Heat treatment of serum has demonstrated improved detection of Dirofilaria immitis antigen in sera of sheltered dogs without knowing the true infection status of the animals and in dogs confirmed experimentally to be infected with heartworm. Utilizing archived sera with necropsy confirmed heartworm infection status (n = 665) and a micro-titer well based ELISA antigen assay, this study evaluated how the composition of heartworm infections affects antigen test results pre- and post-heat treatment, determined subsequent changes to the antigen test sensitivity and specificity, and application of optical density values. The composition of heartworm infections present in dogs with sera initially testing antigen negative consisted of infections by dead 1/34 (2.9 %), immature 10/34 (29.4 %), male only 7/34 (20.6 %), female only 5/34 (14.7 %), and mixed sex infections 11/34 (32.4 %) with 2–62 heartworms of which 6 were microfilaremic. The composition of heartworm infections remaining antigen negative post-heat treatment consisted of infections by dead 1/14 (7.1 %), immature 9/14 (64.3 %), male only 2/14 (14.3 %), and mixed sex infections 2/14 (14.3 %) with 6 and 62 heartworms of which 1 was microfilaremic. The overall sensitivity for all infections, mature heartworms, and mature females before heat treatment were 86.9 %, 90.7 %, and 93.3 % and after heat treatment sensitivity increased to 94.6 %, 98.4 %, and 99.2 % respectively. A decrease in specificity from 97.8%–96.1% was observed following heat treatment of heartworm negative sera. Optical density values for the varying infection intensities present in this study clearly indicate that result intensity is not reflective of the number of heartworms present. This study provides additional context for interpreting post-heat antigen results for dogs originating from animal shelters, demonstrates diagnostic utility of optical density, and highlights the need for improved heartworm diagnostics.

血清热处理已证明改善了对丝虫病的检测在不知道动物的真实感染状况的情况下，在庇护犬的血清中存在抗原；在实验中证实感染了丝虫的犬中也存在这种抗原。利用尸检的已确诊血清并确认了丝虫感染状态（n = 665）和基于微量滴定孔的ELISA抗原测定，该研究评估了丝虫感染的成分如何影响热处理前后的抗原检测结果，确定了随后的变化抗原测试的敏感性和特异性，以及光密度值的应用。最初检测抗原阴性的血清中的犬心丝虫感染的成分包括死者感染的1/34（2.9％），未成熟者的感染10/34（29.4％），雄性仅7/34（20.6％），雌性仅5 / 34（14.7％），以及混合性感染11/34（32.4％）与2–62种丝虫，其中6种为微丝虫。热处理后仍为抗原阴性的丝虫感染的组成包括死者感染1/14（7.1％），未成熟者9/14（64.3％），仅男性2/14（14.3％）和混合性感染2 / 14例（14.3％）中有6例和62例丝虫，其中1例为微丝虫。热处理前，所有感染，成熟丝虫和成年雌性的总体敏感性分别为86.9％，90.7％和93.3％，热处理后的敏感性分别提高到94.6％，98.4％和99.2％。对丝虫阴性血清进行热处理后，发现特异性从97.8％–96.1％下降。本研究中存在的不同感染强度的光密度值清楚地表明，结果强度不能反映存在的丝虫数量。