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Causes of morbidity and mortality in goats in Morogoro district, Tanzania: The influence of management
Small Ruminant Research 29 Ž1998. 167–172
Causes of morbidity and mortality in goats in Morogoro district, Tanzania: The influence of management L.J.M. Kusiluka
a,)
, D.M. Kambarage a , L.J.S. Harrison b, C.J. Daborn c , R.W. Matthewman d
a
Department of Veterinary Medicine and Public Health, P.O. Box 3021, Morogoro, Tanzania Centre for Tropical Veterinary Medicine, Easter Bush, Roslin Midlothian, Scotland EH25 9RG, UK VetAid, Centre for Tropical Veterinary Medicine, Easter Bush, Roslin Midlothian, Scotland EH25 9RG, UK d Natural Resource Institute, Central AÕenue, Chatham Maritime, Kent ME4 4TB, UK b
c
Accepted 13 September 1997
Abstract An investigation on the causes of morbidity and mortality in tethered, stall-fed and pastoral goats was carried out in the tropical highland and semi-arid areas of Morogoro district, Tanzania. Ectoparasitism was found to be common in all management systems with fleas, lice and ticks infesting 84–95%, 77–95% and 37–98% of the animals, respectively. The prevalences of the three ectoparasites were significantly higher in tethered goats in the tropical highland area than in other management systems Ž p - 0.05.. Helminth eggs Ž49–98%., coccidia oocysts Ž71–93%. and diarrhoea Ž14–44%. were common in all herds. The prevalences of diarrhoea and gastrointestinal parasitism were significantly higher in stall-fed goats than in other animals Ž p - 0.05.. Footrot, caseous lymphadenitis, dermatophilosis and mange were encountered only in pastoral goats. Respiratory infections were more common in pastoral than in stall-fed and tethered animals Ž p - 0.05.. Prevalences of footrot and diarrhoea were significantly higher during the rainy than the dry period Ž p - 0.05.. Helminthiasis Ž7.2%., diarrhoea Ž6.1%. and respiratory conditions Ž4.2%. were the major causes of mortalities. q 1998 Elsevier Science B.V. All rights reserved. Keywords: Health problems; Goats; Prevalence; Management
1. Introduction Diseases, considered to be major constraints that hinder the productivity of livestock in Tanzania
)
Corresponding author. Tel.: q255-56-4542r4647; fax: q255-56-3177r4079.
ŽShayo and Mlay, 1986., account for 40–60% of small ruminant losses in the country ŽMtenga et al., 1986.. The most common diseases of goats in Tanzania include helminthiasis, footrot, pneumonia, contagious ecthyma and diarrhoea ŽNyange and Mbise, 1983; Connor, 1985; Njau, 1987a,b; Msami, 1991.. Others include coccidiosis, brucellosis, sheeprgoat pox and ectoparasitism ŽNyange and Machange, 1983; Chukwu, 1987; Kambarage, 1992.. Malnutri-
00921-4488r98r$19.00 q 1998 Elsevier Science B.V. All rights reserved. PII S 0 9 2 1 - 4 4 8 8 Ž 9 7 . 0 0 1 1 0 - 7
168
L.J.M. Kusiluka et al.r Small Ruminant Research 29 (1998) 167–172
tion has also been observed to be common in Tanzanian goats ŽDas and Sendalo, 1989.. Environment and management are important factors influencing disease occurrences and patterns ŽMaiga, 1992; Voh et al., 1993.. Thus, in devising cost-effective disease control programmes, it is important to consider the influences of ecoclimatic factors and management on disease frequency. Therefore, a study was conducted to gather information on the causes of morbidity and mortality in goats kept in different management systems in two ecoclimatic zones in Morogoro district, Tanzania. The study was carried out in the tropical highland ŽMgeta. and semi-arid ŽMlali. areas of Morogoro district, Tanzania. Mgeta, which lies at 1400–1800 m above sea level and receives an average annual rainfall of 1800 mm, has temperature and relative humidity ranges of 9–218C and 75–94%, respectively. Mlali is situated at 500–600 m above sea level and receives an average annual rainfall of 900 mm, with temperature and humidity ranges of 15– 358C and 46–71%, respectively. In both areas, the long rainy season extends from late February to May, while the dry season extends from June to October. Short rains usually occur between November and January. The information gathered will be useful in devising disease control strategies.
