Bovine respiratory disease in naturally infected calves: clinical signs, blood gases and cytokine response


Ozkanlar Y., Aktas M. S., Kaynar O., Ozkanlar S., Kirecci E., Yildiz L.

REVUE DE MEDECINE VETERINAIRE, cilt.163, sa.3, ss.123-130, 2012 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 163 Sayı: 3
  • Basım Tarihi: 2012
  • Dergi Adı: REVUE DE MEDECINE VETERINAIRE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.123-130
  • Atatürk Üniversitesi Adresli: Evet

Özet

Viral and bacterial aetiology, clinical symptoms, venous blood gases and cytokine production were aimed to investigate in naturally infected calves with bovine respiratory disease (BRD). Nasal swap and bronchoalveolar lavage samples and blood samples were obtained from 10 healthy control calves and from 48 calves with respiratory symptoms from 12 different herds and exposed to predisposing factors (insufficient aeration and hygiene) (BRD group) before tulathromycin and carprofen treatment. Virus isolations were achieved in 25% of the swap samples: BVDV (bovine viral diarrhoea virus), BRSV (bovine respiratory syncytial virus) and IBRV (infectious bovine rhinotracheitis virus) were identified in 12.5%. 8.3% and 6.2% of diseased calves respectively. Serum anti-BVDV antibodies were also detected in 68.75% of BRD calves using a sero-neutralization test. Lungs from all virally (directly and indirectly) infected calves were also invaded with bacteria (in majority with Mannheimia hemolytica, and P multocida, alpha-haemolytic Streptococcus and coagulase negative Staphylococcus, at a lesser extend). The prevalence of the total bacterial infections was 100% and poly-infections were also frequent (47.92%). Respiration rate and rectal temperature were significantly increased (P < 0.001) in the affected calves. Nasal and ocular discharge, cough and dyspnoea were additional clinical findings. Venous gas analysis revealed the occurrence of a respiratory acidosis (decrease in blood pH coupled to increase in pCO(2) and decrease in pO(2)) in diseased calves that was positively correlated with the respiratory frequency. Furthermore, serum concentrations of tumour necrosis factor-alpha and interleukin-6 were detected to be significantly high only in newly affected calves. Tulathromycin and carprofen treatment induced clinical recovery after 15 days and 30 days in 91.6% and 95.83% respectively of diseased calves. As a result, blood gases, respiratory rate, rectal temperature and respiratory signs have been deteriorated in these calves. A respiratory acidosis and an early inflammatory cytokine production occur during BRD, mainly related to the BVDV and M. heamolytica as most common agents involved in the disease.