Novel Gyrovirus genomes recovered from free-living pigeons in Southern Brazil

Wild birds carry a number of infectious agents, some of which may have pathogenic potential for the host and others species, including humans. Domestic pigeons (Columba livia) are important targets of study since these increasingly cohabit urban spaces, being possible spillover sources of pathogens to humans. In the present study, two genomes (PiGyV_Tq/RS/Br and PiGyV_RG/RS/Br), representative of Gyrovirus genus, family Anelloviridae, were detected in sera of free-living pigeons collected in Southern Brazil. The genomes exhibit less than 50% identity to previously described members of Gyrovirus genus, suggesting that they constitute a new viral species circulating in pigeons, to which the name "pigeon gyrovirus (PiGyV)" is proposed. The current study characterizes these two PiGyV genomes which, to date, are the first gyrovirus species identified in domestic pigeons.

Testicular Interstitial Cell Tumor with Disseminated Cutaneous Metastasis in a Dog

Background: Although testicular tumors commonly develop in the genital tract of dogs, only few studies have reported about metastatic testicular tumors in dogs to date. Therefore, the present study aimed to describe the gross, histopathological, and immunohistochemical findings in a dog with metastatic interstitial cell tumor.Case: A 6-year-old male Beagle underwent clinical examination due to enlargement of the left testicle and nodules in the skin of the left inguinal region and of the scrotum. The left testicle was cryptorchid (inguinal), and the right testicle was intrascrotal. Both testicles and affected skin fragments were surgically removed. The right testicle was normal in size and did not exhibit gross changes. However, the left testicular parenchyma had been completely replaced by a firm, grayish-to-white neoplastic mass with an irregular surface. The inguinal and scrotal skin fragments were thickened by the neoplastic masses. Histologically, the left testicular parenchyma was completely obliterated by a neoplastic mass consisting of round-to-oval and polygonal cells. The neoplastic cells generally had abundant eosinophilic cytoplasm with indistinct cell limits. The nuclei were round and small, with aggregated chromatin. However, some cells exhibited high degrees of atypia and pleomorphism and large nuclei with granular chromatin. Mitotic figures were observed at high frequencies of up to 11 per high-power field (400×). The mass in the left testicle was diagnosed as malignant interstitial cell tumor. The sections of the inguinal skin and scrotum presented with neoplastic cells similar to those observed in the left testicle, which is consistent with the metastasis of the malignant testicular interstitial cell tumor. On the basis of necropsy, multiple cutaneous and subcutaneous nodules were randomly distributed throughout the body, primarily in the prepuce, head, and limbs. Histological evaluations of the skin nodules, internal iliac lymph nodes, and abdominal skeletal muscles also revealed metastases of the testicular interstitial cell tumor.Discussion: The histopathological findings associated with the immunohistochemical results observed in the present case helped in establishing the diagnosis of malignant interstitial cell tumor. Regarding the histological evaluations, although most neoplastic cells exhibited appearances that are characteristic of Leydig cells, several features indicative of malignancy were also observed. In dogs, malignant interstitial cell tumors are rare, and multiple organ metastases have been described. Among the immunohistochemical markers that were examined (calretinin, vimentin, cytokeratin, placental alkaline phosphatase, and octamer-binding transcription factor 3/4), only vimentin staining produced a positive result. In one study, the antibody against vimentin stained both normal Sertoli and Leydig cells and tumors arising from these cells, but not seminomas, which is an important differential diagnosis in the case described in this study. The negativity for placental alkaline phosphatase also allowed to rule out seminoma in the differential diagnosis of the primary tumor. The skin sections (distant metastases) were negative for T and B lymphocytes and macrophages, thereby ruling out possible differential diagnoses, such as lymphomas or histiocytic tumors, among the cutaneous neoplasms. Therefore, this case report described a malignant testicular interstitial cell tumor with an uncommon disseminated pattern of metastases to the skin in a dog.

