Histological aspects of the renal sexual segment of Brazilian snakes of the Boidae family

Snakes represent a wide and diverse group of species and have anatomical particularities, such as the renal sexual segment (RSS), a structure located in the kidneys and formed from the hypertrophy of the urinary ducts and nephrons. This study aims at describing the histological aspects of the RSS of Boa constrictor, Epicrates cenchria and Corallus hortulanus, all of which are Brazilian snake species from the Boidae family. The reproductive system and kidneys of five male specimens of E. cenchria, three male specimens of C. hortulanus and two male specimens of B. constrictor were obtained. Tissue samples were processed histologically and different stains used (Toluidine Blue, Alcian Blue and Periodic Acid Schiff). The histological evaluation of the RSS of E. cenchria, C. hortulanus and B. constrictor shows that the RSS in these species varies when comparing individuals in the reproductive period with those which are not. It also allows for the observation of the segment's secretory activity in animals in the reproductive stage (mature sperm in the lumen of the seminiferous tubules) as well as in those which are not. Finally, the histological evaluation also reveals the variation of the secretion product in individuals in the reproductive period, in those which are not, and also among individuals within the same reproductive stage.

Case report of hepatic calodiosis in a rescued dog

Calodium hepaticum (syn. Capillaria hepatica) is a nematode responsible for parasitic zoonosis that can cause granulomatous lesions in the liver. Although murids are the main hosts, C. hepaticum has been documented in a wide range of mammals. Here, we report a case of hepatic calodiosis in a 6-month-old dog that was rescued in the municipality of Cuiabá, Mato Grosso state, midwestern Brazil. Even after being attended at a Veterinary Hospital, the case resulted in animal death. Necroscopic examination revealed significant macroscopic changes in the spleen, liver, and encephalus. Microscopic examination revealed parasitic eggs, identified as Calodium cf. hepaticum, that were rounded to oval with a bilamellar cuticle, radially striated, and with bipolar plugs. Considering the difficulty to diagnose this parasite, and the existence of diverse possible hosts in Mato Grosso due to the biodiversity of the state, further investigation is required to understand the true prevalence of C. hepaticum and the importance of this nematode in public health.

Pathological and etiological characterization of cases of bovine abortion due to sporadic bacterial and mycotic infections

Opportunistic bacteria and fungi are commonly reported causes of bovine abortion in a small percentage of fetal losses of infectious etiology in cattle. The objective of this study was to characterize the pathological and etiological findings in fetuses aborted due to secondary bacterial and fungal infections submitted for postmortem examination between 2004 and 2019 in the State of Rio Grande do Sul, Brazil. Nineteen cases of bacterial etiology and five cases of fungal etiology were assessed. In cases of bacterial etiology, gross changes were uncommon and two different microscopic patterns were observed: (1) primary bronchopneumonia with occasional dissemination in cases of Staphylococcus sp., Streptococcus sp., and Mannheimia haemolytica infections; and (2) systemic disease with sepsis in cases of Escherichia coli and Listeria sp. infections. Aspergillus sp. was the main fungal agent identified, and cases of mycotic abortion were characterized by placentitis, dermatitis, and pneumonia. Fetal membranes were available for examination in less than half of the submissions (11/24), and placental lesions were observed in all cases. This study reaffirms the importance of postmortem examinations in the determination of causes of fetal loss in cattle and highlights pathological findings commonly observed in fetuses aborted due to sporadic bacterial and fungal agents.

An abortion storm in dairy cattle associated with neosporosis in southern Brazil

Between December 2016 and April 2017, a spate of abortions occurred in a closed dairy herd from the central eastern region of Paraná, Brazil, in which 75 cows aborted. To identify its cause, organ fragments were collected from an aborted fetus for histopathology, and the blood samples from a stillborn, 4 aborted fetuses, and 9 farm dogs for indirect fluorescent antibody technique (IFAT). These tests found multifocal non-suppurative encephalitis, periportal hepatitis, and multifocal lymphoplasmacytic myocarditis, and detected anti-Neospora antibodies in all aborted fetuses, and in 5 of the 9 dogs. DNA of Neospora caninum was detected in the brain tissue of an aborted fetus. Blood samples of 340 cows and 146 heifers showed 33.5% and 30.8% seropositivity, respectively. In this closed herd, the parasite was probably introduced by infected domesticated or wild carnivores inhabiting the farm, through the infective oocysts present in their stool.

