HEALTH CONTROL FOR SHEEP AND GOATS IN THE HUMID TROPICS OF WEST AFRICA

E.N.W. Oppong
Team Leader
UNDP/FAO Livestock Development Project
P.O. Box 6603, Jos, Nigeria

RESUME

Les petits ruminants représentent la source la plus importante de protéines animales pour les personnes qui habitent la région tropicale humide d'Afrique de l'Ouest. Malheureusement certains facteurs, notamment des taux importants de mortalité, font que leur effectif et leur productivité sont faibles. Les causes majeures de décès sont généralement: (a) la pneumonie et plus particulièrement la peste des petits ruminants (PPR); (b) les diarrhées occasionnées principalement par des gastroentérites d'origine parasitaire et par la PPR; et, (c) des avortements et des morts néo-natales associées à des phénomènes d'inanition.

Les contrôles sanitaires devraient être réalisés à l'échelle des troupeaux villageois plutôt qu'au niveau de troupeaux individuels, voire même à l'animal lui-même. Un ensemble de méthodes visant à l'amélioration du logement des animaux, des méthodes d'élevage et d'alimentation ainsi que des vaccinations de routine contre la PPR, l'administration de vermifuges et la pulvérisation contre les ecto-parasites doivent être recommandées. La PPR, quant à elle, devrait être contrôlée au niveau sous-régional.

SUMMARY

Small ruminants are the main sources of animal protein for people living in the humid tropics of West Africa.

Due to a number of factors including high rates of mortality, however, the numbers and productivity of these animals are low. The major causes of death are: (a) pneumonia especially PPR; (b) diarrhoea, caused mostly by parasitic gastroenteritis and PPR; (c) abortions and neonatal deaths associated with starvation.

Disease control should be based on whole village flocks rather than individual flocks or animals. A package of improved housing, husbandry and feeding as well as routine vaccination against PPR, drenching and spraying against ectoparasites is advocated. PPR should be controlled on a sub-regional basis.

INTRODUCTION

Sheep and goats, mostly the dwarf breeds, are the predominant domestic ruminants in the humid tropics of West Africa. They number about 8 million goats and 5.6 million sheep (Jahnke, 1982). Apart from being the main and preferred source of meat (Jollans, 1960; Oppong, 1965), they perform very important socio-economic functions.

These animals, however, in spite of their numbers and importance, do not meet the protein needs of the inhabitants of the sub-humid zone. They are mostly raised as scavengers and sleep where they will except during the rains when to protect crops they are either tethered or confined in enclosures both night and day. In recent years, however, attempts have been made at semi-intensive raising of sheep especially under plantation crops in Ghana and in villages where, due to crop damage and environmental soiling, sheep and goats are confined and raised intensively.

Their productivity is low estimated at 3 percent for goats (Molokwu, 1982). A number of factors some of which are genetic, mostly poor husbandry resulting in starvation, disease and death, are responsible for this low productivity. Reynolds, Atta-Krah and Francis (1987) have estimated that 40–50 percent of small ruminants fail to survive to 12 months of age. Rombout and Van Vlaenderen (1975) and Bonniwell (1978) found high mortalities of 44 percent and 40 percent respectively in sheep in villages in Côte d'Ivoire and Ashanti in Ghana respectively.

DISEASES OF ECONOMIC IMPORTANCE

The climate of the humid tropics characterized by high rainfall, humidity and heat provides ideal conditions for disease-causing organisms and vectors. Since 1912 (Obrien, 1912), reports and studies on disease of sheep and goats have been made by a number of authors from all over West Africa. They have mostly however encompassed the whole geographical area namely, the humid, sub-humid and arid zones.

In recent years however a number of studies have been made specifically on the diseases of these animals in the humid zone (Oppong, 1973; Bonniwell, 1978; and Adeoye, 1985).

The list of the diseases of sheep and goats in West Africa is an impressive one and though a large number of them are common to all the ecological zones, some have higher prevalence or are enzootic in the humid zones.

