RISK- BASED VACCINATIONS
The “risk-based” vaccines— recommended for horses only if their health, lifestyle or location puts them at increased risk—protect against the following diseases:
• anthrax— a potentially fatal systemic infection caused by the spore-forming bacterium Bacillus anthracis, which is found in the soil in some regions.
• botulism— neuro-poisoning caused by the toxin secreted by Clostridium botulinum bacteria, which can contaminate feed, water or wounds. Horses may die from respiratory failure or complications of recumbency. Shaker foal syndrome is another form of the disease.
• equine influenza— a common, acute viral infection involving the respiratory tract. The virus mutates easily and immunity is short-lived, making horses susceptible to influenza even after recovery.
• equine viral arteritis— a highly contagious disease that causes mild respiratory signs in most horses. EVA can trigger abortion in broodmares. Breeding stallions can be silent carriers, passing the disease along to mares without showing signs of illness themselves.
• Potomac Horse fever— a disease caused by the organism Neorickettsia risticii, contracted when the horse eats infected insects. Characterized by severe fever, diarrhea and laminitis, the disease typically begins to appear with the arrival of warm weather and persist through the summer.
• rhinopneumonitis (equine herpesvirus)—a contagious disease caused by two forms of the same virus, EHV-1 or EHV-4. EHV-1 can cause respiratory issues, abortions in broodmares or neurological problems. EHV-4, known as the respiratory form of EHV, can also cause neurological signs, including progressive weakness and incoordination.
• rotavirus A— primary cause of excessive diarrhea in foals younger than 3 months old. Mortality is less than 1 percent, but the disease is highly contagious. In addition to diarrhea, signs of the virus include depression, failure to nurse and difficulty standing.
• strangles— a highly contagious infection of the lymph nodes, usually of the throat, caused by Streptococcus equi bacteria. Horses can become carriers of this disease and may shed the bacteria even if they look healthy.