Alessandra Aparecida Medeiros-Ronchi

A crescente popularidade dos ratos (Rattus norvegicus) como pets aumentou a demanda por novos cuidados veterinários especializados, destacando a oncologia como um desafio central devido à alta prevalência de neoplasias espontâneas nesta espécie. Embora o conhecimento oncológico seja vasto, ele provém majoritariamente de linhagens de laboratório, criando uma lacuna de dados para a população de pets, que apresenta maior longevidade, heterogeneidade genética e condições ambientais variadas. O presente estudo teve como objetivo caracterizar o perfil anatomopatológico das neoplasias espontâneas em ratos de companhia. Foi realizado um estudo retrospectivo e descritivo no Laboratório de Patologia Animal do Hospital Veterinário da Universidade Federal de Uberlândia (HOVET-UFU), no período de 2020 a 2023. Foram selecionados os prontuários de ratos (Rattus novergicus) com diagnóstico de neoplasias espontâneas e coletados dados de sexo, idade, localização e tipo de tumor. Os resultados confirmaram um perfil oncológico predominantemente de fêmeas (89%) e de idade avançada (53% com 2 anos), alinhado à oncogênese tardia da espécie. Entre os 21 diagnósticos histológicos, o fibroadenoma mamário foi a neoplasia mais frequente (38%), seguido pelo carcinoma mamário e fibroma cutâneo (14% cada). A glândula mamária concentrou a maioria das lesões (55%). A discussão aponta que a predominância do fibroadenoma sobre o carcinoma, em comparação com linhagens de laboratório, sugere que a maior longevidade e as condições de manejo doméstico podem favorecer a expressão de tumores benignos de crescimento lento. A incidência relativamente alta de fibromas cutâneos (14%) também pode ser influenciada pelo viés de seleção, visto que tumores superficiais são mais facilmente detectados pelos tutores. O achado de tumores raros, como o adenocarcinoma intestinal, reforça o limite da extrapolação translacional entre modelos induzidos e populações de pets. Em conclusão, este levantamento fornece um painel histopatológico essencial que valida o papel da idade avançada e da influência sexual na oncogênese do Rattus norvegicus de companhia. O reconhecimento da alta frequência de fibroadenomas é crucial para que clínicos e patologistas refine a orientação prognóstica e a tomada de decisão cirúrgica na clínica de animais exóticos.

The use of alternative in vivo models, such as chicken embryos (CEs), for studying Sporothrix spp. infection aligns with sustainable and ethical research practices but remains poorly explored. This study evaluated the suitability of the pre-nociceptive stage of the CE model for investigating Sporothrix brasiliensis and S. schenckii pathogenesis. S. schenckii, S. brasiliensis, and a feline field isolate of S. brasiliensis were inoculated on the chorioallantoic membrane at 8-day-old CE. Control groups included sterile saline and the probiotic Saccharomyces boulardii. By 3 days post-inoculation, mortality in Sporothrix-challenged groups ranged from 14.28% to 31.4%, with lesion frequencies between 9% and 18.2%. Primary macroscopic findings included greenish hepatic discoloration and hemorrhage. The combined incidence of morbidity and mortality was higher in the Sporothrix groups than in controls; this rate did not differentiate virulence levels among the tested fungal strains. Histopathological analysis of the liver showed no significant changes; however, cerebral inflammation was significantly more pronounced in both S. brasiliensis groups. Molecular analysis revealed no upregulation of interleukin (IL)-1β or IL-6, but an 11.8-fold increase in IL-8 transcripts was detected in embryos challenged with S. brasiliensis. These results demonstrate that Sporothrix brasiliensis, although not previously described as infecting chickens, infected and induced an inflammatory response in 11-day-old CE following experimental challenged with the yeast-like cells via the chorioallantoic membrane. Further studies using CE should be conducted to better understand the host-fungus relationship in experimental infection. Our findings reinforce the potential of the CE model for ethical, early-stage studies of sporotrichosis pathogenesis and the host immune response.