The most common conditions diagnosed in sheep and goats in the humid zone are:

1. Respiratory/pneumonia syndromes
2. Diarrhoea
3. Starvation
4. Abortions and neonatal deaths
5. Ticks and tick-borne diseases
6. Skin conditions
7. Lameness and injuries
8. Other conditions

Table 1. Causes of Mortality in Sheep ARS Nungua (1963 – 1969)

Adapted from Oppong (1973)

The respiratory/pneumonia syndromes

These are mostly viral, bacterial and parasitic in origin. The conditions are predisposed to by the animals being left at the mercy of the sun, rain, cold and often overcrowding and are seen mostly in the wet season April-October or the dry cold months of December and January (Stewart, 1931; Vohradsky, 1966; Oppong, 1973; Oppong and Yebuah, 1981; Bonniwell, 1978; Smith and Van Houtert, 1984 and Smith et al., 1986). The pneumonias are the most common killing diseases accounting for over 35 percent of deaths, (Oppong, 1973; Bonniwell, 1978; Oppong and Yebuah, 1981; Otesile, Kasali and Nzekwu, 1983; Smith and Van Houtert, 1984; Majiyagbe, 1985; Adeoye, 1985 and Opasina, 1985). They include:

1. Peste des petits ruminants (PPR) also referred to as the pneumoenteritis complex or kata caused by a virus is enzootic in humid West Africa. It is considered by many to be the most important single cause of morbidity and often approaching 50–100 percent in sheep and goats especially the latter, mostly in the young particularly in 4 to 12 months old kids (Nduaka and Ihemelandu, 1973; Ojo, 1976; Bonniwell, 1978 and 1983; Opasina, 1983; Adekeye, 1984; Majiyagbe, 1985).

2. Contagious caprine and ovine pleuropneumonia (CCPP & COPP) caused by Mycoplasma mycoides and M. agalactiae in goats and M. arginini and M. ovipneumoniae in sheep respectively are common in humid West Africa (Campbell, 1956, 1957; Mohan and Uzoukwu, 1985). The disease is seen mostly during the wet and cool months of the year.

Bacterial pneumonia caused by Staphylococcus sp., Streptococcus sp., Corynebacterium sp., Pasteurella sp., Escherichia coli and Pseudomonas sp., are commonly seen (Oppong, 1973; Ugochukwu, 1983; Otesile, Kasali and Nzekwu, 1983; Mohan and Uzoukwu, 1985). Sheep and goats of all ages but more so lambs and kids are susceptible to bacterial pneumonia which also occurs during the wet and cold months of April to October and the cold dry season of December and January.

An Oestrus ovis larva-induced respiratory condition found in the humid zone leads to severe nasal discharge and occlusion in sheep. The parasite has also been incriminated in a neoplastic condition of the turbinates which is seen frequently (Vohradsky, 1974; Bonniwell, 1978; Charray, Aman and Tanoh, 1985). The conditions cause a lot of worry and wastage in affected flocks.

Diarrhoea in sheep and goats

This condition is usually associated with internal parasites, PPR bacteria and consumption of green herbage at the beginning of the rains.

Internal parasites

Parasitic gastroenteritis (PGE) - next in importance to the pneumonias, are internal parasites particularly parasitic gastroenteritis (PGE), (Oppong, 1973); Otesile, Kasali and Nzekwu, 1983; Osuagwuy and Akpokodje, 1981, Chiejina and Emehelu, 1986). PGE mortalities range from 11–25 percent of all deaths (Oppong, 1973; Otesile, Kasali and Nzekwu, 1983; Smith et al., 1986) mostly in lambs and kids up to 12 months of age particularly the 3 to 6 months old. Mortalities occur mostly during the rains with a minor peak in April-May and a major peak in September (Bonniwell, 1978; Otesile, Kasali and Nzekwu, 1983; Chiejina and Emehelu, 1986). Haemonchus is usually the main disease (Beal, 1929; Oppong, 1973; Oppong and Yebuah, 1981; Bonniwell, 1978; Otesile, Kasali and Nzekwu, 1983). Other parasites include Ostertagia sp., Trichostrongylus sp., Cooperia sp., Nematodirus sp., and Oesophatustomum sp.

