Felipe Pierezan

Neurological Disease in Cattle in Southern Brazil Associated with Bovine Herpesvirus Infection

The occurrence of neurological disease in cattle caused by Bovine herpesvirus in 11 farms from southern Brazil between 1987 and 2007 is described. Twenty-two animals were necropsied. Major clinical signs included excessive salivation, nasal and ocular discharge, circling, recumbency, depression, incoordination, grinding of teeth, and paddling movements. Necropsy findings in 10 of 22 cattle included hyperemia and softening of the rostral portions of the telencephalic cortex, with flattening of gyri, and malacia. Cattle in 10 cases did not show any gross lesions. Histological examination in most cases revealed nonsuppurative and necrotizing meningoencephalitis with acute neuronal necrosis, edema, eosinophilic intranuclear inclusion bodies in astrocytes and neurons, and infiltration of gitter cells. No histologic lesions could be detected in 4 cases. The initial diagnosis was based upon the clinical, epidemiological, and pathological findings. The diagnosis was confirmed by virus isolation in cell culture followed by virus identification by a glycoprotein C–based polymerase chain reaction. Seven isolates were identified as Bovine herpesvirus 5, and 4 were identified as Bovine herpesvirus 1.

A Retrospective Study of 586 Tumours in Brazilian Cattle

Records from 6,706 necropsy examinations of cattle performed over a 45-year period were surveyed and 586 cases of neoplasia were identified. The organ system most frequently affected by neoplastic disease (n=139 cases) was the alimentary tract. This finding was attributed to a high incidence of squamous cell carcinoma of the upper alimentary tract associated with the chronic ingestion of bracken fern (Pteridium aquilinum). This carcinogenic plant was also associated with a relatively high incidence (n=35 cases) of urinary bladder tumours (enzootic haematuria). Tumours of the alimentary tract were followed, in decreasing order of frequency, by tumours of the skin and subcutis (n=129 cases), haemopoietic tissue (n=101 cases), the eye and periorbital tissues (n=88 cases), the urinary system (n=44 cases), the female reproductive system (n=21 cases), the endocrine system (n=16 cases), the liver and pancreas (n=12 cases), the nervous system (n=6 cases), the respiratory system (n=6 cases) and the mammary gland (n=1 case). The primary anatomical location of 16 tumours was undetermined.

Intoxicações por plantas e micotoxinas associadas a plantas em bovinos no Rio Grande do Sul: 461 casos

From 1990 to 2005, tissues from 2,912 cattle necropsies were examined at the Laboratory of Veterinary Pathology (LPV) of the Federal University of Santa Maria (UFSM), Brazil. These tissues came from necropsies performed by faculty members of the LPV or were mailed-in samples from necropsy performed by veterinarian practitioners. In 461 (15.83%) of these necropsies the cause of death was attributed to the ingestion of poisonous plants. In decreasing order of frequency poisoning by the following plants were registered: Senecio spp (56.14%), Pteridium aquilinum (12.06%), Ateleia glazioviana (10.31%), Solanum fastigiatum (5.04%), Baccharis coridifolia (3.29%), Xanthium cavanillesii (3.07%), Senna occidentalis (2.63%), Ramaria flavo-brunnescens (2.41%), Amaranthus spp (2.19%), Vicia villosa (1.54%), Ipomoea batatas, Prunus sellowii, cytrus pulp (0.44% each), Cestrum parqui, Claviceps paspali, Claviceps purpurea, Brachiaria spp and Lantana sp (0.22% each). In a given outbreak the number of affected cattle was substantially higher than the number of necropsies performed. The following aspects are discussed for each plant: geographical distribution; factors inducing ingestion; morbidity, mortality and lethality rates, clinical signs, necropsy findings, histopathology. For those plants in which information on the active principle and pathogenesis are available, these aspects are included in the discussion.

Epidemiologia, sinais clínicos e distribuição das lesões encefálicas em bovinos afetados por meningoencefalite por herpesvírus bovino-5

