Pneumocystis canis pneumonia in dogs

Abstract

Pneumocystis canis is a potential cause of life-threatening interstitial fungal pneumonia in dogs. It is seen almost exclusively in two canine breeds, miniature Dachshunds and Cavalier King Charles Spaniels (CKCS)1. Historically, Australian veterinarianshadakeyrole in thedocumentation of this entity and its conspicuous breed associations2–4. Affected Dachshunds and CKCS are likely to have an inher- ited immunodeficiency that predisposes them to infection with this commensal organism of the respiratory tract and pharynx1,2,5,6. A high index of suspicion is required to make a timely diagnosis and save affected patients, as these dogs cope poorly with anaesthesia andother measures to procure the specimens required to make a definitive diagnosis. Possible co-infection with Bordetella bronchiseptica must be considered when determining antimicrobial strategies. Affected dogs occasionally have a previous or concurrent history of generalised demodicosis5,7,8. With early interven- tion, affected dogs can be saved, although some require life- long therapy to prevent recurrence. The future challenge is to develop fast molecular techniques to diagnose P. canis† pneumonia (PCP)7,9 and to determine the underlying immune defect in over-represented breeds through the rapidly advancing field of canine genomics10