Moneziasis - heavy moniexia infection was found to be second only to pneumonia in incidence in sheep in the humid zone of Ghana and was considered to be the primary cause of mortality in 11–25 percent deaths of lambs 2 to 6 months of age (Oppong, 1973; Oppong and Yebuah, 1981; Borquaye, 1981). Infection in most cases was so heavy that nothing else but the tapeworms were found in the intestines.

Coccidiosis - was also found to be one of the major causes of enteritis and deaths in sheep kept under plantation crops in the forest zone in Ghana (Borquaye, 1981). Otesile, Kasali and Nzekwu, (1983) observed that 6.3 percent of deaths in goats mostly under 10 months of age on the University of Ibadan Farm were due to coccidiosis.

Fascioliasis - has been reported in sheep and goats (Fry, 1958; Oppong, 1973; Otesile, Kasali and Nzekwu, 1983). Other internal parasitic conditions reported have been Oesophagostomiasis or pimply gut (Beal, 1929; Oppong, 1973; Bonniwell, 1978; Assoku, 1981) and cysticercosis (Beal, 1929).

Starvation

In spite of the apparent availability of herbage in the humid tropics, a number of animals die of starvation. This is often due to the non-availability of the right type or poor nutritional nature of herbage around homesteads and the consequent long distances animals have to walk to graze, losing young animals in the process (Oppong and Yebuah, 1981). Another cause is long confinement either in stockades, pens or tethering during the farming season which results in what Bonniwell (1978) termed “Starvation/Confinement Syndrome”. Starved ewes are unable to suckle their young which are abandoned to die. Starvation accounts for a very high incidence of deaths in lambs and kids. Oppong and Yebuah (1981) recorded 80 (16.4 percent) out of 487 deaths due to starvation in sheep of which 79, i.e. 16 percent, were in the 0 to 12 months old group. In other words, 79 (98 percent) of 80 deaths due to starvation were in lambs. Starvation not only predisposes the animals to succumb to intercurrent infections but also results in arrested or stunted growth and abortions in pregnant ewes and nannies.

Abortions and Neonatal Deaths

Abortions, stillbirths and preweaning deaths are, as a group, one of the most limiting factors in sheep and goat production in the humid tropics. Incidence of 6, 19, 23, 24 and 62.5 percent abortions have been reported in the W.A.D. goat in the humid south of Nigeria (Falade and Sellers, 1976; Ojo, 1980; Osuagwuy and Akpokodje, 1985). Though abortions do occur in sheep as well, not much has been recorded in detail. The causes of abortion could be by any number of infectious diseases, febrile conditions, chemicals, poisons, plant toxins, or starvation. Brucellosis, Chlamydia ovis, toxoplasmosis, malnutrition and starvation have all been reported as causes of abortion in sheep and/or in goats in the humid zone (Falade, Sellers and Oja, 1975; Falade and Sellers, 1976; Akerejola et al., 1979; Okoh, 1980; Osuagwuy and Akpokodje, 1985; Okoh, 1986). Triplet and twin pregnacies (70 percent) as well as first pregnancies (61 percent) have also been noted to end in abortions. Osuagwuh and Akpokodje (1984) observed a higher rate of abortions in goats during the dry season most likely due to starvation. Neonatal deaths including stillbirths and deaths up to a few weeks of birth are very common. Hill (1957, 1960) and Dettmers, Igoche and Akinkuolie (1976) reported 15, 25 and 20 percent respectively of such deaths on the University of Ibadan Farm. Oppong and Yebuah (1981) reported an incidence of 55 percent in Ghana. High neonatal mortality in multiple births of 26.5 percent (Jollans, 1960), 35–47 percent in triplets, (Dettmers, Igoche and Akinkuolie, 1976), and 13.47 (Tuah and Baah, 1985) has been reported. Most of the young died of lack of milk or were too weak to suck.

Ticks and tick-borne diseases

Amblyomma variegatum is occasionally found in the interdigital cleft of sheep and goats causing severe pain and lameness which predispose to bacterial infection. The lameness is sometimes so severe that animals are unable to go out to feed. Bonniwell (1978) did not find ticks as a health hazard in the humid tropics of Ashanti.

