Type C Botulism in Dairy Cattle from Feed Contaminated with a Dead Cat

Abstract

Four hundred twenty-seven of 441 adult Holstein dairy cattle from a 1,200-cow dairy died over a 1-week period during early spring 1998. Affected animals were from 4 late lactation pens, one of which included the bull string. Signs included weakness, recumbency, watery diarrhea, and death. Eighty animals from the 4 pens were dead approximately 8 hours after the first ill cows were noted. Affected cows would collapse on stimulation and extend all 4 limbs with moderate rigidity. Several lacked lingual tonus and had abdominal breathing patterns. The animals had been fed a load of total mixed ration that included a rotten bale of oat hay containing a dead cat. No common toxicants were identified, and pathologic examination revealed no consistent lesions. Testing of tissue from the cat carcass found in the feed sample using mouse protection bioassay identified the presence of type C botulinum toxin. Samples of feed, tissue from affected animals, cat tissue from feed, milk, and serum were also tested using an enzyme-linked immunosorbent assay (ELISA) specific for type C botulinum. Two samples of rumen contents were tested and found to be positive for botulism by ELISA, and 1 of 3 liver samples had a weak positive finding. No botulinum toxin was found in milk or sera using the ELISA.

Botulismo em bovinos leiteiros no Sul de Minas Gerais, Brasil

“…Na América do Norte, as principais fontes de toxinas botulínicas em sistemas de confinamento de bovinos têm sido a cama-de-frango (JEAN et al, 1995;LIVESEY et al, 2004), a silagem e o feno (GALEY et al, 2000;MARTIN, 2003). No Brasil, ORTOLANI et al (1997) O programa sanitário preventivo do rebanho incluía a vacinação contra brucelose, carbúnculo sintomático, febre aftosa, leptospirose e raiva.…”

“…A utilização de dieta completa aumenta os riscos de surtos de grandes proporções, como o ocorrido em um rebanho leiteiro norte-americano, em 1998 (GALEY et al, 2000), no qual morreram 427 vacas de um lote de 441 bovinos, devido à incorporação de uma carcaça de felino no vagão misturador. Nessas condições, a toxina é distribuída homogeneamente na dieta e todo o lote que receber o alimento será acometido.…”

“…Embora vários autores tenham relatado a ausência de toxina botulínica no leite de bovinos acometidos pelo botulismo (GALEY et al, 2000;MOLLER et al, 2003), não existe um consenso a esse respeito e muitos autores indicam o descarte do leite dos lotes acometidos por até 14 dias após o último caso clínico (COBB et al, 2002). Essa medida de proteção ao consumidor aumenta ainda mais o ônus ocasionado pela doença em rebanhos leiteiros.…”

Acute Type C Botulism with Fatal Consequences in a Holstein Breeding Establishment in Northern Italy

“…The clinical signs are caused by highly specific neurotoxins that inhibit the release of neurotransmitters by exocytosis, leading to paralysis [1,2,5]. Neurotoxins can enter feed via toxin-containing rotting animal carcasses [5,10,11] or be produced directly via the primary growth of Cl. botulinum in protein-rich substrates in favourable conditions (temperature between 25 °C and 30 °C, pH value > 4.5, anaerobiosis) [6,12].…”

“…botulinum is classified into 7 or 8 different types (A, B, C (C 1 , C 2 ), D, E, F, G) depending on the antigen properties of the botulinum neurotoxins (BoNT) produced, with intoxication mostly appearing in cattle following the ingestion of neurotoxins of type C and D and, less frequently, of type B [5][6][7][8][9]. The clinical signs are caused by highly specific neurotoxins that inhibit the release of neurotransmitters by exocytosis, leading to paralysis [1,2,5]. Neurotoxins can enter feed via toxin-containing rotting animal carcasses [5,10,11] or be produced directly via the primary growth of Cl.…”