- Email: [email protected]
Occurrences and management of lameness in goats: A case study of Magadu farm, Morogoro, Tanzania
Small Ruminant Research 82 (2009) 149–151
Contents lists available at ScienceDirect
Small Ruminant Research journal homepage: www.elsevier.com/locate/smallrumres
Short communication
Occurrences and management of lameness in goats: A case study of Magadu farm, Morogoro, Tanzania H.E. Nonga a,∗ , M. Makungu b , S.B.P. Bittegeko b , D.G. Mpanduji b a
Department of Veterinary Medicine and Public Health, Faculty of Veterinary Medicine, Sokoine University of Agriculture, P.O. Box 3021, Morogoro, United Republic of Tanzania b Department of Veterinary Surgery and Theriogenology, Faculty of Veterinary Medicine, Sokoine University of Agriculture, P.O. Box 3020, Morogoro, United Republic of Tanzania
a r t i c l e
i n f o
Article history: Received 23 February 2008 Received in revised form 28 January 2009 Accepted 4 February 2009 Available online 9 March 2009 Keywords: Goats Lameness Rain season Predisposing factors
a b s t r a c t A survey of lameness in goats was carried out at Magadu farm, Morogoro, Tanzania during the rainy and dry season of 1996, 1997 and 1998 involving 383, 449 and 438 animals, respectively. Digital lesions as cause of lameness were diagnosed through clinical and radiological evaluations. For the 3 years of study, a significantly (P < 0.001) higher prevalence of lameness was recorded during rain seasons than dry season (7.3%). Under the management conditions employed at Magadu adult goats suffered more (69.5%) than the young ones (31.5%). Of the adults, male goats were more affected by lameness (85%) than females (67.3%). The hind limbs appeared to be most affected (P < 0.05; prevalence 62.4%) by lameness compared to the forelimbs (prevalence 37.6%). Radiography of the affected foot revealed periarticular soft tissue swelling, distension of the joint capsule, widening of the joint space and osteolysis of the articular joint surfaces. To conclude, the study found the occurrences of lameness due to digital diseases were largely related to the climatic conditions and management factors. © 2009 Elsevier B.V. All rights reserved.
1. Introduction In Tanzania, pastoral communities keep goat and sheep for improving socio-economic status (Devendra and Mclorey, 1987). Like many sub-Saharan countries, goat and sheep are estimated to provide up to 30% of the meat and 15% of the milk supplies (Luckins, 1992). Goat and sheep are known to thrive in a wide range of ecological regions. In this part of the continent, they are kept in ecozones too harsh for the beneficial rearing of other animals. Goat and sheep are kept under the traditional management system dominated by indigenous breeds (Mgasa and Arnbjerg, 1993). Like many other livestock’s, goat and sheep do suffer a number of disease conditions known to affect their wellbeing. One of such problems is a disorder of the locomotors
∗ Corresponding author. Tel.: +255 23 2604542; fax: +255 23 2604647. E-mail addresses: [email protected], [email protected] (H.E. Nonga). 0921-4488/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.smallrumres.2009.02.001
system. The foot is the most common seat for lameness and account for 95% of all lameness cases in goats (Mgasa and Arnbjerg, 1993). The predisposing factors for lameness in goats includes poor nutrition, unhygienic ground conditions, hard and rough environment terrain, poor digital conformation, untrimmed hooves, penetrating injuries, trauma, fracture, inflammation of anatomical structures and presence of infectious agents (Mohamed et al., 1996; Bokko and Chaudhari, 2001). The ultimate loss of production in goat associated with lameness is largely attributed by reduced feed intake, lowered reproductive performance, loss of weight and low milk production (Hill et al., 1997). The aetiology of lameness is multifactorial but footrot is known as major cause of lameness in goats (Kusiluka and Kambarage, 1996). Control of lameness is essential for realizing the potential of goat production. For proper control to be instituted, foot diseases and their dynamics must be known. The paucity of information on the aetiology of digital diseases in goat makes the treatment and control difficult. Identifica-