Babesiosis and anaplasmosis have been reported in sheep and goats in the humid tropics; (Obrien, 1912; Beal, 1928; Stewart, 1937, 1943; Edwards, Judd and Squire, 1956; Oppong, 1973; Majiyagbe, 1985) but are generally not considered of serious importance in the Dwarf breeds of the zone (Maclennan, 1970; Devendra and Burns, 1970). In a survey in the Accra Plains of Ghana Assoku (1979) found latent infection rates of 12 percent of Anaplasma marginale and Babesia ovis in sheep and 4.70 percent of A. marginale and 8.9 percent B. ovis in goats without clinical signs of the disease. Similarly Sadig (1985) in a blood smear and latext agglutination survey in Southern Nigeria detected latent anaplasma infection in 54 percent of sheep and 60 percent of 200 goats. These two diseases may only be a serious threat when the resistance of the animal is lowered. There are a number of factors in the humid zone that can lower animal resistance and therefore the importance of babesiosis and anaplasmosis cannot be underrated.

Heartwater on the other hand, has been tentatively diagnosed on postmortem findings (Fry, 1958; Oppong, 1973; Bonniwell, 1978) in the humid zone. This latter author had diagnosed several hydropericardial cases suggestive of heartwater in goats at postmortem. Prior to their death the goats had sudden nervous attacks, made a sudden dash or ran about as if being chased, stopped suddenly, shaking all over and/or collapsed on their sides and died after a few galloping movements.

Ataxic syndromes were observed by Bonniwell (1978) in 41 percent of deaths on a farm in Ashanti. Though he diagnosed heartwater on the farm he did not associate it with the ataxic syndrome. This condition also reported in Côte d'Ivoire, calls for urgent studies to elucidate their aetiology and find appropriate preventive measures.

Skin conditions

A number of skin syndromes are found in sheep and goats. The more common ones in the humid zone are:

Virus diseases: The two most important diseases under this category are sheep and goat pox (Bonniwell, 1978) and Orf or contagious echthyma. The latter is a common affliction with a high morbidity, up to 100 percent but low mortality of about 2.6 percent (Adeoye, 1985). Orf is found mostly in lambs and kids up to 6 months of age and ewes suckling them (Oppong, 1973; Bonniwell, 1978; Odeniyi and Afolabi, 1985). The condition has been diagnosed serologically in sheep and goats in the humid parts of Nigeria indicating that it is enzootic in the area (Opasina, 1985; Obi, 1985).

Parasitic conditions: Sarcoptic scabiei (mange) is a fairly common skin condition of sheep and goats in the humid zone (personal observation: Adeoye, 1985). Other ectoparasites causing discomfort and debilitation include the dog and cat fleas, Ctenocephalides canis and C. felis (Bonniwell, 1978; Obasaju and Otesile, 1980; Adeoye, 1985). The sucking louse Lignonathus ovillus infestation in sheep and goats is common (Obasaju and Olufemi, 1981). Demodicosis and streptothricosis in sheep have been reported (Oppong, 1973).

Bacteria: furunculosis caused by staphylococci but often mixed infection is common.

Lameness and injuries

One of the most common conditions seen in sheep and goats in the humid zone is lameness. Apart from that caused by ticks, overgrown hooves and foot rot caused by Fusiformis necrophorum and Bacteriodes nodosus are common. Corynebacterium pyogenes is also sometimes seen in association with F. necrophorum to cause interdigital dermatitis.

Injuries, lacerations, broken horns and limbs are common among village sheep and goats. These are often inflicted deliberately by people whose crops or food have been tampered with by the animals or hit by motor vehicles. On institutional farms, animals often hurt themselves by forcing their way through barbed wire (Oppong, 1973; Bonniwell, 1978; Smith and Olubunmi, 1983).

Other conditions

A number of other conditions, infections and non-infectious, some debilitating, others causing mortality but not of epizootic proportions also occur. These include:

Bacterial diseases: Caseous lymphadenitis (Otesile, Kasali and Nzekwu, 1983; Smith and Van Houtert, 1984, Falade and Smith, 1985), enterotoxaemia and tetanus (Mackinnon, 1956; Oppong, 1973; Otesile, Kasali and Nzekwu, 1983) and anthrax.

