Luciano A. Pimentel

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.

Malformações congênitas em ruminantes no semiárido do Nordeste Brasileiro

Congenital malformations caused by the ingestion of Mimosa tenuiflora have been reported in ruminants in the semiarid of the Brazilian Northeast. This paper reports malformations diagnosed in ruminants, from 2000 to 2008, by the Veterinary Pathology Laboratory of the Federal University of Campina Grande, Patos, PB, in municipalities of the states of Paraiba, Pernambuco and Rio Grande do Norte. During the period, 47 (3.48%) out of 1.347 ascensions were reported as malformations. Based in the type of malformation and in the origin of the animals, malformations were divided in: 1) caused by the ingestion of M. tenuiflora, and 2) sporadic malformations of unknown causes. In sheep, 21 out of 418 ascensions were malformations, being 18 (4.3%) of malformations caused by M. tenuiflora and 3 (0.71%) of sporadic malformations. In cattle, 14 out of 434 ascensions were malformations, from these 8 (1.84%) were caused by M. tenuiflora and 6 (1.38%) were sporadic malformations. In goats, 12 out of 495 ascensions were malformations, being 9 (1.81%) malformations related with the ingestion of M. tenuiflora and 3 (0.6%) sporadic malformations. More frequent malformations caused by M. tenuiflora were arthrogryposis, micrognatia, palatoschisis, microphtalmia and unilateral or bilateral hypoplasia or aplasia of the incisive bones. Sporadic malformations were acephaly and hermaphrodite, dicephaly and malformations of mesenteric vessel in sheep; atresia ani in three goats; and hydranencephaly, atresia ani, ribs malformation with eventracion, cerebellar hypoplasia with hydrocephalus, pulmonary choristoma and meningocele, and siamese twins in cattle. A case of cerebellar hypoplasia with hydrocephalus was negative on immunohistochemistry to bovine viral diarrhea virus. Malformations caused by M. tenuiflora occurred during the whole year. The highest frequency in sheep seems to be associated with the consumption of the plant by ewes after first rains, in the first two months of gestation, when they are supplemented with concentrates, and M. tenuiflora is the main green forage available. Malformations occur mainly in degraded areas of native forest (caatinga) invaded by M. tenuiflora, with lesser variety of other species.Congenital malformations caused by the ingestion of Mimosa tenuiflora have been reported in ruminants in the semiarid of the Brazilian Northeast. This paper reports malformations diagnosed in ruminants, from 2000 to 2008, by the Veterinary Pathology Laboratory of the Federal University of Campina Grande, Patos, PB, in municipalities of the states of Paraiba, Pernambuco and Rio Grande do Norte. During the period, 47 (3.48%) out of 1.347 ascensions were reported as malformations. Based in the type of malformation and in the origin of the animals, malformations were divided in: 1) caused by the ingestion of M. tenuiflora, and 2) sporadic malformations of unknown causes. In sheep, 21 out of 418 ascensions were malformations, being 18 (4.3%) of malformations caused by M. tenuiflora and 3 (0.71%) of sporadic malformations. In cattle, 14 out of 434 ascensions were malformations, from these 8 (1.84%) were caused by M. tenuiflora and 6 (1.38%) were sporadic malformations. In goats, 12 out of 495 ascensions were malformations, being 9 (1.81%) malformations related with the ingestion of M. tenuiflora and 3 (0.6%) sporadic malformations. More frequent malformations caused by M. tenuiflora were arthrogryposis, micrognatia, palatoschisis, microphtalmia and unilateral or bilateral hypoplasia or aplasia of the incisive bones. Sporadic malformations were acephaly and hermaphrodite, dicephaly and malformations of mesenteric vessel in sheep; atresia ani in three goats; and hydranencephaly, atresia ani, ribs malformation with eventracion, cerebellar hypoplasia with hydrocephalus, pulmonary choristoma and meningocele, and siamese twins in cattle. A case of cerebellar hypoplasia with hydrocephalus was negative on immunohistochemistry to bovine viral diarrhea virus. Malformations caused by M. tenuiflora occurred during the whole year. The highest frequency in sheep seems to be associated with the consumption of the plant by ewes after first rains, in the first two months of gestation, when they are supplemented with concentrates, and M. tenuiflora is the main green forage available. Malformations occur mainly in degraded areas of native forest (caatinga) invaded by M. tenuiflora, with lesser variety of other species.

