Respiratory problems in your horse - not a good wheeze!
Horses and ponies can be susceptible to a number of conditions that affect the respiratory tract. The causes of these can be very varied - from infections and allergies to anatomical defects. The seriousness of the conditions also varies: some conditions will resolve without veterinary treatment but others are life-threatening. Many respiratory conditions lead to coughing, others result in a nasal discharge from the nose or abnormal respiratory noise. If there is any change in your horse's breathing it is always advisable to contact your vet.
What is meant by 'respiratory tract'?
This is a term used to include all the organs and structures which are related to breathing. They include the nose, the pharynx (or throat), the larynx (or 'voice box'), the trachea (or 'wind pipe') and the lungs. 'Airway' is another term for the respiratory tract.
What are the main causes respiratory disease in horses?
The main causes of respiratory problems fall into four categories:
1. Bacterial and viral infections
The two most serious diseases that fall into this category are equine influenza (viral) and Strangles (bacterial). The nature of bacteria and viruses means that these diseases are highly contagious and can spread very rapidly between horses. It is therefore essential that they are recognised and treated early. Other infections include pneumonia, herpesvirus,adenovirus and rhinovirus. Foals and young growing animals are very susceptible to infectious respiratory conditions so it is essential to monitor them closely and to contact your vet at the first signs of a problem.
2. Parasitic infections
Parasites are organisms that live on or within a host and take nourishment from that host - horses are prone to several parasites, worms being the most common. Lungworm spends part of its lifecycle in the lungs and respiratory tract of horses and ponies causing chronic coughing. About 70% of donkeys in the UK are infected with lungworm but they rarely show any signs of infection. Horses and ponies that graze with donkeys are at particular risk of catching this parasite.
Just as humans can have allergies to pollen and dust resulting in sneezing and breathing problems, horses can too. The term used to describe respiratory allergy in horses is chronic obstructive pulmonary disease (COPD). This describes a condition that is very similar to asthma in humans. It may be triggered by an allergic or irritant reaction to the dust or pollen in hay and straw and results in a narrowing of the airways leading to coughing, loss of performance in competitive animals and, in severe cases, wheezing and breathing difficulties. There is also a related condition called summer pasture-associated obstructive pulmonary disease (SPAOPD) which may be caused by pollen and is seen during the warmer summer months.
4. Anatomical problems
Horses can develop physical problems within the structures of the respiratory tract (pharynx, larynx, soft palate, epiglottis, trachea) which can cause partial obstruction of the airways. This can result in abnormal respiratory noises ('whistling' and 'roaring') and impaired breathing. Large breeds (such as warmbloods) are most prone to these problems, especially if doing competitive work, but in most cases they can be corrected by surgery.
5. Exercise-induced ('bleeder')
Exercise-induced pulmonary haemorrhage (EIPH) is seen primarily in racehorses but can affect any horse. After strenuous exercise, affected horses will be seen to suffer nosebleeds. It is now known that this bleeding stems from the lungs and is therefore a serious problem. Research continues into the cause of the problem, but it is currently thought to result from the extreme high blood pressures endured by the smallest blood vessels in the lungs during intense exercise.
What are the signs of respiratory disease in my horse?
Initial symptoms of a respiratory problem:
Signs of acute (rapid onset) respiratory distress:
What should I do if my horse has these symptoms?
What will my vet do?
Your vet will want to know about the days and events before your horse developed the signs.
He/she may ask about:
Your vet will conduct a physical examination of your horse and he/she may want to examine your horse after exercise too. The examination will include:
As described above, there are many different conditions of the respiratory tract. Through the procedures listed above your vet will be able to determine which part of the respiratory tract is affected. They will then advise you on the most appropriate treatment for your horse.
How can I prevent further episodes of respiratory distress?
Some respiratory conditions are very easy to prevent, but for others simply keeping your horse in top condition so that it is less susceptible to any form of disease is the only preventative measure you can make.
Influenza and infections
Vaccination is available for equine influenza infection. Ensure that your horse is fully protected against this condition and has regular booster vaccinations as recommended by your vet.
By implementing a regular and effective worming programme you will reduce the risk of your horse contracting this parasite. Ask your vet for advice on an appropriate worming programme for your horse.
If your vet diagnosed an allergy problem you will need to implement changes in the management of your horse. The purpose of these changes is to reduce your horse's exposure to the allergens that cause the problem. These are known as the rules for 'dust-free management' and they need to be strictly adhered to:
Remember to liaise closely with your vet and keep him/her informed of any change in your horse's condition.