150
H.E. Nonga et al. / Small Ruminant Research 82 (2009) 149–151
tion of the aetiological entities is therefore a very important prerequisite for the control of lameness. The objective of this study was to investigate the prevalence and risk factors associated with lameness and management in goat at Magadu University farm, Morogoro, Tanzania. 2. Materials and methods
Table 1 Prevalence, risk factors and lameness scores for goats at Magadu farm, Morogoro, Tanzania. Year
1998
2.1. Study area and animals
Risk factor
Category
Sample (n)
Prevalence
Age
Adult Kids Male Female Rainy Dry
334 104 40 294 438 419
69.5 13.5 85 67.3 50.9 5.5
Adult Kids Male Female Rainy Dry
393 56 51 342 449 444
11.3 3.6 23.5 10.6 19.8 8.3
Adult Kids Male Female Rainy Dry
403 31 70 333 383 398
14.1 3.2 28.6 13.2 10.2 5.6
Sex Season
The study was conducted at Magadu University farm in Morogoro municipality, Tanzania. Annual average rainfall of the municipality ranges between 500 and 1800 mm and ambient temperature ranges 27–31 ◦ C with minimum night temperature of 14 ◦ C in the coolest months. The municipality areas have a bimodal rain pattern, with about 83% of the rain falling between late February and end of May, and short rains between November and January. The breeds of goats kept by the farm are local breeds, crosses of Norwegians, Toggernburg and Galla crossed with local breeds. The goats were grazed on natural pastures and shrub and provided with concentrates feed (a mixture of maize bran and cotton seed cake) plus mineral supplements. The flocks of goat were managed in separate groups of females, males and kids usually aged between 0 and 10 months. The kids were kept indoor throughout on the raised slatted wooden floored house; occasionally sent out for few hours a day for exercise. Adult goats were housed on rough concrete floored cubicles without bedding. The floors were sometimes wet, covered with faeces and other droppings. No routine hoof trimming and footbath was practiced at the farm during the study period. 2.2. Data collection Both retrospective and prospective data on the occurrences of lameness were collected. Retrospective data for 1996 and 1997 were retrieved from records. Important variables recorded were age, sex, season, nature of lameness, affected limb and treatment given. Prospective data involved clinical examination of 438 and 419 goats during rain and dry season, respectively, in 1998. The animals’ stance and gait were observed from a distance and once abnormal locomotion observed, the animal was separated for detailed clinical examination and radiographic evaluations that were aimed at ascertaining the lesions causing lameness. Signs of limping, holding limbs above the ground, grazing on knees, reluctance to walk and or recumbence were used as basis for selecting animals for detailed lameness examination. Detailed examination involved assessment of the whole leg with attention in the hooves. The hooves and digits of lame goats were cleaned using soapy water and brushes while examining them for lesions. Overgrown hooves and toe were trimmed and the lesions scored using a scale of 0, 1, 2, 3, 4 and 5 (Table 1). The hoof lesions scored three to five were further dressed by using hydrogen peroxide 3% solution, povidone iodine and sprayed with oxytetracycline once a day till the animals recovered. In animals, where infection extended to the joints or those that indicated clear signs of septicaemia, penicillin dihydrostreptomycin (procaine penicillin BP 200 mg and dihydrostreptomycin sulphate BP 200 mg) was adminis-
Age 1997
Sex Season Age
1996
Sex Season
tered intramuscularly at the dose of 8 mg/kg for each ingredient per day for 5 consecutive days. Dexamethazone at a dose of 5 mg/kg administered intramuscularly was also given for 3 consecutively days. Goats having lameness scores of 0–2 were foot-bathed in a 3% formaldehyde solution once a week and all showed a good recovery within the first month of treatment.