Doenças do sistema nervoso central de equídeos no semi-árido

Diseases of the central nervous system (CNS) in equidae are important in these species, and their knowledge in the different Brazilian regions is necessary to determine efficient control and preventive measures. This paper reports epidemiologic aspects, clinical signs and pathology of diseases of the CNS in equidae diagnosed by the Veterinary Pathology Laboratory at the Federal University of Campina Grande in the city of Patos, state of Paraiba, northeastern Brazil, during 2002-2008. During the period, 159 cases or outbreaks of those diseases were studied, 49 (30.8%) affecting the CNS. Hepatic encephalopathy caused by Crotalaria retusa poisoning, with 14 cases (28.5%), was the main disease observed. Tetanus was diagnosed in 13 (26.5%) cases and rabies in 11 (22.4%). In seven (14.2%) cases the death or euthanasia was due to traumatic lesions of the CNS. Also were diagnosed 1 case of leucoencephalomalacia, 1 case of encephalitis by equine herpesvirus-1, 1 case of intracarotid artery injection, 1 outbreak of Eastern equine encephalitis, 1 of Turbina cordata poisoning, and 1 of a tremogenic disease of unknown cause. In 5 cases the diagnosis was inconclusive. This paper indicates the importance of diagnostic veterinary laboratories, in the different Brazilian regions, for the knowledge of livestock diseases.

Fotossensibilização primária em eqüídeos e ruminantes no semi-árido causada por Froelichia humboldtiana (Amaranthaceae)

Photosensitization is common in the Brazilian semiarid, affecting mainly horses, but also donkeys, mules, sheep and cattle. The dermatitis affects mainly non pigmented skin, and the animals recover after being withdrawn from the pastures. To demonstrate the etiology of the disease, Froelichia humboldtiana (Roem. et Schult.) Seub., collected in the field one or two times a week and kept in the refrigerator for 1-4 days, was administered for 30 or more days as the only food ad libitum to 2 donkeys and one white sheep, and as the only forage ad libitum, to one white horse. No clinical signs were observed in those animals, and serum activities of aspartate-aminotransferase (AST), alanine-aminotransferase (AST), and gamma-glutamyltransferase (GGT) were within normal ranges. In another experiment, one sheep was tied by a rope, during the day, in a pasture of exclusively F. humboldtiana for a 26 days period. Skin lesions characteristic of photosensitization appeared 4-5 days after the start of the experiment and became severe until day 26. After the withdrawal of the animal from the pasture on day 26 it fully recovered within 30 days. In another experiment, 4 sheep were tied by ropes in the same pasture, during the day, for a 29 days period. Another 4 control sheep were maintained in a neighboring pasture without F. humboldtiana. Skin lesions characteristic of photosensitization were observed after 11-25 days of F. humboldtiana grazing. Serum activities of AST and GGT, and serum levels of bilirubin were within normal ranges. At the end of the 29 days grazing F. humboldtiana, 2 sheep were euthanized, and 2 were withdrawn from the pastures. No gross or histologic liver lesions were observed on the 2 sheep euthanized; the other 2 sheep recovered within 17 and 20 days after the end of grazing. One mare and its foal grazed in the same pasture during 44 days. The mare that had a pigmented skin had no dermatitis, but the foal showed dermatitis on the white areas of the skin after 25 days of grazing. The two horses were withdrawn from the pastures after 44 days grazing, and the foal fully recovered within 15 days. These experiments indicate that F. humboldtiana causes primary photosensitization in domestic animals. The absence of lesions in animals ingesting the plant collected in the field and kept refrigerated suggests that F. humboldtiana lost toxicity after collection. The absence of lesions in the eyes of affected animal, which are characteristic of primary photosensitization caused by furocoumarins containing plants, suggests that F. humboldtiana contains a naphthodianthrone derivate, similar to those found in Fagopyrum esculentum and Hypericum perforatum which do not cause eye lesions.

