Some canine vector-borne diseases (CVBD) are of major zoonotic concern, and the distribution of many CVBDs has been affected by the emergence of vectors in areas that were previously free from them. The risk for human and canine exposure to the same vector-borne pathogens has increased notably in many parts of the world, but CVBDs remain a relatively low priority compared with other vectorborne diseases that affect humans and livestock. Despite technologic advancements,many aspects of pathogen–vector–host interactions within endemic areas are still poorly understood.The role of healthy, persistently infected dogs and the importance of coinfections need to be addressed.A clear definition of therapeutic- or self-induced recovery, occult infection, nonclinical disease, and disease causation is important for clinical and epidemiologic studies of CVBDs, as well as for research addressing their zoonotic potential, diagnosis, and treatment. In endemic areas, coinfection in dogs is common, and an important question to address is whether coinfections induce synergistic and more clinically relevant immunosuppression compared with single infections, or whether persistent occult infections influence the acquisition and subsequent transmission of other pathogens.Addressing these issues may increase the reliability of currently available predictive models and diagnostic tools for controlling CVBDs.

COMMENTARY: CVBDs are of interest worldwide, but certainly more resources are expended on them in developed countries. The role of global climate change and the mobility of our pets impact the expanded transmission of CVBDs. Since some of these diseases are zoonotic, there has been the suggestion that our pets may be a good tool for early surveillance.Whether we treat our dogs as “canaries in the mine” or not,we need to continue to acquire knowledge about the spread of CVBDs.And since we have good ectoparaciticides, the trend should continue toward reducing the risk for contracting them.—Patricia Thomblison, DVM,MS

Managing canine vector-borne diseases of zoonotic concern: Part one.Otranto D, Dantas-Torres F, Breitschwerdt EB. TRENDS PARASITOL 25:157-163, 2009.