Mauro Pereira Soares

Aspergillosis: a limiting factor during recovery of captive magellanic penguins

The article describes the epidemiology, macroscopic and histological lesions as well as the isolation of Aspergillus flavus and A. fumigatus from Magellanic penguins (Spheniscus magellanicus) during recovery in the Center for Recovery of Marine Animals (CRAM - 32oS/52oW), over a period of two years. From January 2004 to December 2005 the Center received 52 Magellanic penguins, and 23% (12/52) died. Necropsies were performed and tissue samples were collected for histological and microbiological examination. From 12 dead animals, aspergillosis was confirmed in five animals, corresponding to 42% of the mortality. Granulomatous nodules were observed mainly on air sacs and lungs. Histologically, septate and branching hyphae, measuring 3-5 µm and PAS positive were found. Two of these cases were caused by A. fumigatus, two other by A. flavus, and in one the diagnostic was established by macroscopic lesions observed in the necropsy without sample collection for fungal isolation and identification. The five aspergillosis cases occurred in the first year of the study, when a disinfection program was not yet established in the CRAM. This paper points out the importance of aspergillosis in the rehabilitation process of captive penguins, and emphasize the necessity of an environmental disinfection on the aspergillosis prevention, mycosis that caused a high rate of mortality of the seabirds found on the Brazilian coast and admitted in the CRAM.

Tristeza parasitária bovina na região sul do Rio Grande do Sul: estudo retrospectivo de 1978-2005

A retrospective study of tick fever was made, which occurred from 1978-2005 in southern Rio Grande do Sul in the influence area of the Regional Diagnostic Laboratory of the Federal University of Pelotas. From 4,884 cattle specimens, sent by practitioners or which were from necropsies performed at the Diagnostic Laboratory, 231 (4.7%) were diagnosed as tick fever. Data from 221 of those outbreaks were analyzed. Ninety one (41.1%) outbreaks were caused by Babesia bovis, 11 (4.9%) by Babesia bigemina, and 65 (29.41%) by Anaplasma marginale. In other 33 (14.93%) outbreaks of babesiosis there is no information if the disease was caused by B. bovis or B. bigemina, and 21 (9.5%) outbreaks were caused by mixed infection of A. marginale and B. bovis or B. bigemina. Mean morbidity, mortality, and letality rates in 149 outbreaks were 11.17%, 6.81%, and 70.04%, respectively. Most outbreaks occurred during summer (January-March) and autumn (April-June), mainly in 1 to 3-year-old cattle. Clinical signs were depression, weakness, fallen ears, fever, and weight loss. Low packed cell volume values were always found. Hemoglobinury was observed in babesiosis. Neurological signs characterized by gait alterations, muscular tremors, aggressiveness and falling down with tonic and clonic convulsions were observed in babesiosis by B. bovis. The main gross lesions were anemia, jaundice, splenomegaly, hepatomegaly, yellow liver and cardiac hemorrhages. Hemoglobinury was observed in babesiosis, and congestion of the cerebral cortex in babesiosis by B. bovis. It is concluded that B. bovis is the main agent causing thick fever in southern Rio Grande do Sul. In that region with a cattle population of 2,630,000 heads the annual losses due to tick fever can be estimated in 6,220 cattle or US

Aspectos epidemiológicos da seneciose na região sul do Rio Grande do Sul

1,623,000.00. Preventive measures to diminish tick fever losses in the region are necessary.

Intoxicação experimental por Ipomoea asarifolia (Convolvulaceae) em caprinos e ovinos