Plasmodium vivax and Plasmodium falciparum infection in Neotropical primates in the western Amazon, Brazil

The Brazilian Amazon is endemic for malaria and natural infections by Plasmodium spp. have been detected in Neotropical primates. Despite the diversity of primate species in the region, studies on infections by these agents are limited. The aim of the present study was to investigate the frequency of infection by Plasmodium vivax and P. falciparum in free-born primates that were kept in captivity, in the western Amazon, Brazil. Blood samples were collected from 98 Neotropical primates. Detection of P. vivax and P. falciparum DNA was performed using a semi-nested PCR, and the amplified products were sequenced. Plasmodium spp. DNA was detected in 6.12% (6/98) of the primates. P. vivax, and P. falciparum DNA was detected in 2.04% (2/98) and 4.08% (4/98) of these mammals, respectively. Sequencing and phylogenetic analysis confirmed the results obtained from the semi-nested PCR. The presence of infected non-human primates (NHP) can be auxiliary in the maintenance of P. falciparum and P. vivax and may have implications for the malaria surveillance and control in the Brazilian Amazon. It is necessary to structure an efficient surveillance system for the aetiological agents of malaria that infect NHP and humans to reduce the risk of Plasmodium spp. introduction into new areas, to protect all susceptible species.

Columbid circoviruses detected in free ranging pigeons from Southern Brazil: insights on PiCV evolution

Pigeon circovirus (PiCV) is taxonomically classified as a member of the Circovirus genus, family Circoviridae. The virus contains a single stranded DNA genome of approximately 2 kb, with minor length variations among different isolates. The occurrence of PiCV infections in pigeons (Columba livia) has been documented worldwide over the past 20 years; however, in Brazil there were still no reports on PiCV detection. This study identifies seven PiCV genomes recovered from domestic pigeons of South Brazil through high-throughput sequencing and shows a high frequency of PiCV infection, through quantitative real-time PCR. Phylogenetic classification was performed by maximum likelihood analysis of the full genomes, ORF V1 (Rep) and ORF C1 (Cap). The results show that either full genome or Cap based analysis allowed PiCV classification into five major clades (groups A to E), where Brazilian sequences were classified as A, C or D. Recombination analyses were carried out with Simplot and RDP4 and the results show that both Rep and Cap ORFs contain several recombination hotspots, pointing to an important role for such events in PiCV evolution.

Neoplasmas da tireoide em cães: 26 casos

RESUMO: Foram revisados os protocolos de biópsias e necropsias do Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria (LPV/UFSM) entre 2004 e 2014, e todos os casos de tumores que acometeram a glândula tireoide foram selecionados. A partir disso, foram anotados sexo, idade e raça dos cães afetados. Também foi avaliado o significado clínico dos tumores, presença de aumento de volume cervical, lobos afetados, tamanho dos tumores, presença e localização de metástases e padrão histológico dos neoplasmas. Nos 11 anos que compreenderam este estudo, foram diagnosticados 26 tumores de glândula tireoide (quatro eram provenientes de exames de biópsias e 22 de necropsias), 53,9% dos cães eram fêmeas e 46,1% eram machos; 65,4% eram cães com raça definida. Desses, Boxers foram os mais afetados (15,4% dos casos). Dos 23 protocolos em que a idade foi informada, 60,9% dos cães eram idosos e 39,1% eram adultos. A avaliação dos protocolos permitiu constatar que 38,5% dos animais haviam apresentado aumento de volume cervical no momento do exame clínico. Dos cães necropsiados 13,6% morreram ou foram submetidos à eutanásia em decorrência de complicações causadas por metástases dos tumores de tireoide. Dessa forma, em 86,4% dos cães, os neoplasmas foram considerados achados incidentais de necropsia. Nos quatro casos provenientes de material de biópsia, o desfecho não foi conhecido. Em nenhum cão os tumores causaram síndrome clínica devido à hipo ou hiperfunção da tireoide. Em 24 protocolos havia informação sobre os lobos afetados e 75% dos cães tiveram acometimento unilateral da glândula. Os diagnósticos histológicos dos tumores permitiram constatar que 16 (61,5%) neoplasmas eram carcinomas de células foliculares (nesses casos, o padrão folicular-compacto foi o mais frequente [43,75%]), seis (23,1%) eram adenomas de células foliculares, dois (7,7%) eram carcinossarcomas e dois (7,7%) eram tumores de células C (adenoma e carcinoma).