Histopathological and Immunohistochemical Characteristics of Thyroid Carcinoma in the Dog

Thyroid carcinomas are a common form of endocrine neoplasia in dogs. In the present study, we combined histopathology with immunohistochemistry (IHC) to search for the presence of oestrogen receptor alpha (ORα), Cox-2 and Ki67 in canine thyroid carcinomas. Forty-eight thyroid carcinomas were diagnosed throughout the study period. Thyroglobulin and calcitonin IHC distinguished between thyroid tumours with a follicular and medullary (C-cell) origin, respectively. IHC-based diagnosis showed that 42 (87.50%) of the cases were follicular cell carcinoma. In these cases, the follicular-compact pattern was the most frequent (n = 20/42; 47.62%) and six cases (12.5%) were medullary cell (C-cell) carcinomas. Both medullary (C-cell) and follicular carcinomas expressed Ki67 and Cox-2. No differences were observed between medullary and follicular carcinomas with respect to expression of Ki67 (P = 0.34) and Cox-2 (P = 0.9523) markers. A total of 4.17% (n = 2/48) of thyroid carcinomas showed positive nuclear labelling for ORα, suggesting that oestrogen does not directly participate in the pathogenesis of canine thyroid neoplasia.

Lead Poisoning in Cattle Held in a Military Training area

Background: Lead poisoning is one of the major toxic diseases of cattle. Contamination occurs with ingestion of products containing lead, especially batteries, or through contaminated pastures and water sources. Clinical signs are neurological and necropsy findings and histopathological changes may vary depending on the clinical presentation. Although the diseaseis widely reported in the literature, there are rare descriptions of intoxication in cattle raised in military training areas. This work describes the epidemiological, clinical and anatomopathological features of an outbreak of lead poisoning in cattle kept in a military artillery training camp.Case: Fifteen cattle out of a herd of sixty 4-6 year-old, mixed breed castrated males were affected. The cattle were held in a 100 ha of native pasture used for military artillery training. After three weeks in this area, the affected cattle had predominantly neurological clinical manifestations, characterized by somnolence, ambulatory incoordination, muscle tremors,bruxism, aimless walking, blindness and decubitus. The clinical course was 24-72 h. Eight of the 15 affected cattle died and two were necropsied. Necropsy finds were non-specific and the histological lesions of both necropsied cattle were restricted to the brain and kidneys. Laminar neuronal necrosis, neuropil vacuolization (spongiosis) and vascular endothelial hypertrophy were observed in the telencephalic cortex. Additionally there was astrocytic degeneration and neuronophagia.There was degeneration and necrosis of renal tubular epithelium and in one bovine there were intranuclear inclusion bodies in the renal epithelial cells; these inclusion bodies were highlighted using both modified Ziehl-Neelsen and periodic acid Schiff (PAS) stains. The levels of lead found in the kidneys and livers of the two necropsied cattle were respectively51.7 μg/g and 41.00 μg/g for one of the necropsied cattle; and 431μg/g and 39.0 μg/g for the other. After the diagnosis of intoxication, cattle were removed from the area and the remaining seven affected bovines recovered.Discussion: The diagnosis of lead poisoning in cattle in the current study was based on epidemiological, clinical, anatomopathological data and in the determination of lead levels in the kidney and liver. The association of these data provides an invaluable aid in confirming a presumptive diagnosis of lead poisoning. Pasturing on military artillery training fieldsis a rarely described form source of lead for the intoxication in bovine species. In such cases, cattle may ingest the lead directly from the soil or through contaminated pastures containing lead dust on the surface of the leaves. Histologically, laminar neuronal necrosis in the telencephalic cortex, associated with tubular necrosis and intranuclear inclusion bodies intubular epithelial cells, are characteristic features of the intoxication. These changes are usually associated with ischemic anoxia in the nervous system and alteration in nuclear function which interferes in gene expression in the kidney. Lead poisoning in cattle should be differentiated from other neurological conditions, especially rabies, hepatic encephalopathyand several causes of polioencephalomalacia. Areas of military artillery training are unfit for the development of agricultural exploitation activities, as they represent potential sources of contamination for livestock.Keywords: diseases of cattle, toxicology, heavy metal, polioencephalomalacia.

