A. F. M. Dantas

Intoxicação por Crotalaria retusa (Fabaceae) em Eqüídeos no semi-árido da Paraíba

From 2000 to 2003 eight cases of poisoning by Crotalaria retusa L. were observed in horses on 8 farms in the semiarid region of Paraiba and Ceara. C. retusa was found in all farms. The main clinical signs were characteristic of hepatic encephalopathy, with dullness or hyperexcitability, head pressing, compulsive walking or circling and, occasionally, violent uncontrollable galloping. Decreased cranial nerve reflexes, ataxia and weakness were also observed. Other clinical signs were anorexia, weight loss, photosensitization and jaundice. The clinical manifestation period varied from 4 to 40 days, but most horses had a previous history of weight loss. At necropsy the livers were hard, with irregular surface and white areas mixed with dark red areas and increased lobular pattern. Mild jaundice, ascitis, hydropericardium and hydrothorax were also observed. Edema and moderate congestion were seen in the lungs. Histologic changes of the liver were characterized by fibrosis, mainly periportal, megalocitosis and bile duct cell proliferation. Multifocal areas of centrilobular or midzonal hemorrhages were also observed. Centrilobular hemorrhagic necrosis was present in two horses. Alzheimer type II astrocytes were observed, isolated or in groups, mainly in the caudate nucleus and cortex in 4 horses. The poisoning was experimentally produced in 1 adult horse and 3 adult donkeys. The horse received daily 100 g of C. retusa seeds and died 52 days after the beginning of the experiment. The dried whole C. retusa was mixed with grass and given to the 3 experimental donkeys at daily doses of 10g/kg, 5g/kg and 2.5g/kg, respectively. The donkey treated with 5g per kg died 48 days after beginning of the experiment and the other two were sacrificed at 120 days. Clinical signs and pathology were similar to those observed in spontaneous cases, but Alhzeimer type II astrocytes were observed only in the donkey that died 48 days after the beginning of ingestion of the plant material. The concentration of monocrotaline in the whole plant given to the donkeys was 0.5%.

Mimosa tenuiflora as a Cause of Malformations in Ruminants in the Northeastern Brazilian Semiarid Rangelands

Craniofacial anomalies, eye malformations, and permanent flexures of the forelimbs are common malformations seen in ruminants grazing semiarid rangelands of Northeastern Brazil. To investigate the cause of these malformations, we fed 2 suspected plants, Mimosa tenuiflora or Prosopis juliflora, to groups of 4 pregnant goats each. Fresh green M. tenuiflora was collected daily and fed ad libitum to 4 goats in group 1 throughout pregnancy. This treatment group also received a supplemental feed concentrate equivalent to 1% body weight. Four goats in group 2 received a ration with 70% of P. juliflora pods and 30% hay throughout pregnancy. Four control goats were fed supplemental feed concentrate (1% body weight) and hay ad libitum throughout pregnancy. Goats treated with P. juliflora pods and the control goats delivered 9 normal kids. The four goats that were fed M. tenuiflora during pregnancy delivered 4 kids, 3 of which had abnormalities similar to those observed in field cases, including cleft lip, unilateral corneal opacity, ocular bilateral dermoids, buphthalmos with a cloudy brownish appearance of the anterior chamber due to an iridal cyst, and segmental stenosis of the colon. Malformations induced experimentally by M. tenuiflora were similar to those observed in field cases, suggesting that M. tenuiflora is a cause of the field cases observed in the Brazilian semiarid rangelands.

Doenças do sistema nervoso central em caprinos e ovinos no semi-árido

The knowledge of the diseases of domestic animals in the different Brazilian regions is important to determine measures for their control and prevention. The objective of this paper is to report the epidemiology, clinical signs and pathology of the diseases of the central nervous system (CNS) of goats and sheep in the Brazilian semiarid, mainly in the state of Paraiba, diagnosed at the Veterinary Hospital of the Federal University of Campina Grande, from January 2000 to May 2006. During the period, 365 cases or outbreaks were diagnosed in goats and 270 in sheep. From these, 63 (9.92%) were of diseases of the CNS, being 34 (9.31%) in goats and 29 (10.7%) in sheep. The main diseases were abscesses (19.04%), tetanus (15.9%), rabies (9.52%) poisoning by Ipomoea asarifolia (7.93%), listeriosis (6.34%), traumatism (6.34%), polioencephalo-malacia (4.77%), pregnancy toxemia (3.17%), enzootic ataxia (3.17%), and meningitis (3.17%). Other diseases diagnosed in only one opportunity (1.59%) were intoxications by Crotalaria retusa, Ipomoea carnea, Ipomoea sericophylla and Prosopis juliflora, otitis with encephalitis, malformation, lymphoblastic lymphosarcoma, medulloblastoma, and focal symmetric necrosis. In 6.34% of the cases diagnosis was unknown.