3. Results The prevalence and risk factors associated with lameness in goat are shown in Table 1. For the 3 years of study, a significantly (P < 0.001) higher prevalence of lameness was recorded during rain seasons than dry season (7.3%). The prevalence of lameness for 1996 and 1997 were 10.2 and 19.8%, respectively. In 1998, the condition occurred as an outbreak with the recorded prevalence of 51%. During the present study, the common digital lesions recorded were interdigital dermatitis, heel–horn erosion, sole ulcers, punctured sole, white line abscesses, sole abscesses, hoof overgrowth and deformity and soil and grass balling. Among the 246 lame goats found during the rainy season of prospective study, 25 animals were completely recumbent with lesions scoring from 3 to 5 and affected all four legs (Table 2).
Table 2 Score frequencies of digital lesions in fore and hind limbs during rain (wet) and dry seasons in 1998. Scores
Rainy season Fore
Dry season Hind
Scores
Prevalence (%) 47.8 25.6 11.9 8.8 5.9
1 2 3 4 5
50 25 6 4 3
62 35 22 16 11
112 60 28 20 14
Total
88
146
234
Fore
Hind
Total
Prevalence (%)
7 3 0 0 0
10 5 0 0 0
17 8 0 0 0
68 32 0 0 0
10
15
25
Legend of lameness scores: 0: sound digit with no lesion. 1, Slight to moderate inflammation with some erosion between the claws. There is no under running or erosion of the skin or horn. 2: The skin between the claws is inflamed and raw and may involve part, or all, of the soft horn on the inside of the claws. There is no under running of the horn but there is lameness. 3: Severe inflammation of soft tissue around the joint, the horn at the heel may slightly under run together with joint involvement causing lameness. 4: Ulceration on the interdigital skin and around the coronet, separation of the skin horn junction, with under running of the heel or sole but not extending to the outside edge of the sole of the claw and there are discharges and severe lameness. 5: The lesions involve the whole sole, with extensive inflammation, under running of the hard horn of the hoof, fistula formation with pus exudation.
H.E. Nonga et al. / Small Ruminant Research 82 (2009) 149–151
Lameness appeared to affect all age groups. Under the management conditions employed at Magadu farm, adult goats suffered more (69.5%) than the young ones (31.5%). Of the adults, male goats were more affected by lameness (85%) than females (67.3%). The hind limbs appeared to be most affected (P < 0.05; prevalence 62.4%) compared to the forelimbs (prevalence 37.6%) (Tables 1 and 2). Radiography of the affected foot revealed periarticular soft tissue swelling, distension of the joint capsule, widening of the joint space and osteolysis of subchondral bones forming the joint articular surfaces. All affected goats, that were put under treatment recovered from the digital lesions. 4. Discussion The results of this study established the prevalence of lameness in goats and identified the possible risk factors at Magadu farm. The occurrences of lameness cases due to digital lesions were related to climatic conditions and fueled by management factors. It was observed that highest numbers of lameness cases were observed during the rain season. Indeed, in 1998 we recorded an outbreak of lameness that was thought to be attributed by heavy torrential El-Nino rains in Morogoro that persisted for 5 months. The major predisposing factors comprised of exposure to wet, warm, muddy and dirty environment both in animal houses and pastureland. These findings are in agreement with other studies (Mgasa and Arnbjerg, 1993; Hill et al., 1997) where environment has been reported to be the major predisposing factor to digital lesions. Elsewhere, Abbot and Lewis (2005) described warm temperature (about 10 ◦ C) and prolonged rainfall exceeding 50 mm per month as favourable condition for the transmission of anaerobes responsible for footrot in goats. Persistently wet conditions weaken the hooves and interdigital skin thus; ease microbial penetration which may lead to clinical lameness (Eze, 2002). Furthermore, it was found that adult males suffered more