Vesicular stomatitis in horse is an infectious and contagious viral disease. The disease is characterized by developing vesicles in the mouth, coronet, and hairless parts of the body. The disease causes severe lameness and anorexia in horses.
Causes of Vesicular Stomatitis in Horse
The disease is caused by the Vesicular stomatitis virus (VSV), similar to the equine rabies virus. The virus is under the Rhabdoviridae family. The disease is confused with Foot and Mouth Disease (FMD), which does not typically occur in horses.
Epidemiology of VSV in Horses
Horses, cattle, and swine are susceptible to vesicular stomatitis. Sheep and goats are much more resistant to this disease. The VSV may be transmitted to human beings.
The mode of transmission and spread of the virus is not fully discovered. The virus cannot penetrate healthy skin. Still, it can enter through abrasions, wounds, and mucous membranes, thus feeding poor quality rough forage, which causes abrasions in the mouth, facilitating virus spread. The transmission may occur by direct contact with the saliva, vesicular fluid from clinically affected animals, and contaminated food and water. However, several disease outbreaks have occurred in horses that have no contact with infected animals, and it is widely believed that insect vectors transmit the virus.
Clinical Signs of Equine Vesicular Stomatitis
The incubation period of the vesicular stomatitis virus is 1-3 days. There is the onset of mild fever, inflammation of the mouth and tongue mucous membrane, and formation of vesicles.
- The vesicle ruptures and leaves ulcers.
- The resultant irritation leads to salivation and reluctance to eat.
- This can result in considerable loss of conditions.
- In severe cases, ulcers may develop on the nasopharynx, larynx, and nasal turbinates, which result in epistaxis and respiratory distress.
- Lesions found on the coronary band are common and result in lameness, which may culminate in the sloughing of the hoof in severe cases.
- Unless complicated by secondary bacterial infections, the oral lesions usually heal within a couple of weeks.
- Lesions on the horses develop severe coronets and cracked hoof walls.
- Mortality due to vesicular stomatitis is rare but may occur if there is a severe secondary bacterial infection through the vesicles of the mouth, which prevents the animal from eating and drinking.
Diagnosis of Vesicular Stomatitis in Horse
The tentative diagnosis of the disease can be made by:
- History of exposure to a diseased animal.
- Specific clinical signs like vesicles in the mouth and feet.
A confirmatory diagnosis of vesicular stomatitis can be made by
- Isolation of virus from the vesicular fluid.
- Serological examination of two blood samples collected at 10-14 days apart.
- Seroconversion can be detected by Complement Fixation Test (CFT).
Management and Control of Vesicular Stomatitis
The disease can be managed and control in the following ways:
- The infected horses should be isolated from healthy horses and supplied with sufficient water, soft and palatable feed.
- The use of broad-spectrum parenteral antibiotics may be indicated if the horse has a secondary bacterial infection.
- Administration of fluid therapy and electrolytes.
- Nasogastric tube feeding is indicated if the horse is unable to eat or drink.
- Involvement of the feet may necessitate treatment similar to that employed in the case of equine laminitis.
- If the disease is found in an area, insect control and the removal of animals from wooded pasture and their confinement in stables will help curtail the virus’s spread.
Final Advice on Vesicular Stomatitis in Horse
Vesicular stomatitis is a common viral disease of cattle. Similar diseases also occur in goats called contagious ecthyma and in sheep ORF. The disease also affects horses; if the horse is rough feeds forages and pasture having thorny weeds. The disease is self-limiting within few weeks after occurrence if there is no bacterial infection. You must inspect the grass and pasture regularly and try to avoid contact with other animals.