Protozoan: Though the dwarf breeds of sheep and goats in the humid zone are trypanotolerant, Edwards, Judd and Squire, (1956) and Kramer (1966) reported clinical trypanosomiasis caused by T. vivax and T. congolense in Ghana and South-east Nigeria. Oppong (1973) reported a transient T. vivax infection in sheep in Ghana. Kramer (1966) was of the opinion that sheep and goats were infected mechanically and that cattle are the reservoir hosts. A number of recent blood and disease surveys in the humid forest zone have not revealed trypanosomiasis in sheep and goats as being important (Bonniwell, 1978; Otesile, Kasali and Nzekwu, 1983; Smith and Van Houtert, 1984; Smith et al., 1986).

Nutritional and metabolic conditions: Ricketts was found to be a serious problem in housed goats raised in confinement at Ife where 2.7 percent developed the condition (Smith et al., 1986).

Age and season on mortality: Most deaths in sheep and goats in the humid zone are in the under 12 months old animals particularly up to 3 months of age and more so in the restricted animals than in the free as ranging ones. Mack, Sumberg and Okali (1985) observed mortality rates of 11 percent for free ranging kids and 18 percent and 24 percent for restricted goats in southern Nigeria. Higher rates of 40, 44 and 59 percent have been reported for villages in humid zones of Ghana (Bonniwell, 1978), Côte d'Ivoire (Rombaut and Van Vlaenderen, 1975) and Nigeria (Adeoye, 1985) respectively. Higher mortalities, 50 percent to 88 percent, have been reported (Oppong, 1973; Oppong and Yebuah, 1981) (Table 1).

Most deaths (Figure 1) occur during the second shorter rainy season, September-October, and the end of the dry season, March (Oppong, 1973; Bonniwell, 1978; Otesile, Kasali and Nzekwu, 1983; Mack, Sumberg and Okali, 1985, Smith et al., 1986).

Figure 1: Monthly distribution of deaths from pneumonia and helminthiasis

CONTROL AND PREVENTION OF THE MAJOR DISEASE CONDITIONS

Prevention rather than treatment should be the objective in dealing with animal diseases. The methods employed should be cost effective and economical. As most sheep and goats are kept in small household flocks of 3–5 (Oppong, 1965; Bonniwell, 1976; Mack, Sumberg and Okali, 1985) any measures which are expensive are likely to be found unacceptable. Prevention on a village wide basis rather than on individual flock basis will be more effective both in terms of disease control and economics.

Improved housing and management

The first principle should be improvement of husbandry as most diseases can be traced to poor management and nutrition. The pneumonias, helminthiasis, foot rot and tick infestation can all be associated with wet and/or cold conditions.

A roofed enclosure with slatted wooden floors built of local materials, for example, will prevent some if not all of these conditions.

Indeed, due to damage to crops and soiling of the environment around houses and market places, owners of small ruminants in many villages and towns are increasingly being required to house or restrict their animals. Animals should be tethered under shade instead of in the sun and rain during the cropping season.

Sheep and goats should be confined around about 16:00 – 17:00 hours when they return from grazing or scavenging and allowed out the following day after the dew on herbage has dried off. Not only would the animals be kept warm and dry at night from the heavy dew fall, peculiar to the humid tropics, but they would also be sent out to graze when parasitic larvae on herbage had decended to the base of the plants. Also the hooves and the interdigital spaces will be kept dry from muddy floors and wet grass and the incidence of coccidiosis reduced.

Space per animal and ventilation need to be monitored otherwise health problems such as PPR, rickets, diarrhoea, ecthyma and caseous lymphadenitis might set in (Akerejola, 1982; Smith and Van Houtert, 1984; Smith, Van Houtert and Olubonmi, 1987).

