Horse Upper Respiratory Infection

Information on the causes of wquine upper respiratory infections and symptoms of influenza and herpes virus in horses.

respiratory infection, influenza & herpes virus in horses

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  1. What are Upper Respiratory Infections?
  2. What Causes Upper Respiratory Infections?
  3. Diagnosing Upper Respiratory Infections
  4. Help for Upper Respiratory Infections
  5. More Information on Upper Respiratory

What are Upper Respiratory Infections in Horses?

Respiratory infections are a very common health problem affecting horses. An upper respiratory infection affects the throat, lymph nodes and lungs. It causes much discomfort for the horse, often leaving him feeling weak and listless.

If left untreated, upper respiratory infections can lead to serious complications affecting the rest of the body such as kidney damage, laminitis, leg swelling, heart and neurological disease.

What Causes Upper Respiratory Infections in Horses?

An upper respiratory infection is caused by various bacteria, viruses, fungi and parasites. Various bacteria can infect the upper parts of the respiratory system and often cause pneumonia and weaken the immune system. One of the most common bacterial respiratory tract infections is known as strangles.

Viruses such as the Equine influenza virus and the Equine Herpes virus (type 1 and 1V), which are similar to colds and flu in humans, are the primary cause of upper respiratory infections. Although fungal infections of the respiratory system are not as common as bacterial or viral, they may also develop.

The lungs and guttural pouches are often more susceptible to fungal infections. When a parasitic infection invades the respiratory system, roundworms, threadworms or lungworms travel through the lungs and weaken the immune systems of young and aging horses.

Diagnosing Upper Respiratory Infections in Horses

The diagnosis of an upper respiratory infection is based on the symptoms, a complete physical examination and review of the horse’s medical history. Certain diagnostic tests such as x-rays, thoracic ultrasound, endoscopic examination, fine needle aspiration and a lung biopsy may be performed to confirm the diagnosis.

Symptoms and signs

The common symptoms and signs of an upper respiratory infection include:

  • Runny nose
  • Nasal discharge
  • Runny eyes
  • Fever
  • Changes in normal breathing pattern
  • Coughing (dry or moist)
  • Loss of appetite
  • Behavioral changes such as depression


Help for Upper Respiratory Infections in Horses

Treatment of upper respiratory infections involves certain medications, supportive care and environmental factors. Medications such as anti-inflammatories may be prescribed to reduce symptoms. Ensure that your horse is vaccinated against viral infections which will help to minimize the duration and severity of the disease.

Avoid giving your horse human cough syrups or decongestants, as these are potentially dangerous. In order to speed recovery, a comfortable, dry but well-ventilated barn or stable, adequate rest, palatable foods as well as plenty of fresh, clean water and tender loving care are essential.

More Information on Upper Respiratory Infections in Horses

Tips to help prevent upper respiratory infection

There are a number things that you can do to prevent upper respiratory infections in horses and these include:

  • Make sure that your horse’s stable is well-ventilated – always keep the top half of the stable door open
  • Feed your horse pelleted or cubed hay or beet-pulp-based or grain-free feed
  • Reduce exposure to dust and allergens to facilitate easier breathing
  • Clean stables thoroughly
  • Change bedding regularly and check for bedding soaked with urine – use fresh shavings or shredded paper in peat instead of straw
  • Ensure that horses are kept warm and dry in cold and wet conditions as well as after exercise
  • If your horse starts coughing, stop riding him immediately
  • Stable your horse if he is coughing and keep him warm
  • Make sure that your horse’s vaccinations are updated to prevent infections
  • De-worm your horse regularly


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