Full-Genome Sequence of Porcine Circovirus type 3 recovered from serum of sows with stillbirths in Brazil

Two full-genome sequences of porcine circovirus type 3 (PCV3) are reported. The genomes were recovered from pooled serum samples from sows who had just delivered litters with variable numbers of stillbirths. The two circular genomes (PCV3-BR/RS/6 and PCV3-BR/RS/8) are 2,000 nucleotides long and contain two open reading frames (ORFs) oriented in opposite directions that encode the putative capsid (Cap) and replicase (Rep) proteins. The intergenic region contains a stem-loop motif, as reported for other circoviruses. Rolling circle replication motifs and putative helicase domains were identified in the Rep coding region. The degree of overall nucleotide similarity between the genomes reported here and those available at GenBank was higher than 97%. No PCV3 sequence was detected in pooled serum samples from sows which had no stillbirths on the same farms. However, further studies are necessary to confirm the association between PCV3 and the occurrence of stillbirths.

Synergistic effects of resveratrol (free and inclusion complex) and sulfamethoxazole-trimetropim treatment on pathology, oxidant/antioxidant status and behavior of mice infected with Toxoplasma gondii

This study aimed to investigate the synergistic effects of resveratrol and sulfamethoxazole-trimethoprim (ST) on the treatment of mice experimentally infected by Toxoplasma gondii during the chronic phase of the disease considering infection, behavior, and oxidative/antioxidants profile aspects. For the study, 60 mice were initially divided into two groups: uninfected (n = 24) and infected by T. gondii (n = 36). These two groups were later subdivided into other groups and treated with resveratrol (free and inclusion complex containing resveratrol) alone and co-administered with ST: groups A to D were composed by healthy mice and groups E to J were consisted of animals infected by T. gondii (VEG strain). Treatments began 20 days post-infection for 10 consecutive days with oral doses of 0.5 mg kg(-1) of ST (groups B and F), 100 mg kg(-1) of free resveratrol (groups C and G) and inclusion complex of resveratrol (nanoparticles containing resveratrol) (groups D and H), and lastly an co-administration of both drugs (groups I and J). Behavioral tests (memory, anxiety and locomotion) were performed after treatment. Liver and brain fragments were collected to evaluate pathological changes, brain cysts counts, as well as oxidant and antioxidant levels. A reduction on the number of cysts in the brain of animals treated with both drugs combined was observed; there was also reduced number of lesions on both organs. This drug combined effect was also able to reduce oxidative and increase antioxidant levels in infected mice, which might be interpreted as a resveratrol protective effect. In addition, the combination of ST and resveratrol was able to prevent behavioral changes in infected mice. Therefore, the use of co-administration drugs enhances the therapeutic effect acting on a synergic way, reducing the oxidizing effects of the chemical treatment for toxoplasmosis. In addition, resveratrol in inclusion complex when co-administered with ST showed an improved therapeutic effect of ST reducing oxidative damage, liver damage and the number of cysts in the brain of T. gondii infected mice.

