Screening of Respiratory Tract-Associated Nematodes in Moroccan Dogs: Focus on Eucoleus boehmi

Dogs can harbor a range of respiratory tract helminths which can cause clinical signs varying from asymptomatic to serious diseases. Lately, these parasites, notably Eucoleus spp. and Angiostrongylus vasorum, received considerable attention because of their spread in previously nonendemic regions, likely facilitated by several factors such as increased animal movements changes in the distribution and urbanization of wild canid reservoirs, along with climatic and environmental changes. This study aimed to assess the presence and dissemination of these helminths by investigating, for the first time in Morocco, the seroprevalence of A. vasorum and the fecal occurrence of Eucoleus spp. eggs in dogs. Overall, 318 fecal samples collected from dogs across different geographical areas of Morocco were examined using two fecal flotation techniques, centrifugal flotation with 33% zinc sulfate (ZnSO4) and simple flotation with Sheather's sugar solution. Additionally, A. vasorum antigen detection was performed on 286 blood samples using an in-clinic serological test (Angio Detect Test, IDEXX Laboratories). A complete blood count was subsequently performed in dogs that tested positive. Results revealed the occurrence of Eucoleus boehmi eggs in three military working dogs (0.94%), with two being asymptomatic and one showing a mucous nasal discharge. All had mild to moderate eosinophilia (1.33-3.18 K/μL). With regard to the serological assays, all dogs tested negative for A. vasorum antigens. These preliminary findings provide initial evidence of the geographic spread of E. boehmi, suggesting that veterinarians in Morocco should include this infection in the differential diagnosis of dogs displaying upper respiratory tract symptoms. By contrast, despite the absence of dogs seropositive to A. vasorum, the disease cannot be excluded until a better understanding of its distribution is established. Hence, further studies involving larger canine populations across different regions and combining multiple diagnostic methods, including advanced molecular techniques, are highly recommended.