2. Materials and methods In the tropical highland area, a total of 165 indigenous Small East African goats ŽSEA. in 26 small-holder herds and 81 crosses of Small East African= Norwegian Landrace dairy goats ŽCN. in 8 herds were studied. The number of goats in these herds ranged from 1–20 per herd. The SEA goats were tethered in communal grazing areas using ropes Žtethers. of about 3–5 m in length. The tethering sites could be changed once in a day depending on the availability of owner’s time. At night, the animals were kept in houses made of brick walls, earth floor and grass-thatched roof. Animal excreta was allowed to accumulate in these houses for future use as manure in crop fields. Cleaning of houses was
done after 2–3 months; thus, they were usually dirty. All the crossbred goats in the tropical highland area were stall-fed Žzero grazed.; confined in houses with raised, slatted floors and iron sheet or grass roofing. They were fed on grass or fodder cut from communal fields. The houses were also infrequently cleaned. Žcleaned after 2–3 months.. Animals Žtethered and stall-fed. in this area had no access to regular veterinary services. In the semi-arid area, 231 and 443 SEA goats in 32 small-holder herds and five pastoral herds, respectively, were studied. In the small-holder herds, the number of goats ranged from 1–20 per herd, whereas in the pastoral herds the number was 20–200 animals. Goats in the small-holder herds were tethered in communal grazing areas and at night they were housed in one of the family’s house rooms. The rooms were cleaned daily. All pastoral herds belonged to settled pastoralists. In the pastoral management system, goats were herded throughout the day in communal grazing land, and at night they were confined in open kraals Ženclosures constructed using wooden poles or thorny bushes with no roofs.. The kraals were usually not cleaned and thus were muddy especially during the rainy season. Animals in both the small-holder and pastoral herds had no access to veterinary services because they were not readily available and were expensive. As it applies to the tropical highland area, there were no disease control strategies implemented by the animal owners. One herd of 57 crosses of Toggenburg= Small East African goats ŽCT. kept for dairy purposes in the semi-arid area belonging to a Roman Catholic Missionary community was also included in the study. This was the only herd of crossbred goats in the area. These animals were herded in an area of about 1 km radius from the residential premises between 8:00 AM–12:00 noon. Thereafter, they were confined in a 1-ha paddock until 5:00 PM when they were brought back to the house where they were all supplemented with hay. Milking does were, in addition, given concentrates. The house was constructed using wooden planks with a raised, slatted floor and roofed with iron sheets. The house was cleaned daily. This management system was thus categorised as semi-intensive. The animals received regular veterinary attention. For instance, the animals were
L.J.M. Kusiluka et al.r Small Ruminant Research 29 (1998) 167–172
dipped using ethion ŽSupadip w , Copenhagen. once per month to prevent ectoparasitic infestation. Deworming was carried out in April 1994 and September 1994 using levamisole–albendazole ŽMilsan w , Interchem Pharma, Moshi, Tanzania. and ivermectin ŽIvomec w , MSD, Haarlem., respectively. All animals in the selected goat herds Žselected on the basis of cooperation of the farmers., between November 1993 and December 1994 were clinically examined every month and, disease occurrences and mortalities encountered during the visits were recorded. Between the visits, resident livestock field officers were responsible for monitoring disease occurrences Žcarrying out clinical and postmortem examinations.. Animals were examined for gastrointestinal-, ecto-, and haemo-parasites. All those showing clinical disease were thoroughly examined and where possible, samples such as blood, lungs, liver and kidneys were collected and submitted for diagnostic work at the Faculty of Veterinary Medicine, Sokoine University of Agriculture. Faecal samples were collected per rectum from all animals in the herds every month and examined for the presence of helminth eggs and coccidian oocysts using standard techniques ŽMinistry of Agriculture, Fisheries and Food, 1986.. Screening for haemoparasites Ž Trypanosoma, Babesia and Anaplasma species. in blood smears were carried out as described by MacLeod et al. Ž1981. and Brown et al. Ž1981.. Data were analyzed using Epi Info Version 6 Statistics System ŽDean et al., 1994.. Because of the small number of animals in individual herds and similarity in management of goats, and for simplicity of data analysis, data in the small-holder herds of SEA goats were pooled, as were for the pastoral herds. Data for the crossbred CN and CT were analyzed separately to minimise the effects of breed and management as confounding factors. Morbidity was defined as the amount of disease in a population ŽThrusfield, 1986. and included both clinical and subclinical diseases. Hence, both laboratory results and clinical features were used in the computation of morbidity data. The differences in prevalences of diseases between management systems were computed using x 2 test, and the significant level was taken to be 5%.
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3. Results Health problems encountered in goats in different management systems in the tropical highland and semi-arid areas are indicated in Table 1. Ectoparasitic, helminth and coccidial infections, which may result in decreased animal performance Ždecreased weight gains and body conditions. were the most prevalent health problems of goats in all management systems. Other prevalent conditions were diarrhoea and respiratory infections. Footrot, caseous lymphadenitis, dermatophilosis and mange were encountered only in pastoral herds. The prevalences of flea Ž p s 0.0088186., tick Ž p s 0.000001. and louse Ž p s 0.000000. infestation were significantly higher in tethered animals in the tropical highland area than in other management systems. The prevalence of ticks was lowest in stallfed animals. No fleas, ticks or lice were encountered in the herd of crossbred goats that were regularly dipped. Significantly higher prevalences of helminth Ž p s 0.000000., coccidial Ž p s 0.004300. infections and diarrhoea Ž p s 0.00000. were observed in stallfed goats than animals in other management systems. Pastoral goats in the semi-arid area had a significantly higher prevalence of respiratory infections compared to other animals Ž p s 0.000001.. The most common bacterial isolate from cases of respiratory infections was Pasteurella haemolytica. Other isolates were Pasteurella multocida, Staphylococcus aureus and Streptococcus species. No haemoparasites were encountered in the study goats. Seasonal influences on morbidity were encountered only in a few conditions. Footrot and dermatophilosis were encountered only during the rainy season. The majority of diarrhoea 72% Ž249. and respiratory cases 68% Ž169. were also encountered during the rainy season. In contrast, ecto- and endoparasites were encountered throughout the year. The causes of mortality of goats in different management systems in the two ecoclimatic zones are indicated in Table 2. The overall mortality of goats was significantly higher Ž p s 0.000001. in pastoral herds compared to animals in the smallholder herds. Diarrhoea and helminthiasis were the major causes of mortality in all management systems, whereas respiratory infections and footrot were
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Table 1 Causes of morbidity of goats Ž%. in two ecoclimatic zones in Morogoro district, Tanzania ŽNovember 1993–December 1994. Health problems
Fleas a Ticks b Lice c Helminthosisd Coccidiosise Diarrhoeaf Respiratory infections g Footrot Caseous lymphadenitis Dermatophilosis Mange Number of animals examined
Tropical highland zone
Semi-arid zone
Tethering ŽSEA.
