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Capillaria hepatica (syn. Calodium hepaticum) is a globally distributed nematode with a high affinity to the liver of a wide range of mammalian hosts, including humans. Documented reports of the nematode in cats and associated histopathology are rare. Here, we describe a case of C. hepatica infection in a 5-year-old male stray cat from Iran. At post-car accident necropsy, all body parts appeared normal except for the liver, in which a few yellowish-white granulomatous nodules were observed through the capsule and in the organ. Histopathological examination of the tissue revealed a large number of clustered parasite eggs in the parenchyma. The barrel-shaped, un-embryonated eggs (55.19 × 28.37 μm), with inconspicuous caps at both ends, were covered with striated shells. The presence of ova in the liver tissue had resulted in the development of hepatic inflammation with hepatocellular necrosis associated with the development of multifocal granulomas. As predators of small rodents, the cats might have a significant role in the epidemiology of C. hepatica. Infection of hosts through ingestion of embryonated eggs in contaminated water, food, or soil is of major importance in the epidemiology of C. hepatica. Since the rare reports of feline infection have come mainly from accidental detection of the parasite, any hepatic disease presenting difficulties to find an etiological agent may virtually be associated with the infection with this little-known nematode.

Among the nematodes that infect the urinary tract of dogs, the Dioctophyma renale and Capillaria plica are those more frequently reported. For a long time, sedimentation was the only method used to detect eggs of these parasites in urine. The aim of this study was to analyze urine samples (n = 54) of dogs, obtained by bladder catheterization or cystocentesis, by using a modified FLOTAC technique. Animals were divided into two groups, i.e., with (n = 20) and without (n = 34) suspicion of urinary disease. The overall positivity herein observed was 3.8 % (2/54), being all animals (10 %; 2/20) from the group with suspicion of urinary disease. In the first positive sample, a single egg of D. renale was detected, whereas in the second sample two trematode-like eggs were observed. This is the first short survey employed to detect eggs of parasites that inhabit the urinary tract of dogs using a modified FLOTAC technique; in addition, for the first time, eggs of D. renale have been detected using this tool.

Calodium hepaticum (syn. Capillaria hepatica) and Calodium splenaecum (syn. Capillaria splenaecum) are nematodes that infect the liver and spleen, respectively, of mammals. While the host range, distribution, pathology and zoonotic potential of C. hepaticum are well known, very little is known about C. splenaecum. The observed prevalence of these two parasites, the factors associated with prevalence, and the lesions resulting in the different host species were studied in 408 micromammals captured in two periurban areas of Barcelona (NE Spain) from 2011 to 2013. C. hepaticum was found in 4% of 322 wood mice (Apodemus sylvaticus) (with local prevalence up to 16%) and 1 of 2 Norwegian rats (Rattus norvegicus). C. splenaecum was found in 10 % of 38 greater white-toothed shrew (Crocidura russula) (local prevalence up to 30%). Neither parasite was detected in 29 Algerian mice (Mus spretus) and 17 black rats (Rattus rattus). Prevalence of C. hepaticum was significantly higher in wood mice captured in natural areas (6.4%) than those from residential areas (0%), and infected mice were in better body condition. No differences in prevalence were found among age and sex groups, years and seasons. Lesions of hepatic capillariasis in wood mice consisted mainly of mild to moderate multifocal granulomas around degenerating adult parasites and/or eggs, while lesions seen in a rat consisted of multifocal granulomatous hepatitis and bridging fibrosis extending from the necrotic areas caused by the parasites. Splenic lesions found in shrews due to C. splenaecum, representing the first histological description of this parasite, were single nodules that corresponded to finely encapsulated clusters of eggs with adult parasites.

Capillaria hepatica (syn. for Calodium hepaticum) is a zoonotic nematode parasitizing in the livers of rodents as main hosts and in numerous other mammals including humans. It is the causative agent of the rare conditions of hepatic capillariosis and spurious C. hepatica infections in humans. In this review, 163 reported cases of infestations with this parasite (72 reports of hepatic capillariosis, 13 serologically confirmed infestations and 78 observations of spurious infections) are summarized with an overview on the distribution, symptoms, pathology, diagnosis, serology and therapy of this rare human pathogen.