Seneciosis is the main cause of livestock mortality due to poisonous plants in the State of Rio Grande do Sul, Brazil. This paper presents epidemiological data of 24 outbreaks in cattle and one in horses, diagnosed by the Regional Diagnostic Laboratory at Pelotas University in southern Rio Grande do Sul, from 1998 to 2000. Additionally, data of 54 outbreaks which occurred in 1978-1997 were analyzed. The farms where outbreaks occurred in 1998-2000 were visited to obtain clinical and epidemiological data and to verify the presence of Senecio spp. Eleven outbreaks (45.83%) affected cattle up to 3 years of age, and 13 (54.16%) cattle over 3 years. Nine (37.5%) outbreaks affected females and 15 (62.5%) males. Ten (41.66%) outbreaks occurred in spring, 4 (16.66%) in summer, 5 (20.83%) in autumn, and 5 (20.83%) in winter. Morbidity rate was estimated with 4.92% and case fatality with 95.59%. The predomionating Senecio species were S. brasiliensis on 12 farms (57.14%), S. selloi on 10 (47.61%), S. oxyphyllus on 6 (28.57%), S. heterotrichius on 3 (14.28%), and S. leptolobus on 1 farm (4.76%). The main clinical signs were progressive emaciation, incoordination, diarrhea, tenesmus, rectal prolapse and aggressiveness. The clinical manifestation periods of affected cattle observed during the farm visits, or of cattle sent for post-mortem examination,were 24-96 hours in 4 outbreaks (16.66%), 4-7 days in 7 (29.16%), 1-2 weeks in 4 (16.66%), 2-3 weeks in 2 (8.33%), 1-2 months in 2 (8.33%), and 2-3 months in 1 outbreak (4.16%). In 4 outbreaks (16.66%) the clinical manifestation period was not established. In outbreaks with longer clinical manifestation periods some animals showed photosensitization. The main necropsy findings were a hard and enlarged liver, distended gall bladder, edema of the mesenterium and abomasum, and increased amount of liquid in the cavities. Histopathological findings were fibroplasia, megalocytosis and biliary ductal proliferation of the liver, and spongy degeneration of the cerebral white matter. Samples of different Senecio species, in different seasons, were analyzed for detection of pyrrolizidine alkaloids (PAs) by thin layer chromatography. Retrorsine was found in Senecio brasiliensis, S. heterotrichius, S. selloi and S. oxyphyllus. In S. brasiliensis and S. heterotrichius one and two more non-identified PAs were detected, respectively. The total PAs concentration by spectrophotometric method was 0.25% for S. brasiliensis, 0.19% for S. heterotrichius, 0.03% for S. oxyphyllus, and 0.03% for S. selloi. The highest PAs concentration occurred in winter (June/July). No alkaloids were found in samples of S. leptolobus. These results show that S. brasiliensis is the most important cause of seneciosis in southern Rio Grande do Sul. Additional data obtained dealt with 54 outbreaks of PAs poisoning in 1978-1997. During this period, 7 outbreaks (12.96%) affected cattle up to 3 years of age, 39 (72.22%) cattle over 3 years, and 3 outbreaks (5.55%) affected cattle of different ages. In 5 outbreaks (9.25%) the age was not informed. Seven outbreaks (12.96%) affected males, 39 (72.22%) females, 3 (5.55%) both sexes, and in 5 outbreaks (9.25%) the sex was not informed. Twenty-three outbreaks (42.59%) occurred in spring, 9 (16.66%) in summer, 9 (16.66%) in autumn, and 13 (24.07%) in winter. The greater number of outbreaks during 1998-2000 (24 outbreaks in 3 years) in regard to 1978-1997 (54 outbreaks in 20 years) is probably due to a decrease of more than 50% in the number of sheep in the region.