Leptospira Seroprevalence in Capybaras from a Brazilian Urban Area

Background: Leptospirosis remains the most widespread zoonotic disease in the world. As a clinical entity it is strongly associated with regional occupational and environmental exposures.  While the exact global disease burden remains unknown, recent estimates by the leptospirosis Burden Epidemiology Reference Group (LERG) at the World Health Organization have set the number of human cases of severe leptospirosis to over 500,000 per year. This number almost certainly represents an under-representation due to poor surveillance and difficult diagnosis. Leptospira spp. belong to the order Spirochaetales, family Leptospiraceae, composed by 13 pathogenic Leptospira species with more than 260 serovars. Wildlife species are commonly considered to be important epidemiological carriers, mainly because of their frequent reactivity to Leptospira serovars native to their habitat. Capybara (Hydrochaeris hydrochaeris), a known leptospirosis host, is a widespread species in South America. However, reports regarding the importance of this animal in the epidemiology of leptospirosis are rare. Therefore, the objective of this study was to report the results of leptospirosis serological survey of capybaras from a residential park area in southeastern Brazil.Materials, Methods & Results: A total of 172 capybaras were sampled at Itú Municipality, state of São Paulo, southeastern Brazil, from December 2012 to May 2013. Sera samples were examined for Leptospira antibodies by the microscopic agglutination test (MAT), using live antigens grown in liquid medium (EMJH). A complete panel of 7 serogroups (including 10 reference serovars) was used as antigens: serogroup Sejroe (serovars Hardjo and Wolffi), serogroup Grippotyphosa (serovar Grippotyphosa), serogroup Canicola (serovar Canicola), serogroup Icterohaemorrhagiae (serovars Icterohaemorrhagiae and Copenhageni), serogroup Australis (serovars Australis and Bratislava), serogroup Pomona (serovar Pomona), and serogroup Autumnalis (serovar Butembo).   As a results, 46 (26.75%) were serologically positive: 29 (63.05%) for serogroup Sejroe, 7 (15.22%) for serogroup Icterohaemorrhagiae; 9 (19.56%) were seropositive for serogroups Sejroe and Icterohaemorrhagiae; and 1 (2.17%) was positive for serogroups Sejroe and Grippotyphosa.Discussion: L. interrogans sensu stricto is responsible for the most frequent and severe cases of human and animal leptospirosis. Considering the results of our serological survey, it is important to reinforce that in tropical countries, mainly Brazil, India, Thailand, Vietnam, Australia and Barbados, serovars belonging to the Icterohaemorrhagiae serogroup (Icterohaemorrhagiae and Copenhageni) are generally the most prevalent. Therefore, the report of different serogroups in capybaras (as observed in our study) it is an important observation reported. Human leptospirosis is usually due to serovars that are maintained by the animal populations of a region, which spread the bacterium on the environment; thus, it may represent an important additional risk factor for human population. Our study identified a greater serum reactivity to strains that belongs to serogroup Sejroe. In Brazil this serogroup is highly predominant in livestock; thus, our main hypothesis is that some animals were contaminated with Sejroe serovars when they were at their natural habitat and, once in the park, they maintained these serovars through cross transmission.  Therefore, based on our results, it was possible to observe a significant prevalence of serovars belonging to serogroup Icterohaemorrhagiae, and there was also a high prevalence of samples positive to serogroup Sejroe. Thus, our serologic survey showed that capybaras living in an urban area could represent a risk factor for leptospirosis for the human population eventually exposed.

Effects of sulfamethoxazole-trimethoprim associated to resveratrol on its free form and complexed with 2-hydroxypropyl-β-cyclodextrin on cytokines levels of mice infected by Toxoplasma gondii

The aim of this study was to investigate the effects of resveratrol on its free form and complexed with 2-hydroxypropyl-β-cyclodextrin (HPβCD) when associated with sulfamethoxazole-trimethoprim (ST) on cytokines levels of mice (n = 60) experimentally infected by Toxoplasma gondii. Groups A and E were used as controls (untreated): negative and positive, respectively. The onset of treatment started 20 days post-infection (PI), and it lasted for 10 consecutive days. ST was administered orally in doses of 0.5 mg kg(-1) for groups B and F, while 100 mg kg(-1) was the dose for resveratrol in its free form (groups C - G), inclusion complex (groups D and H), and on free and inclusion complex together (groups I - J). On day 31 PI, blood samples were collected in order to evaluate the cytokine profile. The mice that received drug combination (I and J) showed a significant (P < 0.05) reduction in the number of cysts in the brain compared to other infected groups (E - H). The results showed that mice from the Group E had increased (P < 0.001) levels of pro-inflammatory cytokines, while IL-10 levels were reduced when compared to the Group A. Additionally, there were increased levels of IL-4 and IFN-γ in animals of groups C and D, respectively (P < 0.05). Animals of the Group B showed reduced levels of IL-1, IL-4, IL-6, TNF-α, and IFN-γ (P < 0.05). Mice infected and treated (groups F - J) showed increased levels of pro-inflammatory cytokines along with a reduction of IL-10. Treatment with the combination of drugs (the Group J) led to a protective effect, i.e. reduction in pro-inflammatory cytokines. Therefore, resveratrol associated with ST was able to modulate seric cytokine profile and moderate the tissue inflammatory process caused by T. gondii infection, as well as to reduce parasite multiplication.

