Molecular diagnosis of Ehrlichia canis infection in dogs with uveitis

Canine monocytic ehrlichiosis (CME) is an infectious disease caused by a gram-negative bacterium Ehrlichia canis that has a high global prevalence that leads to high rates of morbidity and mortality in dogs. Among the clinical changes, ophthalmic diseases can lead to permanent blindness and it can be an important clinical sign. The objective of this study was to perform nested polymerase chain reaction (PCR) to diagnose E. canis infection in dogs with bilateral uveitis from the Veterinary Hospital of the Santa Cruz State University. Blood samples were collected and DNA for the molecular diagnosis was extracted from 66 adult dogs of both genders and mixed breeds diagnosed with bilateral uveitis. Thirty-five (53%) dogs showed positive results and presented with iridocyclitis, posterior uveitis, panuveitis, or uveitis with secondary glaucoma. This study demonstrates that nested PCR is an important tool for the differential diagnosis of dogs with bilateral uveitis, as it provides evidence of the infectious agent in the animal.