Type 1 immune-mediated polyarthritis in dogs and lack of a temporal relationship to vaccination

To investigate whether there is a temporal relationship between vaccination and the onset of type 1 immune-mediated polyarthritis in dogs.

Retrospective case-control study: 39 dogs from a referral hospital with a diagnosis of type 1 immune-mediated polyarthritis were age-matched with 78 control dogs with other diagnoses. A temporal association between vaccination and polyarthritis was considered positive if recent vaccination had been performed within 28 days of the onset of clinical signs of immune-mediated polyarthritis. The odds ratio association of recent vaccination with immune-mediated polyarthritis was calculated using matched case-control methods.

Of the 39 dogs in the type 1 immune-mediated polyarthritis group, four had been vaccinated within 28 days before onset of clinical signs compared to six dogs in the control group. The odds ratio for a dog developing type 1 immune-mediated polyarthritis if vaccinated within the last 28 days was estimated to be 1·44 (95% confidence interval 0·25 to 8·24, P = 0·88).

There was no evidence of a temporal relationship between vaccination and type 1 immune-mediated polyarthritis, although the large confidence interval on the odds ratio suggests a need for larger studies to confirm this finding.