Blackleg in inadequately immunized calves and their recovery following antibiotic therapy

  • Carolina C Guizelini Faculdade de Medicina Veterinária e Zootecnia (FAMEZ), Universidade Federal de Mato Grosso do Sul (UFMS), MS, Campo Grande, Brazil
  • Otávio AC Silvestre Laboratório de Anatomia Patológica, Faculdade de Medicina Veterinária e Zootecnia (FAMEZ), Universidade Federal de Mato Grosso do Sul (UFMS), MS, Campo Grande, Brazil
  • Carlos AN Ramos Laboratório de Biologia Molecular, Faculdade de Medicina Veterinária e Zootecnia (FAMEZ), Universidade Federal de Mato Grosso do Sul (UFMS), MS, Campo Grande, Brazil
  • Danilo C Gomes Laboratório de Anatomia Patológica, Faculdade de Medicina Veterinária e Zootecnia (FAMEZ), Universidade Federal de Mato Grosso do Sul (UFMS), MS, Campo Grande, Brazil
  • Ricardo Antonio A Lemos Laboratório de Anatomia Patológica, Faculdade de Medicina Veterinária e Zootecnia (FAMEZ), Universidade Federal de Mato Grosso do Sul (UFMS), MS, Campo Grande, Brazil
Keywords: Clostridium chauvoei, cattle disease, clostridial disease, blackleg, immunization

Abstract

Introduction: There is consensus regarding the importance of blackleg vaccination as a preventive measure, and proper immunization protocols are available. However, few studies have evaluated the effectiveness of vaccine protection against Clostridium chauvoei and the treatment of the disease in calves exhibiting early or advanced clinical courses. This study describes twelve blackleg cases in unvaccinated calves and in calves that received a single dose of the vaccine. It also reports the recovery of some calves after antibiotic therapy.

Methodology: Two necropsies of cattle dead from blackleg were performed. Fragments of skeletal muscle from these two cattle were immersed in paraffin for multiplex polymerase chain reaction (PCR) analysis.

Results: Twelve calves up to nine months of age developed signs of blackleg and eight died. Ten of those 9-month-old calves had received only the first dose of a blackleg vaccine at 4 months of age, but no booster. The last two affected calves belonged to a herd that had never been vaccinated. Four out of five calves treated with penicillin for 6-7 days recovered from the disease. The diagnosis of blackleg was based on necropsy, histopathological findings and detection of C. chauvoei in skeletal muscle samples of two necropsied calves using PCR.

Conclusions: The occurrence of cases only in calves that did not receive a booster dose or were not vaccinated indicated that the vaccine used was effective when performed as recommended by the manufacturer. However, neglecting the booster resulted in casualties due to blackleg.

Published
2020-07-31
How to Cite
1.
Guizelini CC, Silvestre OA, Ramos CA, Gomes DC, Lemos RAA (2020) Blackleg in inadequately immunized calves and their recovery following antibiotic therapy. J Infect Dev Ctries 14:788-792. doi: 10.3855/jidc.12613
Section
Brief Original Articles