Aversão alimentar condicionada no controle de surtos de intoxicações por Ipomoea carnea subsp. fistulosa e Turbina cordata em caprinos

Conditioned food aversion is used to train livestock to avoid the ingestion of toxic plants. This technique was used to control Turbina cordata poisoning in goats in one farm, and to control Ipomoea carnea subsp. fistulosa poisoning in another farm. The goats were penned at night and the next morning the green plants were offered for 10 minutes. Goats that ingested any amount of the plant were treated through a gastric tube with 175mg of LiCl/kg body weight. In the flock in which the poisoning by T. cordata was occurring, the goats were averted every two months during the period that the plant was found in the pastures. During the experiment, from December 2009 to April 2011, new cases of poisoning were not observed, and there was a progressive decrease in the number of goats that ingested the plant and were averted. In the farm where I. carnea poisoning was occurring, most of the goats were averted in December 2010, 15-20 days before the first rains. The goats of this flock did not ingest the plant spontaneously in the field until September-October 2011, when, due to the dry season, there was a severe forage shortage, and the goats started to ingest the plant in the field. Later, despite three aversive treatments with 21 days intervals, the goats continued to ingest the plant and some animals became poisoned. In conclusion, conditioned food aversion was effective in to control intoxication by T. cordata. The technique was also effective in conditioning goats to avoid consuming I. carnea during the rainy season, but not during the dry season, with low forage availability in the field. The differences in these results seem to be due to the epidemiology of both poisonings: T. cordata is senescent and unavailable during most of the dry period, and green biomass is typically available either at the very end of the dry season, for a short period of time, and during the rainy season when there is no shortage of forage. In contrast, I. carnea grows in wet areas near water sources, and stays green during the dry period when there is a lack of other forage.

Intoxicação por Cnidoscolus phyllacanthus (Euphorbiaceae) em caprinos

Cnidoscolus phyllacanthus (Euphorbiaceae), with the common name favela, is a generally spiny plant of the Brazilian semiarid. Mainly during the dry season livestock browse its leaves from the shrubs or ingest the dry leaves fallen to the ground. Farmers report the spontaneous poisoning by this plant when livestock has access to shrubs or branches that had been cut. Different parts of the ground fresh plant, diluted in water, are used by people in the semiarid to hunt birds. To determine the toxicity of C. phyllacanthus, leaves of the non-spiny plant were fed by hand to a goat by putting small amount into its mouth. After the consumption of 4.7g/kg body weight, the goat had tachycardia, tachypnoea, dyspnoea, nystagmus, opisthotonos and sternal recumbence. The death occurred 30 minutes after the onset of clinical signs. Fresh leaves from the same plants were given to 8 goats at doses of 0.5-2.5g/kg without causing clinical signs. Three goats showed clinical signs after the ingestion of 3g/kg. Clinical signs were similar to those observed in cyanide poisoning. Two goats given 0.5mg/kg of a 20% solution of sodium thiosulphate recovered immediately after treatment. Another goat recovered spontaneously. Leaves from the same plants were sun-dried during variable periods for 8-30 days, and then given to 8 goats. The goat that ingested the plant dried at the sun during 8 days died after the ingestion of 3 g/kg. The goat that ingested the plant, exposed to the sun for 9 days, showed clinical signs after the ingestion of 1.13g/kg, but recovered spontaneously. The goats that ingested the leaves exposed to the sun during 10-29 days showed clinical signs after the ingestion of 3g/kg, but recovered spontaneously or after treatment with sodium thiosulphate. No clinical signs were observed in the goat that ingested the plant that had been exposed to the sun during 30 days. In another experiment ground leaves of the plant were dried at the sun for 1, 2, 3, and 4 days and given to goats at the dose of 3g/kg. Goats that received the plant dried for 1, 2 or 3 days showed clinical signs, but recovered spontaneously. The goat that ingested the plant dried 4 days showed no clinical signs. Leaves of the spineless C. phyllacanthus used in the experiments, 20 samples of leaves from spiny plants, 3 samples of the ground plant stem, and 2 samples of fruits were positive with the picrosodic paper test for HCN. These results demonstrated that C. phyllacanthus is a cyanogenic plant. After being cut the entire leaves maintain their toxicity for up to 30 days, and the ground leaves for up to 3 days. After the end of the raining season dry leaves fallen to the ground and tested within a short period were negative for HCN. These results have to be taken into account for the use of C. phyllacanthus as forage.