Poisoning of sheep by seeds of Crotalaria retusa: Acquired resistance by continuous administration of low doses

Seeds of Crotalaria retusa containing 6.84% (dry weight) of monocrotaline (MCT) were administered experimentally to sheep. Three sheep that received 136.8mg MCT/kg bw daily for 70 days had no clinical signs. Five out of six sheep ingesting single doses of 205.2 and 273.6mg MCT/kg bw died with acute (three sheep) or chronic intoxication (two sheep). Acute intoxicated sheep had periacinar liver necrosis and chronic intoxicated sheep liver fibrosis and megalocytosis. Another three sheep had no clinical signs after the ingestion of 20 daily doses of 136.8mg MCT/kg, followed by seven doses of 273.6mg MCT/kg, and one single dose of 342mg MCT/kg. These experiments demonstrated that sheep are susceptible to acute intoxication by MCT being intoxicated by a single oral dose of approximately 205.2mg/kg. In contrast, they develop strong resistance to MCT after the daily ingestion of non lethal doses (136.8mg/kg). It is suggested that chronic poisoning does not occur by the repeated ingestion of non acutely toxic doses, but probably by the ingestion of single toxic doses. It is also suggested that sheep do not become intoxicated with the ingestion of C. retusa in the vegetative non-seeding stage.

Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil

Dois surtos de lesoes rinofaciais e dois de lesoes rinofaringeas causadas por fungos com hifas filamentosas, raramente septadas, semelhantes as dos fungos entomophthorales, sao descritos no Estado da Paraiba. Um surto da forma rinofacial afetou 5 ovinos durante a estacao chuvosa. Outro surto desta forma clinica afetou um ovino de um grupo de 40, durante a epoca seca. Os sinais clinicos da forma rinofacial foram de corrimento serosanguinolento bilateral, com aumento de volume das narinas, labio superior, e pele da face. Na necropsia, a mucosa nasal apresentava areas ulceradas de cor marrom escuro, que se estendiam desde a regiao muco-cutanea ate 10cm dentro do vestibulo nasal. A mucosa do palato duro estava, tambem, ulcerada. A superficie de corte das narinas e palato apresentava-se marrom ou avermelhada de aspecto esponjoso e friavel. Um surto de rinofaringite micotica ocorreu em uma plantacao de coco irrigado, afetando 7 ovinos de um rebanho de 60 ovinos adultos. Outro surto desta forma da enfermidade afetou um unico animal de um rebanho de 80, durante a epoca seca. Os animais apresentavam dispneia, com respiracao ruidosa devida ao bloqueio parcial das narinas, e corrimento nasal serosanguinolento. Seis dos oito animais afetados por esta forma da enfermidade apresentaram, em um olho, exoftalmia, ceratite e ulceracao da cornea. Todos os ovinos morreram ou foram sacrificados apos um curso clinico de 7-30 dias. Na necropsia exsudato amarelo consistente foi observado na regiao etmoidal, ossos turbinados, seios paranasais, palatos duro e mole, orbita, faringe, e musculos e linfonodos regionais. No estudo histologico, ambas as formas da doenca mostraram granulomas multifocais com areas necroticas eosinofilicas (material de Splendore-Hoeppli) contendo hifas com 7-30mm de diâmetro, raramente septadas, semelhantes as dos fungos entomophthorales, possivelmente Conidiobolus spp. Surtos de ambas as formas de rinite micotica sao frequentes na regiao semi-arida e em outras regioes do Brasil.

Outbreaks of Eastern equine encephalitis in northeastern Brazil

Outbreaks of eastern equine encephalitis observed from May 2008 to August 2009 in the Brazilian states of Pernambuco, Ceará, and Paraíba are reported. The disease occurred in 93 farms affecting 229 equids with a case fatality rate of 72.92%. Main clinical signs were circling, depression or hyperexcitability, ataxia, and progressive paralysis with a clinical manifestation period of 3–15 days. Main histologic lesions were a diffuse lymphocytic encephalomyelitis with neuronal death, satellitosis, neuronophagia, and hemorrhages being more severe in the cerebral gray matter of the telencephalon, diencephalon, and mesencephalon. Some animals also had areas of malacia in the telencephalon, thalamus, and basal nuclei. From 1 case, the virus was isolated by mice inoculation, and in other 13 cases was identified as Eastern equine encephalitis virus by semi-nested reverse transcription polymerase chain reaction. After DNA sequencing, all samples were identified as eastern equine encephalitis through the BLASTn analysis, but samples from the Ceará and Paraíba states corresponded to the same cluster, while the sample from the state of Pernambuco corresponded to a different cluster.

