Coughs and Sneezes
Here is a quick breakdown of common conditions to look for in horses that suffer from coughs and sneezes
- Nasal discharge
- Enlarged submandibular (under the jaw) lymph nodes
The common viruses encountered include:
Equine herpes viruses
In addition to the above signs, they can cause abortion and neurological disease (hind limb paralysis and incontinence). It is caught from other horses because they shed the virus in nasal secretions that form droplets in the air, for up to three weeks, and other horses can inhale the droplets. Some horses will be carriers of the virus and act as a reservoir for infection. They may not show signs of the disease until they become stressed, e.g. by transport, other illness or vaccination. A diagnosis is usually made by taking a swab from the nose of the horse in order to attempt to isolate the virus. Another option is to take blood serum samples (paired serology) to look at antibodies to the virus. To prevent the disease there are vaccines available and these need to be given every two to three months to be effective. The mare can be vaccinated when pregnant, and a foal can be vaccinated at three months old.
In cases of an outbreak of the neurological form of the disease, the National Trainers Federation and the Thoroughbred Breeders Association recommend a voluntary scheme of isolation policy on the premises, serology on all in-contact horses, separate positive and negative horses and re-test until all the horses have two negative samples.
This spreads rapidly through a population, and is caught by inhalation of droplets from infected horses. More severe signs are seen in younger horses, and they have fever, cough, and a watery nasal discharge. Again diagnosis is either by nasal swab or serology, and it is prevented by vaccination.
Equine viral arteritis.
This is spread by nasal secretions, and venereally. The most important infection can be that of stallions which can lead to them being chronic shedders of the virus. This can often necessitate castration to prevent infection of any mare that is covered.
It can cause severe respiratory signs and death in young foals, abortion swelling of the legs and underbelly, cough, and conjunctivitis. Diagnosis is by serology from a blood sample. There are vaccines to prevent the disease and understandably these are used most commonly in stallions top prevent permanent infection. .
This is associated with mild respiratory infections in horses caused by a picornavirus, and is similar to “a cold” in humans. However, it is very different to Equine Rhino-pneumonitis which is another name for Equine Herpes Virus infection.
- Strep. equi (Strangles) – this causes upper respiratory tract disease and is discussed in a separate article.
- Strep. zooepidemicus
- Strep. pneumoniae
The latter three more commonly cause lower respiratory tract disease in young horses. Signs you may see include:
- Nasal Discharge
- Poor performance
To diagnose bacterial infections, we have to take a sample of fluid from the airways by endoscopy (injecting a small amount of fluid into the windpipe and sucking it back up). This is so we can see what bacteria we are dealing with, and treat it with the appropriate antibiotics.
Other treatments for respiratory disease include rest, dust free environment, drugs such as “bute” to reduce temperature, and TLC.
Non infectious causes.
Recurrent Airway Obstruction/Small Airway Disease (aka COPD). This is essentially an allergic disease, and can be associated with housing, hay, or pasture. Signs are coughing, increased respiratory effort, watery nasal discharge, and exercise intolerance. Diagnosis is usually made by history and clinical signs, but it can be confirmed by endoscopy and/or transtracheal wash. Treatment involves avoiding the allergens responsible, e.g. complete turnout if hay and stabling is responsible, soaking hay or feeding haylage, and using dust free shavings. Ventipulmin is a powder that goes into feed that can be used to open up the airways, and also steroids can be used to control severe cases. These are usually given orally. Sputulosin is sometimes used to water down any thick mucus in the airways, again this goes into the feed.
Human inhalers for asthma can be used to control RAO too, and although this works very well when used correctly, it does have to be administered several times a day and can be expensive.
Less common causes of chest problems
- Aspiration pneumonia (i.e. Inhaling fluids or food )
- Heart disease
- Lung abscesses