Pesquisa de criptococose em cães atendidos no Hospital de Clínicas Veterinárias da UFRGS, Porto Alegre, Brasil

A criptococose, micose causada por espécies encapsuladas do gênero Cryptococcus, acomete o homem e vários animais, podendo ocorrer em indivíduos imunocompetentes, mas freqüentemente está associada a um estado de comprometimento imunológico. A via mais freqüente de contaminação por esta levedura é a inalatória. Foi pesquisada a ocorrência do Cryptococcus em cães com sintomatologia respiratória e/ou neurológica, atendidos no Hospital de Clínicas Veterinárias da Universidade Federal do Rio Grande do Sul (UFRGS). A amostragem foi composta por 112 cães. O exame direto foi realizado em apenas 17 amostras de líquido cefalorraquidiano (LCR), e o cultivo em ágar níger (Guizotia abissynica) a 37°C durante dez dias, a partir de secreção nasal (112), sangue total (112) e LCR (n=17). Para a aglutinação em látex (LA), utilizou-se o kit Crypto-LA (Wampole), para testar soro (n=112) e LCR (n=17). O teste também foi realizado com tratamento prévio com pronase em 36 amostras (32 soros e 4 LCR). Os resultados dos exames direto, cultivo e LA foram negativos para o Cryptococcus em todas as amostras testadas. Apesar da negatividade dos resultados desta amostragem, é plausível a expectativa da ocorrência da infecção pelo Cryptococcus posto que, existe uma população canina cons tantemente exposta ao risco de se contaminarem com propágulos fúngicos, presentes nos excrementos de pombos que coabitam, em grande número, na região de abrangência do estudo

Production and evaluation of albino mutants of Sporothrix schenckii

Melanin is an important factor intrinsically related to the virulence of the Sporothrix schenckii. Mutant albino conidia are usually used as inoculants for the evaluation of the properties of melanin in experimental models for the study of sporotrichosis. The goals of this study were to analyze the presence of melanin in S. schenckii conidia, and to produce and evaluate mutant albino forms of S. Schenckii conidia. Four distinct isolates were cultured in PDA, supplemented or not with triciclazole, and in YEPD. A portion of the samples was exposed to 300 ergs/mm2 of UV radiation to generate mutants albino forms. Following the incubation, cultures were analyzed, CFU were determined, and fragments were removed for the ultrastructural analysis, to be cultured once more in YEPD e BHI. Albino colonies were exposed to visible light; all S. schenckii isolates produced melanin, and survival and viability were 66% and 96% for albino conidia. Melanin granules were visible in the cell wall of pigmented conidia, but not in albino conidia. All conidia reverted to both the pigmented and the yeast forms, and albino colonies photoreactivated. All isolates analyzed in this study generated DHN melanin. Moreover, despite the exposure to UV radiation (300 ergs/mm2) being lethal to a significant portion of the colonies, the viability and conversions to the pigmented and yeast forms in surviving colonies did not appear to be affected. Also, albino colonies photoreactivated upon exposure to visible light

Comparing open wound measuring methods popularly used in experimental studies

O reparo tecidual surge em resposta às lesões e constitui-se de um processo dinâmico para manutenção da integridade do organismo. Nos estudos sobre cicatrização de feridas, tem se utilizado várias técnicas buscando-se uma avaliação da eficácia de meios de tratamento local. Sendo assim, o presente trabalho objetivou comparar três métodos de avaliação experimental de áreas de feridas, sendo eles: o método do relógio, papel milimetrado e avaliação computadorizada. Para realização do experimento, foram utilizados 30 ratos Wistar em condições de bem-estar. Após realizada a anestesia, foram confeccionadas duas lesões no dorso de cada animal com punch de 8 mm, sendo as feridas avaliadas após quatro, sete e 14 dias de tratamento. Observou-se que aos quatro dias de tratamento, todos os métodos apresentaram o mesmo desempenho, enquanto aos sete e 14 dias, o método do relógio, apresentou maior média de área, perdendo precisão, e aos 14 dias, a avaliação computadorizada apresentou resultados mais precisos em relação a ambos os outros métodos. Concluiu-se que a avaliação computadorizada através de software de áreas de feridas cutâneas apresenta resultados mais precisos em relação aos métodos do relógio e papel milimetrado, principalmente em lesões menores.Tissue repair is a response reaction to lesions and aggressions that constitutes a dynamic process to maintain the integrity of the organism. Wound healing experiments have used several approaches in order to assess and compare treatment methods, and these discrepancies hamper comparisons among assays. This study assessed three different methods of wound measurement commonly used in healing assays: clock method, graph paper method, and computer-assisted image analysis. We used 30 Wistar rats, kept in appropriate conditions for animal well-being. After anesthesia, and using an eight-millimeter punch, two lesions were made in the back region of each rat. The wounds were assessed on days four, seven, and 14 after infliction. At four days, all methods generated similar results. By day seven, the clock method had lost precision, likely due to wound shrinkage, and yielded greater means compared to the other two methods. On the last assessment, the computer-assisted method appeared to have more precise results, with the other two generating statistically higher means. Computer-assisted image analysis seems to have maintained wound measuring precision throughout this experiment, even when faced with small lesions. Considering these results, the authors recommend the use of computer-assisted measurements in future experiments