Intoxicação por alcaloides pirrolizidínicos em ruminantes e equinos no Brasil

Casos de intoxicacao por alcaloides pirrolizidinicos (APs) em ruminantes e equinos foram investigados retrospectivamente atraves do acesso aos arquivos de dois laboratorios de diagnostico veterinario no Sul e Nordeste brasileiro. Os dados obtidos foram comparados com aqueles retirados da literatura concernentes a surtos dessa toxicose no Brasil, onde ela e associada com a ingestao de plantas que contem APs dos generos Senecio, Crotalaria e Echium. Formas aguda e cronica da toxicose foram encontradas. A doenca aguda foi observada em associacao com a ingestao de Crotalaria retusa em ovinos e caprinos. C. retusa e Senecio spp. tambem foram responsaveis pela intoxicacao cronica em bovinos, equinos e ovinos. A intoxicacao por APs e uma importante causa de morte em animais pecuarios no Brasil. Essa e a principal causa de morte em bovinos na regiao Central do Rio Grande do Sul e uma das principais causas de morte em equinos na Paraiba. A epidemiologia, os sinais clinicos, a patologia e a importância da intoxicacao por APs sao descritos e discutidos.

Platynosomum fastosum-induced cholangiocarcinomas in cats

Platynosomum fastosum is a feline biliary tract trematode that generally causes asymptomatic infections. In the early 1980s in Brazil, P. fastosum was associated with cholangiocarcinomas, but this finding was not confirmed in the various publications on the parasite during the last 30 years. This study aims to report three cases of cholangiocarcinomas in cats associated with the presence of P. fastosum. From 2000 to 2011, in the Veterinary Hospital of the Federal University of Campina Grande in northeast Brazil, 348 cats were necropsied, 11 of which (3.16%) were parasitized by P. fastosum. Three cases that resulted in death were associated with cholangiocarcinomas that were found to be associated with P. fastosum. Histologically, the tumors consisted of acini composed of cells with pleomorphic nuclei, loose chromatin, evident nucleoli and lightly eosinophilic cytoplasm. Metastases were observed in two cases. The first case involved metastases to the lungs, kidneys, ovary and peritoneum, and in the second case, the lymph nodes, kidneys, heart and encephalon were involved. The other 8 cats died from other causes, and the parasite was an incidental finding. In those cases, the histologic lesions were nonsuppurative cholangiohepatitis and periductal fibrosis with P. fastosum present. Six animals also showed pre-neoplastic changes (hyperplasia and dysplasia) of the biliary duct epithelium. The study concluded that, as observed in other human biliary tract trematodes, P. fastosum causes cholangiocarcinomas in the liver of cats.

High mortality and lesions of the central nervous system in trypanosomosis by Trypanosoma vivax in Brazilian hair sheep.

Here, we report an outbreak of Trypanosoma vivax-induced trypanosomosis in Brazilian hair sheep on a farm in Paraíba state, a non-endemic region in northeastern Brazilian. Of 306 total sheep, 240 showed clinical signs and 216 died. Clinical signs included anorexia, lethargy, anemia, rough hair coat, weight loss, submandibular edema, abortion, and in some cases, neurological signs such as head pressing, lateral recumbence, paddling movements and muscle tremors. T. vivax was identified by blood smear analysis and polymerase chain reaction (PCR). At necropsy, animals exhibited watery blood, pale tissue coloring, and the presence of liquid in the peritoneal cavity and pericardial sac. Histologically, nonsuppurative myocarditis and meningoencephalitis with areas of malacia were observed. After treatment, no parasites were detected by blood smear analysis or PCR. Cattle and buffalo that remained in the same pasture were also infected but presented with asymptomatic infections. Epidemiological data suggest that T. vivax was introduced to the farm and the susceptible flock by buffalos that were asymptomatic carriers of the infection; T. vivax was most likely transmitted by Tabanus spp. bites and also iatrogenically.

Doenças do sistema nervoso de bovinos no semiárido nordestino

Diseases of the nervous system of cattle in the semiarid region of northeastern Brazil were evaluated by a retrospective study of 411 cattle necropsies performed in the Veterinary Hospital of the Federal University of Campina Grande, Patos, Paraiba, from January 2000 to December 2008. Of the 411 cases analyzed, 139 (33.81%) were from cattle that presented nervous signs and the records were reviewed to determine the epidemiological, clinical, and macroscopic and histologic main features. Diagnosis was inconclusive in 28 cases (20.14%). In cases with diagnosis the main diseases were rabies (48.7% of the cases with nervous signs), brain abscesses (7.2%) including three cases of pituitary abscesses, malignant catarrhal fever (6.3%), botulism (6.3%), congenital malformations (4.5%), trauma (4.5%), tuberculosis (2.7%), tetanus (2.7%), infection by bovine hervesvirus-5 (2.7%), non-suppurative encephalomyelitis (2.7%), intoxication by Prosopis juliflora (2.7%), congenital status spongiosus of unknown etiology (1.8%), and polioencephalomalacia (1.8%). Other diseases diagnosed only once (0.9%) were cryptococcosis, listeriosis, thromboembolic encephalitis, lymphosarcoma, trypanosso-miasis, and babesiosis by Babesia bovis.