Pesq. Vet. Bras. 33 (7) Midwestern Brazil (2010, involving a total of 122 cows, 12 calves and 11 people. Dairy cows (3 to 9 years old) were affected in all cases and calves (2 to 9 months old) were affected in five outbreaks, presenting oral lesions. The morbidity ranged between 8 and 100% in cows, and 1.5 to 31% in calves. In the cows, the clinical signs started with vesicles (2-7mm), painful and coalescent papules (3-8 mm), which resulted in ulcers (5-25mm) and scabs in teats, and, occasionally, in the muzzle. The clinical course lasted from 16 to 26 days. The histopathology of bovine skin samples revealed superficial perivascular inflammatory infiltrate of lymphocytes, plasma cells, neutrophils, macrophages and multifocal areas of acanthosis, spongiosis, hipergranulosis and parakeratotic or orthokeratotic hyperkeratosis with adjacent focally extensive ulcers. Eosinophilic inclusion bodies were noted in the cytoplasm of the keratinocytes. PCR to vgf gene of Orthopoxvirus was positive in samples collected from all outbreaks, and in some cases, genomic VACV sequences were identified by nucleotide sequencing of the PCR amplicons. Infectious virus was isolated in cell culture from scabs from one outbreak. Antibodies to Orthopoxvirus were detected in at least 3 or 4 animals in most outbreaks, by ELISA (outbreaks 1, 2, 3, 4, 5 and 7) or virus-neutralization (outbreak 6). Neutralizing titers ranging from 8 to 64 in outbreak 6. In all outbreaks, VACV infection was suspected based on the clinical and pathological findings and it was confirmed by laboratory tests. Upon the etiological confirmation, other agents associated with vesicular disease were discarded. In all outbreaks, at least one milker who handled the affected cows developed malaise, headache, fever, painful vesico-pustular lesions mainly in the hands, but also in the neck and nose. These results confirm the circulation of VACV in the region and call attention for a correct diagnosis and the adoption of prophylactic and control measures.

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Background: Malignant edema is one of the terms used to designate severe necrotizing syndromes in soft tissues by Clostridium spp. which are potentially fatal in farm animals. These species are responsible for myonecrosis, belonging to the group of histotoxic clostridia, and may also culminate in toxemia with the worsening of the lesions. These clostridia and their spores require a gateway such as wounds on mucous membranes or skin, which may occur due to shear, tail cut, injuries during delivery, castration or injections by contaminated needles. This report aims to describe the clinical-pathological findings of a case of malignant edema caused by C. perfringens type A in an equine.Case: A female equine, undefined breed, used as traction animal, had a history of abdominal pain. According to the requisitioning veterinary, the tutor reused needles for medication. On palpation, a compact mass was noticed in the pelvic flexure, as well as edema on the region of head and neck with crackling areas. After surgical intervention for compactation correction, the animal did not show anesthetic recovery and was submited to euthanasia. Tissue samples were collected, fixed in 10% buffered formalin solution, routinely processed for histopathology and stained with hematoxylin and eosin and Gram stain. Samples of serous-sanguineous edema fluid and fragments of the abdominal muscles and neck were collected. The samples were kept under refrigeration and sent for microbiological culture. Necropsy showed the subcutaneous region of the pectoral was markedly gelatinous and yellowish (edema) and subcutaneous emphysema characterized by accumulation of serous-sanguineous fluid and gas bubbles. In microscopy, we verified fibrous-haemorrhagic, emphysematous, suppurative and diffuse superficial histiocytic necrotizing cellulitis and myositis. Gram-positive bacillary aggregates were observed in spleen and subcutaneous sections. Colony suggestive of Clostridium perfringens were submitted to PCR for confirmation of identity followed by genotyping. Lastly, C. perfringens type A was isolated from the muscle fragments and serosanguinolent liquid collected.Discussion: In the present study, the diagnosis of malignant edema caused by Clostridium perfringens type A in an equine was confirmed by the clinical-pathological findings added to the isolation and genotyping of the agent from fragments of injured muscle. Although C. perfringens has been reported in cases of clostridial myositis in horses in the United States, in Brazil there are only reports of sporadic cases associated with C. septicum, C. novyi and C. chauvoei in this species. In histotoxic cases by C. perfringens, alpha toxin is known to be the main virulence factor involved, causing destruction of the phospholipid membrane of erythrocytes, endothelial cells, leukocytes and muscle fibers. As consequence, there is an increase in the vascular permeability of capillaries and, with the spread of the infection, there is production of inflammatory edema with serosanguineous exudate and gas. Typically, anatomopathological findings are characterized by increased volume of the affected region associated with edema with bloody fluid and rancid odor, gas bubbles in the subcutaneous tissue, and fasciae associated or not with necrotic myositis. It is assumed that a contaminated needle injection, performed during the treatment of colic symptoms on the property has been the gateway to infection. The clinical course of clostridial infection in horses is considered acute, ranging from 24 to 48 h. In this case, was observed the animal with signs of cervical and pectoral edema still in the property, a day before euthanasia. This is the first study to confirm Clostridium perfringens as a cause of gas gangrene in horses in Brazil.

