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The importance of video otoscopy in the diagnosis and treatment of chronic otitis in dogs
Revue vétérinaire clinique (2019) 54, 95—102
Disponible en ligne sur
ScienceDirect www.sciencedirect.com
ORIGINAL ARTICLE
The importance of video otoscopy in the diagnosis and treatment of chronic otitis in dogs F. Stephan ∗, D. Saade , M. Nasser Lebanese University, Faculty of Agronomy and Veterinary Medicine, Dekweneh, Lebanon Received 18 July 2019; accepted 30 September 2019 Available online 14 November 2019
KEYWORDS Video otoscopy; Chronic otitis; Ear; Dog; Lebanon
Summary Chronic otitis is one of the most common reasons why dogs are presented to veterinary facilities in Lebanon. The chronicity of this disease is due to the failure to diagnose correctly the primary cause and the incapacity to treat it effectively. The objective of this study is to show the importance of the video otoscopy in the diagnosis and treatment of recurrent otitis externa and/or otitis media. A total of twenty cases (twelve dogs) with chronic otitis externa and/or media were used for this study. Video otoscopy was performed in all 20 cases where it was used for diagnosis in 13/20 cases and treatment in 17/20. Thirteen (65%) of the cases showed a change in the diagnosis after undergoing video otoscopy. Seventeen (85%) of the cases showed an improvement after using the video otoscopy for ear flushing and lavage, in conjunction with home therapy, for treatment purposes. Improvements were judged subjectively seven, fourteen, and twenty-one days after the otoscopic lavage took place. Three (15%) of the cases underwent a surgery due to the presence of polyps that were not removable with the video otoscope. © 2019 AFVAC. Published by Elsevier Masson SAS. All rights reserved.
Introduction
∗
Corresponding author. E-mail addresses: [email protected] (F. Stephan), [email protected] (D. Saade), [email protected] (M. Nasser).
Otitis externa (OE) is an inflammation of the skin that lines the external ear canal and may extend to the auricle. Otitis media (OM) is an inflammation of the middle ear. OE mainly, but also OM, are very frequent dermatologic affections in dogs and often recurrent. These cases represent 5 to 20% of the dermatologic consultations that arrive
https://doi.org/10.1016/j.anicom.2019.09.008 2214-5672/© 2019 AFVAC. Published by Elsevier Masson SAS. All rights reserved.
96 to the clinics in small animal veterinary medicine worldwide [1,2]. Lebanon is a country with an average annual relative humidity of 69.3% and an average monthly relative humidity that ranges from 66% in November to 73% in July. This importance in humidity increases the chances of developing otitis in dog. The challenge for the veterinary practitioner is to put a treatment that will ensure the fast and definitive healing of the animal. It is therefore important to be able to accurately determine the etiological factors of otitis, for each animal, in order to specifically treat each patient. A certain amount of time may be required to make the diagnosis during which complications may develop, adding complexity to the implementation of the treatment. Most veterinarians in Lebanon tend to diagnose otitis using traditional otoscopes that have limitations. This presumption was based on visiting different clinics and asking of their technique to diagnose otitis. These limitations include insufficient illumination, limited magnification, no working channel, and no documentation for medical records. This limits the exact evaluation of the tympanic membrane (TM) or any other problem behind it. For the treatment, veterinary clinicians in Lebanon use drugs based on the otic smear performed at the clinic; in some cases, based on culture performed in a medical laboratory. The administered drugs used are usually ototoxic drugs and are administered to patients without being 100% sure if the dog has a rupture of the TM. This leads to an accumulation of problems and the rising of new problems including but not limited to hearing loss, and vestibular syndrome. This study aims to show the importance of video otoscopy (VO) in the diagnosis and treatment of recurrent OE and/or OM in dogs in two different clinics in Lebanon.
