Canine vector-borne diseases (CVBDs) include a diverse group of pathogens, some of which pose zoonotic concerns. This study evaluated anaplasmosis, babesiosis, dirofilariosis, ehrlichiosis, and leishmaniasis in a group of young dogs. Serology, cytology, and polymerase chain reaction (PCR) methods were used to detect organisms or evidence of infection. The study included 48 autochthonous mix-breed puppies and 10 purpose-bred beagles, which were used as naive controls. Dogs were tested 4 times: when they first entered the study (March/April 2008) and in July 2008, October 2008, and April 2009. Dogs were kept in a private animal shelter in southern Italy in a highly endemic area for CVBDs; they were not treated with ectoparasiticides during the study period. PCR detected the highest number of dogs infected with Anaplasma platys, Babesia vogeli, and Erhlichia canis. Seroconversion was a more sensitive indicator of exposure to Leishmania infantum. Multiple diagnostic modalities were useful in confirming tick-borne infections. Over the course of the study, 20.7% of the dogs were coinfected with multiple pathogens; however, the percentage of new coinfections decreased from baseline (50%) to the first (33.3%) and second (16.6%) follow-up time points. This study provided insight into the pathogens of young dogs in southern Italy and diagnostic testing limitations. It supports the use of multiple diagnostic modalities when confirming vector-borne diseases.

Commentary: There is greater awareness about the emerging threat of CVBDs. Although this research was conducted in southern Italy, the take-home messages are the same wherever CVBDs are seen. The best diagnostic modality may depend upon the stage of infection; in addition, dogs can be infected with more than 1 pathogen making diagnosis more challenging. The expanding range of ticks requires practitioners to be cognizant of diseases in their area and to continue testing if results are negative at first or the patient doesn’t respond to treatment.

Diagnosis of canine vector-borne diseases in young dogs: A longitudinal study. Otranto D, Testini G, Dantas-Torres F, et al. J CLIN MICROBIOL doi:10.1128/JCM.00379-10.