Kernicterus in an Adult Dog

Background: Kernicterus or bilirubin encephalopathy is a condition rarely observed in animal characterized by a yellowish discoloration of the central nervous system. It is a potentially fatal condition due to bilirubin neurotoxic effects caused by the increase of non-conjugated bilirubin pigment, which passes blood brain barrier and has been attributed to an imbalance between albumin and bilirubin levels. Intracellular bilirubin is toxic for cells and can cause decrease in protein synthesis, specially albumin, depression of cell respiration and cellular death. This paper describes kernicterus in a 2-year-old Great Dane female dog.Case: Clinically, the animal showed apathy, lethargy, weight loss and jaundice, which progressed to vomiting and neurological signs characterized by loss of consciousness and eventually coma. Blood parameters were within normal range, except for high levels of alanine aminotransferase (523 U/L), suggesting a liver lesion. The animal was submitted to euthanasia due to the poor prognosis, and at post-mortem examination it showed dehydration and severe jaundice, especially oral, vaginal and ocular mucosas, subcutaneous tissue and blood vessels intima surface. The liver had an accentuated lobular pattern, and the stomach mucosa was reddened. Multiple petechiae were observed in the epicardium, as well as icterus in the blood vessels of the heart. Furthermore, the brain and cerebellum cortex, thalamic region and nuclei region of brainstemshowed extensive icteric areas. Microscopically, the liver presented a mononuclear portal hepatitis, centrilobular necrosis and presence of yellowish pigments. The brain had neuronal necrosis, mild vacuolization of the white matter, perineuronal edema and Alzheimer type II astrocytes, while cerebellum showed Purkinje cells necrosis. Hepatic cooper measurement was within range values, and direct imunofluorescence for the detection of Leptospira sp. was negative.Discussion: Kernicterus pathogenesis has been extensively studied, as the condition is commonly seen in neonatal humans. Diagnosis is based on gross and microscopic lesions in brain, which are consistent with bilirubin encephalopathy caused by the necrosis and degeneration of neurons. This condition is related to cases of intense hyperbilirubinemia, which exceedsthe albumin binding capacity and, therefore, the excess of unconjugated bilirubin that can pass through the blood brain barrier. Liver disease causes deficient production of protein, especially albumin, decreasing the potential binding capacity to bilirubin, and consequently causing hyperbilirubinemia. In this case, the previously detected hepatic lesion suggested by liver enzymes increased, probably led to protein production dysfunction, causing hypoalbuminemia and hyperbilirubinemia. Unfortunately, albumin and bilirubin seric levels could not be measured. Decrease in albumin production along with the excess of unconjugated bilirubin caused the jaundice, and in cases like this one described, the blood brain barrieris compromised and the kernicterus occurs. Unconjugated bilirubin has negative effect in the glutamate uptake causing extracellular accumulation of it, which is consequently neurotoxic, causing necrosis and degeneration leading to a characteristic encephalopathy in animals with kernicterus. In this report, it was not possible to determine the primary hepatic disease, however this caused clinical neurotoxic disease, known as bilirubin encephalopathy.Keywords: kernicterus, icterus, dog.