Seven outbreaks and an isolated case of meningoencephalitis caused by bovine herpesvirus-5 (BoHV-5) in cattle in Rio Grande do Sul, Brazil, occurring in 2002-2004, are described. From a total population at risk of 1,359 cattle, 54 1-18-month-old calves from both sexes and several breeds were affected and 50 died spontaneously or were euthanatized while moribund. The highest frequency of cases was in recently weaned calves or calves submitted to other stressing factors. General rates of morbidity, mortality and lethality were respectively 3.97, 3.67 and 92.59%. Clinical courses varied from 3-10 days and included depression, nasal and ocular discharge, grinding of teeth, circling, blindness, fever, nistagmus, trembling, anorexia, dysphagia, drooling, incoordination, head pressing, rough hair coat, tachycardia, tachypnea, abdominal pain, melena, falls, recumbency, opisthotonus, convulsions and paddling. Nineteen calves were necropsied. Necropsy findings were characterized by hyperemia of leptomeninges, swollen rostral portions of the telencephalon, and flattening of frontal lobes gyri; frequently in these frontal areas there were segmental brown-yellow discoloration and softening (malacia) of the cortex. In cases with more protracted clinical courses there were extensive swelling, softening and hemorrhaging of the telencephalic frontal lobes. Microscopically, all affected cattle had a necrotizing non-suppurative meningoencephalitis with variable distribution among the 19 cases and among the various telencephalic regions of the same case. The severity of these changes were more marked, in decreasing order of intensity, in the telencephalic frontal cortex, basal ganglia (nuclei), thalamus, brain stem, parietal telencephalic cortex, occipital telencephalic cortex and cerebellum. Perivascular inflammatory infiltrate consisted predominantly of lymphocytes, plasm cells, and less frequently of neutrophils. Additional microscopic findings included variable degrees of gliosis, edema, neuronal necrosis in the telencephalic cortex characterized by shrinking and eosinophilia of perikaria and nuclear picnosis (red neuron); basophilic intranuclear inclusion bodies in astrocytes and neurons (21.05% of the cases); sattelitosis; and neuronophagia. The areas of softening in the cortical substance consisted of necrosis of the neuroctodermal elements with maintenance of mesenchymal structures (vessels and microglia), infiltrate of Gitter cells, and, in more severe cases, extensive hemorrhages. In chronic cases, only vascular structures and a few Gitter cells remained in the cortical area leaving a cavity between white matter and leptomeninges (residual lesion).

Doenças de bovinos no Sul do Brasil: 6.706 casos

The diseases affecting cattle in southern Brazil were studied through a review of the necropsy reports filed at the Laboratorio de Patologia Veterinaria of the Universidade Federal de Santa Maria (LPV-UFSM), Rio Grande do Sul, and pertaining to the examination of 6.076 cattle during 1964-2008. Of those exams 29.9% were necropsies performed at the LPV-UFSM and 79.1% were mailed-in organ fragments from necropsies performed at the field by veterinary practitioners. Autolysis and non-representative sampling o mailed in organs were the main reasons for non-conclusive diagnosis. Poisoning by Senecio spp. was the main cause of death in cattle in this study and poisonous plants together with toxi-infections accounted for 22.8% of the cases with conclusive diagnosis. Inflammatory diseases together with parasitic diseases accounted for more than 30% of cattle diseases and babesiosis and anaplasmosis were the main diseases in this category. Other categories were distributed in the following order: neoplasms and tumor-like lesions (13.87%), diseases caused by physical agents (2.7%), metabolic and nutritional diseases (2.46%), circulatory disturbances (1.4%), degenerative diseases (1.1%), developmental disorders (0.54%), iatrogenic diseases and sundry lesions. The high prevalence of tumors in cattle in this study was attributed to the chronic ingestion of Pteridium aquilinum, a common toxicosis in the region. The main diseases in cattle from the studied region are related to environmental factors associated to the predominantly husbandry practices adopted in the region.

Aceturato de diminazeno e dipropionato de imidocarb no controle de infecção por Trypanosoma evansi em Rattus norvegicus infectados experimentalmente

The aim of this study was to evaluate the efficacy of diminazene aceturate and imidocarb dipropionate in the control of Trypanosoma evansi infection in rats (Rattus norvegicus) experimentally infected. Fifty-four male rats were inoculated through intraperitoneal route with 104 T. evansi trypomastigotes. The rats were evaluated daily by periferic blood smears examination and treated when eight flagellated parasites were observed in 1000x microscopic field. Two therapeutics protocols were used. The first one included Groups A, B, C, D in which the rats were submitted to a single dose of the testing drugs administered by intramuscular route at the day 0 and again when T. evansi was observed in the blood smears. The rats of the second protocol (Groups E, F, G, H) were submitted to the same treatment by five consecutive days. Four rats (Group I) were used as control and were not submitted to any treatment. Tested drugs did not show any curative effect when used in the first protocol, since parasitaemia was evident few days after treatment. The use of diminazene aceturate in the second protocol resulted in elimination of the trypomastigotes from circulation. In this case the rats were euthanized at the day 90. The infection recurred 30 days after the administration of imidocarb dipropionate. Histologically, no lesions were found in the liver or kidney. Diminazene aceturate is effective in treating trypanosomosis in rats when used five days consecutively.

