A case–control study of the risk factors for canine juvenile‐onset generalized demodicosis in the USA

Abstract

Canine juvenile-onset generalized demodicosis (JOGD) is a common skin disorder suspected to be associated with multiple risk factors, including breed predispositions. These risk factors have not been well documented in a large population. A retrospective case-control study was conducted by searching the electronic medical records of 1,189,906 dogs examined at 600 hospitals during 2006 in order to assess the risk factors associated with JOGD in the USA. Multivariate analyses were conducted using logistic regression to estimate the relative risk with the odds ratio for variables hypothesized to influence the risk for canine demodicosis. Breeds (odds ratio) found to have the greatest association with a diagnosis of JOGD were American Staffordshire terrier (35.6), Staffordshire bull terrier (17.1) and Chinese shar-pei (7.2). Nonbreed risk factors (odds ratio) significantly associated with a diagnosis of JOGD were the diagnosis of pyoderma (5.5), coccidiosis (2.7) or hookworms (1.5), short coat (1.9) and nonenrollment in a preventative care wellness plan (1.5). Documenting these risk factors may help veterinarians to prioritize differential diagnoses and will aid in the design of prospective studies to elucidate the pathogenesis of demodicosis in dogs.

Treatment of demodicosis in dogs: 2011 clinical practice guidelines

“…In young animals, endoparasiticism, 22 malnutrition and debilitation may lead to an immunocompromized state that favours mite proliferation and development of skin disease. In adult animals, chemotherapy, neoplasms, hypothyroidism or hyperadrenocorticism, for example, may suppress the immune system sufficiently to trigger proliferation of the mites 23–25 .…”

Juvenile‐onset and adult‐onset demodicosis in dogs in the UK: prevalence and breed associations

“…The 0.48% 1‐year period prevalence of demodicosis in dogs under 2 years of age documented here is close to the 0.58% prevalence previously reported for juvenile demodicosis in a large study based on general veterinary hospital records in the USA (Plant et al . ). This may suggest similar demographics in both countries.…”

“…This is in line with a US study which showed that seven of the nine breeds with the highest odds for juvenile demodicosis were breeds of the same genetic clade (Plant et al . ). Juvenile demodicosis has long been suspected to have a hereditary basis, although published evidence for this is sparse (Ferrer et al .…”

“…Some larger and more recent studies from the USA reported prevalence values of 0.58% based on a diagnosis of juvenile demodicosis alone from the electronic records of a large network of veterinary practices (Plant et al . ) and 0.37% for demodicosis overall based on data from one teaching hospital (Bowden et al . ).…”

“…Reports on breed as a risk factor or of breed representation differed markedly within these study groups, with bull dog and bull terrier types and shar‐pei dogs having high odds of diagnosis with juvenile demodicosis (Plant et al . ), but crossbred dogs were the most frequently represented dogs in the study of overall demodicosis (Bowden et al . ).…”