Lontra longicaudis infected with canine parvovirus and parasitized by Dioctophyma renale

A rare case of ectopic dioctophymosis in Leopardus pardalis (Carnivora, Felidae) in Paraguay

An adult female Leopardus pardalis from Jardín Botánico y Zoológico de Asunción, Paraguay was brought in from the wild, and inspected for a parasitic structure attached to the vulva. The parasite was removed and was identified as a Dioctophyme renale female. Blood samples and ultrasound did not show abnormalities in any organ, confirming the ectopic presentation of the parasite. This is the first report of D. renale in the L. pardalis and a first time for ectopic location in vagina and spontaneous elimination in a felid.

Canine distemper virus and canine adenovirus type-2 infections in neotropical otters (Lontra longicaudis) from Southern Brazil

All descriptions of infectious diseases affecting otters were published in the Northern Hemisphere, with no occurrence identified in neotropical otters (Lontra longicaudis). Consequently, a retrospective histopathological study using archival tissue samples from six free-living neotropical otters was done to investigate the possible occurrence of disease patterns associated with common viral infectious disease agents of the domestic dogs. Immunohistochemical (IHC) assays were designed to identify intralesional tissue antigens of canine distemper virus (CDV), and canine adenovirus-1 (CAdV-1) and canine adenovirus-2 (CAdV-2). The most frequent histopathological patterns diagnosed were interstitial pneumonia (83.33%; 6/5) and hepatocellular vacuolar degeneration (50%; 3/6). IHC identified intralesional intracytoplasmic immunoreactivity to CDV antigens in all otters evaluated, with positive immunolabeling occurring within epithelial cells of the lungs, stomach, kidneys, and liver, and skin. Intracytoplasmic CAdV-2 antigens were identified within epithelial cells of the peribronchial glands in four otters with interstitial pneumonia. These findings resulted in singular and simultaneous infections in these neotropical otters, represented the first report of concomitant infections by CDV and CAdV-2 in free-living neotropical otters from the Southern Hemisphere, and suggested that this mammalian species is susceptible to infections by viral disease agents common to the domestic dogs and may develop similar histopathologic disease patterns.

Dioctophimosis: A Parasitic Zoonosis of Public Health Importance

Dioctophyme renale, the giant kidney worm, is a renal nematode from domestic and wild mammals that has zoonotic potential. In humans, dioctophimosis has been reported in several countries, mainly on the Asian continent, totaling more than 40 cases, which describe the parasite mainly infecting the kidneys, bladder, urethra and skin. Infection in animals and humans is related to the ingestion of the infective larva (L3) present in the aquatic oligochaete annelid (mandatory intermediate host) or fish and anurans (facultative paratenic hosts). Thus, the infection is related to the habit of drinking water contaminated with the mandatory intermediate host, as well as raw or undercooked meat from the facultative paratenic hosts. Dioctophimosis destroys the renal parenchyma and, in some cases, can cause the death of its hosts. In this chapter, we discuss the main topics regarding dioctophimosis in humans, domestic and wild animals, highlighting its importance in public health.

Dioctophyme renale (Goeze, 1782) (Nematoda, Dioctophymidae) parasitic in mammals other than humans: A comprehensive review

A comprehensive review of the infection of mammals with the nematode Dioctophyme renale (Goeze, 1782) (Nematoda, Dioctophymidae) is presented. Mammals, including man, are the definitive hosts for this parasite. Several aspects of the infection with the parasite in mammals other than humans are critically evaluated: geographical distribution, host species recorded so far and the relative importance of the different hosts, location of parasites within the host, prevalence and intensity of the infection, diagnostic methods, pathology induced by the parasites, epidemiology and the methods of control and treatment. The authors provide an updated review about the infection, based on a extensive bibliographic search worldwide, and point out the most relevant aspects of the biology of the parasite as well as several research topics which need to be explored for a better understanding of the biology of this interesting and important parasitic nematode.

First description of parasite load and clinicopathological and anatomopathological changes in a dog naturally coinfected with Dioctophyme renale and Leishmania infantum in Brazil

This article reports the case of a domestic dog naturally coinfected with the nematode Dioctophyme renale and with the protozoan Leishmania infantum. The dog exhibited no clinical signs but had normocytic hypochromic anemia, hyperproteinemia, hyperglobulinemia, hypoalbuminemia, and hematuria. Necropsy revealed eight D. renale specimens in the abdominal cavity and in right kidney whose parenchyma was atrophied. Histopathological analysis showed glomerular atrophy, fibrosis and a marked diffuse pyogranulomatous inflammatory infiltrate in the right kidney. Moderate multifocal granulomatous peritonitis was observed in the greater omentum. Several Dioctophyme renale eggs were present amidst the inflammatory infiltrate of the right kidney and greater omentum. Leishmania infantum parasites were detected in perirenal adipose tissue of the right kidney, greater omentum, spleen, bone marrow, and popliteal lymph node. The high D. renale load and the severe and uncommon histological alterations associated with the eggs of this parasite may have been influenced by coinfection with L. infantum.

