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PREVALENCE, TREATMENT OPTIONS AND RISK FACTORS ASSOCIATED WITH RABBIT MANGE IN CENTRAL KENYA

The rabbit is one of the major livestock kept by small scale farmers in many parts of Kenya mainly because of increase in awareness of the advantages offered by the enterprise. However, rabbit industry is constrained by many factors, diseases being major among others. Mange is the second most important disease affecting rabbits. Despite this, there are no records on prevalence and practices on control of rabbit mange in Kenya. Additionally, there are no specific drugs against rabbit mange in Kenya. The aim of the present study was to determine the prevalence, risk factors, control strategies of rabbit mange and efficacy of commonly used anti-mange drugs in Kiambu and Nyeri counties, central Kenya. A cross sectional study using semi-structured questionnaires complimented with observational data sheets and sample collection was undertaken in June and July 2016. A total of 97 rabbit farms were visited in both counties and 171 samples collected from rabbits with clinical signs of mange. The most common clinical signs of mange as reported by farmers were scratching (39.88%), wounds (25.51%), crusts (21.11%) and head tilting (13.49%). Ear scabs (36.3%), alopecia (24%), scratching (11.7%), crusts (8.8%), and dandruff (1.8%) and wounds on the skin (0.6%) were encountered during clinical examination. Psoroptes cuniculi was the only mite isolated from 49.5% of the farms during the baseline survey. The overall mange prevalence was 49.5%. Fleas (Ctenocephalides canis) were also isolated from 5 farms. Inappropriate use of treatment options by farmers, poor maintenance of hygiene in rabbit houses and sourcing of breeding stock from other farmers were identified as potential risk factors for mange mite infestation in rabbits. The most common treatment options used by farmers against mange were ivermectin (25%), carbaryl (16%) and liquid paraffin (12%). Controlled laboratory and field trials were done to determine the efficacy of anti-mange agents commonly used by farmers in Kiambu and Nyeri counties. In the controlled laboratory trial, a total of 24 rabbits were recruited for the study. Twenty were mange-infested while 4 were mange-free. The mange-infested xiiirabbits were randomly placed into 5 treatment groups (G1, G2, G3, G4 and G5) each consisting of 4 rabbits. The 4 mange-free rabbits formed the negative control group (G6). Rabbits in G1 were treated with ivermectin (0.4mg/kg) at an interval of 14 days, G2 were given a combination of carbaryl and liquid paraffin applied every other day until the lesions cleared. G3 were treated with 5 drops of liquid paraffin applied daily till the lesions cleared, G4 were treated with selamectin (6 mg/kg) applied once on the skin behind the neck. G5 served as positive control and were given 5 drops of distilled water applied topically on their ears while G6 served as negative control rabbits. Lesions were scored daily on a scale of 0-4. Ear scabs were collected weekly up to day 28 to check the viability of the mites. Rabbit weights were also taken weekly during the study period. The efficacy of anti-mange mite agents in a field trial were tested in 140 naturally infested rabbits. Results confirmed ivermectin, selamectin, liquid paraffin, carbaryl-liquid paraffin combination and carbaryl alone to be effective against rabbit mange as manifested by reduced lesion scores and lack of viable mites by the end of the trial. There was a significant difference (p<0.05) in lesion scores between positive control and other treatment groups. Mange is a major challenge to rabbit farming in Kenya, therefore, it is recommended that farmers and animal health workers be informed on methods of its control. Present study revealed that maintenance of hygiene in the hutches, isolation of newly purchased rabbits to observe for signs of mange and treatment of mange infested rabbits to be the best methods of controlling mange. Ivermectin, selamectin, liquid paraffin and carbaryl were confirmed to be effective against rabbit mange. Farmers are encouraged to use liquid paraffin as the first option as it is cost effective and easy to administer relative to other treatment option.

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Author: dr. joice chebet
Contributed by: reagan lax
Institution: university of nairobi
Level: university
Sublevel: post-graduate
Type: dissertations