lameness. This finding is probably attributed by their indulging habit of riding and sexual activities that result in high risk of physical damage to hooves and interdigital skin (Mgasa et al., 1994). Males also have more body weight than females, thus any interference of hoof integrity can easily expose them to dangers of trauma. During this study, hind limbs appeared to suffer from lameness causing lesions more than the forelimbs similar to the previous observation reported by West (1983). However, the study conducted by Hill et al. (1997) did not observe a difference between hind and forelimbs. The present study also differs from the observations made by Mgasa et al. (1994) who recorded more lesions causing lameness in forelimbs. The difference seen can partly be explained by the differential distribution of weight between hind and forelegs and the feeding habits. Biomechanics of ruminants indicates more weights in hind limbs than forelimb (Nickel et al., 1986). The browsing behaviour
151
of goats during feeding may also likely to exert more weight on hind limbs. Thus, whenever the hooves of the hind limbs get weakened, lameness becomes the likely outcome. Lack of regular hoof trimming, footbaths and housing of animals on a rough concrete floor as observed in this study may also have contributed to the high prevalence of digital diseases in goats. During the survey, overgrown hooves were trimmed; the animals were then treated using a 3% solution of formalin as footbath and were shifted to slatted wooden floored house, where they recovered from lameness. Tremendous improvement in reducing incidences of footrot has been reported by Abbot and Lewis (2005) where approved footbath solutions were routinely applied in ovine. From this study, lameness due to digital diseases in goats was confirmed to be a problem at Magadu farm. This translates a poor productivity of goats and subsequent economic loss to the farm. The prevalence of lameness appeared to fluctuate between years and was directly influenced by climatic and unhygienic conditions. In order to control the digital diseases, improvement of management systems is strongly suggested. Acknowledgements The authors are grateful to Magadu Farm Manager and Department of Animal Science and Production, Sokoine University of Agriculture for allowing us to a permission to pursue this study to their animals. References Abbot, K.A., Lewis, C.J., 2005. Current approaches to the management of ovine footrot. Vet. J. 169, 28–41. Bokko, B.P., Chaudhari, S.U.R., 2001. Prevalence of lameness in sheep in the northern region of Nigeria. Int. J. Agric. Biol. 3 (4), 519–521. Devendra, C., Mclorey, G.B., 1987. A Textbook of Goats Production in the Tropics. Longman, London, p. 352. Eze, C.A., 2002. Lameness and reproductive performance in small ruminants in Nsukka area of the Enugu state, Nigeria. Small Rumin. Res. 3, 263–267. Hill, N.P., Murphy, P.E., Nelson, A.J., Mouttotou, N., Green, L.E., Morgan, K.L., 1997. Lameness and foot lesions in adult British goats. Vet. Rec. 141, 412–416. Kusiluka, L.J.M., Kambarage, D.M., 1996. Diseases of Small Ruminants in Subsaharan Africa: A Hand Book on Common Diseases of Sheep and Goats in Sub-Saharan Africa, VETAID. Capital Print Ltd. Luckins, A.G., 1992. Trypanosomiasis in small ruminants—a major constraint to livestock productivity. Br. Vet. J. 148, 471–473. Mgasa, M.N., Arnbjerg, J., 1993. Occurrence of lameness and digital lesions in Tanzanian goats. Small Rumin. Res. 10, 55–62. Mgasa, M.N., Thamsborg, S.M., Jorgensen, R.J., Fogh, J., 1994. Health and growth in young goats fed pellected lucerne or concentrate ad libitum. Small Rumin. Res. 13, 109–115. Mohamed, A., Badau, U.A., Kene, R.O.C., 1996. Lameness in sheep and goats in relation to hoof condition in Sahel Zone of Nigeria. Bull. Anim. Health Prod. Afr. 44, 97–100. Nickel, R., Schumer, A., Seiferle, E., Wilkens, H., Wille, K.H., Frewein, J., 1986. The Anatomy of the Domestic Animals, vol. 1. Verlag Paul Parey, Berlin/Hamburg, pp. 30–40. West, D.M., 1983. Observations on an outbreak of foot abscess in sheep. NZ J. Vet. 31, 71–74.