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The aim of this study was to compare testicle morpho-functional characteristics in bulls undergoing a single or two immunizations against GnRH. Nelore (Bos taurus indicus) bulls were randomly allocated into three experimental groups: G1 (n=12), a single 400 μg dose of anti-GnRH vaccine on day 0; G2 (n=11), a first 400 μg dose of anti-GnRH vaccine on day 0 followed by a second (boost) dose 30 days later; and control group (CG, n=12), 1 mL saline 0.9% at day 0. Every 30 days, from day 0 until slaughter at day 90, the bulls were weighed and underwent testicular biometry, semen collection and analysis, and blood sample collection for testosterone measurement. Immediately after slaughter, the testicles were removed and transport at 15°C to the laboratory for histopathological analysis. There was a decrease in testicular height (P=0.0476), width (P=0.0021), and in scrotal circumference (P=0.0001), after either a single (G1) or two (G2) immunizations against GnRH. Both G1 and G2 had lower testosterone concentrations than CG from day 60 on (P<0.01), but in G2, it was also lower than in G1 at day 90 (P=0.0006). All sperm parameters were affected by active immunization against GnRH (P<0.05), and in G2, averages were lesser (P<0.05) than in G1 from day 60 on. No signs of seminiferous tubule degeneration were found in any sample from the CG, contrasting with 75.0% and 100.0% of the samples from G1 and G2, respectively. In summary, immunocastration affected testicle morpho-functional characteristics in bulls in a time- and dose-dependent way.

Background: Brazil has a vast territory and favorable climatic conditions that allow the cultivation of freshwater fish. The intensification of the productive system can cause an imbalance in the aquatic environment as a result of poor water quality, nutritional deficiencies and infectious or parasitic diseases. The laboratory diagnosis and the determination of the prevalence of the main lesions, which occur in a certain region, help to guide towards the etiological diagnosis. This study aimed to describe the main parasitic lesions in fish in the routine at the Veterinary Pathology Laboratory of the Universidade de Brasília. Material, Methods & Results: All records of fish with parasitic lesions were recovered. Those cases in which there was an intralesional parasite and which presented lesions compatible with the parasite were included. The screening of ectoparasites was done by scraping the superficial mucus from the gills and skin. Organ sections were routinely processed for histopathologyand stained with hematoxylin-eosin (HE). In some records, parasitological identification was carried. The information was divided into the species of the affected fish, epidemiology of the outbreak (water quality, temperature, type of breeding), lesion distribution, etiology and macroscopic and microscopic changes. The resulting data was organized in absolute frequency and percentage. In this study, 22 cases were counted, between individual deaths and outbreaks, totaling 83 necropsied teleost fish.Inflammatory changes of parasitic origin were seen in 13/22 (59%) of the cases had lesions of parasitic origin. Skin lesions and gills were the most relevant. Macroscopically, red areas or spots of hyperemia or hemorrhage on the body surface were the most prevalent findings. Under microscopy, proliferative gill inflammation was the most relevant diagnosis. Pscinoodinium pilullare (Dinoflagellida), Ichthyophthirius multifiliis (Ciliophora), and monogenetic worms (Monogenea) were the main parasites found. Trichodina sp. (Ciliophora), Ichtyobodo sp. (Kinetoplastida), Amoebas, and Chilodonella sp. (Ciliophora), were seen in fewer numbers. An unusual case suggestive of parasitism by Eustrongylides sp. (Nematoda), in a pirá-brasília (Simpsonichthys boitonei), specimen has been recorded.Discussion: The diagnoses were based on epidemiology, anatomopathological and parasitological findings. The most frequent and significantly lethal lesion in the study was proliferative and / or hyperplastic branchitis. Proliferative branchitis with lamellar epithelial hyperplasia (LEH) is a response to some type of chemical or mechanical injury to the gill epithelium in order to protect the capillaries from further damage or microbial penetration. However, it also increases the diffusion distance between capillaries and the environment and, therefore, hinders breathing, excretory and osmoregulatory functions. Protozoan infections and monogenetic worms in general generated LEH and skin lesions of mechanical origin. Secondary bacterial infection, were observed in this parasitosis determining the cause of death of the fish. Its pathogenicity comes from the lesions caused by the colonization and histophagy of the epithelial surfaces, mainly gills and skin, causing epithelial proliferation, lamellar cell fusion, epithelial cell degeneration and necrosis forming several ulcers in the epithelium after the release of mature trophies. The pathogenesis of parasitism by Eustrongylides spp. is considerable when there is a large quantity of these larvae that can cause intestinal obstruction, rupture and compression of viscera, of greater importance in small fish. The main parasites of necropsied fish were protozoa and monogenetic worms, which mainly cause branquitis and dermatitis in varying grades.

