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.

Serological and molecular surveillance for influenza A virus in dogs and their human contacts in Oyo State, Nigeria

@#Evidence of influenza A virus (IAV) infection in dogs, a major companion animal of humans, suggests the possibility that they may constitute a new source for transmission of novel influenza viruses to humans. The potential public health risk posed by this possibility of interspecies spread of IAV between dogs and humans necessitated surveillance for the virus in dogs and their human contacts. Sera from 239 asymptomatic pet and hunting dogs in Oyo state, Nigeria were screened for anti-IAV nucleoprotein antibodies using competitive enzyme-linked immunosorbent assay (ELISA) while haemagglutination inhibiting (HI) antibodies in the positive sera were detected using influenza virus H3 and H5 subtypespecific antigens. Suspensions prepared from 239 and 39 nasal swabs from dogs and human contacts, respectively were tested for presence of the highly conserved IAV matrix gene by reverse transcriptase-polymerase chain reaction (RT-PCR). Only 4 (1.7%) of the 239 sera tested were positive by the ELISA. The HI test confirmed the presence of H3 influenza virus subtype-specific antibodies in one (25.0%) of the 4 ELISA-positive sera with a titre of 1:128 while none was positive for H5 subtype-specific antibodies. All the nasal swabs assayed by RT-PCR were negative for IAV nucleic acid. The detection of IAV antibodies in pet and hunting dogs in this study, although at a low rate, suggests that these dogs could play a crucial role in the zoonotic transmission of influenza viruses especially considering the close interaction between them and their human contacts. Continuous surveillance for IAV among dog populations in Oyo State (and Nigeria) is therefore advocated to facilitate early detection of infection or emergence of novel influenza virus strains that could be potentially harmful to humans and or animals.