Estimativas de perdas econômicas causadas por reação granulomatosa local após uso de vacina oleosa contra febre aftosa em bovinos de Mato Grosso do Sul

Abstract

Pesq. Vet. Bras. 34(8) Lesions caused by excessive reaction to foot and mouth vaccine were observed in 1,815 out of 5,000 cattle slaughtered in a slaughterhouse under federal meat inspection. Such lesions resulted in condemnation of the affect parts of the carcasses in accordance with the Brazilian Federal Meat Inspection Regulations. The affected cattle had been vaccinated on May 2012 and then slaughtered in September of the same year. They were allotted to two groups with 1,500 (Groups 1) and 315 cattle (Group 2). Post vaccination lesions were characterized as salient, firm variable sized nodules multifocally distributed in the musculature of the lateral neck. Pus oozed at the cut surface of these nodules. Samples of 28 cattle were submitted for histopathological examination; main findings were pyogranulomas with central variable-sized clear spaces surrounded by marked infiltrate of viable and dead neutrophils, which were surrounded by epithelioid macrophages with vacuolated cytoplasm and occasional multinucleated giant cell. This inflammatory reaction was walled by abundant connective tissue infiltrated by lymphocytes and plasma cells. Samples of the lesion of six cattle were submitted to bacteriological culture with negative results. When affected carcasses went through dressing, there was an average of 1.8 and 2.0 kg of muscle tissue cut off from the carcasses respectively of Group 1 and 2. Economic losses in the farm of origin of the affected cattle was R$ 20,424.00, considering the price paid by kg of cattle for slaughter at the time of the occurrence. This amount at that time was enough to buy 29.17 weaned calves for fattening. If one considers theses 5,000 cattle vaccinated on the farm as the population at risk, the morbidity rate would be 0.36%. These results indicate that the losses due to vaccine reaction, even with no overt clinical signs, may cause important economic losses.

Iatrogenic Postvaccinal Injection Site Granulomas in Cattle

“…In the present study, the gross findings were similar to those reported previously by other researchers [1,10,12]. In both of our cases there was some variation in the size and location of the granulomas and adjacent structures that were being compressed by these inflammatory lesions.…”

“…Leal et al [10] found 1,815 bovine carcasses slaughthered in a federal abattoir in Central Brazil that had injection site granulomas. These animals had been vaccinated with foot-and-mouth disease oily adjuvant vaccines.…”

“…Iatrogenic postvaccinal injection site granulomas can affect animal welfare and production. They cause discomfort, production losses, reduction in live weight and carcass yield and ban on imports of fresh meat [1,5,10,11].…”

<b>Adjuvantes nas vacinas reprodutivas:</b> efeitos adversos, temperatura no sítio da injeção, resposta inflamatória e produção de anticorpos neutralizantes para BVDV e BoHV-1

“…Estas manifestações locais são causadas pelo aumento do fluxo sanguíneo devido a vasodilatação e aumento da permeabilidade vascular, o que resulta no extravasamento e acúmulo de plasma nos tecidos característicos do edema inflamatório . A reação local inflamatória deve ser diferenciada dos efeitos indesejáveis (BALDRICK, 2016) caracterizados por extensos piogranulomas com intenso infiltrado de neutrófilos íntegros e necróticos, macrófagos com citoplasma vacuolizado, além de linfócitos e plasmócitos (LEAL et al, 2014).…”

“…Os óleos são mais reativos que aqueles adjuvantes a base de hidróxido de aluminio e saponina. Os danos teciduais gerados pelos óleos pode ser identificado por histologia local, onde podem ser vistos principalmente piogranulomas, infiltrados de neutrófilos íntegros e necróticos, macrófagos epitelióides com citoplasma vacuolizado, e mais externamente, abundante tecido conjuntivo em meio a linfócitos e plasmócitos (LEAL et al, 2014).…”