Materials and methods Animals The 12 animals included in this study are patients who came for a consultation between August 2018 and June 2019 in two different veterinary facilities in Lebanon, ‘‘Animed Veterinary Hospital’’, which is a facility in Jounieh and has most of its patients coming from Mount Lebanon, and ‘‘Canicat Veterinary Clinic’’, which is a facility in Hamra and has most of its patients coming from Beirut Governate. Lebanon has an average of 66.0% of humidity throughout the year with March being the most humid month and September being the least humid. These patients came regarding ear smell, head shaking, ear scratching, sensitivity to the touch of the ear, deafness, head tilting, or for a second opinion regarding otitis that was not resolved with a previous treatment. Inclusion criteria include animals that have had these symptoms for a period longer than 1 month with failed treatments, or that have had treatments that did not show any improvements and gave rise to new auricular problems. Exclusion criteria include any dog having an acute otitis or dogs already treated with VO. Each ear with chronic otitis was considered an individual case, making a total of twenty cases (Appendix 1).
F. Stephan et al.
Figure 1. A biopsy forceps introduces in the Hopkins with operating sheath, and two stopcocks.
Bacterial sampling Before beginning with the VO, the administered patients were evaluated in the clinic. Some patients had an otic microscopic examination, showing if they had a bacterial or fungal infection, and if so, they had a swab sent to a microbiology lab for analysis, and other patients did not undergo a microscopic examination and the reason for otitis is unknown. The establishment of a sampling of ear pus for the culture in the laboratory is made in most of the cases in the animals which the treatment did not show any improvements. The samples are removed with a sterile cotton swab guided by VO or samples are removed with grasping forceps. The sample of the secretions contained in the EAM is carried out and then introduced into a sterile cotton swab that was stored in a fridge and conveyed in less than 12 hours to the microbiology laboratory concerned. In the laboratory, swabs are put in different growth medium (Mannitol Salt agar, Sabouraud Dextrose agar, Blood agar, and MacConkey agar) to grow all type of pathogens and select them. Also, a slide for Gram staining and visualization of pathogens is performed.
Video otoscopy Equipment The video otoscope used in this study is provided by Karl Storz—Endoskope® and consists of the Hopkins® (64029 BA) which is a forward-oblique 30 degree telescope with an enlarged view, a length of 18 cm, and a tip diameter of 2.7 mm, which is fully immersible and able to be autoclaved. It also has a fiber optic light transmission incorporated which delivers a larger image, making details easier to see. This telescope is protected by an operating sheath (67065C) which is 14.5 Fr. and has a working length of 15 cm with a working channel of 5 Fr. and two stopcocks to be able to flush at the same time; it also includes a blunt Obturator (67065 CO) (Fig. 1). The camera head (TELECAM 2120 30), along with the fiber optic light cable (69495 NA) of a 3.5 mm diameter and a 230 cm length, is connected to the TELE PACK VET X LED unit (RP 100 S1) by a simple adaptor (495KS).
Video otoscopy in the diagnosis and treatment of chronic otitis in dogs
Figure 2.
97
Tele Pack Vet X LED.
The camera head previously mentioned has a PAL color system, is soakable, gas-sterilizable, integrated Parfocal Zoom Lens (f = 25—50 mm), and 2 freely programmable camera head buttons. Regarding the TELE PACK VET X LED unit (Fig. 2), it is an ultimate compact mobile endoscopic video system that integrates different essential component needed for endoscopic imaging including a camera control unit (TELECAM technology), a high performance LED light source, a 15 high resolution LCD monitor with LED backlight, an image capture and documentation system enabling to capture and store still images and videos onto a USB/SD memory module, an insufflation pump. The latter component is not utilized for VO. Biopsy forceps (67161 Z) and grasping forceps (67161T), which are flexible, with double action jaws, 5 Fr., with a length of 34 cm each, were used in different situations during VO. Since the anesthesia has no effect on the ear, we will not be going into details regarding the protocol used for each patient. Patients are anesthetized and monitored throughout the VO.
Method of ear diagnosis and flushing using the video otoscope The animal is anesthetized with an endotracheal tube in place. This tube will prevent aspiration of fluids into the respiratory tract if the TM is ruptured or a myringotomy is to be performed. To allow the image to maintain an equal orientation during the VO, the patient is placed in a lateral recumbency and the clinician at the animal’s ventral aspect. The intertragic incisure allows the video otoscope to enter repeatedly and successfully the ear. After entering, and to minimize the interface of the dorsal fold, the ear is grasped at the base of the pinna and retracted laterodorsally. After passing the fold, the pinna is retracted latero-ventrally to be able to pass the horizontal canal and get to the TM. Continuous introduction of saline water is administered using the video otoscope for lavage and suction should be performed simultaneously. [3].
