Pathological and parasitological aspects of the peacock (Pavo cristatus) infection by Tanaisia(Paratanaisia)bragai

摘要

: Trematodes belonging to the family Eucotylidae, including Tanaisia (Paratanaisia)bragai Santos, 1934are parasites of the kidney and ureter that affect several species of domestic and wild birds. Tanaisia bragai is considered a low pathogenic parasite, but high worm burdens may determine clinical complications, including signs of apathy, weight loss, diarrhea and death. This paper describes the first report of infection by T. bragai in peacocks (Pavo cristatus), which constitutes a new host record and offers data on the lesions associated to this parasitism, although the degree of pathogenicity and parasite load may be considered mild. These birds did not exhibit clinical signs of parasitism. The macroscopic exam revealed discreet yellow spots on the liver. In the histological sections of the kidney, specimens of T. bragai were found in the collecting ducts, which were markedly dilated, with a thickened wall. Other findings included a mild inflammatory reaction in the wall of the ducts (but sometimes absent), flattening of lining epithelial cells and small, multifocal points of calcification around the collecting ducts. The microscopic examination of the parasites revealed trematodes with an elongated body, well-developed sub terminal oral sucker, pharynx present, short esophagus, cecum somewhat undulating or not, with blind end, testes symmetrical, equatorial, irregular in shape or slightly lobed, vitelline fields extending in both pre-ovarian and post ovarian fields, uterus very long, intercecal or sometimes overlapping the cecum and containing large quantities of eggs. The present findings suggest the need for further diagnostic studies on the prevalence of this trematode in peacocks as well as pathologic studies for the determination of the potential pathogenicity of this parasite in this species of bird. Moreover, infected peacocks could serve as carriers of T. bragai to be transferred to other bird species, thereby contributing to the dispersion of the parasite. Index Terms:?? Tanaisia (Paratanaisia)bragai ; trematode; kidney; exotic bird; peacock; Pavo cristatus; pathology Resumo: Os tremat?3deos da fam?-lia Eucotylidae, incluindo Tanaisia (Paratanaisia)bragai Santos, 1934, s?￡o parasitos de rins e ureteres de v??rias esp??cies de aves dom??sticas e silvestres. Tanaisia bragai ?? considerada uma esp??cie pouco patog?anica, mas que pode determinar complica?§?μes cl?-nicas como apatia, perda de peso, diarreia e morte, quando em cargas parasit??rias elevadas. No presente trabalho, descreve-se o primeiro relato de T. bragai parasitando pav?μes (Pavo cristatus Linnaeus, 1758), incluindo os achados parasitol?3gicos e patol?3gicos associados ?? infec?§?￡o. A aus?ancia de sinais cl?-nicos evidencia uma infec?§?￡o moderada, na qual, ao exame macrosc?3pico dos ?3rg?￡os internos, verificou-se a presen?§a de pequenas manchas amareladas no f?-gado. Ao exame histopatol?3gico, foram verificados esp??cimes de T. bragai nos ductos coletores dos rins, que se apresentavam marcadamente dilatados e com adelga?§amento das paredes. Verificou-se tamb??m moderada rea?§?￡o inflamat?3ria (por vezes ausente) na parede dos ductos e pequenos pontos de calcifica?§?￡o ao redor dos mesmos. No interior do ?3rg?￡o foram recuperados parasitos de corpo alongado, com ventosa oral subterminal e bem desenvolvida, ventosa acetabular, faringe, es?′fago curto, cecos intestinais em fundo cego, test?-culos sim??tricos e equatoriais e irregulares, gl?￠ndulas vitel?-nicas presentes nas regi?μes pr?? e p?3s-ovarianas, ?otero longo e contendo grande quantidade de ovos. O presente achado sugere a necessidade de novos estudos diagn?3sticos a fim de determinar a preval?ancia e a import?￠ncia deste parasito para pav?μes. Al??m disso, os pav?μes demonstraram ser hospedeiros definitivos de T. bragai,podendo servir de fonte de infec?§?￡o para o ambiente, contribuindo para a dispers?￡o do parasito. Termos de Indexa?§?￡o:??Tanaisia (Paratanaisia) bragai; trematode; rim; ave ex?3tica; pav?￡o; Pavo cristatus; patologia Introduction Tanaisia (Paratanaisia) bragai (Freitas, 1959) is a digenetic trematode found in the kidney collecting ducts of different species of wild and domesticated birds (Brandolini et al. 1997, Kanev et al. 2002). This species has been identified in Central and South America, Asia and Oceania. In Brazil, T. bragai has been found in the following birds: chicken (Gallus gallus domesticus), pigeon (Columba livia), pheasant (Phasianus colchicus), helmeted Guineafowl (Numida meleagris), tur