Pitiose cutânea em bovinos na região Sul do Rio Grande do Sul

Ipomoea asarifolia causes a tremogenic syndrome in sheep, goats, cattle and buffaloes. The objectives of the experiments were (1) to determine the toxicity to goats of fresh I. asarifolia collected during the raining and the dry season, and the toxicity of the dried plant, and (2) to determine the toxicity of the plant to sheep, and if the active principle is eliminated through the milk. In the first experiment the plant collected in the dry season and in the raining season was fed to 16 goats. The plant collected during the dry season caused clinical signs at the daily doses of 5g and 10g/kg body weight. The plant collected during the raining season was toxic at daily doses of 20g and 30g/kg, indicating that the plant is more toxic during the dry season. The plant collected in the dry season and dried was fed to 9 goats at doses of 1.7g, 2.0g, 3.4g, and 5.1g per kg. Daily doses of 3.0g, 4.0g and 5.1g/kg caused clinical signs, showing that the plant maintains its toxicity after being dried. In the second experiment the fresh plant collected in the dry and in the raining season was fed to 10 sheep. The plant collected in the dry season was toxic at the dose of 5g/kg, and the plant collected in the raining season was toxic at the doses of 10g and 20g/kg. The experimental results suggest that sheep are more susceptible to the poisoning than goats. As some farmers mentioned that suckling non-grazing lambs are poisoned by milk ingestion, I. asarifolia was fed at daily doses of 2.5g, 5.0g and 10g/kg for variable periods to 5 sheep from the day of parturition (2 sheep), after the last day of pregnancy (1 sheep) and 60 days before parturition (2 sheep). The sheep but not the lambs showed clinical signs of intoxication suggesting that the active principle is not eliminated through the milk at doses toxic for the lambs. In one euthanized sheep no gross or histologic lesions were detected. The main ultra-structural findings were found in Purkinje cell dendrites and included swelling, decrease or absence of dendritic spines, decrease or absence of neurotubules and neurofilaments and vacuolation of the dendroplasm. Swelling of the smooth endoplasmic reticulum and granular eletrondense inclusions in dendroplasm was observed. Swelling of astrocyte foot processes was conspicuous. It is suggested that these alterations are a result of continuous tremors induced by the plant with liberation of glutamate causing excitotoxicity, which probably constitutes a neuronal mechanism of defense.

Arthrogryposis in Murrah buffaloes in southern Brazil

An outbreak of cutaneous pythiosis is described in cattle from southern Rio Grande do Sul, Brazil. Cattle were introduced into flooded pastures and developed ulcerative and wet cutaneous lesions on distal limbs and Planum nasale. Histologically, the lesions were characterized by multiple granulomas with intralesional hyphae, better seen in the methenamine silver stain, and surrounded by abundant fibrous tissue. Diagnosis was based on epidemiology, gross and histological lesions, and by positive immuno-histochemical reaction with anti-Pythium insidiosum polyclonal antibody. Morbidity was 23.8% and lesions were observed 15-90 days after cattle were introduced in the flooded area. Affected cattle had spontaneous healing without treatment. It is suggested that the disease is more frequent than what was earlier thought, mainly in flooded areas of the Southern region of the Rio Grande do Sul State.

Seneciose crônica em ovinos no sul do Rio Grande do Sul

Congenital arthrogryposis is described in a Murrah buffalo herd. The disease was characterized by curvature and multiple articular rigidity of the hindlimbs or of all limbs without associated defects except for one case of brachygnatia. Histologically there was reduction of motor neurons from the ventral horns of the spinal cord and hypoplasia of the limb muscles. Analysis of the herd breeding records suggests that the disease is genetically transmitted by an autosomal recessive trait.

Experimental intoxication by larvae of Perreyia flavipes Konow, 1899 (Hymenoptera: Pergidae) in pigs and some aspects on its biology.

Two outbreaks of Senecio spp. poisoning in grazing sheep in southern Rio Grande do Sul are described. The disease occurred in 2006 on two farms that were heavily infested with Senecio spp. and had shortage of forage. The morbidity in both outbreaks was 10% and 9.5%, respectively. In one case the sheep were born and had grown up on the farm. On the other, the sheep flock was introduced into the farm some months before the outbreak. Clinical signs included progressive emaciation, apathy, weakness, jaundice and photodermatitis. At necropsy, the sheep had an augmented yellowish and firm liver with irregular capsular surface, and an extended and edematous gallbladder. There was distension and edema of the gallbladder. The cut surface the liver showed well-circumscribed whitish nodules measuring 1-3mm in diameter, which were randomly scattered throughout the hepatic parenchyma. There was also edema of mesentery and ascitis. Histopathological findings of the liver included hepatomegalocytosis, bile duct hyperplasia and periportal fibrosis. There were also swollen hepatocytes, randomly scattered necrotic hepatocytes and nuclear pseudo inclusions. Hepatic encephalopathy (status spongiosus) was observed in the brain in all necropsied sheep. The diagnosis of Senecio poisoning was based on epidemiological data, clinical signs, necropsy findings and histological lesions. It was concluded that despite infrequent, Senecio spp. poisoning in sheep may occur when animals are placed in areas heavily invaded by the plants. Although sheep can efficiently control Senecio spp. in paddocks, this apparently depends on the stocking rate, and outbreaks may occur when stocking rate is less than 0.2 sheep per hectare and when there is severe shortage of forage.