Epidemiologia e distribuição de lesões extrarrenais de uremia em 161 cães

Resumo: Com o objetivo de determinar a epidemiologia e as características morfológicas, incluindo a localização anatômica, das lesões extrarrenais de uremia, bem como determinar as principais lesões do sistema urinário associadas à ocorrência de uremia, foram revisados os protocolos de necropsias de cães realizadas no Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria de janeiro de 1996 a dezembro de 2012 (17 anos). Nesse período foram necropsiados 4.201 cães, sendo que 161 (3,8%) apresentaram lesões extrarrenais de uremia. Em 134 cães (83,2%) foram descritos sinais clínicos associados à uremia. As lesões extrarrenais mais frequentes, em ordem decrescente, foram: gastrite ulcerativa e hemorrágica (56,5%), mineralização de tecidos moles (55,9%), edema pulmonar (47,2%), estomatite e/ou glossite ulcerativa (30,4%), endocardite/trombose atrial e aórtica (28,6%), hiperplasia das paratireoides (9,3%), osteodistrofia fibrosa (8,1%), anemia (6,2%), laringite ulcerativa (5%), enterite ulcerativa/hemorrágica (3,7%), esofagite fibrinonecrótica (1,9%) e pericardite fibrinosa (1.9%). Na maioria dos casos as lesões extrarrenais de uremia foram decorrentes de azotemia prolongada por lesões renais graves, sendo as mais prevalentes a nefrite intersticial e a glomerulonefrite.

Sulfamethoxazole-trimethoprim associated with resveratrol for the treatment of toxoplasmosis in mice: Influence on the activity of enzymes involved in brain neurotransmission

This study aimed to investigate the influence of sulfamethoxazole-trimethoprim (ST) associated with resveratrol on the enzymatic activities of acetylcholinesterase (AChE), adenylate kinase (AK), pyruvate kinase (PK), and creatine kinase (CK) in the brain of mice experimentally infected by Toxoplasma gondii. For that, 60 mice were divided into ten groups with 6 animals each: groups A to D composed by healthy mice and groups E to J consisting of animals infected by T. gondii (VEG strain). Animals started treatment 20 days post-infection for 10 consecutive days with oral doses of 0.5 mg kg(-1) of ST (groups B and F), 100 mg kg(-1) of free resveratrol (groups C and G) and inclusion complex of resveratrol (nanoparticles containing resveratrol) (groups D and H), as well as with an association of both drugs (groups I and J). The results showed increased (P < 0.001) AChE activity on infected animals (groups E-J) when compared to not-infected (A) animals, and also uninfected animals treated with ST (group B) had increased AChE activity. AK activity decreased (P < 0.001) in the infected and untreated (group E), differently from the other groups that did not differ. PK activity did not differ between groups (P > 0.05). When comparing control groups (uninfected (A) and infected (E)), we verified a significant (P < 0.001) increase in CK activity in the brain, and it is noteworthy that the animals treated with resveratrol associated with ST (group I and J) had similar CK activity to those animals from the group A. Treatment with the combination of ST and resveratrol was able to reduce (P < 0.05) the number of parasitic cysts in the brain, thus reduced inflammatory infiltrates in the liver, and prevented the occurrence of hepatocytes lesions due to toxoplasmosis in mice. Based on these results, it is possible to conclude that increased AChE and CK activities after T. gondii infection did not change with the treatment of ST-resveratrol association. In addition, decreased AK activity caused by T. gondii infection was normalized by ST-resveratrol treatment. T. gondii infection and treatment does not affect PK activity in brain.