Outbreak of canine parvovirus 2b and Clostridium difficile infection in Asian small-clawed otters

A concurrent outbreak of infection by canine parvovirus 2b (CPV-2b) and Clostridium difficile producing A and/or B toxins occurred in Asian small-clawed otters (Amblonyx cinereus). The 5 clinically affected otters were 6- to 24-mo-old intact females that had severe diarrhea, dehydration, were acutely comatose, and died 1-4 d after the onset of clinical signs. Postmortem examination was performed in 3 of 7 otters. Macroscopically, the small intestine was diffusely reddened and contained red-to-brown, malodorous, watery digesta without formed feces (3 of 3). Histologic examination identified loss of enterocytes and necrosis of crypt epithelial cells. Denuded villi were often covered by mixed bacterial colonies with a predominance of gram-positive cocci to short rods in addition to larger gram-positive and -negative rods. There was also splenic lymphoid follicle depletion (2 of 3). Immunofluorescence assay revealed CPV antigen in enterocytes (2 of 3), mesenteric lymph nodes (3 of 3), and spleen (1 of 3). Immunohistochemistry revealed CPV antigen in enterocytes, lymphocytes, and dendritic cells of the Peyer patches and spleen (3 of 3), and lingual epithelial cells (1 of 2). CPV was isolated from tissues from 2 of 3 otters, and DNA sequencing identified CPV-2b for the 1 isolate tested. C. difficile producing A and/or B toxins were identified in the intestinal content by ELISA (3 of 3). To our knowledge, an outbreak of CPV-2b infection and C. difficile with clinically significant gastrointestinal disease has not been described previously in otters. The source of the viral infections remains unknown; however, these agents should be considered in otters and other mesocarnivores with similar clinical and pathologic findings.

The role of freshwater fish in the life cycle of Dioctophyme renale in Southern Brazil

Brazil stands out by the diverse records of Dioctopphyme renale in different hosts; however, there is little information about the life cycle of the nematode in the region. This study aims to report on third-stage larvae infections in fish in southern Brazil. In this context, 324 fish of different species belonging to Characiformes, Cyprinodontiformes and Siluriformes were collected in an urban area of Rio Grande do Sul State, where domestic and wild hosts were reported with the nematode. Of the total fish examined, 25(7.7%) were found to be parasitized by third-stage larvae of D. renale which were found encysted in the stomach serous membrane and in the celoma cavity of Hoplosternum littorale (Siluriformes) with a prevalence of 53.2% (25/47) and mean intensity of infection of 4.4 larvae/host (1 to 13 larvae). The occurrence of larvae in H. littorale indicates the presence of parasitosis in the region; however, the contribution of this fish species as a source of infection for dogs in urban areas must be considered with caution given the difficulties these dogs may face in the capture and predation of the fish to the point of effectively maintaining the urban cycle of D. renale. In addition, the low level of larvae registered in the total sample of fish examined indicates that these hosts are unlikely to play an important role in the transmission of D. renale to domestic animals in the region of the study.

Occurrence of Dioctophyme renale larvae (Goeze, 1782) (Nematoda: Enoplida) in a new host from southern Brazil

Abstract Dioctophymatosis is caused by the giant kidney worm Dioctophyme renale which occurs in dogs, cats, and wild mammals. In Brazil, the disease has been diagnosed in dogs from several states around the country. In the present study, the occurrence of D. renale larvae in snakes from southern of Brazil is reported. Three specimens of Philodryas patagoniensis (Serpentes: Dipsadidae) (common names in Brazil: “parelheira”, “papa-pinto”) roadkill in the county of Capão do Leão, State of Rio Grande do Sul, southern Brazil, were necropsied. Two third-stage larvae of D. renale were found in the coelomic cavity of P. patagoniensis. This study reveals a new host for D. renale larvae in the southern region of the State of Rio Grande do Sul, Brazil. This particular geographic area of the country has stood out as several cases of D. renale infection have been reported in a number of vertebrates from this region including domestic dogs and cats and wild animals such as carnivores, fish, and freshwater turtles.