Improving cestode diagnosis in domestic dogs and cats: the need for accurate and non-invasive techniques

Cestode infections in companion animals pose a significant diagnostic challenge due to intermittent egg shedding and the limitations of traditional coproscopic techniques. This study aimed to evaluate the performance of microscopy and PCR in detecting cestodes in dogs and cats, using necropsy as the gold standard. A total of 81 animals (46 dogs and 35 cats) were examined by necropsy, with gastrointestinal tracts inspected for cestodes. Fecal samples were collected and analyzed by coproscopy and PCR targeting cestode infections. Necropsy identified cestodes in 7 (8.6 %; 95 % CI: 4.3 - 16.8) out of 81 animals: Dipylidium caninum was found in 3 (3.7 %; 95 % CI: 1.3 - 10.3) of animals (1/46 dogs; 2/35 cats), and Hydatigera taeniaeformis in 4 (11.4 %; 95 % CI: 4.5 - 26.0) out of 35 cats. Coproscopy and PCR detected only infection with H. taeniaeformis in 2 (5.7 %; 95 % CI: 1.6 - 18.6), and 3 (8.6 %; 95 CI: 3.0-22.4) cats, respectively., No PCR positives were recorded for D. caninum, despite its presence at necropsy. Overall agreement with necropsy was moderate for both methods (coproscopy k = 0.42; PCR k = 0.58), with higher sensitivity and agreement for Taenia spp. and H. taeniaeformis detection. These findings highlight the poor sensitivity of current non-invasive diagnostic methods for cestodes, particularly D. caninum, and the limited correlation between infection intensity and fecal detection. The study advocates for the urgent need for a commercially available coproantigen test to improve the accuracy of diagnosis.