Utilização de três métodos imuno-histoquímicos na detecção de aspergilose e zigomicose em animais

Visando a otimização do uso da técnica de imuno-histoquímica (IHQ) na detecção de Aspergillus spp. e zigomicetos (membros da família Mucoraceae), utilizaram-se dois anticorpos monoclonais fungo-específicos em fragmentos de tecidos de animais (fixados em formol e embebidos em parafina) com diagnóstico histomorfológico prévio de aspergilose e zigomicose, os quais foram submetidos a três sistemas de detecção diferentes (dois biotinilados e um não biotinilado). Os dois anticorpos apresentaram alta especificidade e sensibilidade nos tecidos examinados. Não ocorreram reações cruzadas entre os anticorpos utilizados e os agentes etiológicos avaliados (incluindo casos de aspergilose, zigomicose, candidíase e pitiose). No entanto, reações inespecíficas foram observadas nas hifas em alguns casos, as quais puderam ser eliminadas através de um dos métodos de detecção utilizados. Para a aspergilose, o método da estreptavidina-biotina-fosfatase alcalina não apresentou reações inespecíficas nas hifas. Enquanto que nos casos de zigomicoses, as reações inespecíficas não ocorreram no método por polímero (não biotinilado). A técnica de IHQ mostrou-se uma ferramenta muito útil na detecção e confirmação dos casos de aspergilose e zigomicose neste estudo retrospectivo.

Características histomorfológicas e histoquímicas determinantes no diagnóstico da criptococose em animais de companhia

Sete casos de criptococose (seis gatos e um cão) foram estudados para estabelecer as características histomorfológicas e histoquímicas determinantes no diagnóstico histopatológico dessa condição. Os dados complementares relacionados à epidemiologia, aos aspectos clínicos, à localização das lesões e às alterações macroscópicas foram obtidos dos protocolos de necropsias e biópsias. Na histologia, as leveduras foram observadas no interior de macrófagos ou livres no parênquima, associadas à reação inflamatória linfo-histioplasmocítica que variou de escassa a acentuada. Pela técnica de hematoxilina-eosina (HE) as leveduras eram arredondadas, com célula central contendo um núcleo, circundada por um halo claro (cápsula geralmente não corada). As técnicas histoquímicas do ácido periódico de Schiff (PAS), Grocott e Fontana-Masson (FM) foram utilizadas e evidenciaram a parede das células das leveduras. Pelo FM observou-se a melanina presente nessas células. As técnicas do azul Alciano e da mucicarmina de Mayer evidenciaram principalmente a cápsula polissacarídica das leveduras. O diâmetro das células das leveduras variou de 1,67 a 10,00µm e o diâmetro total das leveduras encapsuladas variou entre 4,17 e 34,16µm. Os brotamentos foram melhor visualizados através do PAS e ocorreram em base estreita, de forma única ou múltipla, principalmente em polos opostos das células das leveduras ou formando uma cadeia. O diagnóstico definitivo de criptococose foi estabelecido através do exame histopatológico, baseando-se na morfologia característica do agente (levedura encapsulada) e em suas propriedades tintoriais (histoquímicas), principalmente nos casos em que a cultura micológica não foi realizada.

Aspectos epidemiológicos, clinicopatológicos e imuno-histoquímicos de carcinomas de células escamosas vulvares em 33 vacas

