Occurrence of Caprine Pasteurellosis, Bacterial Isolates and their Sensitivity Pattern to Antimicrobial Agents in Oyo State, Nigeria

Background and Objective: Pneumonic pasteurellosis is one of the clinically important diseases of small ruminants with great socio-economic impacts. As common as this condition is in Nigeria, there is no adequate data on its occurrence among indigenous breeds, sex and ages of goats vis-à-vis the prevalent bacterial organisms and their antimicrobial susceptibility. This study, therefore, investigates the occurrences, prevalent bacterial pathogens, and their antimicrobial sensitivity patterns of pneumonic pasteurellosis in Nigerian breeds of goats in Ibadan, Nigeria. Materials and Methods: Nasal swabs were collected from 62 pneumonic goats at Akinyele sheep and goat market (June-December 2023), with signalments and body condition scores documented. Bacterial isolates were identified using growth patterns on blood and MacConkey agars, Gram staining, and biochemical tests; Gram-positive cocci were further tested on Mannitol Salt Agar and by the coagulase test. Five isolates of each organism underwent antibiotic susceptibility testing according to CLSI guidelines. Results: Out of the overall 40/62 (64.52%) positivity, we observed 100% in West African Dwarf, 68.42% in Red Sokoto, and 54.55% in Sahel goats. Age distribution of positivity revealed 72.22% in adults and 53.85% in young goats. Female goats had 80% positivity compared to males with 57.14%. Pasteurella multocida (38.71%) was the most prevalent isolate culpable for the disease among the sampled subjects. This was followed by Staphylococcus aureus (35.48%), and lastly by Mannheimia haemolytica (25.81%). Antimicrobial susceptibility testing demonstrated that P. multocida was highly sensitive to cipSeptember 1, 2025rofloxacin, clindamycin, ofloxacin, and enrofloxacin but resistant to oxytetracycline and tylosin. Mannheimia haemolytica was very sensitive to enrofloxacin and sulphadimidine and moderately sensitive to ciprofloxacin. Staphylococcus aureus showed high sensitivity to gentamicin and moderate sensitivity to enrofloxacin, ciprofloxacin, erythromycin, and clindamycin. Conclusion: Pneumonic pasteurellosis is more common in the West African Dwarf breed, females, and adults compared to the Red Sokoto, males, and young goats in Nigeria. The most prevalent organisms are Pasteurella multocida, Staphylococcus aureus, and Mannheimia haemolytica. Enrofloxacin and ciprofloxacin are the best drugs of choice recommended for the treatment of pasteurellosis in Nigerian breeds of goats.