Peer-reviewed veterinary case report
Heartworm exposure and inflammation signs in healthy dogs
By Félix, Naianne Araújo et al.·Published in Topics in companion animal medicine·2026·Laborató, Brazil·View original on PubMed →
PetCaseFinder translated the abstract of this peer-reviewed paper into plain English so pet owners can read it. We do not publish original research — every detail traces back to the citation above. How we work →
Original publication title: Seroprevalence of Dirofilaria immitis and assessment of systemic inflammatory indexes in apparently healthy dogs from coastal northeastern Brazil.
- Species:
- dog
Plain-English summary
A group of 100 healthy dogs from northeastern Brazil was tested for heartworm (Dirofilaria immitis), and 17% were found to have the infection. While these dogs showed no obvious symptoms, blood tests revealed changes in their immune system, such as lower lymphocyte counts and higher protein levels. This suggests that heartworm can be present without noticeable signs, and early detection is important. Regular testing and preventive measures are recommended to protect dogs and reduce the risk of spreading the disease to humans.
People also search for: heartworm symptoms in dogs · healthy dog heartworm test · dog blood test results explained
Abstract
Dirofilaria immitis is a vector-borne zoonotic parasite of considerable veterinary and public health significance. This study aimed to determine the seroprevalence of D. immitis and investigate associated hematological and inflammatory changes in clinically healthy dogs from the coastal municipalities of Beberibe and Cascavel, Ceará, Brazil. Between November 2024 and March 2025, blood samples were collected from 100 clinically healthy dogs (72 from Beberibe and 28 from Cascavel). Diagnostic testing included immunochromatographic assays for D. immitis antigens and microscopic evaluation for circulating microfilariae. Seropositivity for D. immitis was detected in 17 % of dogs, while microfilariae were identified in 7 %, including one discordant case (microfilaremic but antigen-negative). Hematological analysis revealed significantly reduced lymphocyte counts (p < 0.01) and elevated total plasma protein concentrations (p < 0.05) in D. immitis-positive animals. Furthermore, the platelet-to-lymphocyte ratio (PLR) was significantly increased in infected dogs (p < 0.05), whereas neutrophil counts and other systemic inflammatory indices (NLR, SII, SIRI) exhibited non-significant upward trends. These findings indicate the silent circulation of D. immitis among clinically healthy dogs and point to early hematological and immune system alterations. Notably, the elevation of PLR may serve as a potential biomarker for subclinical immune-vascular involvement in heartworm disease. The study underscores the importance of continued regional surveillance and vector control measures to reduce the risk of zoonotic transmission.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/41314600/