Why Should I Isolate My Horse After It Comes Back From An Equine Hospital?
It's a good general practice to isolate and monitor any horse that has been off the farm, especially one that has been to an equine hospital. This is often a touchy area for equine hospitals - telling people to isolate and monitor their horses might suggest to owners that the hospital has an infectious disease problem, and lead to negative perceptions of the facility or having people take their business elsewhere. However, it's been proven time and again that the "head in the sand" approach does not work for infectious diseases. Discussions of infectious disease risks in horses that have been hospitalized should be taken as an indication that the facility has an open and proactive infection control program. Therefore, places that talk about disease rates may very well be the safest facilities, because they are monitoring infectious disease, taking precautions and showing that they care about infection control.
Horses coming home from equine hospitals are always going to be at some increased risk of shedding infectious agents. Here's why:
- Some healthy horses carry various infectious agents at any given time. Stress, shipping, diet change, antibiotic treatment and other factors that occur during hospitalization can result in increased shedding of these organisms that the horse was already carrying. For example, equine herpesvirus lives dormantly in a reasonable percentage of healthy horses. They don't usually shed the virus, but may start shedding when they are stressed. So, a horse that was not shedding herpesvirus could start shedding as a result of hospitalization, and thereby expose other horses on the farm. Similarly, stress, shipping, diet change, antibiotics and anesthesia can cause horses that were already carrying low levels of Salmonella to start shedding high levels of the bacterium, potentially resulting in disease in the affected horses or transmission to others.
- Horses can acquire infectious agents in hospitals. An inherent risk of visiting any hospital (like any fair or other event) is exposure to infectious agents. Horses that go to hospitals are at higher risk of picking up things because of the reasons described above. The more horses present and the poorer the infection control program, the greater the risk. Regardless of the quality of infection control at the equine hospital, some risk always remains, but a good infection control program can greatly reduce the risk.
- Horses that return from hospitals are often at higher risk of becoming infected with (i.e. more susceptible to) various bacteria and viruses for a short time after they return home. Therefore, they might be at greater risk of picking up something that is circulating on the farm already but not causing major problems to the otherwise healthy horses.
Routine isolation and monitoring of horses returning from equine hospitals is a good management practice. The likelihood of a problem developing is low, but it's much better to have problems occur when the horse is isolated so they can be contained. A short isolation period lets horses get rid of infectious agents they have picked up or started shedding as a result of hospitalization, so they don't expose other horses. It also lets you identify problems that develop (e.g. diarrhea, cough, fever) as a result of being off the farm, before the horse is expose to other animals on the farm.
The ability to properly quarantine horses on a farm is variable, depending on the facility, but effort should be taken to provide the greatest degree of isolation/quarantine that is feasible and practical. Every farm should have an infection control program that includes a plan on how to handle horses that have returned from equine hospitals.