Displasia renal em cães: estudo retrospectivo (2008-2013)

Background: Renal dysplasia, which has been reported in some dogs and human patients, refers to a developmental disorder of renal parenchyma due to imperfect inductive interaction between the mesonephric duct and the metanephric blastemal. In dogs, the characteristic histological findings on which diagnosis is based include (1) persistent metanephric ducts surrounded by primitive mesenchyme, (2) fetal or immature glomeruli, (3) fetal or immature tubules, and (4) anomalous presence of interstitial fibrous tissue. The aim of this study was to report the major pathological and immunohistochemical features of nine young dogs necropsied with renal dysplasia.Cases: The necropsy files from the Laboratório de Patologia Veterinária (LPV) of the Universidade Federal do Mato Grosso (UFMT) were reviewed between the years 2008 and 2013. Dogs diagnosed with chronic kidney failure and macroscopic and histopathological renal lesions consistent with renal dysplasia were selected. Kidney fragments in paraffin blocks were cut and stained with hematoxylin and eosin and by immunohistochemistry (IHC) using anti-vimentin and anti-cytokeratin monoclonal antibodies. The staining was considered positive for the presence of at least one renal cell marked with brown cytoplasmic staining clear and unambiguous. A total of 787 necropsies of dogs were performed. Of these, 64 had a clinical diagnosis of chronic renal failure of which 9 were classified as renal dysplasia. The age of the dogs ranged from 3 months to 2 years. Clinical signs were characterized by anorexia and non-regenerative anemia in 88.9%, vomiting 66.7%, dehydration 55.6%, uremia 55.6%, convulsion 33.4%, abdominal pain 22.3% and diarrhea in 11.2% of cases. At necropsy the main macroscopic changes in the kidneys were external surface with pale staining, in 6 of 9 dogs necropsied. Additionally, 5 dogs, cystic cavities of various sizes from 0.1 to 5 cm in diameter, diffusely distributed in the renal subcapsular surface and cutting were observed. Of the 64 dogs with diagnosis of chronic renal failure, 14.06% had dysplastic kidney changes, characterized by dilatation of Bowman’s space, glomerular and tubular atrophy, immature glomeruli and tubules, lymphocytic interstitial inflammation and fibrosis. In the dogs with renal dysplasia, it was observed that the tubular structures showed marked glomerular labeling for vimentin. Moreover, the kidneys of normal dogs showed weak or absent for marking tubes and glomerular structures for vimentin, and strong staining for cytokeratin in tubular cells, glomerular cells and collecting ducts.Discussion: Renal morphological damage observed in these nine dogs less than two years old, that contained degenerative and inflammatory changes, fibrosis and glomerular atrophy, but mostly immature glomeruli and tubules were associated with atypical renal dysplasia. This condition develops when the urethral diverticulum and metanephric blastoma not properly form in the embryonic stage, resulting in abnormal metanephric differentiation and formation of structures that do not recapitulate the normal nephrogenesis. Abnormal kidney function in young animals caused chronic renal failure resulting in death. The results of immunohistochemical observed in this study can complement the diagnosis of renal dysplasia. The morphological normality can be observed in the proportion of mesenchymal and epithelial tissue in the different structures of the kidney by staining with anti-cytokeratin and anti-vimentin. In the present study, there was moderate to strong labeling of vimentin in glomerular and tubular structures being dysplastic kidney would be expected to occur in normal dogs predominant staining with cytokeratin. Based on the clinic, pathological and immunohistochemical findings it is concluded that the animals developed renal dysplasia.

