Detection of coronavirus in capybaras (Hydrochoeris hydrochaeris) by transmission electron microscopy in São Paulo, Brazil / Detección de coronavirus in capybaras (Hydrochoeris hydrochaeris) por microscopía electrónica de transmisión en São Paulo, Brasil

Coronaviruses are enveloped, positive-stranded RNA, belongs to the Nidovirales order, Coronaviridae family and are classified into three groups. Groups 3a and 3c comprising the avian coronaviruses. They are worldwide in distribution and can cause respiratory, enteric and in some cases hepatitis and neurological diseases in a wide variety of animals, resulting in economic losses to breeders and breeding. In this study, we describe an outbreak of diarrhea in a herd of capybaras found in the city of Piracicaba, São Paulo, Brazil. The animals had sudden symptoms of anorexia, profuse and watery diarrhea, yellowish or greenish, dehydration, weight loss, sharp and twisting of limbs leading to death in less than a week, mostly weaned and with an age of three months. A total of 59 stool samples and 10 fragments of small intestine were processed for negative staining technique (rapid preparation). By transmission electron microscope a large number of particles with morphology similar to coronavirus, pleomorphic, rounded or elongated features with radial projections form a corona and measuring 80-140 nm in diameter, was visualized in all samples analyzed. The technique was extremely useful for rapid viral diagnosis in the affected animals.

Coronavirus están envueltos en una cadena positiva de ARN, (orden Nidovirales, familia Coronaviridae) y se clasifican en tres grupos. Grupos que integran la tercera 3c y los coronavirus aviario. Se distribuyen por todo el mundo y pueden causar enfermedades respiratorias, entéricas y, en algunos casos, hepatitis y enfermedades neurológicas en una amplia variedad de animales, resultando en pérdidas económicas a la ganadería y los criadores. En este trabajo se describe un brote de diarrea en un rebaño de capibaras en la ciudad de Piracicaba, São Paulo, Brasil. Los animales presentaron súbitamente, los síntomas de anorexia, diarrea, profusa y acuosa, de color amarillento o verdoso, deshidratación, pérdida de peso, agudo, torsión de los miembros y la muerte en menos de una semana, en su mayoría con tres meses de edad. Un total de 59 muestras de heces y 10 trozos de intestino delgado se procesaron por la técnica de contraste negativo (preparación rápida). En todas las muestras analizadas, al microscopio electrónico de transmisión se visualizó un gran número de partículas con morfología similar a los coronavirus, pleomórficas, con características redondeadas o alargadas con proyecciones radiales en forma de corona midiendo de 80-140 nm de diámetro. La técnica es sumamente útil para el diagnóstico rápido de virus en animales afectados.

Growth of broad-nosed caiman, Caiman latirostris (Daudin, 1802) hatchlings, fed with diets of animal origin

The study was carried out to evaluate the growth rate of broad-nosed caiman, Caiman latirostris hatchlings, fed on four animal protein diets: (a) dead poultry from a poultry farm; (b) dead piglet from nursery and farrowing house in a swine farm; (c) whole tilapia (Tilapia rendalli e Oreochromis niloticus); and (d) a balanced mixture of a, b, and c sources. Sixteen seven-month old caimans, average weight of 208 g and, 38 cm of total lenght (TL) were distributed in four treatments. Four groups of four caimans each were placed in cement enclosures inside a greenhouse. Diets were supplied at the average rate of 97.8 percent ± 34.8 percent of the body weight per week (average and standard deviation; wet weight basis). Body mass and total length of caimans were measured every 30 days for six months (Nov. 1995-April. 1996). An analysis of variance with repeated measures was performed. Diets provided suitable growth for weight and TL (mean ± standard deviation, respectively): (a) 2,157 ± 743 g and 79.5 ± 6.9 cm; (b) 1,811 ± 222 g and 75.7 ± 1.9 cm; (c) 2,431 ± 780 g and 80.7 ± 5.8 cm; (d) 1,683.5 ± 736 g and 74.5 ± 7.2 cm. There was no significant effect of diet on weight, but diet effect on TL of hatchlings approached significance (p < 0.10). It is concluded that all diets have good potential, in growth sense, to be used in commercial farms or ranches and for captivity propagation programs of caimans

Growth of broad-nosed caiman, Caiman latirostris (Daudin, 1802) hatchlings, fed with diets of animal origin

The study was carried out to evaluate the growth rate of broad-nosed caiman, Caiman latirostris hatchlings, fed on four animal protein diets: (a) dead poultry from a poultry farm; (b) dead piglet from nursery and farrowing house in a swine farm; (c) whole tilapia (Tilapia rendalli e Oreochromis niloticus); and (d) a balanced mixture of a, b, and c sources. Sixteen seven-month old caimans, average weight of 208 g and, 38 cm of total lenght (TL) were distributed in four treatments. Four groups of four caimans each were placed in cement enclosures inside a greenhouse. Diets were supplied at the average rate of 97.8% ± 34.8% of the body weight per week (average and standard deviation; wet weight basis). Body mass and total length of caimans were measured every 30 days for six months (Nov. 1995-April. 1996). An analysis of variance with repeated measures was performed. Diets provided suitable growth for weight and TL (mean ± standard deviation, respectively): (a) 2,157 ± 743 g and 79.5 ± 6.9 cm; (b) 1,811 ± 222 g and 75.7 ± 1.9 cm; (c) 2,431 ± 780 g and 80.7 ± 5.8 cm; (d) 1,683.5 ± 736 g and 74.5 ± 7.2 cm. There was no significant effect of diet on weight, but diet effect on TL of hatchlings approached significance (p 0.10). It is concluded that all diets have good potential, in growth sense, to be used in commercial farms or ranches and for captivity propagation programs of caimans.

Avaliou-se o crescimento de filhotes de jacaré-do-papo-amarelo (Caiman latirostris) submetidos a quatro dietas: (a) frango proveniente de óbito em aviário; (b) leitão proveniente da mortalidade de maternidade e creche em criações de suínos; (c) tilápia (Tilapia rendalli e Oreochromis niloticus) integral; e (d) uma mistura das fontes a, b e c. Dezesseis jacarés de sete meses de idade, com média de 208 g de massa corporal e 38 cm de comprimento total (CT), foram distribuídos nos quatro tratamentos, em lotes de quatro animais, alojados em recintos de cimento no interior de uma estufa com cobertura plástica. As dietas foram fornecidas a uma taxa de 97,8% ± 34,8% do peso vivo por semana (média e desvio-padrão; base na matéria úmida). O peso e o CT dos jacarés foram tomados a cada 30 dias durante 6 meses (nov./1995 a abril/1996). Foi efetuada uma análise de variância para medidas repetidas. As dietas proporcionaram índices de crescimento elevados, considerando o peso e o CT dos filhotes ao final do estudo: (a) 2.157 ± 743 g e 79,5 ± 6,9 cm; (b) 1.811 ± 222 g e 75,7 ± 1,9 cm; (c) 2.431 ± 780 g e 80,7 ± 5,8 cm; (d) 1.683,5 ± 736 g e 74,5 ± 7,2 cm; média e desvio-padrão. Não houve efeito significativo da dieta no peso, mas o resultado da análise esteve próximo de ser significativo para a variável CT (p 0,10). Conclui-se que todas as dietas testadas têm bom potencial, em termos de crescimento, para utilização em programas de propagação em cativeiro do jacaré-do-papo-amarelo, bem como em criação comercial em ciclo completo e ranching.