Development of experimental sporothrichosis in a murine model with yeast and mycelial forms of Sporothrix schenkii

Sporotrichosis is a subcutaneous disease that affects both men and a variety of animals caused by the dimorphic fungus Sporothrix schenckii. The aims of this study were to observe differences in virulence between inocula containing the yeast (Y) or mycelial (M) forms, to compare the reactions induced by the two inocula injected in different anatomical sites, and to verify the possibility of horizontal transmission of the disease by contact between infected and healthy animals. All animals were observed during a period of nine weeks. Mice were inoculated subcutaneously in the paw pads and in the regions of the hip and shoulder joints. Another group of non-inoculated healthy mice was kept in direct contact with mice developing the subcutaneous lesions. Animals of groups Y and M developed lesions due to infections and clinical symptoms very characteristic of sporothrichosis. Lesions were more prominent and with longer duration when occurring in the pads than in any other site of inoculation. Non-inoculated mice remained healthy as it occurred to animals in the control group. The development of typical clinical symptoms for sporothrichosis in all inoculated groups suggests that no difference exists in virulence between the yeast and mycelial forms of the same isolated of S. schenckii. Moreover, the paw pads appear to be the site of choice for the inoculation for experimental sporotrichosis in the murine model. In addition, this study also showed that the contact with sick animals and contaminated materials is insufficient to transmit the infection to immune competent animals with intact skin

Brain Neoplasms in Elderly Dogs

Background: The prevalence of intracranial neoplasms in dogs represents 2.1 to 4.0% of the cases. Brain tumors may be primary or metastatic. The objective of this study was to describe two cases of intra encephalic neoplasia in elderly dogs received for necropsy by the Veterinary Oncology Service in the Federal University of Pelotas.Cases: Case 1: A 12-year-old female canine, without breed and medium size, was received for necropsy. The animal has had behavioral changes. Macroscopic examination of the encephalus revealed asymmetry and congestion. The organs were collected and fixed in 10% formalin. In the brain cleavage we noticed an extensive brown-gray mass with reddish areas, expansive, moderately demarcated, soft to cut and discrete hydrocephalus. Serial fragments of the brain and fragments of the organs were sent for processing. The slides were stained with the hematoxylin and eosin technique for histopathological analysis. At the microscopic examination, cuboidal cells were observed in the encephalus sometimes in acinar arrangements, of extensive and very limited pattern, diagnosed as ependymoma. Case 2: It is a 15-year-old, female poodle dog, with several tumors. During necropsy multiple subcutaneous nodules, mesentery, intestinal serosa, stomach and liver were noticed. At the cut these were firm and whitish. No macroscopic changes were observed in the other organs. Fragments of organs and brain were collected and a serial section of the encephalus was performed for further processing and histological analysis. In the histopathological analysis the masses were constituted by proliferation of sometimes rounded cells, elongated, with rounded nuclei and eosinophilic cytoplasm, allowing the diagnosis of mesothelioma. The same cell pattern was observed in other organs. In the frontal cortex of the encephalus there were small foci of cells similar to those observed in the mesentery, as well as metastatic emboli in the meningeal and encephalic vessels, characterizing the diagnosis of metastatic mesothelioma.Discussion: Neoplasms of the central nervous system may be primary or metastatic. The ependymoma observed in case 1 was only diagnosed after visualization of the encephalic mass during necropsy, pointing to the importance of postmortem examination. Brain neoplasms in dogs occur with a frequency and variety similar to that of humans. Most of these are found in older dogs, and 95% of those affected are over five years of age. One situation that may occur in ependymomas is the development of obstructive hydrocephalus by the expansion of the neoplasm into the ventricular system. The animal studied in case 1 presented behavioral changes for weeks before death, and at necropsy ventricular dilation was evidenced, suggesting that hydrocephalus had occurred and the behavioral changes due to tumor localization. Metastatic brain neoplasms occur due to the hematogenous spread of many tumors. The species in which the metastatic neoplasms are most commonly described is the canine. Metastases of mesotheliomas in the central nervous system are rare, which reinforces the need for a thorough postmortem examination, as evidenced in the second case of this study, since the animal did not manifest clinically signs of neurological involvement and the metastasis was only identified microscopically by serial cuts of the encephalon. It can be concluded that detailed, systematic and serial post-mortem examination of the central nervous system should be part of the diagnostic routine even if no clinical neurological signs are evident. The reports presented here are of importance since they are considered rare diagnoses of primary and metastatic brain tumors

