Contagious Equine Metritis: A Review

Contagious equine metritis is a highly contagious genital infection of mares, spread venereally, and was first described in 1977. Although most contagious equine metritis outbreaks involved Thoroughbreds, infection in other breeds has also occurred. The disease has been reported in Europe, Australia and the United States. In Canada, contagious equine metritis has been designated a reportable disease under the Animal Disease and Protection Act.Contagious equine metritis is characterized by an endometritis and infertility and infected mares show no signs of systemic infection. Clinical signs have not been observed in stallions. An asymptomatic carrier state exists in both mares and stallions.Infected mares respond clinically to the topical and parenteral administration of antibacterial drugs. However, a proportion of mares remain carriers of the contagious equine metritis organism. Treatment of stallions is successful. Haemophilus equigenitalis has been proposed as the species name of the Gram-negative, microaerophilic coccobacillus.Sample collection and laboratory methods for the diagnosis of contagious equine metritis are described.