Stall-feeding ŽCN.
Tethering ŽSEA.
Pastoral ŽSEA.
Semi-intensive ŽCT.
94.5 97.6 94.5 51.5 70.9 16.4 3.6 0.0 0.0 0.0 0.0 165
87.6 37.0 82.7 97.5 92.6 45.7 4.9 0.0 0.0 0.0 0.0 81
87.1 89.4 81.8 66.7 76.5 22.0 0.8 0.0 0.0 0.0 0.0 132
84.3 87.3 76.8 75.4 80.9 43.9 41.4 16.4 8.4 0.7 1.4 560
0.0 0.0 0.0 49.0 80.7 14.0 10.5 0.0 0.0 1.8 5.3 57
SEA s Small East African goats; CN s Norwegian Landrace= Small East African goats; CT s Toggenburg= Small East African goats. a 2 x s 11.78, df s 3, p s 0.0088186. b 2 x s 171.68, df s 3, p s 0.000001. c 2 x s 86.10, df s 3, p s 0.000000. d 2 x s 74.71, df s 4, p s 0.000000. e 2 x s 15.20, df s 4, p s 0.004300. f 2 x s 69.85, df s 4, p s 0.00000. g 2 x s 186.22, df s 4, p s 0.000001.
Table 2 Causes of goat mortality Ž%. in two ecoclimatic areas in Morogoro district, Tanzania ŽNovember 1993–December 1994. Health problems
Helminthiasis Diarrhoea Respiratory infections Dermatophilosis Footrot Caseous lymphadenitis Mange Abscesses Strangulation Bloat Predation Unknown Overall mortality a No. of animals examined
Tropical highland zone
Semi-arid zone
Tethering ŽSEA.
Stall-feeding ŽCN.
Tethering ŽSEA.
Pastoral ŽSEA.
Semi-intensive ŽCT.
0.0 0.6 0.0 0.0 0.0 0.0 0.0 0.0 0.6 0.0 0.6 0.6 11.1 165
2.3 3.7 0.0 0.0 0.0 0.0 0.0 0.0 1.2 1.2 1.2 1.2 2.4 81
2.3 1.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.5 5.3 132
11.4 7.5 7.5 1.3 2.3 0.0 0.2 0.0 0.0 0.0 0.0 4.5 34.6 560
5.3 7.0 0.0 0.0 0.0 0.0 1.8 0.0 0.0 0.0 0.0 1.8 15.8 57
SEA s Small East African goats; CN s Norwegian Landrace= Small East African goats; CT s Toggenburg= Small East African goats. a 2 x s 113.34, df s 4, p s 0.000001.
L.J.M. Kusiluka et al.r Small Ruminant Research 29 (1998) 167–172
significant in pastoral goats. Minor causes of mortality were dermatophilosis, footrot, mange, strangulation and bloat.
4. Conclusions Helminthiasis, coccidiosis, ectoparasite and respiratory infections were the major diseases observed in animals in this study. These disease conditions have also been reported in other sub-Saharan countries ŽShavulimo et al., 1988; Maiga, 1992., including some parts of Tanzania ŽKilonzo and Khama, 1989; Msami, 1991; Kambarage, 1992; Njombe, 1993.. Diarrhoea was also common in all herds ŽNdamukong, 1987; Tuah, 1988; Das and Sendalo, 1989.. The high prevalence of gastrointestinal parasites in crossbred animals that were stall-fed compared to the indigenous animals ŽSEA., which were tethered may be attributed to combined effect of breed differences ŽShavulimo et al., 1988. and poor house hygiene leading to frequent contamination of feed and water troughs with infected faeces. The low prevalence of helminthiasis in crossbred goats of the herd in the semi-arid area may be due to the deworming carried out in April and September 1994. Diarrhoea, which was more common in stallfed and pastoral goats than in tethered goats, may have been caused by bacteria, viruses, dietary factors and gastrointestinal parasites ŽBlood, 1994.; the latter were common in the screened goats. The high prevalence of ectoparasitism in all management systems with the exception of Toggenburg crossbreed goats may be attributed to both the use of communal grazing areas and poor house hygiene. The low tick infestation in stall-fed animals may be due to total confinement and feeding animals on fodder from areas not heavily contaminated with ticks. The practice of allowing manure to accumulate in animal houses for use in crop field fertilisation Žwhich was common in the tropical highland area. may have resulted in increased warmth and humidity that favoured proliferation of the parasites ŽObasaju and Otesile, 1980; Obasaju and Olufemi, 1981; Dipeolu and Ayoade, 1982.. The absence of ectoparasites in the crossbred goats could be attributed to the monthly dipping schedule and the fact that this herd was isolated from other communal herds, thus
