Immune-mediated thrombocytopenia in dogs: Is vaccination a factor?
A recent report looks into whether veterinarians should be concerned with immunization in dogs with a history of this disease.
Nov 01, 2012
No statistically significant association between recent vaccination and a diagnosis of presumptive primary immune-mediated thrombocytopenia (IMT) was found in a recent retrospective study that examined 48 dogs presumed to have IMT and 96 control dogs.1
If vaccination is deemed necessary, vaccine administration can be staggered throughout the year. Medications or supplements the patient was receiving just before or during the first episode of IMT also should be avoided (when possible) in all future treatment protocols in that patient. All of these precautions may apply to other known immune-mediated conditions as well.Although a statistically significant relationship between vaccination and IMT was not found in this study, the authors note that one cannot rule out the possibility of an infrequent association between the two or a transient, nonclinical, postvaccination IMT.1 They discuss several important limitations of the study, including a lack of information regarding the number of vaccines in the subject's lifetime, an inherent difficulty of confirming the diagnosis of idiopathic IMT, a small sample size and the study's retrospective nature. So it is difficult to conclude whether recent or cumulative vaccinations may or may not increase the risk of idiopathic IMT.
Because of the limited availability and variable sensitivity and specificity of antiplatelet antibody testing, IMT is typically diagnosed based on clinical and laboratory criteria, exclusion of other disease processes and response to treatment. IMT usually results in a severe thrombocytopenia (< 50,000/μl).