Background: Piscinoodinium pillulare is a mandatory mastigophore protozoan with no parasitic specificity, and an important ectoparasite of tropical and temperate psiculture. This parasite is responsible for serious health problems in Brazilian native fish. Another important pathogenic protozoan in psciculture belongs to the genus Trichodina spp., which is commonly found on the surface of fish, gills, fins, and integument. The aim of the present study was to describe an outbreak of P. pillulare andTrichodina spp. in three species of fish intensively created, emphasizing the anatomopathological and epidemiological aspects.Cases: Five animals were necropsied, among them three tambaquis (Colossoma macropomu), one pirapitinga (Piaractus brachypomus) and one tilapia (Oreochromis niloticus) from an intensive psciculture in the Federal District. Out of 1500 fishes, 18 (1.2%) became ill and died. It was reported that the animals showed decreased feed intake, discomfort, dyspnea, opercular movements, red skin lesions and consequent death. In the direct examination of scraping of the body surface of a fish, preparedbetween lamina and coverslip, a ciliated ectoparasite, with a circular bell shape, measuring approximately 20-180 μm, adhered, with morphology consistent with Trichodina spp. was evidenced. During necropsy, fragments of different organs were collected and fixed in 10% formalin, routinely processed for histology, embedded in paraffin, cut to five microns thick and stained with hematoxylin and eosin (HE). Macroscopically, there were pale scaly areas in the medial-lateral regions, moderate increase amountof mucus with brown to green lumps on the body surface, partial loss of the fins, swollen gills with whitish mucus and multifocal hemorrhagic areas on the skin and between the scales. Microscopically, moderate multifocal lymphoplasmocytic branchitis was observed with cell hyperplasia and fusion of secondary lamellae associated with trophons (protozoa), consistent with P. pillulare.Discussion: The diagnosis of infection by P. pillulare and Trichodina spp. in this study was based on the epidemiological and clinical-pathological findings. Regarding the first ones, we highlight the variety of fish species affected. P. pillulare is an example of a commensal parasite present on the substrate of culture tanks, and exerts a type of non-obligatory parasitism that uses the fish as a substrate for its fixation under favorable conditions. In this case, only Trichodina spp. was observed during the traditional evaluation of body surface and gills scraping, and histopathology was essential for the verification of the agent P. pillulare. Routine histopathological analysis may also provide a definitive diagnosis, observing the trophons attached to the gill filaments. Atrophy and fusion of secondary lamellae, which promote proliferative lesions in the gills associated with the interlamellar presence of parasites, are responsible for hypoxia, loss of balance and erratic movements. Although they were observed in a small number, Trichodina spp. are believed to be responsible, on a larger scale, for hemorrhagic lesions on the skin and between fish scales. These findings were similar to those of the literature, and the diagnosis of these parasites allows producers and technicians to adopt adequate treatment, as well as prophylactic measures that provide good environmental conditions in order to avoid economic losses.Keywords: fish diseases, protozoa, fish ectoparasites.

A renal nephroblastoma is described in a free-living black-tufted marmoset (Callithrix penicillata) in Central Brazil. The monkey was found dead and subjected to necropsy. Gross anatomic changes consisted of a ruptured left kidney, which was almost completely effaced by a white to yellow, partially encapsulated friable mass. The left ureter was distended due to obstruction by a red, spherical, 2mm in diameter friable mass. The urinary bladder was also distended. Histologically the renal and ureteral masses consisted of a triphasic embryonal neoplasm composed of embryonic epithelium forming glomeruli and tubules, polygonal blastemal cells, and a mesenchymal stroma. The embryonic epithelium exhibited rare nuclear immunoreactivity for WT-1, whereas blastemal cells exhibited robust cytoplasmic and rare nuclear immunoreactivity for WT-1; blastemal cells were also immunoreactive for vimentin. No immunoreactivity was detected for pan-cytokeratin (AE1/AE3), actin, and desmin. Morphological and immunohistochemical features of the present neoplasm are consistent with those described for renal nephroblastoma.