IBR

From Cow
IBR in a cow, showing upper respiratory symptoms
Oal lesions in above cow, showing gingivitis, faucitis and mucosal ulcers
Severe fibrino-necrotic tracheitis in a feedlot weanling calf with IBR[1]

Infectious Bovine Rhinotracheitis (IBR) is a highly contagious viral disease of cattle worldwide caused by Bovine Herpesvirus-1 (BHV-1). High rates of co-infection of BoHV-1 and BoHV-5 in bovines has been demonstrated in some countries[2].

It appears to be endemic in coutries where effective vaccination strategies are economically impractical[3], with seroprevalence rates approaching 50% of sampled herds[4].

Cause

BHV-1 is spread via aerosol contamination of feedyards or in housing in cattle kept indoors[5]. The virus is shed in secretions from the eye nose and reproductive organs. The virus has also been shown to associate with shipping fever, a disease caused by Mycoplasma hemolytica, suggesting immunosuppression effects of the herpes viral agent.

Clinical signs

Clinical signs in affected cattle include fever, respiratory distress, nasal discharge, conjunctivitis, abortions[6] and encephalitis. Abortions can also be triggered by exposure of non-protected pregnant cows with modified live IBR vaccine. Hemorrhages may be found in the membranes of the nasal cavity, larynx and/or trachea. Genital disease presents as haematuria, dysuria, pollakiuria, vaginal swelling, vaginal discharge, a raised tailhead and erosive ulcers in the mucosal surface.

Abortion storms are not infrequent in some countries, often associated with purchase and movement of bovines and semen of often unknown IBR status[7].

Diagnosis

Diagnosis is based on presenting clinical signs in affected cattle, and isolation of viral particles using PCR testing[8]. Immunoflorescent antibody staining of fetal tissues has also been used to assist diagnosis.

Treatment

Treatment is usually symptomatic. Broad-spectrum antimicrobial therapy is recommended in calves showing lower respiratory signs or fever. Tetracyclines, enrofloxacin or ceftiofur are recommended.

Dietary boron supplements have been shown to be ineffective at minimising clinical signs or recovery rates[9].

Preventative vaccination has been shown to be effective[10], although susceptibility to viral challenge isn't significantly reduced by preventative worming at the time of vaccination[11].

References

  1. Dept of Agriculture, Ireland
  2. Campos FS et al (2009) High prevalence of co-infections with bovine herpesvirus 1 and 5 found in cattle in southern Brazil. Vet Microbiol 139(1-2):67-73
  3. Njiro SM et al (2011) A study of some infectious causes of reproductive disorders in cattle owned by resource-poor farmers in Gauteng Province, South Africa. J S Afr Vet Assoc 82(4):213-218
  4. Raizman EA et al (2011) Seroprevalence of infectious bovine rhinotracheitis and bovine viral diarrhea virus type 1 and type 2 in non-vaccinated cattle herds in the Pacific Region of Central Costa Rica. Trop Anim Health Prod 43(4):773-778
  5. Makoschey B et al (2010) IBR and BVD control: the key to successful herd management. Berl Munch Tierarztl Wochenschr 123(11-12):519-521
  6. Yang N et al (2012) Survey of nine abortifacient infectious agents in aborted bovine fetuses from dairy farms in Beijing, China, by PCR. Acta Vet Hung 60(1):83-92
  7. Blickenstorfer S et al (2010) Infectious bovine rhinotracheitis (IBR) in the canton of Jura: an epidemiological outbreak investigation. Schweiz Arch Tierheilkd 152(12):555-60
  8. Thonur L et al (2012) One-step multiplex real time RT-PCR for the detection of bovine respiratory syncytial virus, bovine herpesvirus 1 and bovine parainfluenza virus 3. BMC Vet Res 8:37
  9. Fry RS et al (2011) Effect of dietary boron on physiological responses in growing steers inoculated with bovine herpesvirus type-1. Res Vet Sci 90(1):78-83
  10. Xue W et al (2011) Protection from persistent infection with a bovine viral diarrhea virus (BVDV) type 1b strain by a modified-live vaccine containing BVDV types 1a and 2, infectious bovine rhinotracheitis virus, parainfluenza 3 virus and bovine respiratory syncytial virus. Vaccine 29(29-30):4657-4662
  11. Schutz JS et al (2012) Effects of gastrointestinal parasites on parasite burden, rectal temperature, and antibody titer responses to vaccination and infectious bovine rhinotracheitis virus challenge. J Anim Sci 90(6):1948-1954