Figure 3.
Initial cause.
Evaluation of the improvement Dogs that have showed absence of ear itching, pain at ear palpation, purulent secretions in the EAM, ear inflammation, and head shaking are considered to have shown improvement. Some of these symptoms are subjective and others are evaluated with the use of a handheld otoscope. Dogs are re-examined 7, 14, and 21 days after VO to evaluate the otitis’ treatment and resolution of symptoms.
Statistical analysis Since the outcome of this study is not numerical and only has a categorical value, the statistical method used here is ‘‘Frequency tables’’ in ‘‘STATISTICA® v.12’’. By using this method, we were able to classify if there was a change in the diagnosis while using VO and if there was any improvement after the use of the video otoscope.
Results Initially, the cause of otitis was divided into 3 parts: 9 (45%) were attributed to bacterial, 5 (25%) were attributed to fungal, and 6 (30%) in unknown (Fig. 3).
98
Figure 4.
F. Stephan et al.
Initial agents.
The main agents causing otitis initially include E. coli (25%), Staphylococcus pseudintermedius (10%), Malassezia pachydermatis (20%), and Candida albicans (5%). Unidentified cocci (10%) were also present. The remaining 30% are attributed to the unknown category which includes the cases without any specific diagnosis for the otitis. These values were put in Fig. 4. The chart below (Fig. 5) represents the cause of otitis when samples are taken during VO. Note that there were 0 fungal infections in the ear (since there was already a treatment in place after the initial diagnosis) and the number of bacterial infections stayed the same (but in different dogs, check Appendix 1) while giving rise to another cause of otitis. In 7 of the dogs, the purpose of the VO was for the treatment and not for the diagnosis of the chronic otitis. With samples removed during VO, we found that the reason causing chronic otitis were not the same, or in the same proportions, as the ones before VO, with the presence of Pseudomonas aeruginosa and polyps. The Fig. 6 shows the shift in the proportions of the agents during VO. Regarding the diagnosis during VO, there was a change in the diagnosis in 65% of the cases while the other 35% were not diagnosed. (Fig. 7). Finally, concerning the improvement of the chronic otitis after VO, 17 (85%) showed an improvement and 3 (15%) went into surgery (Fig. 8). When using the video otoscope for treatment purposes, the ear is cleared from all the pus and debris which are removed with the grasping forceps and intense flushing and
Figure 5.
Cause of otitis during VO.
Video otoscopy in the diagnosis and treatment of chronic otitis in dogs
Figure 6.
Agents causing otitis during VO.
Figure 7.
Change of diagnosis after VO.
99
lavage. The result of this cleaning procedure is shown in Figs. 9 and 10.
Discussion
Figure 8.
A study [4] published in 1983 showed the importance of anesthetizing the animal and taking samples with a sterile swab from the horizontal canal instead of going in with the swab as deep as possible. This study reflects on the work done with the video otoscope to show the importance of going into the horizontal canal and taking samples next to the tympanic membrane where most of the pathogens adhere.
In this study, we were able to prove the efficacy of the video otoscope as a tool for diagnosis and treatment. In our study, 13 of the cases already diagnosed and treated had a change in their diagnosis. This can be explained with the change in diagnosis; each ear diagnosed with the use of a traditional otoscope and a sterile cotton swab showed the presence of
Improvements after VO.
100
F. Stephan et al.
Figure 9. VO of the ear before lavage. Credits: Dr F. Stephan, Dr D. Saade.
Figure 10. VO of the ear after lavage. Credits: Dr F. Stephan, Dr D. Saade.