Contents lists available at ScienceDirect
Small Ruminant Research journal homepage: www.elsevier.com/locate/smallrumres
Short communication
Occurrences and management of lameness in goats: A case study of Magadu farm, Morogoro, Tanzania H.E. Nonga a,∗ , M. Makungu b , S.B.P. Bittegeko b , D.G. Mpanduji b a
Department of Veterinary Medicine and Public Health, Faculty of Veterinary Medicine, Sokoine University of Agriculture, P.O. Box 3021, Morogoro, United Republic of Tanzania b Department of Veterinary Surgery and Theriogenology, Faculty of Veterinary Medicine, Sokoine University of Agriculture, P.O. Box 3020, Morogoro, United Republic of Tanzania
a r t i c l e
i n f o
Article history: Received 23 February 2008 Received in revised form 28 January 2009 Accepted 4 February 2009 Available online 9 March 2009 Keywords: Goats Lameness Rain season Predisposing factors
a b s t r a c t A survey of lameness in goats was carried out at Magadu farm, Morogoro, Tanzania during the rainy and dry season of 1996, 1997 and 1998 involving 383, 449 and 438 animals, respectively. Digital lesions as cause of lameness were diagnosed through clinical and radiological evaluations. For the 3 years of study, a significantly (P < 0.001) higher prevalence of lameness was recorded during rain seasons than dry season (7.3%). Under the management conditions employed at Magadu adult goats suffered more (69.5%) than the young ones (31.5%). Of the adults, male goats were more affected by lameness (85%) than females (67.3%). The hind limbs appeared to be most affected (P < 0.05; prevalence 62.4%) by lameness compared to the forelimbs (prevalence 37.6%). Radiography of the affected foot revealed periarticular soft tissue swelling, distension of the joint capsule, widening of the joint space and osteolysis of the articular joint surfaces. To conclude, the study found the occurrences of lameness due to digital diseases were largely related to the climatic conditions and management factors. © 2009 Elsevier B.V. All rights reserved.
1. Introduction In Tanzania, pastoral communities keep goat and sheep for improving socio-economic status (Devendra and Mclorey, 1987). Like many sub-Saharan countries, goat and sheep are estimated to provide up to 30% of the meat and 15% of the milk supplies (Luckins, 1992). Goat and sheep are known to thrive in a wide range of ecological regions. In this part of the continent, they are kept in ecozones too harsh for the beneficial rearing of other animals. Goat and sheep are kept under the traditional management system dominated by indigenous breeds (Mgasa and Arnbjerg, 1993). Like many other livestock’s, goat and sheep do suffer a number of disease conditions known to affect their wellbeing. One of such problems is a disorder of the locomotors
∗ Corresponding author. Tel.: +255 23 2604542; fax: +255 23 2604647. E-mail addresses: [email protected], [email protected] (H.E. Nonga). 0921-4488/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.smallrumres.2009.02.001
system. The foot is the most common seat for lameness and account for 95% of all lameness cases in goats (Mgasa and Arnbjerg, 1993). The predisposing factors for lameness in goats includes poor nutrition, unhygienic ground conditions, hard and rough environment terrain, poor digital conformation, untrimmed hooves, penetrating injuries, trauma, fracture, inflammation of anatomical structures and presence of infectious agents (Mohamed et al., 1996; Bokko and Chaudhari, 2001). The ultimate loss of production in goat associated with lameness is largely attributed by reduced feed intake, lowered reproductive performance, loss of weight and low milk production (Hill et al., 1997). The aetiology of lameness is multifactorial but footrot is known as major cause of lameness in goats (Kusiluka and Kambarage, 1996). Control of lameness is essential for realizing the potential of goat production. For proper control to be instituted, foot diseases and their dynamics must be known. The paucity of information on the aetiology of digital diseases in goat makes the treatment and control difficult. Identifica-