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precluding acquisition of infestation from other herds ŽIwuala and Okpala, 1978.. The higher prevalence of respiratory infections in pastoral goats than in other animals may be predisposed to by high stocking rates, coupled with increased dust Žduring the dry season., dampness in the kraals Žrainy season. and the chilling effects at nights in the poorly built houses. Haemoparasites were not seen in smears taken from animals throughout the study period, indicating that they may be of little or no significance in the study area. The causes and percent mortalities observed in this study are similar to those reported by others in Tanzania ŽConnor, 1985; Njau, 1987b; Njombe, 1993. and elsewhere in Africa ŽILCA, 1979; Otesile et al., 1983; Adeoye, 1984; Tuah, 1988.. For instance, Adeoye Ž1984. found that helminthiasis was responsible for 27.3% and 2.6% of the mortalities in sheep and goats, respectively, in southwest Nigeria as also reported in the Northwest Province of Cameroon ŽNdamukong, 1987.. The high overall mortality in pastoral goats may be related to lack of control programmes due to remoteness of the areas; lack of awareness of and reluctance to seek veterinary services and, too large herds that lead to poor attention of individual animals. The results of this study thus show that management factors such as confinement in houses, grazing systems and house hygiene, to a variable extent, influence the prevalence of diseases in animals in Tanzania. These factors need to be considered when advising animal owners on appropriate animal husbandry and disease control strategies to be adopted. Acknowledgements We are grateful to the animal owners for allowing us to use their animals. We are also thankful to the NRRD Animal Health Programme of ODA ŽUK. for funding this study. References Adeoye, S.O., 1984. Disease profiles of sheep and goats in two villages in southwest Nigeria. In: Sumberg, J.E., Cassaday, K.
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ŽEds.., Sheep and Goats in Humid West Africa. Proc. of the Workshop on Small Ruminant Production Systems in the Humid Zone of West Africa, 23–26 January, Ibadan, Nigeria, pp. 13–16. Blood, D.C., 1994. Pocket Companion in Veterinary Medicine. Balliere Tindall, London, 729 pp. Brown, C.G.D., Gray, A.R., Scott, G.R., Sewell, M.M.H., Walker, A.R., Wilde, J.K.H., 1981. Protozoal and rickettsial diseases. In: Robertson, A. ŽEd.., Handbook of Tropical Veterinary Laboratory Diagnosis, Section 3. Centre for Tropical Veterinary Medicine, Edinburgh, pp. 1–23. Chukwu, C.C., 1987. Brucellosis in Africa: Part II. The importance. Bull. Anim. Health Prod. Afr. 35, 92–98. Connor, R.J., 1985. Helminthiasis in goats: Observations on the epidemiology and control of gastrointestinal nematode infections. Report on Work Conducted by the Veterinary Investigation Centre, Mtwara, Southern Tanzania. ODA, London, pp. 159–175. Das, S.M., Sendalo, D.S.C., 1989. Small Ruminant Research Highlights in Tanzania. Ministry of Agriculture, Livestock Development and Cooperatives, Dar es Salaam, pp. 1–40. Dean, A.G., Dean, J.A., Columbier, D., Brendel, K.A., Smith, D.C., Dicker, R.C., Sullivan, K., Fagan, R.F., Arner, T.G., 1994. Epi Info, Version 6. A Word Processing, Database and Statistics System for Epidemiology on Microcomputers. Centres for Disease Control and Prevention, Atlanta, GA. Dipeolu, O.O., Ayoade, G.O., 1982. The epizootiology of infestation of sheep with Ctenocephalides canis in a livestock farm in Nigeria. Bull. Anim. Health Prod. Afr. 30, 31–34. ILCA, 1979. Small Ruminant Production in the Humid Tropics. ILCA Systems Study 3. ILCA, Addis Ababa, pp. 40–76. Iwuala, M.E., Okpala, I., 1978. Studies on ectoparasitic fauna of Nigerian livestock: I. Types and distribution patterns on hosts. Bull. Anim. Health Prod. Afr. 26, 339–359. Kambarage, D.M., 1992. Sarcoptic mange infestation in goats. Bull. Anim. Health Afr. 40, 239–244. Kilonzo, B.S., Khama, I.R.S., 1989. The effects of goat Ž Capra hircus . age and sex on flea infestation in Tanzania. Bull. Anim. Health Prod. Afr. 37, 61–66. MacLeod, W.G., Rowland, A.C., Sewell, M.M.H., 1981. In: Robertson, A. ŽEd.., Handbook on Tropical Veterinary Diagnosis. Section 2: General Techniques. Centre for Tropical Veterinary Medicine, University of Edinburgh, pp. 11–14. Maiga, S., 1992. Small ruminant morbidity and mortality in the delta of Niger, Mali. Small Rumin. Res. 9, 181–188, Technical note. Ministry of Agriculture, Fisheries and Food, 1986. Manual of Veterinary Parasitological Techniques. Reference Book 418. Her Majesty’s Stationery Office, London, p. 24. Msami, H.I., 1991. Caprine pneumonias associated with My-