an agent which underwent a treatment to clear it from the ear. After finishing the treatment, the ear had a recurrence of otitis which led to the diagnosis with VO. The diagnosis with the video otoscope showed the presence of a new agent each time (Fig. 5). This shows that the use of a video otoscope for the diagnosis of chronic otitis is really important since it shows that 100% of the cases diagnosed with the video otoscope did actually show a change. Results of cytologic examination before the VO were recorded in some of the patients. Of the 20 ears, 14 ears were sampled before VO. These 14 ears showed a presence of bacteria in 64% of the cases, of which 36% E. coli, 14% cocci, and 14% S. pseudintermedius, and 36% of fungal agents, of which 29% of Malassezia pachydermatis and 7% of C. albicans (Figs. 11 and 12). However, for the cytologic examination of samples taken from 13 ears during VO (Figs. 11 and 12), we had a 69% of
bacterial agents, of which 31% E. coli, 15% P. aeruginosa, and 23% S. pseudintermedius, 0% of fungal agents, and 31% of other agents, of which 8% was dirt and 23% were polyps (Fig. 13). This change in proportions of agents as well as the appearance of new agents shows the importance and the misdiagnosis of otitis leading to the recurrence of otitis. Also, this change can be due to the fact that the treatment of the otitis before VO could have had an effect on the previously diagnosed agents, giving rise to new agents or changing in the proportions of the pathogens present while sampling the ear during video otoscopy. In a study [5] comparing two different techniques for sample collection in case of OE, which include a cotton swab and a rubber tube, there was a change in the percentages of bacteria and yeast in each of the techniques, showing that the technique of the cotton swab is not 100% reliable to be able to make a diagnosis.
Figure 11.
Causes of chronic otitis in 14 sampled ears.
Video otoscopy in the diagnosis and treatment of chronic otitis in dogs
Figure 12.
101
Agents causing chronic otitis in sampled ears before and during VO.
All the dogs discharged after VO were prescribed ear cleaners for home use in conjunction with a local treatment administered according to each case. This study has several limitations. Variations in interpretation of findings of cytologic and otoscopic examinations and in treatment plans were inherent because dogs were managed by several clinicians. The study relied solely on medical records and telephone contacts for all data. The small number of dogs treated, and the absence of a control group prevented relevant statistical analysis. Also, client compliance was critical, and we believe that thorough lavage of the ear canal followed by intensive and meticulous management by the owner are key to the resolution of symptoms and success of the treatment.
Figure 13. View of a polyp under VO. Credits: Dr F. Stephan, Dr D. Saade.
Two, more detailed, studies [6,7], also showed the increase of Malassezia species, S. pseudintermedius, and P. aeruginosa, in ears with OE compared to healthy ears. These results are in coherence with the results of this study. The video otoscope was also used as a treatment for chronic OE and/or media. This procedure did show subjectively, in Fig. 8, an improvement in 17 out of 20 of the dogs at the re-evaluation, after flushing and cleaning the ear canal with the video otoscope, in conjunction with local treatment administered at home. There was loss of ear smell, head shaking, ear scratching, sensitivity to the touch of the ear, and head tilting. Recurrence of clinical signs were not reported after 7, 14, and 21 days post VO. A previous study [8] did show an improvement in OM when treated with otoscopic lavage of the tympanic bulla combined with medical management. Of the 20 dogs that did undergo otoscopy for treatment purposes, 3 had to undergo a surgery due to the presence of polyps in the ear canal that were not easy to remove with the video otoscope.
Conclusion VO, in conjunction with medical treatment prescribed at discharge, seems to be an effective technique to diagnose and treat recurrent OE or OM. This being said, video otoscopy is useful for high-quality practices and should be the standard of practice in Lebanon. To be able to become an expert with this technique, veterinarians can work closely with experienced endoscopists or attend workshops and courses regarding the use of video otoscopes. Clients can understand the value of endoscopy in general and become more receptive as it is an excellent aid for client education and management of the disease with the images and movies it offers.
Funding and ethical statement This study has no financial or personal relationship with other people or organizations that could inappropriately influence or bias the content of this study.
102
Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at https://doi.org/10. 1016/j.anicom.2019.09.008.
Disclosure of interest The authors declare that they have no competing interest.
References [1] Gotthelf L. Small animal ear diseases: an illustrated guide. 2nd ed. Elsevier Saunders; 2005. [2] Hnilica KA. Small animal dermatology: a color atlas and therapeutic guide. 3rd ed. Elsevier Saunders; 2011.
