What is known about Tritrichomonas foetus infection in cats? / O que sabemos sobre a infecção por Tritrichomonas foetus em gatos?

Abstract Tritrichomonas foetus is a parasite that has been definitively identified as an agent of trichomonosis, a disease characterized by chronic diarrhea. T. foetus colonizes portions of the feline large intestine, and manifests as chronic and recurrent diarrhea with mucus and fresh blood, which is often unresponsive to common drugs. Diagnosis of a trichomonad infection is made by either the demonstration of the trophozoite on a direct fecal smear, fecal culture and subsequent microscopic examination of the parasite, or extraction of DNA in feces and amplification by the use of molecular tools. T. foetus is commonly misidentified as other flagellate protozoa such as Giardia duodenalis and Pentatrichomonas hominis. Without proper treatment, the diarrhea may resolve spontaneously in months to years, but cats can remain carriers of the parasite. This paper intends to serve as a source of information for investigators and veterinarians, reviewing the most important aspects of feline trichomonosis, such as trichomonad history, biology, clinical manifestations, pathogenesis, world distribution, risk factors, diagnosis, and treatment.

Resumo Tritrichomonas foetus é um parasito que foi identificado definitivamente como agente de tricomoníase, caracterizada por diarreia crônica. T. foetus coloniza porções do intestino grosso dos felinos e se manifesta como uma diarreia crônica e recorrente, com muco e sangue, geralmente irresponsiva às drogas comumente usadas no tratamento. O diagnóstico da infecção por tricomonadídeos é feito pela demonstração de trofozoítos no exame direto de fezes frescas, cultura fecal e subsequente exame microscópico ou extração do DNA do parasito na amostra fecal e amplificação, utilizando-se técnicas moleculares. T. foetus é comumente confundido com outros protozoários flagelados, como Giardia duodenalis e Pentatrichomonas hominis. Sem tratamento adequado, a diarreia pode cessar espontaneamente em meses ou anos, porém os gatos podem permanecer portadores do parasito. Esse artigo pretende servir como fonte de informação para pesquisadores e veterinários, revisando os mais importantes aspectos da tricomoníase felina, como histórico, biologia, manifestações clínicas, patogênese, distribuição mundial, fatores de risco, diagnóstico e tratamento.

Effect of a broad spectrum antiparasitic drug ivermectin in acute and chronic experimental giardiasis using different dose regimens

In this study, the maximal excretion of Giardia lamblia cysts was three weeks post infection [pi]. The administration of ivermectin subcutaneously proved to be effective in treating hamsters infected for two and three weeks, respectively. It was found that the dose of 300 mug/kg bw was much more efficient than 200 mg/kg bw. The cure rate was 99.1% in the former and 98.7% in the later. In chronic giardiasis where infection was kept for six weeks, the cure rate was 99.5% two weeks after treatment with 300 g/kg bw of ivermectin. An assessment of cure was performed also by histopathological examination of upper 2/3 of small intestine of the hamsters. Localization and counting of the parasite were carried out immunohistochemically

Gill infection of Leporinus macrocephalus Garavello & Britski, 1988 (Osteichthyes: Anostomidae) by Henneguya leporinicola n. sp. (Myxozoa: Myxobolidae). Description, histopathology and treatment

Piauçus (Leporinus macrocephalus), were raised in 300 m2 ponds (density of 10 fish/m2) presenting asphyxia signals and daily mortality of 27 fishes. Specimens with 8-cm total body length, were collected for necropsy. Mucus of body surface and pieces of organs were collected and examined microscopically, in wet mounts, stained or in histological sections. The smears examination showed the presence of several spores in the secondary lamellae of the gill filaments, identified as Henneguya leporinicola n.sp (Myxozoa: Myxobolidae). Histopathological study showed epithelial hyperplasia and fulfilling of the spaces between the secondary lamellae, congestion and telangiectasia sinusoidal. It was also observed hyperplasia of the goblet cells and several cysts of parasite with 70.3 microns diameter. Such cysts were situated among the secondary lamellae, covered or not by the hyperplasic epithelium. With this diagnostic, three applications of formalin solution 10 ml/m3 were carried out. Fifteen days after that, fish were examined again to ascertain whether the treatment was efficient on disease caused by the protozoa. The tissue alterations present in the gills after the treatment were just a moderate sinusoidal congestion and a slight epithelial hyperplasia on the base of the secondary lamellae.