Canine demodicosis: a retrospective study of a veterinary hospital population in California, USA (2000–2016)

Background Demodex spp. are cutaneous mites that cause clinical disease when present in increased numbers. There is an association in some dogs with underlying systemic disease or immunosuppressive medications. Hypothesis/Objectives Retrospective study to document breed predisposition, identify any concurrent diseases or underlying immunosuppressive conditions, and to determine the frequency of demodicosis recurrence after treatment completion. Animals There were 431 dogs with demodicosis presented to a veterinary teaching hospital in California, USA, from 2000 to 2016. Methods Inclusion in this study required a diagnosis of demodicosis based on direct demonstration of the mite. Records were reviewed for signalment, disease history, potential underlying aetiologies, diagnosed concurrent diseases, medications and demodicosis treatment. Analyses were performed to evaluate for potential breed predispositions and because of the large number of dogs with allergic dermatoses, analyses for this diagnosis as a disease associated with demodicosis was also performed. E‐mailed surveys and follow‐up telephone calls were used to assess for information about disease recurrence. Results The pit bull terrier group and West Highland white terrier, based on calculated odds ratio, were breeds predisposed to developing demodicosis. For dogs with demodicosis, allergic dermatoses was an associated disease. Relapse or recurrence of disease after treatment was uncommon, affecting 11% of the dogs with long‐term follow‐up. Conclusions/Clinical Importance This study identified, in dogs attending the institution based in California, USA, breed predilections for canine demodicosis and associated concomitant diseases. It also revealed a low occurrence of disease relapse, recurrence or persistence. Résumé Contexte Demodex spp. est un acarien de la peau qui cause une dermatose lorsque présent en grande quantité. Il y a une association chez certains chiens avec une maladie systémique sous jacente ou des traitements immunosuppressifs. Hypothèses/Objectifs Une étude rétrospective a été menée pour étudier la prédisposition raciale, identifier une maladie concourante ou une atteinte immunosuppressive sous‐jacente et déterminer la fréquence des récidives de démodécie après traitement. Sujets Il y avait 431 chiens atteints de démodécie présentés au centre hospitalier universitaire vétérinaire de Californie, USA, de 2000 à 2016. Méthodes L'inclusion dans cette étude nécessitait un diagnostic de