coplasma infections. MSc Thesis. Swedish University of Agricultural Sciences, Uppsala, Sweden, pp. 1–15. Mtenga, L.A., Ndemanisho, E.E., Sarwatt, S.V., 1986. Systems of small ruminant production in Tanzania. Proc. of the Fourth Tanzania Veterinary Association Scientific Conference, 2–4 December 1986, Arusha, Tanzania, pp. 115–128. Ndamukong, K.J.N., 1987. Sheep and goat production in the northwest Province of Cameroon with special reference to parasitic gastroenteritis. PhD Thesis, University of Edinburgh, pp. 128–271. Njau, B.C., 1987a. Clinical diagnosis of orf outbreak in goats. Bull. Anim. Health Prod. Afr. 35, 243–245. Njau, B.C., 1987b. Gastrointestinal nematodes of small ruminants at Kingo’ri in northern Tanzania. Bull. Anim. Health Prod. Afr. 35, 298–303. Njombe, A.P., 1993. Small ruminant production in Tanzania. Proc. Tanzania Soc. Anim. Prod. 20, 130–145. Nyange, J.F.C., Machange, G.A., 1983. Outbreak of pox in sheep and goats in Mbuguni Shambarai Area of Arusha Region, Tanzania. Bull. Anim. Health Prod. Afr. 33, 59–61. Nyange, J.F.C., Mbise, A.N., 1983. Suspected contagious caprine pleuropneumonia and canine parvovirus enteritis in Northern Tanzania. Proceedings of the First Tanzania Veterinary Association Scientific Conference, Arusha, Tanzania, pp. 158–166. Obasaju, M.F., Olufemi, B.E., 1981. The infestation of sheep and goats with lice in Ibadan, Nigeria. Bull. Anim. Health Prod. Afr. 29, 259–262. Obasaju, M.F., Otesile, E.B., 1980. Ctenocephalides canis infestation of sheep and goats. Trop. Anim. Health Prod. 12, 116–118. Otesile, E.B., Kasali, O.B., Nzekwu, C.K.N., 1983. Mortality in goats at the University of Ibadan Teaching and Research Farm. Bull. Anim. Health Prod. Afr. 31, 281–285. Shavulimo, R.S., Rurangirwa, F., McGuire, T., Chema, S., 1988. Disease as a constraint to the introduction of exotic goats in western Kenya. Bull. Anim. Health Prod. Afr. 36, 102–110. Shayo, S.A., Mlay, G.I., 1986. The performance of the livestock industry in Tanzania: 1972–1980. Proceedings of the Fourth Tanzania Veterinary Association Conference, 2–4 December 1986, Arusha, Tanzania, pp. 25–36. Thrusfield, M., 1986. Veterinary Epidemiology. Butterworth, London, p. 230. Tuah, A.K., 1988. The causes of high mortality rates in immature small ruminants and management systems to reduce wastage. In: Adeniji, K.O. ŽEd.., Proc. Workshop on the Improvement of Small Ruminants in West and Central Africa, 21–25 November, Ibadan, Nigeria, pp. 137–148. Voh, A.A., Mohamed, A.K., Otchere, E.O., Adewuyi, A.A., 1993. Prevalence and seasonality of diseases of ruminants under traditional agropastoral management in Northern Nigeria. Bull. Anim. Health Prod. Afr. 41, 233–238.
Causes of morbidity and mortality in goats in Morogoro district, Tanzania: The influence of management L.J.M. Kusiluka
a,)
, D.M. Kambarage a , L.J.S. Harrison b, C.J. Daborn c , R.W. Matthewman d
a
Department of Veterinary Medicine and Public Health, P.O. Box 3021, Morogoro, Tanzania Centre for Tropical Veterinary Medicine, Easter Bush, Roslin Midlothian, Scotland EH25 9RG, UK VetAid, Centre for Tropical Veterinary Medicine, Easter Bush, Roslin Midlothian, Scotland EH25 9RG, UK d Natural Resource Institute, Central AÕenue, Chatham Maritime, Kent ME4 4TB, UK b
c
Accepted 13 September 1997
Abstract An investigation on the causes of morbidity and mortality in tethered, stall-fed and pastoral goats was carried out in the tropical highland and semi-arid areas of Morogoro district, Tanzania. Ectoparasitism was found to be common in all management systems with fleas, lice and ticks infesting 84–95%, 77–95% and 37–98% of the animals, respectively. The prevalences of the three ectoparasites were significantly higher in tethered goats in the tropical highland area than in other management systems Ž p - 0.05.. Helminth eggs Ž49–98%., coccidia oocysts Ž71–93%. and diarrhoea Ž14–44%. were common in all herds. The prevalences of diarrhoea and gastrointestinal parasitism were significantly higher in stall-fed goats than in other animals Ž p - 0.05.. Footrot, caseous lymphadenitis, dermatophilosis and mange were encountered only in pastoral goats. Respiratory infections were more common in pastoral than in stall-fed and tethered animals Ž p - 0.05.. Prevalences of footrot and diarrhoea were significantly higher during the rainy than the dry period Ž p - 0.05.. Helminthiasis Ž7.2%., diarrhoea Ž6.1%. and respiratory conditions Ž4.2%. were the major causes of mortalities. q 1998 Elsevier Science B.V. All rights reserved. Keywords: Health problems; Goats; Prevalence; Management
1. Introduction Diseases, considered to be major constraints that hinder the productivity of livestock in Tanzania
)
Corresponding author. Tel.: q255-56-4542r4647; fax: q255-56-3177r4079.