Pacientes com carcinoma de células escamosas - relação do tratamento com o prognóstico

Background: Squamous cell carcinoma (SCC) is a malignant cutaneous neoplasm which occurs frequently in small animals. Histopathology or fine needle aspiration cytology is necessary to confirm diagnosis; macroscopic diagnosis is not possible since the lesions are very similar to others of distinct etiologies. Owing to the fact that it is a neoplasm, diagnosis and treatment are usually not well accepted by owners, especially since it can cause esthetic changes to the animal and adjunct treatments can cause unwanted side effects. The objective of this study was to report clinical cases of SCC with distinct tumor subtypes and relate the recommended treatment with prognosis of patients.Case: Two dogs and one cat with SCC that were subjected to physical and dermatological examination, and tested negative for sporotrichosis, cryptococcosis, and manges. Dog 1 (male, 9-year-old, yellow Labrador retriever) exhibited inspiratory dyspnea for three weeks owing to an ulcerative hemorrhagic lesion on the nose. In view of the site of the lesion, a radiographic exam was requested, and the bony portion of the septum was found to be compromised. Cat 2 (female, 10-year-old, bicolor, mixed-breed cat) exhibited a focal, punctate, ulcerated, hemorrhagic lesion on the nose. Dog 3 (female, 10-year-old, white Dogo Argentino) exhibited several ulcerative lesions, and papulae, plaques and comedones on the ventral region of the abdomen.Treatment for deep pyoderma and comedone syndrome were initially instituted; on follow-up, more ulcerative lesions were present, which prompted the inclusion of neoplasm as a differential diagnosis. In cases 1 and 3, histopathology was performed with diagnosis of undifferentiated and differentiated SCC, respectively. In both cases, surgical margins were compromised after resection of the lesion. In case 2, high malignancy SCC was diagnosed with cytology. Use of sunscreen was recommended in all cases, as well as avoidance of sun exposure during the hours not recommended by the National Cancer Institute. In case 1, a nosectomy with partial resection of the nasal septum was recommended as well as chemotherapy with intra-tumoral administration of carboplatin (1.5 mg/cm3 of lesion) and vincristine sulfate (0.05 mg/ kg/IV/week) every 15 days.However, the owner opted for the nosectomy alone with one month of chemotherapy with vincristine sulfate. In case 2, polychemotherapy was instituted using daunorubicin (4 mg/kg/IV/week) and vincristine sulfate (0.05 mg/kg/IV/week) every 15 days for four weeks, with maintenance for six weeks, with total remission of the lesion at the end of treatment. In case 3, eight intralesional chemotherapy sessions were performed (carboplatin – 1.5 mg/cm3 of lesion) every 15 days; maintenance was kept for two months with biweekly administration. The patient exhibited actinic lesions on the third month after the protocol was suspended, which was treated with isotretinoin (3 mg/kg/day PO) until remission; reduction of solar exposure was recommended. The animal in case 1 exhibited intense dyspnea three months after the end of treatment and the lesion was incompatible with preservation of quality of life and euthanasia was performed. In the other two cases, patients were followed-up annually and remained in remission throughout life.Discussion: Adherence to proposed treatment by the owner is directly related to a better prognosis. On the punctate and focal lesion in the cat, administrations of daunorubicin (4 mg/kg/IV/week) and vincristine sulfate (0.05 mg/kg/IV/week) in a total of 10 cycles resulted in an excellent prognosis. On the dog with multifocal lesions, partial resection and intralesional administration of carboplatin (1.5 mg/lesion/cm3) in a total of eight biweekly applications following maintenance for two months resulted in a good prognosis