Experimental infection in gerbils by Conidiobolus lamprauges

Conidiobolomycosis is an emerging entomophthoramycosis caused by fungi Conidiobolus spp. Animal models are essential for the study of infectious disease in various areas such as pathogenesis, diagnostic methods, treatment and prevention. There is not currently an animal model for conidiobolomycosis. The aim of this study was to create an experimental infection protocol for Conidiobolus lamprauges in gerbils (Meriones unguiculatus). The study animals were randomly divided into four groups of four animals: immunosuppressed with cyclophosphamide (CPA) and infected with C. lamprauges (G1), immunocompetent and infected with C. lamprauges (G2), immunosuppressed with CPA (G3), and an immunocompetent control group (G4). Clinical signs were observed only in G1 animals, where the mortality rate reached 75% by day 7 after infection (AI) with a median survival of 2 days. C. lamprauges was detected only in G1, both by PCR and by isolation. Necropsies of the G1 animals showed lesions in the nasal cavity and lung tissue. These lesions were characterized by polymorphonuclear infiltrate cells and by the presence of hyphal structures under silver staining. This animal model will be useful for further investigation of diseases caused by C. lamprauges, particularly of those associated with immunosuppression factors in naturally occurring animal infections.

Hemostatic assessment of dogs associated with hepatic parasite load of Leishmania infantum chagasi

Leishmania infantum chagasi liver parasite load was compared to hemostatic abnormalities, as well as to clinical, laboratorial, and histopathological findings in dogs with visceral leishmaniasis. The liver parasite load of 30 dogs L. infantum chagasi naturally-infected was evaluated by quantitative real- time PCR and the results were compared with serum biochemistry and primary and secondary hemostasis findings. Moreover, hepatic histological lesions were described in these dogs. Prolonged bleeding time, prothrombin time (PT), and activated partial thromboplastin time (APTT), were observed in the group with visceral leishmaniasis. Eleven dogs presented inflammatory liver lesions, with predominance of mild multifocal mononuclear periportal hepatitis. No association between the presence of parasites and abnormalities in screening tests was observed by Spearman's rank correlation coefficient. The clinical progression in leishmaniasis is associated with the occurrence of hemorrhagic diathesis, which depends not only on the presence of the parasite but also the inflammatory process, compromised immunological response, hepatic and renal failure in symptomatic dogs.

Ovarian and Uterine Horn Agenesis Accompanied by Ectopic Fetal Mummifcation in Canine

Background: The uterine horn agenesis or aplasia is a rare anomaly consisting of absence or incomplete development of the paramesonephric ducts that origin the uterine horns. This change occurs during fetal formation and may occur concomitantly to agenesis of the ovary and/or ipsilateral kidney. The extra-uterine pregnancy consists of fetal growth outside the uterine cavity and can occur as a tubal or abdominal pregnancy. We report here the case of a 7-years-old mix breed dog, attended at the Veterinary Hospital of the Federal University of Mato Grosso, with accidental diagnosis of agenesis of uterine horn and ovaries and ectopic fetal mummifcation.Case: A 7-years-old mix breed dog, not spayed, was attended at the Veterinary Hospital of the Federal University of Mato Grosso (HOVET-UFMT), complaining of mucous bloody vaginal discharge. The patient had regular estrus and was multiparous. There was no mating history in the last estrus neither trauma over the past months. In previous pregnancies the patientpresented eutocic labors. On physical examination the dog showed apathy although it was alert, pale mucous membranes, presence of perivulvar blackish secretion and discreet abdominal enlargement. As preoperative exams, a complete blood count, liver and renal function (serum creatinine and alanine aminotransferase) were performed. It has also performedthe abdominal ultrasound examination, which revealed the presence of uterus flled with hypoechoic luminal content and a thickened and irregular wall. The patient was referred to therapeutic ovariohysterectomy (OHE). After anesthesia and antisepsis, the access to the abdominal cavity was made, where there was a mummifed fetus with approximately 15.5 cmfrom neck to tail set, equivalent to 57 days of gestation. After removal of the papyraceus fetus, the uterus was found and then, when exposed, there was only the left uterine horn flled by content and ovarie, both were removed. After inspection, the synthesis of the abdominal cavity was carried out as the routine. During the postoperative period, the patient had no complications or other clinical signs similar to those observed in the initial presentation. Antibiotic (enrofloxacin 5 mg/kg every 12h), analgesic (dipyrone 20 mg/kg every 8 h) and non-steroidal anti-inflammatory (meloxicam 0.2 mg/kg every 24 h) were prescribed. The fetus and uterus were sent to the Veterinary Pathology UFMT Laboratory (PVL-HOVET).The fetus was covered by omentum and fat. After the initial incision, there was a hard fbrous capsule surrounding the mummifed fetus. There were no recent signs of rupture or scarring resulting from previous trauma in the uterus. Its size was 15x4.8x2.8 cm and it was flled out with mucus bloody brownish secretion (pyometra). Microscopically, had purulent inflammatory infltrate, diffuse and severe in mucosa and submucosa associated with cell debris and moderate hyperplasia glands containing microabscesses inside.Discussion: Reports of extra-uterine fetal mummifcation in dogs and cats are scarce. Even being reported infrequently in dogs if congenital uterine and ovarian abnormalities are found during surgery, a detailed inspection of the abdominal cavity should be performed in order to rule out the possible presence of the ipsilateral ovary. Even with the lack of specifc clinical signs, fetal ectopy can be diagnosed through a detailed clinical examination and image exams. Exploratory laparotomy can be used as a diagnostic and therapeutic tool, since the treatment is the excision of ectopic tissue and OHE in cases of uterine rupture.Keywords: aplasia, fetus, mummifcation, unicornuate uterus.

