammary tumors in ruminants. Acta argic. Sloven. 102, 83–86. Monsang, S.W., Pal, S.K., Kumar, M., Roy, J., Sharma, C.S., Singh, M.N., 2014. Bilateral mastectomy for successful management of chronic suppurative mastitis in a Black Bengal doe (Capra hircus). J. Anim. Health and Prod. 2, 2–30. Nichols, S., 2008. Teat laceration repair in cattle. Vet. Clin. N. Am. Food Anim. Pract. 24, 295–305. Pasquini, C., Spurgeon, T., 1989. Anatomy of Domestic Animals, 5th edn. Sudz Publishing, Pilot Point. Petridis, I.G., Barbagianni, M.S., Ioannidi, K.S., Samaras, E., Fthenakis, G.C., Vloumidi, E.I., 2017. Doppler ultrasonographic examination in sheep. Small Rumin. Res. 152, 22–32. Phiri, A.M., Muleya, W., Mwape, K.E., 2010. Management of chronic gangrenous mastitis in a 3-year-old cow using partial (quarter) mastectomy. Trop. Anim. Health Prod. 42, 1057–1061. Sabuncu, A., Ozlem, Enginler, S., Yildar, E., Karacam, E., Dal, G.E., Kahraman, B.B., 2015. Unilateral mastectomy as an alternative treatment for gangrenous mastitis in a Saanen goat. Int. J. Vet. Sci. Med. 3, 9–12.
Fig. 6. Diagram showing sites of ligation of vascular supply of the sheep’s udder during mastectomy. a. medial suspensory ligament, b. lateral suspensory ligament, c., c’. external pudendal vessels at the inguinal ring, d., d’. perineal vessels (between the base of the udder and the vulva), e., e’. subcutaneous abdominal veins.
2008). Teat injuries extending in the teat duct or cistern have a poorer prognosis than partial-thickness lacerations. Time of attendance to injuries is also important: prognosis is poorer for injuries that had taken place over 4 h earlier; moreover, in injuries that had taken place 12 h prior to dealing with them, prognosis is considered to be extremely poor. Certainly, if animals with wounds would be presented for suturing, even after 48 h post-trauma, wounds can be attended and sutured. However, in cases that a period of 96 h has elapsed, it would be preferable to allow the wounds to heal by second intention (Anderson and Hull, 2002; Couture and Mulon, 2005; Nichols, 2008). Mastectomy is considered as a high-risk procedure, due to the potential of blood loss, potentially general toxaemia and ensuing shock and potential adverse effects of general anaesthesia (Anderson and Hull, 2002; Cable et al., 2004). Nevertheless, prognosis regarding the surgical procedure is considered to be good, especially taking into consideration that it is a salvage procedure. Histopathological examination of tissue samples must be performed, if surgery is performed as part of therapeutic management regime in cases of neoplasia, hyperplasia or in the presence of masses to aid in diagnosis and prognosis. Removal of the superficial inguinal lymph nodes in ewes, in which neoplasia had been diagnosed or suspected, should always be performed, in order to improve prognosis and be more accurate in staging (Cable et al., 2004). References Ali, A.O., 1986. An ovine mammary adenoma. Vet. Pathol. 23, 217–218. Anderson, D.M., 2012. Surgical hemostasis. In: Tobias, K.M., Johnston, S.A. (Eds.), Veterinary Surgery: Small Animal, 2nd edn. Elsevier, Missouri, pp. 214–220. Anderson, D.E., Hull, B.L., Pugh, D.G., 2002. Diseases of the mammary gland. In: Pugh, D.G. (Ed.), Sheep and Goat Medicine. Saunders, Philadelphia, pp. 341–358.
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sheep. N. Z. Vet. J. https://doi.org/10.1080/00480169.2019.1618222. Turner, A.S., McIlwraith, C.W., 1989. Techniques in Large Animal Surgery, 2nd edn. Lea & Febiger, Philadelphia, pp. 351–352. Vasileiou, N.G.C., Cripps, P.J., Ioannidi, K.S., Chatzopoulos, D.C., Gougoulis, D.A., Sarrou, S., Orfanou, D.C., Politis, A.P., Gonzalez-Valerio, T.C., Argyros, S., Mavrogianni, V.S., Petinaki, E., Fthenakis, G.C., 2018. Extensive countrywide field investigation of subclinical mastitis in sheep in Greece. J. Dairy Sci. 101, 7297–7310. Vasileiou, N.G.C., Sarrou, S., Papagiannitsis, C., Chatzopoulos, D.C., Malli, E., Mavrogianni, V.S., Petinaki, E., Fthenakis, G.C., 2019. Antimicrobial agent susceptibility and typing of staphylococcal isolates from subclinical mastitis in ewes. Microb. Drug Resist. https://doi.org/10.1089/mdr.2019.0009. Wooldridge, A.A., Gill, M.J., Lemarchand, T., Eilts, B., Taylor, H.W., Otterson, T., 1999. Gynecomastia and mammary gland adenocarcinoma in a Nubian buck. Can. Vet. J. 40, 663–665. Yeshwantkumar, C., Nirmala, G.C., 2008. Surgical management of gangrenous mastitis in a pregnant goat. Vet. World 1, 250.
Schummer, A., Wilkens, H., Volmerhaus, B., Habermehl, K.H., 1981. The circulatory system, the skin, and the cutaneous organs of the domestic mammals. In: In: Nickel, R., Schummer, A., Seiferle, E. (Eds.), The Anatomy of the Domestic Animals, vol. 3 Verlag Paul Parey, Berlin. Skarda, R.T., Tranquilli, W.J., 2007. Local and regional anesthetic and analgesic techniques: ruminants and swine. In: Tranquilli, W.J., Thurmon, J.C., Grimm, K.A. (Eds.), Lumb & Jones’ Veterinary Anesthesia and Analgesia, 4th edn. pp. 643–681 Ames: Blackwell, Ames, Iowa. Steiner, A., 2004. Teat surgery. In: Fubini, S.L., Ducharme, N.G. (Eds.), Farm Animal Surgery. Saunders, Philadelphia, pp. 408–419. Toral, P.G., Hervás, G., Frutos, P., 2015. Reductions in milk Δ9-desaturation ratios to oral dosing of cobalt-acetate are accompanied by the downregulation of SCD1 in lactating ewes. J. Dairy Sci. 98, 1961–1971. Tsioli, V., Spanos, S.A., Bikiaris, D., Grigoriadou, I., Barbagianni, M.S., Fthenakis, G.C., Papazoglou, L.G., Sideri, A.I., Galatos, A.D., 2019. Comparative evaluation of metallic skin staples or polypropylene sutures for primary closure of teat wounds in
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