150
H.E. Nonga et al. / Small Ruminant Research 82 (2009) 149–151
tion of the aetiological entities is therefore a very important prerequisite for the control of lameness. The objective of this study was to investigate the prevalence and risk factors associated with lameness and management in goat at Magadu University farm, Morogoro, Tanzania. 2. Materials and methods
Table 1 Prevalence, risk factors and lameness scores for goats at Magadu farm, Morogoro, Tanzania. Year
1998
2.1. Study area and animals
Risk factor
Category
Sample (n)
Prevalence
Age
Adult Kids Male Female Rainy Dry
334 104 40 294 438 419
69.5 13.5 85 67.3 50.9 5.5
Adult Kids Male Female Rainy Dry
393 56 51 342 449 444
11.3 3.6 23.5 10.6 19.8 8.3
Adult Kids Male Female Rainy Dry
403 31 70 333 383 398
14.1 3.2 28.6 13.2 10.2 5.6
Sex Season
The study was conducted at Magadu University farm in Morogoro municipality, Tanzania. Annual average rainfall of the municipality ranges between 500 and 1800 mm and ambient temperature ranges 27–31 ◦ C with minimum night temperature of 14 ◦ C in the coolest months. The municipality areas have a bimodal rain pattern, with about 83% of the rain falling between late February and end of May, and short rains between November and January. The breeds of goats kept by the farm are local breeds, crosses of Norwegians, Toggernburg and Galla crossed with local breeds. The goats were grazed on natural pastures and shrub and provided with concentrates feed (a mixture of maize bran and cotton seed cake) plus mineral supplements. The flocks of goat were managed in separate groups of females, males and kids usually aged between 0 and 10 months. The kids were kept indoor throughout on the raised slatted wooden floored house; occasionally sent out for few hours a day for exercise. Adult goats were housed on rough concrete floored cubicles without bedding. The floors were sometimes wet, covered with faeces and other droppings. No routine hoof trimming and footbath was practiced at the farm during the study period. 2.2. Data collection Both retrospective and prospective data on the occurrences of lameness were collected. Retrospective data for 1996 and 1997 were retrieved from records. Important variables recorded were age, sex, season, nature of lameness, affected limb and treatment given. Prospective data involved clinical examination of 438 and 419 goats during rain and dry season, respectively, in 1998. The animals’ stance and gait were observed from a distance and once abnormal locomotion observed, the animal was separated for detailed clinical examination and radiographic evaluations that were aimed at ascertaining the lesions causing lameness. Signs of limping, holding limbs above the ground, grazing on knees, reluctance to walk and or recumbence were used as basis for selecting animals for detailed lameness examination. Detailed examination involved assessment of the whole leg with attention in the hooves. The hooves and digits of lame goats were cleaned using soapy water and brushes while examining them for lesions. Overgrown hooves and toe were trimmed and the lesions scored using a scale of 0, 1, 2, 3, 4 and 5 (Table 1). The hoof lesions scored three to five were further dressed by using hydrogen peroxide 3% solution, povidone iodine and sprayed with oxytetracycline once a day till the animals recovered. In animals, where infection extended to the joints or those that indicated clear signs of septicaemia, penicillin dihydrostreptomycin (procaine penicillin BP 200 mg and dihydrostreptomycin sulphate BP 200 mg) was adminis-
Age 1997
Sex Season Age
1996
Sex Season
tered intramuscularly at the dose of 8 mg/kg for each ingredient per day for 5 consecutive days. Dexamethazone at a dose of 5 mg/kg administered intramuscularly was also given for 3 consecutively days. Goats having lameness scores of 0–2 were foot-bathed in a 3% formaldehyde solution once a week and all showed a good recovery within the first month of treatment.