Evaluation of hepatitis E virus infection between different production systems of pigs in Brazil

The objectives of this study were to (1) investigate the occurrence of hepatitis E virus (HEV) in pigs from large-scale and family-scale farms, (2) genetically characterize the strains isolated, and (3) study the pathogenesis of swine HEV infection via immunohistochemistry. A total of 50 pigs from 10 farms in Mato Grosso State, Brazil were divided according to type of production system into either large-scale farms (n = 5) or family-scale farms (n = 5). Samples of liver, gallbladder, small and large intestines, bile, and feces from the pigs were analyzed by nested PCR with primers targeting the ORF2 region of HEV and by immunohistochemistry. Of the eight HEV-positive samples from pigs of family-scale farms, phylogenetic analysis revealed that seven of the swine HEV isolates clustered with subtype 3b of genotype 3 and one isolate was categorized with subtype 3 f. The HEV antigen was detected mainly in the small intestine samples from family-scale farms, suggesting an early stage HEV infection. HEV was not detected in the samples of pigs from large-scale farms, reinforcing the need for additional studies to evaluate the risk of transmission of HEV to humans from pigs from family-scale farms in Mato Grosso State.

NATURAL INFECTION BY Trypanosoma cruzi IN ONE DOG IN CENTRAL WESTERN BRAZIL: A CASE REPORT

SUMMARY It is estimated that about 10 million people are infected with Trypanosoma cruzi worldwide, mostly in Latin America and more than 25 million are at risk of acquiring this infection in endemic areas. Dogs are an important reservoir for this pathogen and thus, considered a risk factor for human populations. This report describes one case of Chagas disease in a dog from Cuiabá, Mato Grosso State, Brazil. The diagnosis was obtained by direct examination of trypomastigote forms in blood smears. Amastigotes forms were visualized in microscopy of the bone marrow, lymph nodes, kidneys, liver and brain. The T. cruzi (ZIII) infection was confirmed by Polymerase Chain Reaction, and sequencing. The animal presented multisystemic failure and died. Although acute Chagas disease in humans is not reported in Cuiabá, this is the first report of a canine case in this region. This case represents a warning, to health professionals and authorities, to the possibility of transmission of this zoonosis in Cuiabá.

