Dogs, distemper, and multiple sclerosis in the United States

Area of Science:

• Epidemiology
• Veterinary Medicine
• Neurology

Background:

• Multiple sclerosis (MS) is a chronic neurological disease with an unknown etiology.
• Geographic variations in MS prevalence suggest environmental factors may play a role.
• Canine distemper (CD) has been hypothesized as a potential environmental trigger for MS.

Purpose of the Study:

• To investigate the potential association between canine distemper (CD) and the geographic distribution of multiple sclerosis (MS) in US white male veterans.
• To compare MS case/control ratios with CD risk indices and dog bite data.

Main Methods:

• Utilized the Veterinary Medical Data Program for diagnostic information from veterinary medical centers.
• Analyzed data from a 2-year surveillance program for human bites by animals by the Center for Disease Control.
• Compared state-level MS distributions with CD admission proportions, CD case-to-population ratios, and dog bites per capita.

Main Results:

• No positive correlation was found between any of the canine distemper (CD) risk indices and the geographic distribution of multiple sclerosis (MS).
• State distributions for MS did not align with CD prevalence or dog bite incidence.
• Veterinary Medical Data Program data and CDC surveillance data were used for comparison.

Conclusions:

• The study found no evidence to support a link between canine distemper (CD), general dog exposure, or dog bites and the etiology of multiple sclerosis (MS).
• These findings suggest that CD and related exposures are unlikely contributors to MS development.
• Further research into other environmental or genetic factors influencing MS is warranted.