Eduardo Kenji Masuda

Estudo retrospectivo de 1.647 tumores mamários em cães

Mammary gland tumors are common in dogs and are the most common type of neoplasm of female dogs. The main purposes of this study were to establish the prevalence of the mammary gland tumors, as well as of its different histologic types (neoplastic and non-neoplastic), diagnosed in the Laboratorio de Patologia Veterinaria of the Universidade Federal de Santa Maria. There were 1,304 biopsy reports of mammary gland tumors during 1990-2008 and 132 necropsy reports of dogs with mammary tumors in 2000-2008. Data about breed, gender, and age of dogs, tumor localization, morphologic diagnosis, and metastasis occurrence were analyzed. In the biopsy cases, 1,495 tumors were diagnosed, considering the presence of more than one type of tumor in some of the dogs. From those, 1,465 were neoplastic and 30 were non-neoplastic. Within the neoplasms, 390 (26.6%) were benign and 1,075 (73.3%) were malignant. The benign/malignant ratio was 1:2.75. During the years 2000-2008, 1,125 necropsies of dogs were performed, 132 (11.64%) of which with mammary gland tumors. There were 152 morphologic diagnoses, being 150 of neoplastic and two of non-neoplastic lesions. Simple carcinoma was the most prevalent histologic type, both among biopsy and necropsy cases. On necropsy cases, metastases to lymph nodes and distant organs were seen in 39 (29.5%) and 64 (53,3%) cases, respectively.

Aspectos clínicos, morfológicos e imuno-histoquímicos da pitiose gastrintestinal canina

Four suspect and two confirmed cases of gastrointestinal pythiosis were found in a retrospective study of biopsy and necropsy cases of dogs received in the Laboratorio de Patologia Veterinaria at the Universidade Federal de Santa Maria. The two diagnosed and published cases have had the etiology confirmed by culture and zoosporogenesis induction or by nested-PCR. On this study, the etiologic diagnosis of four suspect cases was confirmed by immunohistochemistry using anti-Pythium insidiosum policlonal antibody. Epidemiology, clinical signs, gross and microscopic lesions, histochemistry, immunohistochemistry, and differential diagnoses are reported and discussed.

Virological and clinico-pathological features of orf virus infection in experimentally infected rabbits and mice.

Many aspects of the biology of orf virus (ORFV) infection remain poorly understood and attempts to establish animal models have yielded conflicting and non-reproducible results. We herein describe the characterization of ORFV infection and disease in rabbits and mice. A protocol of intradermal inoculation was employed to inoculate 10(8.5)TCID₅₀/mL of ORFV strain IA-82 in the skin of ears, of the back and labial commissures. All inoculated rabbits presented a clinical course characterized by erythema, macules, papules/vesicles or pustules that eventually dried originating scabs. Local signs started around days 3 and 4 post-inoculation (pi) and lasted 3-10 days. Virus was recovered from lesions between days 2 and 14pi. Histological examination of lesions revealed focal proliferative dermatitis with ballooning degeneration and eosinophilic intracytoplasmic inclusion bodies in keratinocytes, histological hallmarks of contagious ecthyma in sheep. A similar, albeit milder clinical course occurred in 5/10 inoculated mice; virus was recovered from lesions from three animals. Inoculated lambs - used as controls - developed severe lesions of contagious ecthyma. VN tests performed at day 28pi failed to detect neutralizing antibodies in all inoculated animals. In contrast, convalescent rabbit sera were positive by ELISA at dilutions from 100 to 400. These results show that rabbits are susceptible to ORFV infection and thus may be used to study selected aspects of ORFV biology.

