Search

O cancro é uma das principais causas de morbilidade e mortalidade em animais de companhia. Em felinos domésticos, as neoplasias do sistema hematopoiético são as que apresentam uma maior expressão, e destas, o linfoma é o que possui um maior número de casos reportados. As neoplasias mamárias são consideradas como o terceiro tipo de tumores mais frequente em gatos. Vários estudos identificaram diferentes agentes infeciosos e parasitários como estando envolvidos na carcinogénese de diferentes tumores em oncologia humana e veterinária. No entanto, a informação relacionada com a função biológica dos agentes de transmissão vetorial na carcinogénese de tumores em felinos é escassa. Para além disso, a imunodepressão devida ao tumor e aos tratamentos oncológicos poderá permitir a multiplicação dos agentes infeciosos e originar a manifestação/agravamento de sinais clínicos associados a estes agentes, que poderão ser interpretados como sendo devidos aos tumores ou aos seus tratamentos. Neste estudo, pretendemos avaliar a prevalência de agentes de transmissão vetorial dos géneros Babesia, Hepatozoon, Ehrlichia/Anaplasma, Mycoplasma e Leishmania em felinos com linfomas e tumores mamários. No presente estudo foram analisados 61 felinos, dos quais 31 animais diagnosticados com linfoma através de citologia e/ou histopatologia, e 30 gatos com diagnóstico histopatológico de tumor mamário , provenientes da região centro de Portugal. A presença de ADN dos agentes de transmissão vetorial no sangue total destes animais foi analisada através de PCR convencional. Todos os felinos incluídos no estudo testaram negativo para os seis géneros testados. De acordo com os nossos resultados, a prevalência de agentes de transmissão vetorial na população de gatos com linfoma e tumores mamários estudada é baixa. Serão necessários outros estudos, com diferentes populações e com outros tumores, para confirmar os nossos resultados. No entanto, estes agentes deverão ser considerados em doentes oncológicos com sinais clínicos compatíveis com infeção por agentes de transmissão vetorial, principalmente considerando a imunodepressão associada à doença oncológica e aos seus tratamentos. Para além disso, os animais com doenças oncológicas e infetados por agentes de transmissão vetorial deverão ser estudados no sentido de avaliar a possível implicação destes agentes na carcinogénese de doenças oncológicas. Cancer is one of the main causes of morbidity and mortality in companion animals. The neoplasias of the hematopoietic system are the most frequent tumors reported in domestic cats, and among these, lymphoma is the most common. Mammary tumors are considered to be third most frequent type of tumor in domestic felines. Several studies have identified different infectious and parasitic agents as being involved in the carcinogenesis of different tumors in human and veterinary oncology. Nevertheless, the available information related to the biological role of vector-borne infections/diseases in feline carcinogenesis is scarce. Moreover, immunodepression associated with tumor and cancer treatments may allow the proliferation of infectious agents and lead to the manifestation/aggravation of clinical signs associated with these agents, which may be interpreted as being due to the tumors or their treatments. The aim of this study was to evaluate the prevalence of vector-borne agents of genera Babesia, Hepatozoon, Ehrlichia/Anaplasma, Mycoplasma and Leishmania in cats with lymphomas and mammary tumors. In the present study, 61 cats from the central region of Portugal diagnosed with lymphoma (n=31) by cytology and/or histopathology and with histopathological diagnosis of mammary tumor (n=30) were analyzed. The presence of vector-borne agents DNA in the total blood of these animals was investigated by conventional PCR. All felines included in the study tested negative for the six selected genera. According to these results, the prevalence of vector-borne agents amongst the analyzed feline population with lymphoma and mammary tumors is low. Further studies, with different populations and with other tumors are needed to confirm these results. However, these agents should be considered in oncology patients with clinical signs compatible with infections by vector-borne agents, especially considering the immunodepression associated with oncologic diseases and its treatments. Furthermore, animals with oncologic diseases infected with vector-borne agents should be further studied in order to evaluate the possible implications of these agents in tumor carcinogenesis.

Among the Apicomplexa parasites, Hepatozoon spp. have been mainly studied in domestic animals and peri-urban areas. The epidemiology of Hepatozoon spp. is poorly investigated in natural systems and wild hosts because of their scarce veterinary and economic relevance. For most habitats, the occurrence of these parasites is unknown, despite their high ecosystemic role. To fill this gap for alpine small mammals, we applied molecular PCR-based methods and sequencing to determine the Hepatozoon spp. in 830 ear samples from 11 small mammal species (i.e., Apodemus, Myodes, Chionomys, Microtus, Crocidura and Sorex genera) live-trapped during a cross-sectional study along an altitudinal gradient in the North-Eastern Italian Alps. We detected Hepatozoon spp. with an overall prevalence of 35.9%. Two species ranging from 500 m a.s.l. to 2500 m a.s.l. were the most infected: My. glareolus, followed by Apodemus spp. Additionally, we detected the parasite for the first time in another alpine species: C. nivalis at 2000–2500 m a.s.l. Our findings suggest that several rodent species maintain Hepatozoon spp. along the alpine altitudinal gradient of habitats. The transmission pathway of this group of parasites and their role within the alpine mammal community need further investigation, especially in consideration of the rapidly occurring environmental and climatic changes. First Record of Hepatozoon spp. in Alpine Wild Rodents: Implications and Perspectives for Transmission Dynamics across the Food Web