Defeitos congênitos diagnosticados em ruminantes na Região Sul do Rio Grande do Sul

Two pigs were dosed with 5 and 10g/kg bw of fresh Perreyia flavipes larvae collected at the municipality of Pelotas. Two other pigs were dosed with 0.87 and 1.7g/kg of dry P. flavipes (equivalent to 5 and 10g/kg bw of fresh larvae). Another pig was dosed with 0.17g/kg of dry larvae, daily, during 20d. Forty-eight hours after the ingestion, all pigs that ingested single doses showed clinical signs and marked rise in serum aspartate aminotransferase. Alanine aminotransferase and gamma glutamiltransferase were also slightly increased. The pig dosed with 10g/kg of fresh larvae died in 96h. The others recovered in 4-5days after ingestion. No clinical signs were observed in the pigs dosed during 20d with 0.17g/kg of dry larvae. The main lesion observed in the pig dosed whit 10g/kg of fresh larvae was a centrilobular liver necrosis. These results confirmed the toxicity of P. flavipes for swine, demonstrated that the larvae maintain the toxicity after being dried, and suggest no cumulative effect in the larval toxicity. The larvae collected in the field were conditioned in boxes containing swards of native grasses and covered with gauze to prevent the escape of adults on emergence. The larvae pupated from August 11 to September 25. Emergency of adults occurred from February 10 to March 4. Adult females and males live only for 18-36 and 24-48h, respectively. The eggs had an incubation period of 26-33d. The larval period extend from March 1 to August 24.

Intoxicação por larvas de Perreyia flavipes em bovinos na região sul do Rio Grande do Sul

Congenital defects in cattle, sheep and buffalo were studied through a review of necropsy files of the Regional Diagnostic Laboratory of the Veterinary Faculty at the Federal University of Pelotas between 1978 and 2009. The occurrence of congenital defects in cattle, sheep and buffalo were 0.88%, 0.36%, and 7.54%, respectively, from all specimens received. Cattle congenital defects of undetermined etiology represented 45.83% of the congenital defects, known hereditary and probably hereditary diseases represented 6.25%, and 29.16%, respectively, and defects associated to environmental factors represented 16.66%. In cattle, of the 48 congenital defects observed 21 (43.75%) affected the skeletal system (chondrodysplasia, scoliosis, lateral deviation of the mandible, palatoschisis and unclassified defect), nine (18.75%) affected the central nervous system (hypoplasia of olfatory and frontal lobes, cerebellar cortical degeneration, spina bifida, congenital hypomielinogenesis, hereditary hypermetria, cerebellar hypoplasia, and pachygiria), nine (18.75%) the muscular system (arthrogryposis), three (6.25%) the cardiovascular system (patent ductus arteriosus and unclassified malformation), one (2.08%) the lymphatic system (hereditary lymphatic hypoplasia), one (2.08%) the alimentary system (atresia ani), and one (2.08%) the eye (congenital blindness). In five cases (10.41%) different systems were affected (diprosopus). Different hereditary diseases (hereditary hypermetry, arthrogryposis, and lymphatic hypoplasia) or diseases suspected of being hereditary (chondrodysplasia) were diagnosed in cattle. Also occurred, with less frequency, congenital defects associated with environmental factors (hypomyelinogenesis due to cooper deficiency) or probably environmental factors (cleft palate, cerebellar hypoplasia, and cerebellar cortical degeneration). In sheep all observed defects were sporadic and affected various systems (anomalous twins and aprosopia). In buffalo all congenital defects were hereditary (arthrogryposis, myotonia and mechano-bullous genodermatoses) or suspected of being hereditary (albinism, megaesophagus and hydranencephaly/cerebellar hypoplasia). It is concluded that sporadic congenital defects are not important in the three species studied. Despite the low frequency congenital defects associated with environmental factors could be important in some regions or farms. Hereditary or probably hereditary diseases are important, not only by the mortality rates, but also because the risk of dissemination of the genes in the different breeds. In water buffalo the high prevalence of hereditary diseases was a consequence of the high consanguinity of the Brazilian buffalo population. Control measures need to be taken to avoid the spread of recessive genes in cattle and buffalo.