F. Stephan et al. [3] Radlinsky MG. Veterinary clinics of North America: small animal practice. Adv Otoscopy 2016;46:171—9. [4] Dickson DB, Love DN. Bacteriology of the horizontal ear canal of dogs. J Small Animal Pract 1983;24(7):413—21. [5] Choi N, Edginton HD, Griffin CE, Angus JC. Comparison of two ear cytological collection techniques in dogs with otitis externa. Veterinary Dermatol 2018;29, 413-e136. [6] Crespo MJ, Abarca ML, Caba˜ nes FJ. Occurrence of Malassezia spp. in the external ear canals of dogs and cats with and without otitis externa. Med Mycol 2002;40:115—21. [7] Oliveria LC, Leite CAL, Brilhante RSN, Carvalho CBM. Comparative study of the microbial profile from bilateral canine otitis externa. Can Veterinary J 2008;49:785—8. [8] Palmeiro BS, Morris DO, Wiemelt SP, Shofer FS. Evaluation of outcome of otitis media after lavage of the tympanic bulla and long-term antimicrobial drug treatment in dogs: 44 cases. J Am Veterinary Med Assoc 2004;225(4):548—53.
Disponible en ligne sur
ScienceDirect www.sciencedirect.com
ORIGINAL ARTICLE
The importance of video otoscopy in the diagnosis and treatment of chronic otitis in dogs F. Stephan ∗, D. Saade , M. Nasser Lebanese University, Faculty of Agronomy and Veterinary Medicine, Dekweneh, Lebanon Received 18 July 2019; accepted 30 September 2019 Available online 14 November 2019
KEYWORDS Video otoscopy; Chronic otitis; Ear; Dog; Lebanon
Summary Chronic otitis is one of the most common reasons why dogs are presented to veterinary facilities in Lebanon. The chronicity of this disease is due to the failure to diagnose correctly the primary cause and the incapacity to treat it effectively. The objective of this study is to show the importance of the video otoscopy in the diagnosis and treatment of recurrent otitis externa and/or otitis media. A total of twenty cases (twelve dogs) with chronic otitis externa and/or media were used for this study. Video otoscopy was performed in all 20 cases where it was used for diagnosis in 13/20 cases and treatment in 17/20. Thirteen (65%) of the cases showed a change in the diagnosis after undergoing video otoscopy. Seventeen (85%) of the cases showed an improvement after using the video otoscopy for ear flushing and lavage, in conjunction with home therapy, for treatment purposes. Improvements were judged subjectively seven, fourteen, and twenty-one days after the otoscopic lavage took place. Three (15%) of the cases underwent a surgery due to the presence of polyps that were not removable with the video otoscope. © 2019 AFVAC. Published by Elsevier Masson SAS. All rights reserved.
Introduction
∗
Corresponding author. E-mail addresses: [email protected] (F. Stephan), [email protected] (D. Saade), [email protected] (M. Nasser).
Otitis externa (OE) is an inflammation of the skin that lines the external ear canal and may extend to the auricle. Otitis media (OM) is an inflammation of the middle ear. OE mainly, but also OM, are very frequent dermatologic affections in dogs and often recurrent. These cases represent 5 to 20% of the dermatologic consultations that arrive
https://doi.org/10.1016/j.anicom.2019.09.008 2214-5672/© 2019 AFVAC. Published by Elsevier Masson SAS. All rights reserved.
96 to the clinics in small animal veterinary medicine worldwide [1,2]. Lebanon is a country with an average annual relative humidity of 69.3% and an average monthly relative humidity that ranges from 66% in November to 73% in July. This importance in humidity increases the chances of developing otitis in dog. The challenge for the veterinary practitioner is to put a treatment that will ensure the fast and definitive healing of the animal. It is therefore important to be able to accurately determine the etiological factors of otitis, for each animal, in order to specifically treat each patient. A certain amount of time may be required to make the diagnosis during which complications may develop, adding complexity to the implementation of the treatment. Most veterinarians in Lebanon tend to diagnose otitis using traditional otoscopes that have limitations. This presumption was based on visiting different clinics and asking of their technique to diagnose otitis. These limitations include insufficient illumination, limited magnification, no working channel, and no documentation for medical records. This limits the exact evaluation of the tympanic membrane (TM) or any other problem behind it. For the treatment, veterinary clinicians in Lebanon use drugs based on the otic smear performed at the clinic; in some cases, based on culture performed in a medical laboratory. The administered drugs used are usually ototoxic drugs and are administered to patients without being 100% sure if the dog has a rupture of the TM. This leads to an accumulation of problems and the rising of new problems including but not limited to hearing loss, and vestibular syndrome. This study aims to show the importance of video otoscopy (VO) in the diagnosis and treatment of recurrent OE and/or OM in dogs in two different clinics in Lebanon.