Achados de necropsia relacionados com a morte de 335 eqüinos: 1968-2007

The necropsy reports of 335 horses necropsied at the LPV-UFSM between 1968-2007 were reviewed in order to determine the necropsy findings related with cause of death or reason for euthanasia. The distribution of these findings by organ system were as follows: digestive (79/335 [23.6%]), striated muscle and skeleton (47/335 [14.0%]), nervous (37/335 [11.0%]), respiratory (35/335 [10.4%]), integument (31/335 [9.3%]), hematopoietic (24/335 [7.2%]), cardiovascular (13/335 [3.9%]), reproductive (12/335 [3.5%]), urinary (7/335 [2.1%]), and endocrine (3/335 [0.9%]). The cause of death was not possible to be determined in 47 (14.0%) necropsied horses. Displacements of the intestines (17/79 [21.5%]) were the main findings in digestive system, followed by obstruction and impactation (14/79 [17.7%]). Torsion were the type of displacement more frequently observed in the intestines (14/17 [82.4%]). Among those the more prevalent affected the small intestine (7/14 [50%]). Most horses dying from fractured bones were 1-5-year-old. The most prevalent diseases in the nervous system were leukoencephalo-malacia and trypanosomiasis, whereas respiratory depression due to anesthesia was the leading cause of death related to the respiratory system. Equine infectious anemia was the most diagnosed infectious disease and the main reason leading to euthanasia.

Doenças de ovinos da região Central do Rio Grande do Sul: 361 casos

An 18-year (1990-2007) database search in the files of the Laboratory of Veterinary Pathology (LPV) of the Universidade Federal de Santa Maria (UFSM), Rio Grande do Sul state, Brazil was carried out. In this period, 19,476 exams in domestic animals were done. Out of these exams, 6,816 (34.9%) were necropsies and 12,660 (65.1%) were performed in mailed samples from practitioners. Experimental cases were excluded from this study and corresponded to 54 necropsies and 15 histopathologic exams. After the exclusion 354 (5.1%) necropsies and 163 (1.2%) histopathologic exams were found in sheep. Out of these, 265 (74.8%) cases were conclusive in the group of necropsies and 96 (59%) were conclusive in the group of the histopathologic exams. The resulting 361 conclusive cases were grouped according to the etiology: 150 (41.6%) cases of poisoning or toxi-infections; 142 (39.3%) cases of infectious and parasitary diseases; 31 (8.6%) of metabolic and nutritional diseases; 13 (3.6%) cases of neoplasms and neoplasm-like lesions; 7 (1.9%) cases of diseases caused by physical agents; 6 (1.7%) cases of iatrogenic conditions; and 4 (1.1%) of developmental diseases. Eight cases did not fit in any of the above categories and were grouped under the denomination of other conditions. Hemonchosis and poisoning by Nierembergia veitchii were the most prevalent diseases in sheep during the 18 years of this study.

Intoxicação por Solanum fastigiatum (Solanaceae) em bovinos: epidemiologia, sinais clínicos e morfometria das lesões cerebelares

Nineteen cases of Solanum fastigiatum (Solanaceae) poisoning in cattle from three municipalites in the State of Rio Grande do Sul, Brazil, occurring from 2003 to 2005, are described. Morbidity and mortality rates were respectively 6.7% and 3.4%. Average age of affected cattle was five-year-old (2 to 8-year-old) and duration of clinical courses was 3-18 months. Clinical signs observed in all affected cattle were cerebellar deficits characterized by hypermetry, incoordination, falls, muscle tremors, transitory seizures and wide base stance. One affected bovine had encephalic traumatic subdural hemorrhage and another had gross atrophy of the cerebellum. Histologically, lesions were restricted to the cerebellum and consisted of partial or complete vacuolation of the perikaria of Purkinje neurons with occasional axonal spheroids in the granular cell layer and in the white matter of the cerebellum. In advanced cases there were extensive loss of cerebellar Purkinje neurons and proliferation of the Bergmanns glia. The morphometric evaluation of the numbers of Purkinje neurons and of the thickness of the cerebellar molecular layer indicated decreased numbers of Purkinje neurons with consequent decrease in the molecular layer thickness.

Forma nervosa de listeriose em caprinos

A neurologic disease was observed in three young adult goats (indentified as A-C) from a herd of 100 goats during October-December, 2004. Clinical signs included head tilt, torticollis, nystagmus, staggering, falls and eventually recumbency and paddling, with stiff limbs. Treatment of Goat C with antibiotics resulted in a temporary remission of the clinical signs. The clinical courses where 5, 10 and 30 days respectively for Goats A, B and C. Goat A died spontaneously and the other two where euthanatized in extremis. No gross changes were observed. Histologic lesions were predominantly unilateral, with inflammatory and degenerative changes, extending from the medulla oblongata to the thalamus. In all 3 cases there were perivascular cuffings of one or more types of mononuclear cells (lymphocytes, plasma cells, activated macrophages) and occasionally neutrophils associated with areas of malacia where Gitter cells filled spaces of parenchymal loss. Additionally, Goat B had microabscesses in the medulla, pons, and mesencephalon and multifocal neutrophilic and lymphocytic infiltrates within the fascicles of the trigeminal nerve and in the cerebellar leptomeninges. In the brainstem of Goat C, there was multifocal granulomatous inflammation which included epithelioid macrophages and occasional multinucleated giant cells. Listeria sp antigen was detected by imunohistochemistry in routinely processed sections of mesencephalon from Goats A and C and of pons from Goat B.