This study aimed to evaluate the virulence and infection response of Campylobacter jejuni (CJ) strains isolated from chickens, as well as a standard strain isolated from humans, to understand better the pathogen-host relationship between CJ and chicken embryos (CE) with an active immune system. With its well-developed vascular structures, the CE model offers a valuable method for studying complex biological systems. We assessed embryo mortality, weight, macroscopic and microscopic lesions, bacterial multiplication within the embryo, and macrophage and lymphocyte (T and B cell) counts using flow cytometry. Additionally, histopathological lesions were examined. CJ killed CE at a dose of 3.7 log CFU/CE; however, lower doses (2.5 log CFU/CE) did not result in embryo death but instead caused macroscopic damage along with mild to moderate lesions. Certain strains were also capable of stimulating the immune system; however, this response varied depending on the strain. These findings underscore the importance of studying the virulence, infection dynamics, and immune responses of various CJ strains, highlighting the utility of the CE model for these investigations.

The chicken embryo has emerged as a useful in vivo model for evaluating drug delivery strategies; however, the influence of the inoculation route on toxicity and pharmacokinetic outcomes remains insufficiently explored. This study investigated how different inoculation routes affect the toxicity and pharmacokinetics of free and nanoencapsulated norfloxacin, indomethacin, and lidocaine in the chicken embryo model. On embryonic day 10, formulations were administered via four routes: the shell membrane, the allantois, the chorioallantoic membrane, or the amniotic cavity. Toxicity was assessed after six days based on mortality, embryo weight, and histological alterations in the liver and kidney. Pharmacokinetic parameters of commercial and nanoformulated norfloxacin were determined in serum and allantoic fluid following a single administration through the same routes. Norfloxacin did not affect embryo weight, whereas commercial lidocaine increased it, and both free and nanoencapsulated indomethacin significantly reduced embryo weight. Histological alterations were observed exclusively after amniotic administration of nanoformulations, including renal inflammatory or degenerative changes and hepatic degeneration, depending on the compound. Nanoencapsulated norfloxacin (PEC@LUVNOR) achieved higher and more delayed maximum serum concentrations (Cmax) than the commercial formulation across most routes, with route-dependent differences in time to Cmax. In contrast, higher concentrations of the commercial formulation were observed in allantoic fluid. Overall, these findings demonstrate that both formulation type and administration route critically influence in vivo performance, supporting the chicken embryo as a relevant model for comparative evaluation of drug delivery systems.

Mammary tumors are the most common neoplasms in female dogs, with mastectomy being the primary treatment. The impact of mastectomy type on survival remains unclear. This study evaluated the effect of different surgical techniques on the survival of female dogs with mammary carcinomas. A total of 307 dogs with 734 mammary tumors were analyzed. Ages ranged from 1 to 17 years, with mixed breeds comprising 48.9%. Most tumors (92.9%) were malignant, predominantly carcinoma in a mixed tumor (30.2%). Unilateral mastectomy was the most common technique (65.8%). Lumpectomy showed the shortest mean survival (179 days) and was associated with a 4.9-fold increased risk of death (p = 0.009). There was no significant association between surgical technique and overall survival or recurrence of mammary carcinoma (p = 0.2). This study relied on owner-reported data for survival and tumor recurrence. Lumpectomy appears to be associated with shorter survival times in female dogs with mammary carcinoma. Therefore, it may be advisable to reconsider this technique as a primary treatment option.