Materials and methods Animals The 12 animals included in this study are patients who came for a consultation between August 2018 and June 2019 in two different veterinary facilities in Lebanon, ‘‘Animed Veterinary Hospital’’, which is a facility in Jounieh and has most of its patients coming from Mount Lebanon, and ‘‘Canicat Veterinary Clinic’’, which is a facility in Hamra and has most of its patients coming from Beirut Governate. Lebanon has an average of 66.0% of humidity throughout the year with March being the most humid month and September being the least humid. These patients came regarding ear smell, head shaking, ear scratching, sensitivity to the touch of the ear, deafness, head tilting, or for a second opinion regarding otitis that was not resolved with a previous treatment. Inclusion criteria include animals that have had these symptoms for a period longer than 1 month with failed treatments, or that have had treatments that did not show any improvements and gave rise to new auricular problems. Exclusion criteria include any dog having an acute otitis or dogs already treated with VO. Each ear with chronic otitis was considered an individual case, making a total of twenty cases (Appendix 1).
F. Stephan et al.
Figure 1. A biopsy forceps introduces in the Hopkins with operating sheath, and two stopcocks.
Bacterial sampling Before beginning with the VO, the administered patients were evaluated in the clinic. Some patients had an otic microscopic examination, showing if they had a bacterial or fungal infection, and if so, they had a swab sent to a microbiology lab for analysis, and other patients did not undergo a microscopic examination and the reason for otitis is unknown. The establishment of a sampling of ear pus for the culture in the laboratory is made in most of the cases in the animals which the treatment did not show any improvements. The samples are removed with a sterile cotton swab guided by VO or samples are removed with grasping forceps. The sample of the secretions contained in the EAM is carried out and then introduced into a sterile cotton swab that was stored in a fridge and conveyed in less than 12 hours to the microbiology laboratory concerned. In the laboratory, swabs are put in different growth medium (Mannitol Salt agar, Sabouraud Dextrose agar, Blood agar, and MacConkey agar) to grow all type of pathogens and select them. Also, a slide for Gram staining and visualization of pathogens is performed.
Video otoscopy Equipment The video otoscope used in this study is provided by Karl Storz—Endoskope® and consists of the Hopkins® (64029 BA) which is a forward-oblique 30 degree telescope with an enlarged view, a length of 18 cm, and a tip diameter of 2.7 mm, which is fully immersible and able to be autoclaved. It also has a fiber optic light transmission incorporated which delivers a larger image, making details easier to see. This telescope is protected by an operating sheath (67065C) which is 14.5 Fr. and has a working length of 15 cm with a working channel of 5 Fr. and two stopcocks to be able to flush at the same time; it also includes a blunt Obturator (67065 CO) (Fig. 1). The camera head (TELECAM 2120 30), along with the fiber optic light cable (69495 NA) of a 3.5 mm diameter and a 230 cm length, is connected to the TELE PACK VET X LED unit (RP 100 S1) by a simple adaptor (495KS).
Video otoscopy in the diagnosis and treatment of chronic otitis in dogs
Figure 2.
97
Tele Pack Vet X LED.
The camera head previously mentioned has a PAL color system, is soakable, gas-sterilizable, integrated Parfocal Zoom Lens (f = 25—50 mm), and 2 freely programmable camera head buttons. Regarding the TELE PACK VET X LED unit (Fig. 2), it is an ultimate compact mobile endoscopic video system that integrates different essential component needed for endoscopic imaging including a camera control unit (TELECAM technology), a high performance LED light source, a 15 high resolution LCD monitor with LED backlight, an image capture and documentation system enabling to capture and store still images and videos onto a USB/SD memory module, an insufflation pump. The latter component is not utilized for VO. Biopsy forceps (67161 Z) and grasping forceps (67161T), which are flexible, with double action jaws, 5 Fr., with a length of 34 cm each, were used in different situations during VO. Since the anesthesia has no effect on the ear, we will not be going into details regarding the protocol used for each patient. Patients are anesthetized and monitored throughout the VO.
