The International Collating Centre, Newmarket, and other sources reported the following disease outbreaks in the second quarter of 2004:

Abortions caused by equine herpes virus (EHV-1) among vaccinated mares were diagnosed on a Thoroughbred stud farm in Argentina. Sporadic cases on several premises were recorded in France, Italy, Ireland (including two premises where EHV-4 was isolated), Japan, Switzerland, and the United Kingdom. The latter two countries reported neonatal foal deaths caused by EHV-1. Sporadic cases of paralytic disease attributable to EHV-1 were reported from two racing stables in the United Kingdom.

Respiratory disease attributable to EHV-4 was diagnosed on numerous premises in France and in an eventing stable in the United Kingdom. Coital exanthema caused by EHV-3 was identified on four premises in the United Kingdom among non Thoroughbreds following covering.

Equine influenza was reported extensively in France among several different breeds of horses, in the United Kingdom at two boarding premises, and in Central Kentucky from a recently imported Andalusian stallion while still in quarantine