Revised Recommendations for Annual Heartworm Testing

We all know, or at least we should, to test our dogs for heartworm every year. We've been used to getting our dogs' blood tested for presence of heartworm antigen.

That's all fine and dandy this test produces increasing number of false negative results. That is not so good at all.
Heartworm prevalence map 2013. Image American Heartworm Society

The new recommendation is to test for antigen as well as for microfilaria.

Combination of these tests is the most reliable way to screen dogs for heartworm disease.

A filter test positive for microfilaria. There are usually a few red blood cells still present that can be seen as small dots. The microfilaria stain a magenta color and are about the same diameter as the diameter of a red blood cell. Image Vet133

Source article:
Revised Recommendations for Annual Heartworm Testing

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