ŽShayo and Mlay, 1986., account for 40–60% of small ruminant losses in the country ŽMtenga et al., 1986.. The most common diseases of goats in Tanzania include helminthiasis, footrot, pneumonia, contagious ecthyma and diarrhoea ŽNyange and Mbise, 1983; Connor, 1985; Njau, 1987a,b; Msami, 1991.. Others include coccidiosis, brucellosis, sheeprgoat pox and ectoparasitism ŽNyange and Machange, 1983; Chukwu, 1987; Kambarage, 1992.. Malnutri-
00921-4488r98r$19.00 q 1998 Elsevier Science B.V. All rights reserved. PII S 0 9 2 1 - 4 4 8 8 Ž 9 7 . 0 0 1 1 0 - 7
168
L.J.M. Kusiluka et al.r Small Ruminant Research 29 (1998) 167–172
tion has also been observed to be common in Tanzanian goats ŽDas and Sendalo, 1989.. Environment and management are important factors influencing disease occurrences and patterns ŽMaiga, 1992; Voh et al., 1993.. Thus, in devising cost-effective disease control programmes, it is important to consider the influences of ecoclimatic factors and management on disease frequency. Therefore, a study was conducted to gather information on the causes of morbidity and mortality in goats kept in different management systems in two ecoclimatic zones in Morogoro district, Tanzania. The study was carried out in the tropical highland ŽMgeta. and semi-arid ŽMlali. areas of Morogoro district, Tanzania. Mgeta, which lies at 1400–1800 m above sea level and receives an average annual rainfall of 1800 mm, has temperature and relative humidity ranges of 9–218C and 75–94%, respectively. Mlali is situated at 500–600 m above sea level and receives an average annual rainfall of 900 mm, with temperature and humidity ranges of 15– 358C and 46–71%, respectively. In both areas, the long rainy season extends from late February to May, while the dry season extends from June to October. Short rains usually occur between November and January. The information gathered will be useful in devising disease control strategies.
2. Materials and methods In the tropical highland area, a total of 165 indigenous Small East African goats ŽSEA. in 26 small-holder herds and 81 crosses of Small East African= Norwegian Landrace dairy goats ŽCN. in 8 herds were studied. The number of goats in these herds ranged from 1–20 per herd. The SEA goats were tethered in communal grazing areas using ropes Žtethers. of about 3–5 m in length. The tethering sites could be changed once in a day depending on the availability of owner’s time. At night, the animals were kept in houses made of brick walls, earth floor and grass-thatched roof. Animal excreta was allowed to accumulate in these houses for future use as manure in crop fields. Cleaning of houses was
done after 2–3 months; thus, they were usually dirty. All the crossbred goats in the tropical highland area were stall-fed Žzero grazed.; confined in houses with raised, slatted floors and iron sheet or grass roofing. They were fed on grass or fodder cut from communal fields. The houses were also infrequently cleaned. Žcleaned after 2–3 months.. Animals Žtethered and stall-fed. in this area had no access to regular veterinary services. In the semi-arid area, 231 and 443 SEA goats in 32 small-holder herds and five pastoral herds, respectively, were studied. In the small-holder herds, the number of goats ranged from 1–20 per herd, whereas in the pastoral herds the number was 20–200 animals. Goats in the small-holder herds were tethered in communal grazing areas and at night they were housed in one of the family’s house rooms. The rooms were cleaned daily. All pastoral herds belonged to settled pastoralists. In the pastoral management system, goats were herded throughout the day in communal grazing land, and at night they were confined in open kraals Ženclosures constructed using wooden poles or thorny bushes with no roofs.. The kraals were usually not cleaned and thus were muddy especially during the rainy season. Animals in both the small-holder and pastoral herds had no access to veterinary services because they were not readily available and were expensive. As it applies to the tropical highland area, there were no disease control strategies implemented by the animal owners. One herd of 57 crosses of Toggenburg= Small East African goats ŽCT. kept for dairy purposes in the semi-arid area belonging to a Roman Catholic Missionary community was also included in the study. This was the only herd of crossbred goats in the area. These animals were herded in an area of about 1 km radius from the residential premises between 8:00 AM–12:00 noon. Thereafter, they were confined in a 1-ha paddock until 5:00 PM when they were brought back to the house where they were all supplemented with hay. Milking does were, in addition, given concentrates. The house was constructed using wooden planks with a raised, slatted floor and roofed with iron sheets. The house was cleaned daily. This management system was thus categorised as semi-intensive. The animals received regular veterinary attention. For instance, the animals were
L.J.M. Kusiluka et al.r Small Ruminant Research 29 (1998) 167–172
