Peer-reviewed veterinary case report
Are heartworm antigen tests reliable for dogs in southern South
By Vezzani, D et al.·Published in Research in veterinary science·2008·Ecologí·View original on PubMed →
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Original publication title: Are antigen test kits efficient for detecting heartworm-infected dogs at the southern distribution limit of the parasite in South America? Preliminary results.
- Species:
- dog
Plain-English summary
A study looked at heartworm testing in dogs from Southern Greater Buenos Aires, where the parasite is less common. Out of nearly 5,000 blood samples, only 88 dogs (about 1.8%) had heartworm microfilariae, but many of these dogs tested negative on standard antigen tests. This means that some dogs with heartworm might not show up as positive on these tests, likely due to a low number of worms in the area. The researchers suggest that using antigen tests alongside other diagnostic methods could help get a more accurate diagnosis for heartworm in these regions.
People also search for: dog heartworm test accuracy · heartworm symptoms in dogs · heartworm treatment for dogs
Abstract
The aim of this study was to evaluate the performance of commercial heartworm antigen tests in dogs harbouring Dirofilaria immitis microfilariae near its distribution limit in South America. A total of 4934 blood samples of adult dogs from Southern Greater Buenos Aires were examined to detect circulating microfilariae in the buffy coat interface between December 2005 and April 2006. Microfilariae were detected in 88 (1.8%) blood samples and all the microfilariae observed were identified as D. immitis by acid phosphatase stain technique. In a first trial, 69 (78.4%) out of the 88 serum were positive by Speed((R)) Diro. Then, a new test was performed over 25 microfilariae-positive serum samples randomly selected among the 88 previously tested samples and using simultaneously Speed((R)) Diro, Witness((R)) Dirofilaria and Snap((R)) 3dx. This second trial showed identical results for the three different tests, in which 19 (76%) samples were positive. Therefore, more than 20% of microfilaremic dogs were antigen negative. The main hypothesis that could explain our finding is a low worm burden in the study area. According to our preliminary results, it is highly recommendable the complementary use of antigen tests and other procedures to obtain an accurate diagnostic near the distribution limit of the parasite.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/17881020/