Method of ear diagnosis and flushing using the video otoscope The animal is anesthetized with an endotracheal tube in place. This tube will prevent aspiration of fluids into the respiratory tract if the TM is ruptured or a myringotomy is to be performed. To allow the image to maintain an equal orientation during the VO, the patient is placed in a lateral recumbency and the clinician at the animal’s ventral aspect. The intertragic incisure allows the video otoscope to enter repeatedly and successfully the ear. After entering, and to minimize the interface of the dorsal fold, the ear is grasped at the base of the pinna and retracted laterodorsally. After passing the fold, the pinna is retracted latero-ventrally to be able to pass the horizontal canal and get to the TM. Continuous introduction of saline water is administered using the video otoscope for lavage and suction should be performed simultaneously. [3].
Figure 3.
Initial cause.
Evaluation of the improvement Dogs that have showed absence of ear itching, pain at ear palpation, purulent secretions in the EAM, ear inflammation, and head shaking are considered to have shown improvement. Some of these symptoms are subjective and others are evaluated with the use of a handheld otoscope. Dogs are re-examined 7, 14, and 21 days after VO to evaluate the otitis’ treatment and resolution of symptoms.
Statistical analysis Since the outcome of this study is not numerical and only has a categorical value, the statistical method used here is ‘‘Frequency tables’’ in ‘‘STATISTICA® v.12’’. By using this method, we were able to classify if there was a change in the diagnosis while using VO and if there was any improvement after the use of the video otoscope.
Results Initially, the cause of otitis was divided into 3 parts: 9 (45%) were attributed to bacterial, 5 (25%) were attributed to fungal, and 6 (30%) in unknown (Fig. 3).
98
Figure 4.
F. Stephan et al.
Initial agents.
The main agents causing otitis initially include E. coli (25%), Staphylococcus pseudintermedius (10%), Malassezia pachydermatis (20%), and Candida albicans (5%). Unidentified cocci (10%) were also present. The remaining 30% are attributed to the unknown category which includes the cases without any specific diagnosis for the otitis. These values were put in Fig. 4. The chart below (Fig. 5) represents the cause of otitis when samples are taken during VO. Note that there were 0 fungal infections in the ear (since there was already a treatment in place after the initial diagnosis) and the number of bacterial infections stayed the same (but in different dogs, check Appendix 1) while giving rise to another cause of otitis. In 7 of the dogs, the purpose of the VO was for the treatment and not for the diagnosis of the chronic otitis. With samples removed during VO, we found that the reason causing chronic otitis were not the same, or in the same proportions, as the ones before VO, with the presence of Pseudomonas aeruginosa and polyps. The Fig. 6 shows the shift in the proportions of the agents during VO. Regarding the diagnosis during VO, there was a change in the diagnosis in 65% of the cases while the other 35% were not diagnosed. (Fig. 7). Finally, concerning the improvement of the chronic otitis after VO, 17 (85%) showed an improvement and 3 (15%) went into surgery (Fig. 8). When using the video otoscope for treatment purposes, the ear is cleared from all the pus and debris which are removed with the grasping forceps and intense flushing and
Figure 5.
Cause of otitis during VO.
Video otoscopy in the diagnosis and treatment of chronic otitis in dogs
Figure 6.
Agents causing otitis during VO.
Figure 7.
Change of diagnosis after VO.
99
lavage. The result of this cleaning procedure is shown in Figs. 9 and 10.
Discussion
Figure 8.
A study [4] published in 1983 showed the importance of anesthetizing the animal and taking samples with a sterile swab from the horizontal canal instead of going in with the swab as deep as possible. This study reflects on the work done with the video otoscope to show the importance of going into the horizontal canal and taking samples next to the tympanic membrane where most of the pathogens adhere.
In this study, we were able to prove the efficacy of the video otoscope as a tool for diagnosis and treatment. In our study, 13 of the cases already diagnosed and treated had a change in their diagnosis. This can be explained with the change in diagnosis; each ear diagnosed with the use of a traditional otoscope and a sterile cotton swab showed the presence of
Improvements after VO.
100
F. Stephan et al.
Figure 9. VO of the ear before lavage. Credits: Dr F. Stephan, Dr D. Saade.