3. Results The prevalence and risk factors associated with lameness in goat are shown in Table 1. For the 3 years of study, a significantly (P < 0.001) higher prevalence of lameness was recorded during rain seasons than dry season (7.3%). The prevalence of lameness for 1996 and 1997 were 10.2 and 19.8%, respectively. In 1998, the condition occurred as an outbreak with the recorded prevalence of 51%. During the present study, the common digital lesions recorded were interdigital dermatitis, heel–horn erosion, sole ulcers, punctured sole, white line abscesses, sole abscesses, hoof overgrowth and deformity and soil and grass balling. Among the 246 lame goats found during the rainy season of prospective study, 25 animals were completely recumbent with lesions scoring from 3 to 5 and affected all four legs (Table 2).
Table 2 Score frequencies of digital lesions in fore and hind limbs during rain (wet) and dry seasons in 1998. Scores
Rainy season Fore
Dry season Hind
Scores
Prevalence (%) 47.8 25.6 11.9 8.8 5.9
1 2 3 4 5
50 25 6 4 3
62 35 22 16 11
112 60 28 20 14
Total
88
146
234
Fore
Hind
Total
Prevalence (%)
7 3 0 0 0
10 5 0 0 0
17 8 0 0 0
68 32 0 0 0
10
15
25
Legend of lameness scores: 0: sound digit with no lesion. 1, Slight to moderate inflammation with some erosion between the claws. There is no under running or erosion of the skin or horn. 2: The skin between the claws is inflamed and raw and may involve part, or all, of the soft horn on the inside of the claws. There is no under running of the horn but there is lameness. 3: Severe inflammation of soft tissue around the joint, the horn at the heel may slightly under run together with joint involvement causing lameness. 4: Ulceration on the interdigital skin and around the coronet, separation of the skin horn junction, with under running of the heel or sole but not extending to the outside edge of the sole of the claw and there are discharges and severe lameness. 5: The lesions involve the whole sole, with extensive inflammation, under running of the hard horn of the hoof, fistula formation with pus exudation.
H.E. Nonga et al. / Small Ruminant Research 82 (2009) 149–151
Lameness appeared to affect all age groups. Under the management conditions employed at Magadu farm, adult goats suffered more (69.5%) than the young ones (31.5%). Of the adults, male goats were more affected by lameness (85%) than females (67.3%). The hind limbs appeared to be most affected (P < 0.05; prevalence 62.4%) compared to the forelimbs (prevalence 37.6%) (Tables 1 and 2). Radiography of the affected foot revealed periarticular soft tissue swelling, distension of the joint capsule, widening of the joint space and osteolysis of subchondral bones forming the joint articular surfaces. All affected goats, that were put under treatment recovered from the digital lesions. 4. Discussion The results of this study established the prevalence of lameness in goats and identified the possible risk factors at Magadu farm. The occurrences of lameness cases due to digital lesions were related to climatic conditions and fueled by management factors. It was observed that highest numbers of lameness cases were observed during the rain season. Indeed, in 1998 we recorded an outbreak of lameness that was thought to be attributed by heavy torrential El-Nino rains in Morogoro that persisted for 5 months. The major predisposing factors comprised of exposure to wet, warm, muddy and dirty environment both in animal houses and pastureland. These findings are in agreement with other studies (Mgasa and Arnbjerg, 1993; Hill et al., 1997) where environment has been reported to be the major predisposing factor to digital lesions. Elsewhere, Abbot and Lewis (2005) described warm temperature (about 10 ◦ C) and prolonged rainfall exceeding 50 mm per month as favourable condition for the transmission of anaerobes responsible for footrot in goats. Persistently wet conditions weaken the hooves and interdigital skin thus; ease microbial penetration which may lead to clinical lameness (Eze, 2002). Furthermore, it was found that adult males suffered more