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Infectious Diseases

Infectious diseases in horses can be caused by viral, bacterial, fungal, and parasitic organisms. The most common diseases requiring isolation of the patient are those associated with fever, diarrhea, and respiratory disease. Some hospitalized horses are at increased risk of contracting a contagious infection because of the physiologic stress they are under due to their primary disorder.

Examples of infectious diseases

  • Equine influenza virus
  • Equine herpes virus
  • Streptococcus equi equi (also known as strangles)
  • Lyme disease
  • Potomac Horse Fever
  • Salmonella spp.
  • Clostridium difficile
  • Coronavirus

Safety measures

The Equine Medical Center’s biosecurity measures and isolation facility ensure a safe hospital environment for all patients.

The Equine Center's state-of-the-art Isolation Unit provides a critical service to the mid-Atlantic region, physically separating horses with potentially contagious diseases from hospitalized horses and the general equine population to minimize the risk of patient-to-patient infection. The Isolation Unit is a Biosafety Level 2 facility that provides the following:

  • Eight individually ventilated stalls under negative air pressure to prevent cross-contamination.
  • A temperature-controlled environment that is conducive to the recovery of critically ill horses with potentially contagious illnesses.
  • 24-hour monitoring of horses in need of intensive care.

Biosecurity measures are as important at referral hospitals as they are at farms. At the Equine Center, any horse suspected to have an infectious disease will be admitted to the Isolation Unit to limit exposure of animals and personnel. This practice is essential for the prevention of disease outbreaks in the hospital population.

We adhere to strict biosecurity guidelines throughout the hospital and follow rigorous cleaning protocols:

  • Hospital stalls are scrubbed with a chemical soap disinfectant.
  • Isolation stalls are disinfected two times, and all equipment associated with that patient is disinfected and cultured to make sure that no organisms are present after cleaning.
  • Bio-hazard waste is stored in special containers and hauled away to be incinerated.

Infectious disease prevention on the farm

Equine diseases are spread in a variety of ways, including the following:

  • Direct contact between horses.
  • Contact with feces.
  • Contact with insect or animal vectors.
  • Contact with aerosol particles.
  • Contact with contaminated needles.

Often overlooked but equally important modes of disease transmission include contact with contaminated equipment, tack, transport vehicles, clothing, boots, or hands.

Contact with other horses at events/shows is another common way of spreading disease. It is important to limit close contact with other horses as much as possible. Owners should bring their own equipment to these events and not share equipment with other participants. Upon returning home, show horses should be stabled away from other resident horses that rarely leave the farm to limit their exposure to infectious diseases. The equipment used during the event, as well as the truck and trailer, should be cleaned and disinfected upon return to the farm.

Among the various water sources used on animal facilities, surface water, such as a pond, river, stream, or cistern, presents a great concern for disease exposure because it is difficult to control water quality and to limit exposure to insects. A Coggins test for equine infectious anemia and a screening test for strangles or history of no occurrence in the previous six months are essential for preventing the occurrence of infectious diseases on a farm.

The most common way infectious diseases are spread is via a new horse arriving at the property.

  • It is essential to isolate any new horse from the resident horses for at least two weeks. During that period, the isolated horse should be checked twice daily for presence of fever or any signs of illness.
  • Separate equipment — buckets, grooming supplies, tack, and stable equipment — should be used for the new arrival.
  • The isolated horse should always be handled last or in protective wear, such as disposable boots and overalls.

Good husbandry practiced daily is the most effective way to reduce the spread of disease.

  • Horses should be checked daily for any signs of illness or injury.
  • Deworming and vaccination programs should be implemented, and records of each horse should be maintained.
  • Manure should be picked up at least once daily in stalls and paddocks; pastures should also be cleaned on a regular basis.
  • Water buckets and troughs need to be cleaned daily.
  • Any ill horses should be isolated from the rest of the population. A veterinarian should be contacted immediately.

Vermin and insect control is essential in the prevention of infectious diseases, such as Lyme disease, Potomac Horse Fever, and Equine protozoal myeloencephalitis. The following steps can be taken to deter insects and vermin:

  • Using insect repellents.
  • Emptying the manure pit regularly.
  • Storing water and feed in vermin-proof containers.
  • Disposing of old and uneaten feed.
  • Limiting spots for vermin to hide and breed.
  • Proper cleaning and disinfection of stable equipment, tack, grooming supplies, truck, and trailer should be performed regularly.
  • Cleaning consists of removal of any organic material and washing in soapy water. When organic material is gone, trailers, tools, buckets, and grooming supplies should be disinfected with a 10% bleach solution.
  • Transport vehicles, tires, stable floors and walls, and stable equipment should be disinfected with 10% bleach solution or quaternary ammonium compounds.
  • Personnel must maintain hygiene by washing hands or using alcohol wipes between the handling of different horses, especially when sick horses are present at the farm.