Figure 10. VO of the ear after lavage. Credits: Dr F. Stephan, Dr D. Saade.
an agent which underwent a treatment to clear it from the ear. After finishing the treatment, the ear had a recurrence of otitis which led to the diagnosis with VO. The diagnosis with the video otoscope showed the presence of a new agent each time (Fig. 5). This shows that the use of a video otoscope for the diagnosis of chronic otitis is really important since it shows that 100% of the cases diagnosed with the video otoscope did actually show a change. Results of cytologic examination before the VO were recorded in some of the patients. Of the 20 ears, 14 ears were sampled before VO. These 14 ears showed a presence of bacteria in 64% of the cases, of which 36% E. coli, 14% cocci, and 14% S. pseudintermedius, and 36% of fungal agents, of which 29% of Malassezia pachydermatis and 7% of C. albicans (Figs. 11 and 12). However, for the cytologic examination of samples taken from 13 ears during VO (Figs. 11 and 12), we had a 69% of
bacterial agents, of which 31% E. coli, 15% P. aeruginosa, and 23% S. pseudintermedius, 0% of fungal agents, and 31% of other agents, of which 8% was dirt and 23% were polyps (Fig. 13). This change in proportions of agents as well as the appearance of new agents shows the importance and the misdiagnosis of otitis leading to the recurrence of otitis. Also, this change can be due to the fact that the treatment of the otitis before VO could have had an effect on the previously diagnosed agents, giving rise to new agents or changing in the proportions of the pathogens present while sampling the ear during video otoscopy. In a study [5] comparing two different techniques for sample collection in case of OE, which include a cotton swab and a rubber tube, there was a change in the percentages of bacteria and yeast in each of the techniques, showing that the technique of the cotton swab is not 100% reliable to be able to make a diagnosis.
Figure 11.
Causes of chronic otitis in 14 sampled ears.
Video otoscopy in the diagnosis and treatment of chronic otitis in dogs
Figure 12.
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Agents causing chronic otitis in sampled ears before and during VO.
All the dogs discharged after VO were prescribed ear cleaners for home use in conjunction with a local treatment administered according to each case. This study has several limitations. Variations in interpretation of findings of cytologic and otoscopic examinations and in treatment plans were inherent because dogs were managed by several clinicians. The study relied solely on medical records and telephone contacts for all data. The small number of dogs treated, and the absence of a control group prevented relevant statistical analysis. Also, client compliance was critical, and we believe that thorough lavage of the ear canal followed by intensive and meticulous management by the owner are key to the resolution of symptoms and success of the treatment.
Figure 13. View of a polyp under VO. Credits: Dr F. Stephan, Dr D. Saade.
Two, more detailed, studies [6,7], also showed the increase of Malassezia species, S. pseudintermedius, and P. aeruginosa, in ears with OE compared to healthy ears. These results are in coherence with the results of this study. The video otoscope was also used as a treatment for chronic OE and/or media. This procedure did show subjectively, in Fig. 8, an improvement in 17 out of 20 of the dogs at the re-evaluation, after flushing and cleaning the ear canal with the video otoscope, in conjunction with local treatment administered at home. There was loss of ear smell, head shaking, ear scratching, sensitivity to the touch of the ear, and head tilting. Recurrence of clinical signs were not reported after 7, 14, and 21 days post VO. A previous study [8] did show an improvement in OM when treated with otoscopic lavage of the tympanic bulla combined with medical management. Of the 20 dogs that did undergo otoscopy for treatment purposes, 3 had to undergo a surgery due to the presence of polyps in the ear canal that were not easy to remove with the video otoscope.
Conclusion VO, in conjunction with medical treatment prescribed at discharge, seems to be an effective technique to diagnose and treat recurrent OE or OM. This being said, video otoscopy is useful for high-quality practices and should be the standard of practice in Lebanon. To be able to become an expert with this technique, veterinarians can work closely with experienced endoscopists or attend workshops and courses regarding the use of video otoscopes. Clients can understand the value of endoscopy in general and become more receptive as it is an excellent aid for client education and management of the disease with the images and movies it offers.
Funding and ethical statement This study has no financial or personal relationship with other people or organizations that could inappropriately influence or bias the content of this study.
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Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at https://doi.org/10. 1016/j.anicom.2019.09.008.
Disclosure of interest The authors declare that they have no competing interest.
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