Pathology of nasal infection caused by Conidiobolus lamprauges and Pythium insidiosum in sheep

Conidiobolomycosis and pythiosis are important diseases of sheep in midwestern Brazil. Veterinary practitioners consider it difficult to differentiate between these diseases because they have similar clinical features. In this study, 186 sheep were subjected to necropsy examination over a 6-year period. Thirty (16.1%) cases of rhinitis in sheep that were caused by Conidiobolus lamprauges (n = 15) or Pythium insidiosum (n = 15) were investigated further. The lesions of C. lamprauges infection were mainly rhinopharyngeal (86.7%), localized to the ethmoidal region and associated with exophthalmos. The lesions appear as a white to yellow, firm mass that microscopically appears as a granulomatous inflammatory reaction with numerous giant cells. In contrast, P. insidiosum infection is associated with rhinofacial (93.3%) lesions that mainly involve the frontal region and hard palate and appear as an irregular, friable, yellow to red mass. Microscopically, pythiosis presents as diffuse necrotizing eosinophilic rhinitis. Immunohistochemistry using polyclonal antisera raised specifically against the two organisms was used to confirm the identity of the infectious agent in each disease. This study reports the first immunohistochemical diagnosis of conidiobolomycosis and the first description of a rhinopharyngeal lesion caused by P. insidiosum in sheep.

Spinal cord compression in cattle after the use of an oily vaccine

An outbreak of compressive myelopathy in cattle associated with the improper use of an oil vaccine is described. Neurological signs were observed in 25 out of 3,000 cattle after 60 days of being vaccinated against foot and mouth disease. The clinical picture was characterized by progressive paralysis of the hind limbs, difficulty in standing up, and sternal recumbency during the course of 2-5 months. A filling defect between the L1 and L3 vertebrae was seen through myelography performed in one of the affected animals. A yellow-gray, granular and irregular mass was observed in four necropsied animals involving the spinal nerve roots and epidural space of the lumbar (L1-L4) spinal cord; the mass was associated with a whitish oily fluid. This fluid was also found in association with necrosis of the longissimus dorsi muscle. Microscopic changes in the epidural space, nerve roots, and spinal musculature were similar and consisted of granulomas or pyogranulomas around circular unstained spaces (vacuoles). These spaces were located between areas of severe diffuse hyaline necrosis of muscle fibers and resembled the drops of oil present in the vaccine.

Spontaneous poisoning by larvae of Perreyia flavipes (Pergidae) in sheep

From a flock of 175 Texel sheep 25 animals died after consumption of a sawfly larvae subsequently identified as Perreyia flavipes. The disease occurred in June-July 2006 on a farm located in the county of Encruzilhada do Sul, Rio Grande do Sul, Brazil. Although there were 11 cattle in the same paddock, none of them was affected. High numbers of compact masses containing up to 150 larvae were scattered in the paddock where the animals were grazing. Most affected sheep showed severe apathy during 24-36 h before death, but weakness, muscular tremors and depression were also observed. Necropsy was performed on six sheep and the main macroscopic lesions were hemorrhages in the subcutaneous tissues, endocardium, gallbladder wall, and abomasal mucosa. In all animals was found hydrothorax, hydropericardium, ascites, and mild jaundice. Edema in the abomasal folds, mesentery, perirenal tissues, and gallbladder wall were also seen. The livers were yellowish with disseminated pinpoint hemorrhages in the parenchyma and had an enhanced lobular pattern. Perreyia flavipes larval body fragments and heads were found in the forestomach contents of the six sheep. Feces were scant, dry and formed balls coated by mucus and streaks of blood. Similar contents were also present at the end of the cecum. Prominent microscopic lesions included severe and diffuse periacinar or massive necrosis of hepatocytes associated with multifocal random hemorrhages. Diffuse necrosis of lymphoid follicles in lymph nodes and Peyer's patches, lymphoid depletion and necrosis in germinative centers of the spleen, and diffuse vacuolization in the renal tubular epithelia were also seen.

Histopathological and immunohistochemical aspects of Neospora caninum diagnosis in bovine aborted fetuses

Lesions suggestive of protozoal infection such as nonsuppurative myositis, nonsuppurative myocarditis, nonsuppurative pneumonia associated with focal cellular necrosis and multifocal necrotizing nonsuppurative encephalitis were observed in 89 (34%) out of 258 aborted bovine fetuses. Immunohistochemistry (IHC) revealed tachyzoites and cysts of Neospora caninum in 55 (61.8%) of these 89 fetuses. Several fetal variables were tested by multivariate logistic regression, in which increasing odds for positivity in IHC were associated with the presence of lesion in the lung (OR=12.11) and less autolytic brain tissue (brain consistency, OR=5.73). However, autolysis in the brain precluded presumptive diagnosis made by histopathology in 53% of the fetuses examined. These results indicate that, when fetal brain is autolyzed, the lung may be adequately used for the presumptive diagnosis of N. caninum infection. The results also confirmed that, even autolyzed, the brain is the most suitable organ for anti-N. caninum IHC.