Mammary tumors are common neoplasms in female dogs and pose a clinical challenge because of their high malignancy potential. This retrospective study analyzed the medical records of 724 female dogs with 1,638 mammary tumors treated between 2012 and 2022 to assess epidemiological and clinicopathological associations. Malignant tumors (84.6%) were larger than benign ones (3.4 cm vs. 2.3 cm, P5 cm, and ulceration. Tumors >5 cm in size were associated with histological grade III, ulceration, adhesion, and regional metastases. In the multivariate analysis, tumor malignancy was 3.2 times more likely with each additional tumor, 3.3 times more likely with each additional year of age, and 4.8 times more likely with ulcerated tumors. These findings highlight the importance of early diagnosis, comprehensive evaluation, and regular monitoring, especially in high-risk dogs such as elderly and overweight female dogs.

Osteomyelitis is a severe systemic infectious disease characterized by destructive and progressive bone inflammation, which is usually bacterial in origin, and occasionally viral or fungal. The objective was to report the case of a dog with fungal osteomyelitis, detailing the diagnosis and treatment evolution. A male, crossbreed dog, four months old, was treated at the Veterinary Hospital of the Federal University of Uberlândia (HOVET-UFU), presenting hyperthermia, hyporexia, reactive lymph nodes, lameness and open wound in the right forelimb (RF), in addition to secretion purulent and exposed bone. The radiograph showed Salter Harris I fractures in the physeal cartilages of the right ulna and signs of aggressive polyostotic bone lesion in RF. Fungal and bacterial cultures isolated Enterococcus sp., Penicillium sp. and Acremonium sp. The diagnosis obtained was fungal osteomyelitis. Based on the antibiogram and antifungigram, the drugs amoxicillin with potassium clavulanate, omeprazole and itraconazole were used and the animal was radiographically monitored every 30 days. After 150 days, signs of bone remodeling in the joint and adjacent bones were more evident and the treatment was terminated. The dog presented 28 months free of relapses. It should be noted that the medical management of a wound should not be directed solely at healing, requiring radiography and, in cases of suspected osteomyelitis, tests to exclude differential diagnoses, as well as to choose the most suitable drug, effective in each case. A osteomielite é uma doença infecciosa sistêmica grave, caracterizada pela inflamação óssea destrutiva e progressiva, que geralmente possui origem bacteriana, e, ocasionalmente, viral ou fúngica. Objetivou-se relatar o caso de um cão com osteomielite fúngica, detalhando o diagnóstico e a evolução do tratamento. Foi atendido no Hospital Veterinário da Universidade Federal de Uberlândia (HOVET-UFU) um cão, macho, 8,9 kg, mestiço, quatro meses de idade, apresentando hipertermia, hiporexia, linfonodos reativos, claudicação e ferida aberta em membro torácico direito (MTD), além de secreção purulenta e exposição óssea. A radiografia evidenciou fraturas Salter Harris I em cartilagens fisárias da ulna direita e sinais de lesão óssea agressiva poliostótica em MTD. As culturas fúngica e bacteriana isolaram Enterococcus sp., Penicillium sp. e Acremonium sp. O diagnóstico obtido foi osteomielite fúngica. Com base no antibiograma e antifungigrama, foram utilizados os fármacos amoxicilina com clavulanato de potássio, omeprazol e itraconazol e o animal foi acompanhado radiograficamente a cada 30 dias. Após 150 dias os sinais de remodelamento ósseo da articulação e ossos adjacentes eram mais evidentes e o tratamento foi finalizado. O cão permaneceu por 28 meses livre de recidivas. Ressalta-se que a conduta médica diante de uma ferida não deve ser direcionada somente à cicatrização, sendo necessária a realização de radiografia e, em casos de suspeita de osteomielite, exames para exclusão dos diagnósticos diferenciais, bem como, para a escolha do fármaco mais eficaz em cada caso.