Carcinomas de células escamosas vulvares (CCEVs) em bovinos foram estudados retrospectivamente quanto à prevalência, epidemiologia, quadro clinicopatológico e aspectos imuno-histoquímicos. O grau de pigmentação da pele vulvar foi também avaliado. Nos 48 anos analisados retrospectivamente, foram computados materiais de necropsias e biópsias de 7.483 bovinos recebidos no Laboratório de Patologia Veterinária da UFSM. Desses, em 664 (8,87%) casos de neoplasmas foram identificados, sendo 33 (4,97%) casos de CCEVs. Dezenove eram vacas da raça Holandesa, três da Charolesa, uma era Jersey e 10 eram sem raça definida. A principal alteração macroscópica foi aumento de volume vulvar, sangrante e com miíase concomitante. As massas tumorais eram firmes, ulceradas e com áreas amarelas. Foi possível reavaliar microscopicamente 30 dos 33 casos. Desses, oito eram CCEVs bem diferenciados, 17 eram moderadamente diferenciados e cinco eram pobremente diferenciados. A avaliação de lesões intraepiteliais escamosas (LIEs) foi realizada em tecidos de 21 casos que tinham epitélio de revestimento. Hiperplasia epitelial foi observada em 10 casos; displasia leve em dois, moderada em um e acentuada em cinco casos; em três casos não havia LIEs. A técnica de Fontana-Masson para melanina foi realizada em 21 casos. Desses, em 17 a pigmentação do epitélio da epiderme vulvar era ausente, em dois era leve e em outros dois era moderada. Independentemente do grau de diferenciação dos CCEVs, houve imunomarcação acentuada da maioria dos ceratinócitos neoplásicos para pancitoceratina bovina pela técnica de imuno-histoquímica (IHQ). Papilomavírus bovino não foi detectado pela IHQ neste estudo.

Aspectos anatomopatológicos da leptospirose em cães: 53 casos (1965-2011)

Os aspectos anatomopatológicos da leptospirose foram estudados em 53 cães que tiveram diagnóstico definitivo confirmado por imuno-histoquímica do tecido renal. Na necropsia, as principais lesões observadas incluíram icterícia (79,2%) e hemorragia (75,5%), principalmente no pulmão (56,6%). Alterações macroscópicas hepáticas (56,6%) e renais (50,9%) foram frequentes e caracterizavam-se principalmente por descolorações (30,2% e 32,1% respectivamente), acentuação do padrão lobular hepático (26,4%) e estriações brancas na superfície de corte dos rins (22,6%). Lesões extrarrenais de uremia ocorreram na metade dos casos (50,9%). Hepatomegalia (11,3%), nefromegalia (9,4%) e irregularidade da superfície capsular dos rins (3,8%) foram menos comuns. Na histologia dos rins (n=53), as lesões encontradas (98,1%) foram quase que exclusivamente agudas ou subagudas (96,2%) e caracterizavam-se por graus variados de nefrose tubular (86,8%) e nefrite intersticial não supurativa (60,4%), com evidente dissociação degenerativo-inflamatória. Na histologia do fígado (n=42), as lesões encontradas (97,6%) eram constituídas principalmente por dissociação dos cordões de hepatócitos (78,6%), colestase intra-canalicular (33,3%) e necrose hepática (31%). Lesões reativas, como hipertrofia das células de Kupffer, leucocitostase sinusoidal e infiltrado inflamatório mononuclear nos espaços porta, foram vistas em muitos casos (42,8%). Na histologia do pulmão (n=28), hemorragia (85,7%) e edema (57,1%) alveolares foram muito prevalentes. Neutrófilos e macrófagos nos espaços alveolares (35,7%) e neutrófilos no interior de pequenos vasos pulmonares (17,9%) também foram achados frequentes. Os resultados aqui demonstrados devem servir de alerta aos patologistas veterinários brasileiros, pois a apresentação anatomopatológica da leptospirose canina em nossa região (Região Central do Rio Grande do Sul, Brasil) não se modificou nos últimos 50 anos, mantendo-se semelhante àquela descrita internacionalmente até a década de 1980, mas muito diferente do que é atualmente reconhecido para os Estados Unidos, o Canadá e parte da Europa Ocidental. Recomendamos que os critérios histopatológicos para o diagnóstico da leptospirose canina devem incluir a presença concomitante de nefrite tubulointersticial aguda ou subaguda, hepatite reativa não específica e lesão alveolar difusa, incluindo hemorragia alveolar difusa com capilarite, em um cão que durante a necropsia demonstre icterícia, hemorragias e lesões extrarrenais de uremia na ausência de esplenomegalia.

