Prevalence and risk factors associated with canine dermatophytoses among dogs in Kwara and Osun States, Nigeria

Background: Dermatophytosis (ringworm) is a zoonotic fungal skin infection caused predominantly by Microsporum canis, Microsporum gypseum and Trichophyton spp. It is highly transmissible and, while normally self-limiting, could be problematic due to its potential to cause disease in certain human populations. The occurrence and associated risk factors of dermatophytoses in dogs presented at three veterinary clinics in Osogbo, and Ilorin, Nigeria between July and November 2019 were investigated in this study. Methodology: This was a descriptive cross-sectional study of 325 dogs with lesions suggestive of dermatophytosis, selected by simple random sampling from veterinary clinics of two hospitals, purposively selected for the study due to high patronage of the veterinary hospitals by dog owners. Using conventional mycological sampling techniques, plucked hairs and skin scrapings were obtained the dogs. The samples were emulsified in 10% potassium hydroxide, examined microscopically for fungal elements and cultured using standard mycological procedures. Information on dog demographic characteristics and risk factors for dermatophytosis were collected using structured questionnaire. The association between risk factors and demographic variables with the occurrence of dermatophytoses was determined using Chi-square test (with Odds ratio and 95% confidence interval) and p value < 0.05 was considered statistically significant. Results: Positive cultures for dermatophytes were obtained from samples of 48 (14.8%) dogs with M. canis 37.5% (18/48), M. gypseum 27.0% (13/48) and T. mentagrophytes 8.3% (4/48). Other fungi identified were Aspergillus flavus 12.5% (6/48) and Malassezia canis 12.5% (6/48). The age distribution of positive dogs were < 1 year (50.0%, n=24), 1-3 years (29.2%, n=14) and > 3 years (20.8%, n=10), while the risk factors associated with dermatophytosis included sex of dogs (p=0.0428), history of dermatophytosis (p<0.0001), clinical presentation (p<0.0001) and lesion type, especially kerion and pustular lesions (p=0.0297). Conclusion: These findings established the occurrence of dermatophytosis in dogs kept for companionship (i.e., pets), security and breeding purposes in one northern and southern States of Nigeria. Our findings underscore the need for routine mycological investigations in dogs to facilitate early detection of cases and prompt institution of treatment interventions, thereby preventing zoonotic transmission of dermatophytes to their owners, handlers and veterinarians.

Detection and molecular characterization of a first isolate of rabbit haemorrhagic disease virus in Nigeria.

Rabbit haemorrhagic disease virus (RHDV) was recovered from necropsied rabbits that died during an outbreak characterized by epistaxis, incoordination, paralysis, and multi-organ haemorrhages in Ilorin, Nigeria. The haemagglutination test (HA) and RT-PCR assay targeted against a fragment of the RHDV VP60 gene were performed on liver, spleen, and kidney homogenates; faeces; and urine obtained from the rabbits. Amplicons were purified, sequenced, and phylogenetically analysed. The liver homogenates yielded the highest HA titres while RT-PCR of liver, spleen, and kidneys yielded the expected 1252 bp band. Sequence and phylogenetic analyses revealed that the Nigerian RHDV strain (RHDV/NGR/ILN/001) was 98.57%, 97.95%, and 96.70% homologous with RHDV2 (RHDVGI.2) strains from the Netherlands, Germany, and France, respectively. RHDV/NGR/ILN/001 induced tracheal, intestinal, and mediastinal lymph node haemorrhages, pulmonary oedema and congestion, and enlarged, necrotic liver in experimentally inoculated rabbits. The implications of this study, which is the first report of RHDV in Nigeria, are discussed.

Surveillance for avian influenza virus in captive wild birds and indigenous chickens in Nigeria.

Several reports of avian influenza virus (AIV) have been made on commercial chickens and wild birds in sub-Saharan Africa, but there is paucity of information of AIV among captive wild birds and indigenous chickens. Blood samples were obtained randomly from captive wild birds and chickens. AIV nucleoprotein antibody detection involved the use of enzyme immunoassay (ELISA) and subsequent subtyping with H5 and H7 AIV antigens (haemagglutination inhibition). Four hundred birds belonging to nine families and 14 species were sampled, and overall prevalence of 23% (92/400) was obtained (captive wild birds (10.4%, 5/48), indigenous birds (47.3%, 87/184) and exotic commercial birds (0.0%, 0/168)). Twelve ELISA-positive birds (13.04%) were positive to H7 antigen. Univariate analysis indicated statistical significance of AIV prevalence in captive wild birds (p < 0.0001) and exotic birds (p < 0.0001) using indigenous chickens as reference. This study gave an evidence of exposure of captive wild birds and indigenous chickens to AIV in Nigeria. Scavenging activities common among indigenously raised chickens, unrestricted movement of nonflying wild birds within the captive complex and free access by migrating wild birds to captive wild birds and local chickens were likely factors observed to promote AIV transmission. Continuous surveillance can further highlight the roles played by these birds in the epidemiology of AIV.