This research was commissioned after anecdotal reports from veterinarians and exporters working in the cattle live exports supply chain of sporadic, severe outbreaks of eye disease in cohorts of Bos taurus cattle destined for long-haul shipping to Russia or China. Outbreaks occurred in pre-export quarantine, on board the vessels or during post-arrival quarantine. Eyes were often so severely affected that it resulted in the loss of the animal. The costs associated with treatment and loss of animals suitable for sale was significant.
It was concluded that eye disease in these cattle was a multifactorial disease with different possible causative agents and several risk factors. One risk factor over which exporters had some control was the degree to which cattle were immune to disease before receival in pre-export quarantine. It was agreed that an experiment would be conducted to test the hypothesis that providing adequate immunotherapy to cattle in time for full immunity to develop before receival in pre-export quarantine, would greatly reduce the incidence of eye disease in quarantine, on vessels and during post-arrival quarantine. The trial was to be conducted over three voyages.
A review of the scientific principles, an understanding of eye disease causation and epidemiology and well-established treatment protocols were used to produce best practice guidelines for the live export industry. The challenges associated with implementing these guidelines are well recognised.
It is suggested that wherever possible and practical, exporters aim to access cattle destined for export at least four weeks before collection at quarantine such that full courses of appropriate vaccines can be given and eye disease outbreaks minimised.