Aspectos epidemiológicos, clínicos, hematológicos e anatomopatológicos da leucemia eritroide aguda (LMA M6) em gatos

Os aspectos epidemiológicos, clínicos, hematológicos e anatomopatológicos da leucemia eritroide aguda (LMA M6) foram estudados em 10 gatos que morreram em consequência dessa condição. Os resultados obtidos diferem daqueles previamente descritos na literatura nos seguintes aspectos: 1) a doença ocorreu na forma de um modelo bimodal relacionado à idade dos gatos afetados, em que 50% tinham 1-3 anos de idade e 50% tinham 10 anos de idade ou mais; 2) quase todos os gatos afetados (87,5%) demonstravam policromasia, possivelmente decorrente de eritropoese extramedular; 3) em todos os casos havia múltiplos focos de células hematopoéticas, principalmente eritropoeticas, em múltiplos órgãos, que incluíam baço (85,7%), linfonodos (71,4%), fígado (57,1%) e rim (28,6%); 4) em alguns casos (28,6%) esses focos podiam ser vistos macroscopicamente, na forma de metástases, mas sempre diferiam histologicamente da medula óssea quanto à proporção dos precursores eritroides envolvidos; 5) em pelo menos um caso ocorreu um continuum patologicum até outra forma de LMA (LMA M4), um fenômeno denominado "infidelidade de linhagem". Esse artigo discute essas diferenças e reforça os critérios fundamentais para se estabelecer o diagnóstico definitivo dessa que é a forma mais importante de leucemia em gatos na nossa região.

Intoxicação por organofosforado em bovinos no Rio Grande do Sul

Descreve-se um surto de intoxicação por organofosforado (ORF) em bovinos na mesorregião centro ocidental do Rio Grande do Sul. A água fornecida a 49 bovinos foi contaminada com ORF e carbamato (CM). Vinte bovinos morreram após quadro clínico de poucas horas. Foram observados os clássicos sinais clínicos de hiperestimulação do sistema parassimpático incluindo incoordenação motora, agressividade, sialorreia, tremores musculares e, em alguns casos, diarreia. Na necropsia e histopatologia não foram observadas alterações morfológicas significativas. ORF e CM foram detectados por cromatografia em camada delgada em amostras de tecido de dois bovinos afetados. Adicionalmente, uma amostra da água consumida pelos bovinos foi positiva para ORF e CM e outras duas foram positivas para ORF. Uma análise quantitativa realizada por cromatografia gasosa no conteúdo do abomaso de um bovino afetado, revelou 0,93µg/g de mancozebe (CM) e 0,07 µg/g de forato (ORF).

Linfedema primário congênito em bovinos Red Angus

Casos de linfedema congênito foram observados acometendo 12 terneiros cruza Red Angus na região Central do Rio Grande do Sul. Os terneiros afetados apresentavam graus variáveis de edema subcutâneo ao nascimento, envolvendo principalmente os membros pélvicos, mas também outras regiões do corpo. A injeção de solução a 5% de azul de metileno no espaço interdigital dos membros pélvicos de três terneiros afetados e um controle, indicaram uma interrupção no fluxo da linfa, sugerindo uma falha dos linfáticos periféricos distais em contactar os troncos centrais. Na necropsia de três terneiros afetados, edema subcutâneo foi observado de modo variável nos membros pélvicos, prepúcio e abdômen ventral. Não foi observado edema nas cavidades orgânicas. Em dois casos, observou-se hipoplasia dos linfonodos poplíteos associadas à dilatação dos vasos linfáticos. Testes de DNA demonstraram que todos os terneiros afetados nasceram de vacas inseminadas pelo mesmo touro, sugerindo uma base genética para a doença. Levando em consideração que uma pequena porcentagem de terneiros nasceram de vacas inseminadas pelo touro suspeito, é provável que um modo autossômico recessivo esteja envolvido na hereditariedade da doença.