What Are The Normal Bacteria Of The Horses Airway?

Last Updated on January 24, 2022

If your horse has a respiratory problem, your veterinarian might suggest that samples be taken to check for abnormal bacteria. But what are the normal bacteria of the horses’ airway, and which ones can cause a problem?

Most people don’t realize that not all bacteria are bad! We are led to believe that bacteria cause diseases, but many types of bacteria cause no harm at all. In fact, some bacteria are even beneficial, and we would not be able to stay healthy without them!

Let’s take a look at bacteria and the role they play in respiratory problems in horses.

What Causes Respiratory Problems In Horses?

Respiratory problems in horses are unfortunately very common. They can be caused by infectious agents, such as viruses and bacteria. Other respiratory disorders in horses can be caused by allergens that trigger an inflammatory response.

Equine respiratory disorders can normally be divided into two types. The first of these affect the nasal passages, sinuses, larynx, pharanx, and trachea. These are referred to as upper respiratory tract (URT) disorders.

The second category of respiratory problems affects the lungs. The lungs are where oxygen and carbon dioxide transfer takes place. These are called lower respiratory tract (LRT) disorders.

What Causes Respiratory Problems In Horses

If you are concerned that your horse has respiratory problems, you should look for the following symptoms:

  • Difficulty Breathing – your horse might be breathing faster than normal or taking deeper breaths.
  • Coughing – your horse might only cough at certain times, or throughout the day.
  • Nasal Discharge – check to see if this is clear or purulent and if it comes from one or both nostrils.
  • Swollen Lymph Nodes – feel under your horse’s throat; does it seem more swollen than normal?
  • Lethargy – is your horse reluctant to exercise? Is he resting more than normal?

If you suspect that your horse has a respiratory problem, it is best to seek veterinary advice as soon as possible. You should also isolate your horse until a diagnosis is made, in case he has an infectious disease. Your veterinarian may need to carry out a number of tests to make a diagnosis.

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What Are The Normal Bacteria Of The Horses Airway?

Your veterinarian might decide to take samples to check for bacteria to help with the diagnosis. However, how do you know which are good and bad bacteria?

This might sound odd, but it is completely normal for horses to have some bacteria in their respiratory tract! Many of these bacteria will never cause a problem, but some of them are responsible for some fairly nasty diseases.

Your veterinarian has several different methods of taking a sample to check for bacteria. One option is to put a swab inside the horses’ nasal passage, via the nostril. For lower respiratory tract diseases it may be necessary to use an endoscope to collect a sample from the trachea or lungs.

Normal Bacteria Of The Horses Airway

Wherever the sample is taken from, it will be cultured to see what bacteria grow. Your veterinarian will then interpret these results to decide if one of the bacteria identified is causing your horse’s respiratory problems.

The problem here is that many of these bacteria will live normally in your horses’ respiratory tract without causing a problem. However, they are opportunistic bacteria and if the horse becomes debilitated, they will quickly multiply and start to cause problems.

The following are all opportunistic bacteria that commonly colonize the equine respiratory tract:

  • Streptococcus equi zooepidemicus
  • Actinobacillus equuli
  • Bordetella bronchiseptica
  • Escherichia coli
  • Pasteurella spp
  • Pseudomonas aeruginosa

What Is The Most Common Infectious Respiratory Disease Of Horses?

There are many infectious respiratory diseases of horses, and there is no one that is more common than any other. The most common type of infectious respiratory disorder will depend on many factors, such as the region, average age of the horse population, and vaccination status of the horses.

The most common infectious respiratory diseases of horses include equine influenza, equine herpes virus, and strangles. Other less common diseases are equine adenovirus and equine rhinitis.

Horseman’s Veterinary Encyclopedia, Revised and Updated

All of these diseases are infectious because they are caused by either bacteria or viruses. This means they can be transmitted easily from horse to horse. This is why strict biosecurity measures are so important if you suspect that your horse has an infectious respiratory disease.

To avoid transmitting respiratory diseases, affected horses should be isolated and not allowed to make contact with any unaffected horses. You should change your clothes after attending to an infected horse, as some viral and bacterial infections can be spread this way. It is also important to ensure that your horse is vaccinated against any common equine infectious diseases in your region.

What Is Inflammatory Airway Disease In Horses?

Inflammatory airway disease is a non-infectious respiratory disorder of horses. This disease is very similar to recurrent airway obstruction, except that it occurs mainly in younger horses and has fewer long-term effects.

Inflammatory airway disease is normally seen in horses aged up to six years of age. The symptoms include coughing, nasal discharge, and exercise intolerance.

The cause of this disease is an allergen-linked response to airborne factors such as molds, fungi, and other organic materials. When these allergens are inhaled the airways become inflamed, causing them to constrict and become irritated. Some horses with inflammatory airway disease may also have a secondary bacterial infection.

Most young horses with inflammatory airway disease make a full recovery. Your veterinarian may prescribe a course of corticosteroids to help reduce the inflammation. It will also be necessary to rest the horse, as exercise will make the condition worse.

Summary – What Are The Normal Bacteria Of The Horses Airway

So, as we have learned, the normal bacteria of the horses’ airway include some such as Streptococcus equi zooepidemicus. Horses can get many different types of respiratory diseases, some of which are caused by bacteria. Other causes include viral agents and allergens.

We’d love to hear your thoughts! Does your horse have a breathing problem that he can’t seem to shake off? Or maybe you’ve come across an unusual respiratory problem in horses? Leave a comment below and we’ll get back to you!