Vaccinia viruses isolated from cutaneous disease in horses are highly virulent for rabbits

Two genotypically distinct Vaccinia viruses (VACV), named P1V and P2V, were isolated from an outbreak of cutaneous disease in horses in Southern Brazil. We herein investigated the susceptibility of rabbits, a proposed animal model, to P1V and P2V infection. Groups of weanling rabbits were inoculated intranasally (IN) with P1V or P2V at low (10(2.5) TCID50), medium (10(4.5)TCID50), or high titer (10(6.5)TCID50). Rabbits inoculated with medium and high titers shed virus in nasal secretions and developed serous to hemorrhagic nasal discharge and severe respiratory distress, followed by progressive apathy and high lethality. Clinical signs appeared around days 3-6 post-inoculation (pi) and lasted up to the day of death or euthanasia (around days 5-10). Virus shedding and clinical signs were less frequent in rabbits inoculated with low virus titers. Viremia was detected in all groups, with different frequencies. Viral DNA was detected in the feces of a few animals inoculated with P1V and P2V, low titer, and with P2V at high titer. Gross necropsy findings and histological examination showed diffuse interstitial fibrousing pneumonia with necrosuppurative bronchopneumonia and intestinal liquid content. Neutralizing antibodies were detected in all inoculated animals surviving beyond day 9 pi. These results show that rabbits are highly susceptible to VACV isolated from horses, and develop severe respiratory and systemic disease upon IN inoculation. Thus, rabbits may be used to study selected aspects of VACV infection and disease.

Aspectos clínico-hematológicos e lesões vesicais na intoxicação crônica espontânea por Pteridium aquilinum em bovinos

Spontaneous cases of chronic poisoning by Pteridium aquilinum in cattle were studied. The clinical forms of the disease were squamous cell carcinoma (SCCs) of the upper digestive tract (UDT) and bovine enzootic hematuria (BEH). The cases were from the midland Region of the Midwest of Rio Grande do Sul State, Brazil, and were submitted to the Laboratorio de Patologia Veterinaria of the Universidade Federal de Santa Maria. Clinical signs and blood work were evaluated at terminal phase of disease. Cattle with UDT SCCs had progressive weigth loss, ruminal atony, cough, dysphagia, bloating, and regurgitation. In cattle with BEH, hematuria was observed in all cases, followed by progressive weight loss. Non-regenerative anemia was detected in 33.33% of the cattle with UDT SCCs form and in 66.66% of the cattle with BEH form. Changes in white blood count occurred in some cases but drop in lymphocyte numbers was uncommon in both forms of disease. For the morphological study, urinary bladders from 46 cattle with UDT SCCs and 11 cattle with BEH were analyzed. Grossly, 16/46 bladders from the UDT SCCs form had gross lesions (red or pale vesical nodules, hemorrhages, and papilomas; red urine was detected at necropsy of only three cases). In BEH form, the bladder had nodules, large neoplastic masses, red urine, papilomas, and hemorrhages. Pyelonephritis and hydronephrosis were seen in a few cases. Microscopically, in the UDT SCCs form, 44/46 (95.65%) bladders had 22 different types of morphological changes, characterized by neoplastic lesions (5/22) and non-neoplastic lesions (17/22); the latter were subdivided in non-neoplastic epithelial changes (6/17), general changes of the lamina propria (6/17), and inflammatory changes (5/17). The bladder changes in BEH form were of 19 different types, characterized by neoplastic lesions (5/19) and non-neoplastic lesions (14/19), which were subdivided in non-neoplastic epitelial changes (9/14), general changes of the lamina propria (3/14), and inflammatory changes (2/14). In BEH, mesenchymal neoplasms were more observed than epithelial ones, and most of them were malignant. Immunohistochemistry was utilized to characterize the histogenesis of poorly differentiated neoplasms. In conclusion, the morphological study demonstrated that urinary bladder lesions identical to the those seen in cattle with BEH, are very often present in cattle with the UDT SCCs form.Spontaneous cases of chronic poisoning by Pteridium aquilinum in cattle were studied. The clinical forms of the disease were squamous cell carcinoma (SCCs) of the upper digestive tract (UDT) and bovine enzootic hematuria (BEH). The cases were from the midland Region of the Midwest of Rio Grande do Sul State, Brazil, and were submitted to the Laboratorio de Patologia Veterinaria of the Universidade Federal de Santa Maria. Clinical signs and blood work were evaluated at terminal phase of disease. Cattle with UDT SCCs had progressive weigth loss, ruminal atony, cough, dysphagia, bloating, and regurgitation. In cattle with BEH, hematuria was observed in all cases, followed by progressive weight loss. Non-regenerative anemia was detected in 33.33% of the cattle with UDT SCCs form and in 66.66% of the cattle with BEH form. Changes in white blood count occurred in some cases but drop in lymphocyte numbers was uncommon in both forms of disease. For the morphological study, urinary bladders from 46 cattle with UDT SCCs and 11 cattle with BEH were analyzed. Grossly, 16/46 bladders from the UDT SCCs form had gross lesions (red or pale vesical nodules, hemorrhages, and papilomas; red urine was detected at necropsy of only three cases). In BEH form, the bladder had nodules, large neoplastic masses, red urine, papilomas, and hemorrhages. Pyelonephritis and hydronephrosis were seen in a few cases. Microscopically, in the UDT SCCs form, 44/46 (95.65%) bladders had 22 different types of morphological changes, characterized by neoplastic lesions (5/22) and non-neoplastic lesions (17/22); the latter were subdivided in non-neoplastic epithelial changes (6/17), general changes of the lamina propria (6/17), and inflammatory changes (5/17). The bladder changes in BEH form were of 19 different types, characterized by neoplastic lesions (5/19) and non-neoplastic lesions (14/19), which were subdivided in non-neoplastic epitelial changes (9/14), general changes of the lamina propria (3/14), and inflammatory changes (2/14). In BEH, mesenchymal neoplasms were more observed than epithelial ones, and most of them were malignant. Immunohistochemistry was utilized to characterize the histogenesis of poorly differentiated neoplasms. In conclusion, the morphological study demonstrated that urinary bladder lesions identical to the those seen in cattle with BEH, are very often present in cattle with the UDT SCCs form.