Quarantine

Many outbreaks of disease among sheep and goats especially helminthiasis, coccidiosis and PPR have been traced to introduction of newly purchased market or other animals into the flock (Bonniwell, 1978; Smith and Van Houtert, 1984; Majiyagbe, 1985). Separation, deworming and vaccination of such animals with the Tissue Culture Rinderpest Vaccine (against PPR) and spraying before addition to the flock prevent the incidence of these diseases. Smith and Van Houtert (1984) modified by Majiyagbe (1985) recommend 28–30 days quarantine of newly introduced sheep and goats (Table 2). The drawback with this programme is the cost if only one or two or less than 10 animals are involved and also the unlikely availability of the hyperimmune-rinderpest serum.

Feeding

Adequate feed and wholesome water will prevent some of the starvation and neonatal deaths, abortions and stillbirths.

Confined or restricted animals should be zero-grazed, goats with browse material, sheep with browse material and grass. In addition they should be fed crop residues (cereal straws, maize cobs, groundnut haulms etc.) and household waste (cassava, yam and plantain peels) where these are available. Free ranging animals could be fed the above as supplementary feed each evening when they return from scavenging. Mineral salt licks should be made available ad libitum. Supplementation should be year-round but particularly during the cropping season when animals are confined and during the dry season, January to March, when herbage is in short supply.

A package for housing and feeding of the West Africa Dwarf goat under intensive conditions in the humid tropics being developed by the West African Dwarf Goat Project, (a joint project of the Department of Animal Sciences of the Obafemi Awdewo University at Ife, the Department of Tropical Animal Production of the National Agricultural University, Wageningen and the International Livestock Centre for Africa) is already yielding results by cutting down on mortalities.

Table 2. Protocol for control of PPR amongst Small Ruminants

* Smith and Van Houtert (1984) modified by Majiyagbe (1985).

Parasitism

Not only do internal parasites kill, but they also cause enormous losses in productivity and low resistance to other diseases. Apart from deworming during quarantine, sheep and goats should be strategically dewormed once during the dry season, January-March, to allow shed ova and larvae that may emerge to be destroyed by dehydration to reduce herbage contamination during the subsequent rains. They should be dewormed again in June-July when infection picked up during the early part of the rains would have developed into young adults and before massive pasture contamination with ova and larvae. The new broad spectrum anthelmintics such as Fenbendazole and Oxfendazole are the drugs of choice.

External parasites should be controlled by washing animals or spraying them and their sleeping places with acaricides. The pyrethroids such as Deltamethrin, Flumethrine and Cyfluthrine have been found to be effective, with low animal toxicity and long-acting effect. Spraying or washing should be at fortnightly intervals during the rainy season, April to October and monthly during the dry season. This would control ticks as well as fleas and lice. Tick control would prevent tick-borne diseases.

Routine vaccinations and medications

Peste des petits ruminants - sheep and goats should be routinely vaccinated twice a year against this most devastating disease. First in February/March before the rains, and again in November/December before the onset of the cold harmattan period for those too young to have been vaccinated in February/March. Animals are most susceptible to the disease during the rains and the dry season. The Tissue Culture Rinderpest Vaccines (TCRV) has been found to confer immunity for over one year to sheep and goats (Majiyagbe, 1985 and Taylor, 1985). Vaccination and other routine treatments such as deworming against PGE and coccidiosis should be aimed at whole village flocks instead of on individual or household flocks.

Where animals are being raised in large numbers on sheep and goat farms, especially under plantation crops or alley farms, routine vaccination and treatments should be vigorously pursued.

All deaths should be promptly investigated so that major disease outbreaks or diseases of high morbidity but low mortality can be detected for prompt control and preventive measures to be instituted accordingly.

Routine disease surveys on whole village flocks should be carried out yearly to monitor any latent diseases and appropriate preventive measures taken.

Animal health package

A package of vaccination against PPR, deworming and acaricide washing should together with improved housing, feeding and mineral supplementation cut down drastically the high incidence of mortalities characteristic of current small ruminant production (Table 3).

Table 3. Disease control package for village sheep and goats in the sub-humid region of West Africa

ROLE OF GOVERNMENTS IN THE CONTROL OF HEALTH PROBLEMS OF SHEEP AND GOATS IN THE HUMID TROPICS OF WEST AFRICA

There are Veterinary Departments and Departments of Animal Husbandry or Animal Production within the Ministries of Agriculture in all the countries encompassing the humid sub-region of West Africa.