lameness. This finding is probably attributed by their indulging habit of riding and sexual activities that result in high risk of physical damage to hooves and interdigital skin (Mgasa et al., 1994). Males also have more body weight than females, thus any interference of hoof integrity can easily expose them to dangers of trauma. During this study, hind limbs appeared to suffer from lameness causing lesions more than the forelimbs similar to the previous observation reported by West (1983). However, the study conducted by Hill et al. (1997) did not observe a difference between hind and forelimbs. The present study also differs from the observations made by Mgasa et al. (1994) who recorded more lesions causing lameness in forelimbs. The difference seen can partly be explained by the differential distribution of weight between hind and forelegs and the feeding habits. Biomechanics of ruminants indicates more weights in hind limbs than forelimb (Nickel et al., 1986). The browsing behaviour
151
of goats during feeding may also likely to exert more weight on hind limbs. Thus, whenever the hooves of the hind limbs get weakened, lameness becomes the likely outcome. Lack of regular hoof trimming, footbaths and housing of animals on a rough concrete floor as observed in this study may also have contributed to the high prevalence of digital diseases in goats. During the survey, overgrown hooves were trimmed; the animals were then treated using a 3% solution of formalin as footbath and were shifted to slatted wooden floored house, where they recovered from lameness. Tremendous improvement in reducing incidences of footrot has been reported by Abbot and Lewis (2005) where approved footbath solutions were routinely applied in ovine. From this study, lameness due to digital diseases in goats was confirmed to be a problem at Magadu farm. This translates a poor productivity of goats and subsequent economic loss to the farm. The prevalence of lameness appeared to fluctuate between years and was directly influenced by climatic and unhygienic conditions. In order to control the digital diseases, improvement of management systems is strongly suggested. Acknowledgements The authors are grateful to Magadu Farm Manager and Department of Animal Science and Production, Sokoine University of Agriculture for allowing us to a permission to pursue this study to their animals. References Abbot, K.A., Lewis, C.J., 2005. Current approaches to the management of ovine footrot. Vet. J. 169, 28–41. Bokko, B.P., Chaudhari, S.U.R., 2001. Prevalence of lameness in sheep in the northern region of Nigeria. Int. J. Agric. Biol. 3 (4), 519–521. Devendra, C., Mclorey, G.B., 1987. A Textbook of Goats Production in the Tropics. Longman, London, p. 352. Eze, C.A., 2002. Lameness and reproductive performance in small ruminants in Nsukka area of the Enugu state, Nigeria. Small Rumin. Res. 3, 263–267. Hill, N.P., Murphy, P.E., Nelson, A.J., Mouttotou, N., Green, L.E., Morgan, K.L., 1997. Lameness and foot lesions in adult British goats. Vet. Rec. 141, 412–416. Kusiluka, L.J.M., Kambarage, D.M., 1996. Diseases of Small Ruminants in Subsaharan Africa: A Hand Book on Common Diseases of Sheep and Goats in Sub-Saharan Africa, VETAID. Capital Print Ltd. Luckins, A.G., 1992. Trypanosomiasis in small ruminants—a major constraint to livestock productivity. Br. Vet. J. 148, 471–473. Mgasa, M.N., Arnbjerg, J., 1993. Occurrence of lameness and digital lesions in Tanzanian goats. Small Rumin. Res. 10, 55–62. Mgasa, M.N., Thamsborg, S.M., Jorgensen, R.J., Fogh, J., 1994. Health and growth in young goats fed pellected lucerne or concentrate ad libitum. Small Rumin. Res. 13, 109–115. Mohamed, A., Badau, U.A., Kene, R.O.C., 1996. Lameness in sheep and goats in relation to hoof condition in Sahel Zone of Nigeria. Bull. Anim. Health Prod. Afr. 44, 97–100. Nickel, R., Schumer, A., Seiferle, E., Wilkens, H., Wille, K.H., Frewein, J., 1986. The Anatomy of the Domestic Animals, vol. 1. Verlag Paul Parey, Berlin/Hamburg, pp. 30–40. West, D.M., 1983. Observations on an outbreak of foot abscess in sheep. NZ J. Vet. 31, 71–74.