Vaccinia viruses isolated from skin infection in horses produced cutaneous and systemic disease in experimentally infected rabbits.

The susceptibility of rabbits to two isolates of Vaccinia virus (VACV) recovered from cutaneous disease in horses in Southern Brazil was investigated. Rabbits were inoculated in the ear skin with both VACV isolates, either in single or mixed infection. All inoculated animals presented local skin lesions characterized by hyperaemia, papules, vesicles, pustules and ulcers. Infectious virus was detected in the lungs and intestine of rabbits that died during acute disease. Histological examination of the skin revealed changes characteristic of those associated with members of the genus Orthopoxvirus. These results demonstrate that rabbits develop skin disease accompanied by systemic signs upon intradermal inoculation of these two equine VACV isolates, either alone or in combination, opening the way for using rabbits to study selected aspects of the biology and pathogenesis of VACV infection.

Acute and latent infection by bovine herpesvirus type 2 in a guinea pig model.

Bovine herpetic mammillits is a self-limiting cutaneous disease of the udder and teats of cows associated with bovine herpesvirus 2 (BoHV-2) whose pathogenesis is poorly understood. This article describes the use of guinea pigs (Cavia porcellus) to study the pathogenesis of BoHV-2 infection. Twelve weanling female guinea pigs inoculated subcutaneously with BoHV-2 in the genitalia and teats developed local hyperemia, edema, vesicles, ulcers and scabs. Infectious virus was recovered between days 3 and 7 post-infection (pi) from the genital area (9/12) and teats (1/12); and all inoculated animals seroconverted (virus-neutralizing titers of 16-128). Histological examination of lesions revealed lymphoplasmacytic perivascular infiltrates and intranuclear inclusion bodies in keratinocytes. PCR examination of tissues collected at day 35 pi detected latent viral DNA predominantly in lumbosacral spinal segments. In another experiment, eight females inoculated with BoHV-2 in the genitalia and treated with dexamethasone (Dx) at day 35 pi developed mild to moderate local signs, yet no virus could be recovered from lesions. PCR examination of spinal segments from these animals confirmed the presence of latent viral DNA. These results demonstrate that guinea pigs are susceptible to BoHV-2 infection and therefore may be used to study selected aspects of BoHV-2 biology.

Estudo retrospectivo de 207 casos de tumores mamários em gatas

This study aimed to determine the most prevalent mammary tumors in cats and associate them to some prognostic factors. The files from the Laboratorio de Patologia Veterinaria (LPV) of the Universidade Federal de Santa Maria (UFSM) were reviewed, and 1.427 feline biopsies and autopsy protocols between the years 2000 and 2011 were found. Based on the information retrieved from the files, a relationship was established among the tumors and some prognostic factors such as sex, age, breed, reproductive status, use of contraceptives, number and location of affected glands, ulcers, size of the neoplasm, distant metastases, and affected lymph nodes. Thus, it was observed that mammary cancer is the second most prevalent diagnosis, following skin tumors. All cats with mammary tumors were female, being the elderly and mixed breed the most affected. Malignant neoplasms were the most frequently diagnosed, followed by non-neoplastic tumors, and benign neoplasms. Smaller tumors were mostly carcinomas. Ulcerations were present not only in malignant neoplasms but also in non-neoplastic changes. Distant metastases were found mainly to the lungs and skin.

