Factors affecting the occurrence of canine parvovirus in dogs

• All dogs up to 12 months of age were more likely to be CPV-positive.
• Dogs with anthelmintic treatment were at a lower risk of being CPV infected.
• Depression and dehydration were associated with a high risk of being CPV infected.

Canine parvovirus (CPV) is the most important enteric virus infecting canids worldwide. The purpose of this study was to detect CPV in naturally infected dogs from several veterinary clinics distributed throughout Portugal between 2012 and 2014 and to identify risk factors associated with CPV infection. From 209 dogs suspected of being infected with CPV, historical data and clinical signs were collected. Fecal samples were screened for CPV by PCR assay and those positive were confirmed by sequencing. The data was analyzed using logistic regression to investigate associations between each of the predisposing factors and CPV status. Of the samples collected, 77.5% tested CPV-positive. Statistical analysis showed that animals in the three age categories (p < 0.001) were at list 12 times more likely to be CPV-positive than older animals. The anthelminthic treatment [OR = 0.45, p = 0.04] and the rectal temperature (hypothermia, [OR = 0.12, p = 0.004]) contributed to decrease the likelihood of the dogs be infected with CPV. On the other hand, clinical signs such as depression [OR = 4.4, p = 0.02] and dehydration status [OR = 2.38, p = 0.001] made dogs more likely to be CPV-infected. The results indicate that although having a high morbidity, only 18% of the Portuguese dog population died in the study. Some of the risk factors identified in this study have not been commonly reported, yet they are easy to obtain and can be used as prognostic indicators in the veterinary practice.