Susceptibility of Malassezia pachydermatis to azole antifungal agents evaluated by a new broth microdilution method

Malassezia pachydermatis   is considered an opportunistic pathogen of the outer ear duct in dogs and cats. This yeast can also be found in the skin, rectum, anal sacks and vagina. Eighty-two samples of this yeast isolated from dogs with the symptoms of external otitis from the Porto Alegre region were tested for their susceptibility to antifungal agents using the Broth Microdilution Method. The testing antifungal agents were Ketoconazole, Fluconazole and Itraconazole. Experimental essays determined that Sabouraud dextrose broth supplemented with 1% Tween 80 was the most appropriate medium for culture, for a ten-fold dilutions for the inocula, and 48 hours as the interval of readings. The ranges of the Minimal Inhibitory Concentrations (MICs) for the 82 samples were (a) Ketoconazole, from 0.015 to 0.25 mg/mL (mean of 0.08 mg/mL), (b) Fluconazole, from 1 to 32 mg/mL (mean of 9.22 mg/mL), and (c) Itraconazole, from 0.007 to 0.125 mg/mL (mean of 0.05 mg/mL). The isolates of M. pachydermatis showed an excellent level of susceptibility to antifungal azole agents, with all strains being susceptible to Itraconazole, and with only 2.4 % and 3.7% being resistant to Fluconazole and Kketoconazole, respectively. The use of the broth microdilution method allows the assessment of the susceptibility of large numbers of samples from M. pachydermatis isolates to the most common antifungal agents. The proposed procedure is easy to perform and considerably inexpensive compared with other existing tests, which makes this a method of choice for laboratorial use. A standardization of procedures currently used in veterinary mycology laboratories is required. Consistent results among laboratories could greatly benefit the establishment of proper comparisons between studies on antifungal susceptibility and therapeutic trials

ESTUDO DA FREQUÊNCIA DE ALTERAÇÕES COMPORTAMENTAIS EM FELINOS DOMÉSTICOS

A interação homem-animal ocorre há muitos anos e devido a isso, há o aumento contínuo na população de animais. Atualmente, há pouco espaço e tempo disponibilizado devido à rotina dos tutores, logo a espécie felina tende a se adaptar mais facilmente, a esse ambiente. Entretanto, se não houver recursos ambientais onde o animal possa expressar seu comportamento natural, haverá o surgimento de alterações comportamentais. O objetivo deste estudo foi identificar e relatar as alterações comportamentais nos felinos domésticos. Foi elaborado um questionário online contendo 31 questões objetivas. As repostas foram anônimas e consideravam os dados gerais dos tutores e felinos, a forma de distribuição do ambiente e questões relacionadas a alterações comportamentais. Foi demonstrado, que os fatores relacionados à falta de manejo como, o baixo período disponibilizado para a interação tutor-animal, baixa frequência de troca de brinquedos e número e o elevado número de animais por residência podem estar relacionados ao aparecimento de alterações consideradas indesejáveis pelos tutores. Dessa forma, conclui-se que na população estudada houve uma maior frequência de destruição de objetos com arranhadura e eliminação inapropriada. Assim é de grande importância orientar os tutores sobre as características etológicas da espécie, com o intuito de proporcionar qualidade de vida e bem-estar aos felinos e aos tutores

Lesões cutâneas traumática em pequenos animais: características e tratamentos / Traumatic skin injuries in small animals: characteristics and treatments

A ferida é provocada por uma quebra da continuidade cutânea, com comprometimento da proteção do tecido ou de funções fisiológicas. Na rotina clínica da Medicina Veterinária as causas são muitas, como mordidas por brigas; acidentes de trânsito; lacerações de objetos pontiagudos; lesões térmicas e lesões cirúrgicas. Imediatamente após a ocorrência do trauma dá-se início o processo cicatricial, a lesão estimula uma sequência de eventos que vão regenerar o tecido lesionado. É necessário conhecer o tipo de lesão causada e o processo cicatricial envolvido para determinar o tratamento adequado para auxiliar na cicatrização. Diante disso esta revisão tem por objetivo expor e discutir o processo de cicatrização, as possíveis causas e tratamentos utilizados em lesões cutâneas