Efficacy and Chemotherapeutic Control of Coccidiosis in Rabbits Under Smallholder Production Systems in Central Kenya

Abstract

Rabbit production is a fast growing industry in Kenya. Despite this growth, knowledge on treatment and control of rabbit diseases is limited among farmers. The major disease affecting rabbits in the country is coccidiosis. Rabbit sector continues to experience huge losses in terms of morbidities and mortalities arising from coccidiosis. Currently, there are no labelled anti-coccidials for rabbits in Kenya and the ones used are labelled for poultry with unknown efficacies and safety in rabbits. The objectives of this study were: To determine the most commonly used coccidia control strategies in Nyeri and Kiambu counties; to assess efficacy of available treatment options under experimental coccidiosis, and to validate the laboratory results in natural coccidial infections in the field. A cross-sectional baseline survey involving farm visits was undertaken in the two counties to establish the commonly used coccidiosis control strategies. In each visit, a semi-structured questionnaire was administered and an observational data sheet filled. Further, faecal samples were collected in each farm to determine the prevalence and intensity of coccidial infection. Knowledge, attitude and practices on various coccidiosis control strategies were assessed. Sixty rabbits were then randomly recruited into 6 treatment groups (1A, 2B, 3C, 4D, 5E, 6F) each with 10 rabbits, in a controlled laboratory environment for safety and efficacy trials. Groups 1A and 3C served as uninfected-untreated negative control and infected-untreated positive control groups, respectively. Treatments were administered as follows in different groups; 2B was treated with amprolium hydrochloride, 4D with diclazuril, 5E with sulphachloropyrazine and 6F with trimethoprim-sulphamethoxazole combination. The following parameters were monitored: coccidian oocyst shedding, faecal scores and lesion scores in experimental cases. The drugs were then tested on naturally infected rabbits in the field. The experiment was undertaken in strict adherence to guidelines approved by University of Nairobi Ethics and Animal Use Committee. The data was analyzed to determine descriptive statistics and associations. The results

revealed that most rabbit farmers in the study area are smallholder, 53.6% of the farms having less than 10 rabbits. In most of the farms (54.6%), owners were responsible for making day to day management decisions and bulk of them (41.2%) had attained tertiary level of education. There was a strong correlation (r = 0.64) between level of education and good rabbit husbandry practices, those with tertiary education having well managed rabbitries. The most commonly kept rabbit breeds were New Zealand white (25.4%), Cross breeds (24.2%) and California white (12.9%). The overall prevalence of coccidial infection was 79.4%. The most commonly used drugs for treatment by farmers were sulphachloropyrazine (22%), trimethoprim-sulphamethoxazole (14%) and amprolium hydrochloride (9%). Majority of farmers used sulphachloropyrazine (41%) and sulphadimidine (31% for prevention of coccidiosis). Sulphachloropyrazine and diclazuril (diclosol 1%®) were effective against rabbit coccidiosis in both controlled experimental and field trials in terms of reduction of oocysts shedding, and recorded lesion scores and faecal scores approaching those of negative control group. Trimethoprim-sulphamethoxazole registered moderate to satisfactory efficacy during field trials while amprolium hydrochloride was not effective in both field and laboratory trials. This study recommends training of farmers, field extension and veterinary officers to build capacity for rabbit production in the country, including the need for prudent use of available efficacious anti-coccidials to avoid development of drug resistance. Further studies to determine if efficacies of trimethoprim-sulphamethoxazole and amprolium can be improved at higher dosages are recommended.