Canine Gastrointestinal Nematodiases and Associated Risk Factors in Kigali City, Rwanda

Abstract

Canine nematodes pose a public health risk to humans and livestock; however, the prevalence of canine nematodiases in Rwanda is unknown. This study aimed at determining the prevalence of canine nematodiases and identifying the risk factors for such infections in Kigali, the capital city of Rwanda. A cross-sectional study involved 93 dogs selected across Kigali city. Faecal samples were collected from apparently healthy dogs, and nematode eggs were identified and quantified using the McMaster technique. Risk factors for canine nematodiases were analysed by a multivariable binary logistic regression model. The overall prevalence of gastrointestinal (GI) nematodiases in dogs was 33.3% (95% CI: 23.8-42.9). The most prevalent species was Ancylostoma spp with 32.3% (95% CI: 22.8-41.8). Nearly 38.7% and 3.2% of the dogs infected with Ancylostoma spp and Toxocara canis had high egg counts per gram (EPG) of faeces (≥550), respectively. Approximately 96.8% of dogs infected with nematodes had monoinfection. Logistic regression analysis showed that dog's age (1 to 2.5 years old), location (Gasabo and Kicukiro districts), and feeding practices were significantly associated with prevalence of canine nematodiases. In particular, the adjusted odds ratio (AOR) was more than 5 times higher for dogs fed on uncooked animal products and leftovers from households and restaurants compared to those who ate food prepared for them. The AOR was also about 16 times higher for dogs that scavenged and ate leftovers from households compared to those who ate food prepared for them. The findings of this study indicate that the prevalence of GI nematodes in domestic dogs in Kigali city, Rwanda, was 33.3% (95% CI: 23.8-42.9). The identified nematodes, namely, Ancylostoma spp. and Toxocara canis, are zoonotic, and dogs and humans are at risk of contracting these nematodes. The factors associated with canine GI nematodes in Kigali city include feeding practices and the dog's age and location (district). Dog owners need to rethink procedures for deworming and feeding their dogs. Again, the public should be made aware of the role of dogs in transmitting zoonotic nematodes to humans.

Figure 1

Administrative districts (red boundaries) and sectors (black boundaries) of Kigali city. The blue dots show the location of households owning sampled dogs across the study sites. The locations are Kigali, Nyamirambo, and Mageragere sectors of Nyarugenge district; Kicukiro, Niboye, and Gatenga sectors of Kicukiro district; and Gisozi, Kimironko, and Kacyiru sectors of Gasabo district. Data on the location of each study dog was collected using GPS and allowed generating the map using ArcGis10.2 software.

Figure 2

Parasitic egg load in dogs suffering from ancylostomiasis and toxocariasis in Kigali city. Counts ≥ 500 EPG were found in 38.7% of dogs infected with Ancylostoma spp. The one dog infected with T. canis was also infected with hookworm (1/31) and had count ≥ 500 EPG. In addition, 35.5% and 22.6% of those infected with Ancylostoma spp had moderate egg load and light egg load, respectively (Figure 2).