There are also Ministries of Science and Technology, Higher Education etc. responsible for National Research Institutes whose mandates and activities include fostering of research on animal production and animal diseases. Other departments or parastatals such as the National Livestock Production Department in Nigeria, State Farms and Livestock Investigation and Breeding Centres are also involved directly with animal production. There are, in addition, faculties of agriculture and veterinary medicine with departments of animal production or animal science in the universities.

Some of the countries have national bodies set up to coordinate specifically the improvement of sheep and goat productivity such as the Nationally Coordinated Research Project on Small Ruminants of the Ministry of Science and Technology of Nigeria and sheep improvement farms as in Côte d'Ivoire, societies encompassing farmers, and research scientists, such as the National Animal Science Associations. There are also National Veterinary Medical/Science Associations whose activities impinge on disease problems of animals including sheeps and goats.

All these organizations receive encouragement by way of assistance in finance either as regular subventions or occasional donations from their National Governments.

International Research Organizations such as ILCA and IITA have collaborative research activities with some of the above agencies which deal with animal disease problems. Such collaboration is with the blessing of or fostered by the national governments.

Though disease problems of sheep and goats in West Africa have been reported upon by veterinarians and agriculturalists since the beginning of this century, (Beal, 1921; Beaton, 1930; Henderson, 1934), the involvement of governments in their production and disease control in the humid zone of West Africa is only recent (Oppong, 1966; Quartey, 1978). The veterinary services were set up primarily “to find out ways and means of improving local cattle” (Beal, 1921). This policy is largely true today.

Governments in West Africa have generally through the veterinary services carried out routine vaccinations, control of disease outbreaks and surveillance (Quartey, 1978) mostly in cattle. In recent years, however, Ghana, Côte d'Ivoire and Nigeria as well as other countries of the West African sub-region in collaboration with the Food and Agriculture Organization of the United Nations (FAO) have embarked on sheep and goat improvement including their disease control.

The government's role in small ruminant productivity since the 1970s has been mostly to set up sheep and goat multiplication farms or centres such as at Ejura and Techniman in Ghana, Katsina (sheep) and Zugu (goats) and a large number of Livestock Investigation and Breeding Centres in Nigeria. On most of these farms the objective has been “to improve indigenous breeds of sheep and goats and also to demonstrate modern production technology to farmers” (David-West, 1985). An aspect of the improvement has been “to upgrade mutton quality and quantity of crossbreeding” (Tafida, 1985).

The role of the Government of Nigeria in small ruminant production has been summed up by the Director of the Federal Livestock Department of Nigeria (David-West, 1985) as being:

1. Policy formulation and development which include planned government expenditure and allocation of resources to research and production, breeding policy, nutrition policy and feeding security, disease control and eradication.

2. Training and provision of extension services to livestock farmers.

3. Disease control.

4. Provision for research and efficient information flow.

5. Provision of credit to farmers.

6. Establishment of elite farms such as Livestock Breeding and Investigation Centres.

All governments in the sub-region follow and implement similar policies. The pace however is not quick enough and results not too obvious due to a late start and the current economic climate.

Recommendations

Governments should set up within the Departments of Animal Husbandry and Veterinary Services, if they already do not exist, Small Ruminant Extension Units (SREU). Staff from these units will work closely with sheep and goat farmers to help them improve housing, feeding and disease control measures.

Governments should encourage or assist research institutions to study vigorously the improvement of sheep and goat husbandry and their disease control and make available their results to the SREU for implementation.

Governments should encourage or assist in the timely provision of vaccines such as PPR, acaricides and anthelmintics for the control of sheep and goat diseases.

Governments should provide coordination for all the agencies within their territories dealing with some aspects of sheep and goat production and disease control.

Governments should collaborate with each other within West Africa to set up a sub-regional programme to control and eradicate PPR. Towards this the assistance of FAO may be sought.

The condition “Ataxic” syndrome in sheep should as a matter of urgency be investigated, with a view to understanding its aetiology and preventive measures instituted. To this end an international and/or sub-regional collaborative effort is required.

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