Focal symmetrical encephalomalacia in a goat.

Focal symmetrical encephalomalacia (FSE) is the most prominent lesion seen in the chronic form of enterotoxemia caused by Clostridium perfringens type D in sheep. However, this lesion has not been reported in goats. The current paper reports a case of FSE in a goat from the state of Paraíba in the Brazilian semiarid region. As reported by the farmer, 30, 4–48-month-old animals from a flock of 150 goats died after showing nervous signs, including blindness and recumbence, for periods varying between 1 and 14 days. The flock was grazing native pasture supplemented with wheat and corn bran. Additionally, lactating goats were supplemented with soybeans. A 4-month-old goat with nervous signs was examined clinically and then necropsied 3 days after the onset of clinical signs. Bilateral, focal, and symmetrical areas of brown discoloration were observed in the internal capsule and thalamus. Histologic lesions in these areas consisted of multifocal, bilateral malacia with a few neutrophils; endothelial cell swelling; perivascular edema; and hemorrhages. The etiology of these lesions was not determined. However, FSE is considered pathognomonic for C. perfringens type D enterotoxemia in sheep, and it is speculated that this microorganism was the etiologic agent in the present case. The flock had been vaccinated against type D enterotoxemia only once, approximately 3 months before the beginning of the outbreak. Insufficient immunity due to the incorrect vaccination protocol, low efficacy of the vaccine used, and a diet including large amounts of highly fermentable carbohydrates were suspected to be predisposing factors for this outbreak.

Meningoencephalitis caused by Naegleria fowleri in cattle of northeast Brazil

Primary amoebic meningoencephalitis is an acute disease of the central nervous system of humans and animals caused by Naegleria fowleri. This report describes a case of meningoencephalitis caused by N. fowleri in a crossbred, one-year-old bovine with progressive neurological signs. At necropsy there was thickening of the meninges and multifocal areas of malacia in the thalamus, caudal and rostral colliculi, parietal and occipital cortex, and cerebellum. Histologically there was multifocal necrosupurative meningoencephalitis associated with areas of malacia containing amoebic trophozoites. Immunohistochemistry of the brain was positive for N. fowleri. The disease should be included among the differential diagnosis of diseases of the central nervous system in cattle in areas where animals are exposed to hot, stagnant water.

Pythiosis of the digestive tract in sheep

Cutaneous and rhinofacial infections by Pythium insidiosum have previously been reported in sheep in Brazil. In the current study, a new form of pythiosis involving the alimentary tract of 2 nursing lambs from 2 different farms in the semiarid region of Brazil is described. The first lamb showed food regurgitation, lethargy, and anorexia, and died 5 days after the presentation of clinical signs. The second lamb had no history of gastrointestinal disease before death. Necropsy findings were similar in both lambs. The mucosa of the esophagus, reticulum, rumen, omasum, and abomasum showed ulcerated areas covered by yellowish caseous granular exudate. The lesions were transmural and extended to the serosal surfaces, and adhesions were observed between the serosa of the forestomachs and abomasum to the liver and diaphragm. Histologic lesions consisted of pyogranulomatous necrotizing transmural esophagitis, rumenitis, reticulitis, omasitis, and abomasitis with vascular thrombosis and intralesional hyphae. Pythium insidiosum was confirmed as the etiology by immunohistochemistry and culture. The presence of sheep in the vicinity of water ponds during the hot, dry season when forage is not available in the pastures seems to be the main predisposing factor for the occurrence of pythiosis in sheep in the Brazilian semiarid region.