Immunopathological investigations on bovine digital epidermitis

Paraffin-embedded fragments of bovine digital skin lesions were sectioned and stained with Warthin-Starry, haematoxylin and eosin, Grocott's methenamine silver and immunohistochemical techniques. Microorganisms observed in the silver-stained sections were classified into four major morphological groups. Spirochaetes were the most prevalent organisms, but bacillary and coccoid elements were also present in most sections. Immunohistochemical probing demonstrated that approximately 80 per cent, 46 per cent and 41 per cent of the digital and interdigital dermatitis sections stained positively with polyclonal antisera to Treponema pallidum, Campylobacter jejuni and Fusobacterium necrophorum, respectively. An unidentified branching filamentous organism (presumed to be an actinomycete) was consistently present in the sections of samples from mild interdigital lesions.

Aspectos clínico-patológicos associados à circovirose suína no Rio Grande do Sul

No período de janeiro a julho de 2004, foram realizadas 97 necropsias de suínos que apresentaram subdesenvolvimento, aumento generalizado de linfonodos, palidez ou icterícia de mucosas e, ocasionalmente, problemas respiratórios. As principais lesões macroscópicas encontradas incluíram aumento generalizado de linfonodos, pulmões não colapsados com bordos arredondados e áreas de consolidação, especialmente crânio-ventrais, além de edema de septos interlobulares. Os rins estavam pálidos, aumentados de volume e com pontos brancos que, difusamente distribuídos na superfície, infiltravam em forma de estrias até a zona cortical. Alguns apresentavam pequenos pontos vermelhos, semelhantes a petéquias, difusamente distribuídos no córtex renal. O achado histológico comum foi a presença, em graus variáveis, de infiltrados linfo-histiocitários em linfonodos, pulmões e rins. O teste imuno-histoquímico utilizando anticorpo policlonal anti-circovírus suíno tipo 2 foi positivo em amostras provenientes de 50 (89,2%) entre 56 suínos examinados.

Intoxicação experimental por Trema micrantha (Ulmaceae) em caprinos

Sete caprinos receberam, por sonda esofágica, uma suspensão aquosa de folhas verdes de Trema micrantha moídas e um outro recebeu folhas verdes da planta à vontade. Os sinais clínicos iniciaram-se 2 dias após a ingestão e ocorreram em seis caprinos, cinco dos quais morreram em até 4 dias. Os animais doentes permaneciam longos períodos em estação, com cabeça baixa, olhar fixo, apáticos e inapetentes. Tenesmo, incoordenação e movimentos rítmicos laterais da cabeça também foram observados. T. micrantha mostrou-se tóxica a partir de 30g/kg de peso corporal. A alteração macroscópica mais significativa foi observada no fígado, que se apresentou friável, amarelado e com acentuado padrão lobular. Ao corte, havia áreas vermelhas, deprimidas e entremeadas por áreas mais claras. Em um animal, a coloração do fígado era vermelha, homogênea, mais clara que o normal e sem evidenciação do padrão lobular. Petéquias foram constatadas entre a escápula e o esterno, no epicárdio, no mediastino e nas serosas dos órgãos da cavidade abdominal. A principal alteração histológica foi necrose coagulativa centro-lobular que, em alguns casos, atingia todo o lóbulo, associada à congestão, hemorragia e alterações degenerativas nos hepatócitos circunjacentes. No sistema nervoso, havia tumefação de neurônios, mais proeminente no córtex frontal, associado a edema perineuronal e perivascular.