The horse belongs to a stable in De Baca County, New Mexico, that has been under quarantine since June 18th. According to Dr. David Fly, the New Mexico state veterinarian, no other horses at the premises are reporting symptoms, although only 5-10% of horses in an infected herd tend to exhibit clinical signs. This is only the second confirmed case in the United States this year – the other infected horse lived in Starr County, Texas, which led to transport restrictions on horses from Texas.
In response to this new case, Texas has added transport restrictions on animals entering from New Mexico. Included in the restrictions, is the fact that any farm animal entering Texas from a state that has confirmed a Vesicular Stomatitis in the last 30 days must be accompanied by a veterinarian certificate confirming the animals is from non-quarantined premises.
The Vesicular Stomatitis virus is in the same virus family as Rabies, and can infect other mammals as well as horses, including cattle. The disease is incubated for 2 to 8 days, most often causing drooling as the first symptom, before developing into lesion formation on the tongue, lips, gums, nostrils and teats. These lesions would develop into open ulcers and cause the horse to stop feeding, leading to weight loss. Once a stable is infected, it is believed that transmission takes place by contact with infected saliva, or contact with fluid from ruptured lesions.