dipped using ethion ŽSupadip w , Copenhagen. once per month to prevent ectoparasitic infestation. Deworming was carried out in April 1994 and September 1994 using levamisole–albendazole ŽMilsan w , Interchem Pharma, Moshi, Tanzania. and ivermectin ŽIvomec w , MSD, Haarlem., respectively. All animals in the selected goat herds Žselected on the basis of cooperation of the farmers., between November 1993 and December 1994 were clinically examined every month and, disease occurrences and mortalities encountered during the visits were recorded. Between the visits, resident livestock field officers were responsible for monitoring disease occurrences Žcarrying out clinical and postmortem examinations.. Animals were examined for gastrointestinal-, ecto-, and haemo-parasites. All those showing clinical disease were thoroughly examined and where possible, samples such as blood, lungs, liver and kidneys were collected and submitted for diagnostic work at the Faculty of Veterinary Medicine, Sokoine University of Agriculture. Faecal samples were collected per rectum from all animals in the herds every month and examined for the presence of helminth eggs and coccidian oocysts using standard techniques ŽMinistry of Agriculture, Fisheries and Food, 1986.. Screening for haemoparasites Ž Trypanosoma, Babesia and Anaplasma species. in blood smears were carried out as described by MacLeod et al. Ž1981. and Brown et al. Ž1981.. Data were analyzed using Epi Info Version 6 Statistics System ŽDean et al., 1994.. Because of the small number of animals in individual herds and similarity in management of goats, and for simplicity of data analysis, data in the small-holder herds of SEA goats were pooled, as were for the pastoral herds. Data for the crossbred CN and CT were analyzed separately to minimise the effects of breed and management as confounding factors. Morbidity was defined as the amount of disease in a population ŽThrusfield, 1986. and included both clinical and subclinical diseases. Hence, both laboratory results and clinical features were used in the computation of morbidity data. The differences in prevalences of diseases between management systems were computed using x 2 test, and the significant level was taken to be 5%.
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3. Results Health problems encountered in goats in different management systems in the tropical highland and semi-arid areas are indicated in Table 1. Ectoparasitic, helminth and coccidial infections, which may result in decreased animal performance Ždecreased weight gains and body conditions. were the most prevalent health problems of goats in all management systems. Other prevalent conditions were diarrhoea and respiratory infections. Footrot, caseous lymphadenitis, dermatophilosis and mange were encountered only in pastoral herds. The prevalences of flea Ž p s 0.0088186., tick Ž p s 0.000001. and louse Ž p s 0.000000. infestation were significantly higher in tethered animals in the tropical highland area than in other management systems. The prevalence of ticks was lowest in stallfed animals. No fleas, ticks or lice were encountered in the herd of crossbred goats that were regularly dipped. Significantly higher prevalences of helminth Ž p s 0.000000., coccidial Ž p s 0.004300. infections and diarrhoea Ž p s 0.00000. were observed in stallfed goats than animals in other management systems. Pastoral goats in the semi-arid area had a significantly higher prevalence of respiratory infections compared to other animals Ž p s 0.000001.. The most common bacterial isolate from cases of respiratory infections was Pasteurella haemolytica. Other isolates were Pasteurella multocida, Staphylococcus aureus and Streptococcus species. No haemoparasites were encountered in the study goats. Seasonal influences on morbidity were encountered only in a few conditions. Footrot and dermatophilosis were encountered only during the rainy season. The majority of diarrhoea 72% Ž249. and respiratory cases 68% Ž169. were also encountered during the rainy season. In contrast, ecto- and endoparasites were encountered throughout the year. The causes of mortality of goats in different management systems in the two ecoclimatic zones are indicated in Table 2. The overall mortality of goats was significantly higher Ž p s 0.000001. in pastoral herds compared to animals in the smallholder herds. Diarrhoea and helminthiasis were the major causes of mortality in all management systems, whereas respiratory infections and footrot were
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Table 1 Causes of morbidity of goats Ž%. in two ecoclimatic zones in Morogoro district, Tanzania ŽNovember 1993–December 1994. Health problems
Fleas a Ticks b Lice c Helminthosisd Coccidiosise Diarrhoeaf Respiratory infections g Footrot Caseous lymphadenitis Dermatophilosis Mange Number of animals examined
Tropical highland zone
Semi-arid zone
Tethering ŽSEA.
Stall-feeding ŽCN.
Tethering ŽSEA.
Pastoral ŽSEA.
Semi-intensive ŽCT.
94.5 97.6 94.5 51.5 70.9 16.4 3.6 0.0 0.0 0.0 0.0 165
87.6 37.0 82.7 97.5 92.6 45.7 4.9 0.0 0.0 0.0 0.0 81
87.1 89.4 81.8 66.7 76.5 22.0 0.8 0.0 0.0 0.0 0.0 132
84.3 87.3 76.8 75.4 80.9 43.9 41.4 16.4 8.4 0.7 1.4 560
0.0 0.0 0.0 49.0 80.7 14.0 10.5 0.0 0.0 1.8 5.3 57
SEA s Small East African goats; CN s Norwegian Landrace= Small East African goats; CT s Toggenburg= Small East African goats. a 2 x s 11.78, df s 3, p s 0.0088186. b 2 x s 171.68, df s 3, p s 0.000001. c 2 x s 86.10, df s 3, p s 0.000000. d 2 x s 74.71, df s 4, p s 0.000000. e 2 x s 15.20, df s 4, p s 0.004300. f 2 x s 69.85, df s 4, p s 0.00000. g 2 x s 186.22, df s 4, p s 0.000001.