Mesothelioma is a rare malignant neoplasm that affects the mesothelial cells lining the thoracic and abdominal cavities, such as the pleura, peritoneum, and pericardium. It is most prevalent in dogs and cattle, but the causes of this disease in animals are uncertain. In felines, it mainly affects the pleura, with an unfavorable prognosis. This paper explores a rare case of metastatic peritoneal mesothelioma in a 2-year-old female mixed breed cat, emphasizing its uniqueness due to the feline’s age. The patient, previously treated at a private clinic, presented moderate abdominal distension as the only clinical sign. Abdominal ultrasound and peritoneal fluid cytology led to the provisional diagnosis of mesothelioma/ carcinomatosis. One day after exploratory laparotomy, the animal died and was subsequently sent for necropsy. During macroscopic analysis, nodules were observed in the peritoneum, diaphragm, omentum, stomach serosa, and large intestine, and the diagnosis of solid epithelioid peritoneal mesothelioma with lung metastasis was confirmed after microscopic analysis. The diagnosis of mesothelioma is challenging, and the importance of immunohistochemical panels with specific markers such as cytokeratin AE1/AE3 and calretinin is highlighted. Considering that mesothelioma is a pathology with a poor prognosis, it is essential to include this disease in the list of differential diagnoses within veterinary oncology. O mesotelioma é uma neoplasia maligna rara que afeta as células mesoteliais que revestem as cavidades torácica e abdominal, como a pleura, o peritônio e o pericárdio. É mais prevalente em cães e bovinos, mas as causas desta doença em animais são incertas. Nos felinos acomete principalmente a pleura, com prognóstico desfavorável. Este artigo explora um caso raro de mesotelioma peritoneal metastático em uma gata sem raça definida de 2 anos de idade, enfatizando sua singularidade devido à idade do felino. O paciente, previamente atendido em clínica particular, apresentava distensão abdominal moderado como único sinal clínico. A ultrassonografia abdominal e a citologia do líquido peritoneal levaram ao diagnóstico provisório de mesotelioma/carcinomatose. Um dia após a laparotomia exploratória, o animal veio a óbito e posteriormente encaminhado para necropsia. Durante a análise macroscópica, foram observados nódulos no peritônio, diafragma, omento, serosa estomacal e intestino grosso e o diagnóstico de mesotelioma peritoneal epitelioide sólido com metástase pulmonar foi confirmado após análise microscópica. O diagnóstico do mesotelioma é desafiador, sendo destacada a importância de painéis imunohistoquímicos com marcadores específicos como citoqueratina AE1/AE3 e calretinina. Considerando que o mesotelioma é uma patologia de prognóstico ruim, é fundamental incluir esta doença na lista de diagnósticos diferenciais dentro da oncologia veterinária.

Resumo A hiperplasia fibroadenomatosa mamária (HFM) se caracteriza por rápida hipertrofia e hiperplasia do estroma e epitélio ductal das glândulas mamárias. Ela corresponde a 20% dos nódulos mamários e ocorre com maior frequência em felinos, fêmeas e jovens. Diante da elevada casuística de HFM, este estudo objetivou relatar um caso de sucesso terapêutico de HFM em uma gata, utilizando o procedimento de ovariohisterectomia (OH) associado a um fármaco antagonista de progesterona, a fim de contribuir com o esclarecimento quanto aos sinais clínicos, diagnóstico e tratamento desta afecção. Uma gata, sem raça definida, com sete meses de idade e 2,9 kg de peso vivo, apresentou aumento de volume das glândulas mamárias uma semana após o primeiro ciclo estral. Foi negado o histórico de acasalamentos e uso de contraceptivos. Todas as glândulas mamárias se encontravam hiperplásicas de forma assimétrica, cianóticas, consistência firme, alopécicas, com diâmetro variando entre 2,5 cm a 4 cm, ausência de aderências, com sensibilidade dolorosa à palpação. A gata foi diagnosticada com HFM por meio dos sinais clínicos, histórico e citopatologia. O protocolo terapêutico consistiu em OH associada ao uso de aglepristone. Ressalta-se que este protocolo é uma boa opção quando não há interesse do tutor na reprodução do animal, oferecendo resultados rápidos, eficazes e com chances reduzidas de recidivas.