Bovine Respiratory Disease Complex (BRDC)

Posted by Dr. Steve Dudley on June 11 2009 14:34

Many factors contribute: Viruses, stress, dust, bacteria, and Mycoplasma.

Viruses

1. IBR (Red nose)

   • Most important cattle respiratory virus.
   • Signs: Red nose, runny eyes and nose, depression and decreased intake.

2. PI3

   • Causes disease in young
   • Often combined with secondary infections to cause pneumonia.

3. BRSV

   • Usually causes disease in newly weaned cattle.
   • Signs: Very high fever, watery eyes and nasal discharge.

4. BVD

   • Not considered a primary respiratory pathogen.
   • Decreases immune function that leads to respiratory disease.

Bacteria

1. Mannheimia hemolytica (Pasteurella hemolytica)

   • Most common bacteria isolated from fatal BRDC.
   • Usually see about 2 weeks after environmental or management stress.
   • Signs: Fever, increased respiration, coughing, decreased intake, depressed and weak.

2. Pasteurella multocia

3. Haemophilus somnus

   • See similar signs as Pasteurellosis.
   • Some forms also cause brain and heart lesions.

Mycoplasma Bovis

1. Does NOT respond well to antibiotics.
2. Often eat well and have nasal discharge.
3. Signs: Swollen joints, most death loss 3-6 weeks after arrival.

Vaccination

1. Respiratory Vaccines – IBR, PI3, BRSV, BVD.
2. Ideally vaccinate with a MLV 30 days before weaning.
3. PMH
   • Choose a product that contains leukotoxin.
   • Use in high risk calves less than 600 lbs.
   • When vaccinating, don’ t mass medicate at the same time, because antibiotics will kill the vaccine.
   • Don’t treat within 48 hours after vaccinating.

Treatments

1. Antibiotics: LA 200, Nuflor, Micotil, Exceed, Naxcel, Excenel, Baytril, others.
2. Anti-inflammatories: Dexamethasone, Banamine.