Table 2 Causes of goat mortality Ž%. in two ecoclimatic areas in Morogoro district, Tanzania ŽNovember 1993–December 1994. Health problems
Helminthiasis Diarrhoea Respiratory infections Dermatophilosis Footrot Caseous lymphadenitis Mange Abscesses Strangulation Bloat Predation Unknown Overall mortality a No. of animals examined
Tropical highland zone
Semi-arid zone
Tethering ŽSEA.
Stall-feeding ŽCN.
Tethering ŽSEA.
Pastoral ŽSEA.
Semi-intensive ŽCT.
0.0 0.6 0.0 0.0 0.0 0.0 0.0 0.0 0.6 0.0 0.6 0.6 11.1 165
2.3 3.7 0.0 0.0 0.0 0.0 0.0 0.0 1.2 1.2 1.2 1.2 2.4 81
2.3 1.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.5 5.3 132
11.4 7.5 7.5 1.3 2.3 0.0 0.2 0.0 0.0 0.0 0.0 4.5 34.6 560
5.3 7.0 0.0 0.0 0.0 0.0 1.8 0.0 0.0 0.0 0.0 1.8 15.8 57
SEA s Small East African goats; CN s Norwegian Landrace= Small East African goats; CT s Toggenburg= Small East African goats. a 2 x s 113.34, df s 4, p s 0.000001.
L.J.M. Kusiluka et al.r Small Ruminant Research 29 (1998) 167–172
significant in pastoral goats. Minor causes of mortality were dermatophilosis, footrot, mange, strangulation and bloat.
4. Conclusions Helminthiasis, coccidiosis, ectoparasite and respiratory infections were the major diseases observed in animals in this study. These disease conditions have also been reported in other sub-Saharan countries ŽShavulimo et al., 1988; Maiga, 1992., including some parts of Tanzania ŽKilonzo and Khama, 1989; Msami, 1991; Kambarage, 1992; Njombe, 1993.. Diarrhoea was also common in all herds ŽNdamukong, 1987; Tuah, 1988; Das and Sendalo, 1989.. The high prevalence of gastrointestinal parasites in crossbred animals that were stall-fed compared to the indigenous animals ŽSEA., which were tethered may be attributed to combined effect of breed differences ŽShavulimo et al., 1988. and poor house hygiene leading to frequent contamination of feed and water troughs with infected faeces. The low prevalence of helminthiasis in crossbred goats of the herd in the semi-arid area may be due to the deworming carried out in April and September 1994. Diarrhoea, which was more common in stallfed and pastoral goats than in tethered goats, may have been caused by bacteria, viruses, dietary factors and gastrointestinal parasites ŽBlood, 1994.; the latter were common in the screened goats. The high prevalence of ectoparasitism in all management systems with the exception of Toggenburg crossbreed goats may be attributed to both the use of communal grazing areas and poor house hygiene. The low tick infestation in stall-fed animals may be due to total confinement and feeding animals on fodder from areas not heavily contaminated with ticks. The practice of allowing manure to accumulate in animal houses for use in crop field fertilisation Žwhich was common in the tropical highland area. may have resulted in increased warmth and humidity that favoured proliferation of the parasites ŽObasaju and Otesile, 1980; Obasaju and Olufemi, 1981; Dipeolu and Ayoade, 1982.. The absence of ectoparasites in the crossbred goats could be attributed to the monthly dipping schedule and the fact that this herd was isolated from other communal herds, thus
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precluding acquisition of infestation from other herds ŽIwuala and Okpala, 1978.. The higher prevalence of respiratory infections in pastoral goats than in other animals may be predisposed to by high stocking rates, coupled with increased dust Žduring the dry season., dampness in the kraals Žrainy season. and the chilling effects at nights in the poorly built houses. Haemoparasites were not seen in smears taken from animals throughout the study period, indicating that they may be of little or no significance in the study area. The causes and percent mortalities observed in this study are similar to those reported by others in Tanzania ŽConnor, 1985; Njau, 1987b; Njombe, 1993. and elsewhere in Africa ŽILCA, 1979; Otesile et al., 1983; Adeoye, 1984; Tuah, 1988.. For instance, Adeoye Ž1984. found that helminthiasis was responsible for 27.3% and 2.6% of the mortalities in sheep and goats, respectively, in southwest Nigeria as also reported in the Northwest Province of Cameroon ŽNdamukong, 1987.. The high overall mortality in pastoral goats may be related to lack of control programmes due to remoteness of the areas; lack of awareness of and reluctance to seek veterinary services and, too large herds that lead to poor attention of individual animals. The results of this study thus show that management factors such as confinement in houses, grazing systems and house hygiene, to a variable extent, influence the prevalence of diseases in animals in Tanzania. These factors need to be considered when advising animal owners on appropriate animal husbandry and disease control strategies to be adopted. Acknowledgements We are grateful to the animal owners for allowing us to use their animals. We are also thankful to the NRRD Animal Health Programme of ODA ŽUK. for funding this study. References Adeoye, S.O., 1984. Disease profiles of sheep and goats in two villages in southwest Nigeria. In: Sumberg, J.E., Cassaday, K.
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