Surtos de doença por herpesvírus canino 1 em filhotes de cães no sul do Brasil

Canid herpesvirus 1 (CHV-1) is a widespread pathogen of dogs and produces infertility, abortions and severe systemic disease in young puppies. Clinical data indicate the circulation of CHV-1 among Brazilian dogs yet definitive diagnosis has rarely been accomplished. This article describes the clinicopathological findings of four independent cases/outbreaks of neonatal disease by CHV-1 in Bulldog puppies followed by virus identification and genetic characterization. Three events occurred in a kennel holding dogs of different breeds at reproductive age (March 2013, October 2013 and April 2014). Puppies from three French or English Bulldog litters, aging 9 to 30 days were affected, presenting dyspnea, agonic breathing, pale mucous, abdominal pain and tension, evolving to death within about 24 hours. At necropsy, the puppies presented necrohemorrhagic hepatitis, multifocal and moderate necrohemorrhagic nephritis and fibrinonecrotic interstitial pneumonia. Virus isolation was positive in clinical specimens from one litter and CHV-1 DNA was detected by PCR in tissues from all four cases. Virus-neutralizing assays with samples of the affected kennel revealed 9/12 adult animals with high antibody titers to CHV-1. Nucleotide sequencing of glycoprotein B, C and D genes revealed 99-100% of identity among the viruses and with CHV-1 sequences available in GenBank. Phylogenetic analyses of gC sequences showed a segregation of the samples, even among three isolates from the same kennel. These findings support CHV-1 infection as the cause of disease and death in these dog litters, reinforcing the need for correct etiologic diagnosis, prevention and immunization against CHV-1 in dogs from Southern Brazil.

Relação entre a linfopenia e a persistência da papilomatose alimentar em bovinos intoxicados crônica e espontaneamente por samambaia (Pteridium aquilinum)

Papilomavirus bovino tipo 4 (BPV-4) e responsavel pelo desenvolvimento de papilomas no trato alimentar superior (TAS) de bovinos. Os passos necessarios para o crescimento, o desenvolvimento e a regressao dos papilomas estao intimamente relacionados com o estado imunologico do animal. A ingestao de samambaia (Pteridium aquilinum) tem sido relacionada como o principal fator envolvido na persistencia da infeccao pelo BPV-4 no TAS. A teoria que estabelece a relacao entre papilomatose alimentar e a formacao de CCEs sugere a producao de um estado imunossupressivo cronico pela planta, permitindo a persistencia dos papilomas no TAS. Os papilomas serviriam entao como sitios de desenvolvimento dos CCEs atraves da interacao entre as proteinas do BPV-4 e os carcinogenos da samambaia. O objetivo deste estudo foi avaliar a relacao entre a quantidade de linfocitos circulantes e a papilomatose alimentar em casos de intoxicacao espontânea cronica por P. aquilinum em bovinos com CCE no TAS. Quarenta bovinos com CCEs no TAS foram avaliados quanto a idade, a intensidade da papilomatose alimentar no TAS e ao leucograma. Tres bovinos tinham leucopenia e um apresentava neutrofilia. A media de linfocitos foi de 5.395 (±1.696) na papilomatose leve, 4.560 (±1.561) na moderada e 5.007 (±1.786) na acentuada. Nao houve diferenca estatisticamente significativa entre o grau de papilomatose, a idade e a quantidade de linfocitos circulantes. Imunossupressao por linfopenia foi um achado esporadico (tres casos) neste estudo. Os resultados indicam que a persistencia da papilomatose alimentar em casos espontâneos de intoxicacao cronica por samambaia em bovinos nao tem relacao com a quantidade de linfocitos circulantes e que talvez esteja relacionada a outros fatores imunologicos.