A Common Cold – or Worse?
It’s quite common at this time of the year to see the occasional discharge from your horse’s nostrils. But should you be worried? How do you tell if your horse has a cold, or if he is suffering from a more serious respiratory condition?
Causes of Respiratory Disease
The five most common reasons that a horse experiences problems with his respiratory tract are:-
1. Bacterial and viral infections
3. Parasitic infections
4. Exercise induced
5. Anatomical issues
In this article we will look at viral infections in more detail, one of which is the common cold.
Equine rhinovirus is the technical term for the common cold (don’t confuse this with equine “rhino” or “rhinopneumonitis,” which is caused by the equine herpesvirus and is a far more serious condition). It is a mild condition, affecting the upper respiratory tract. Symptoms include nasal discharge, a cough and the horse may seem below par for a few days. Just like the colds we suffer from, there is no treatment. After a few days the horse should look and feel brighter.
If your horse has a thick discoloured discharge, a temperature, swollen glands beneath the jaw, swollen eyes, no appetite or interest in his surroundings, suspect that the problem is more than a common cold and call the vet.
Sometimes symptoms will be very mild and go unnoticed, and it can be hard to know your horse has the andeno-virus. Foals seem to show more clinical signs, including nasal discharge, coughing, shortness of breath, fever, and inflammation of the eyes. Treatment is not normally necessary, as it generally clears up by itself, but foals should be monitored closely.
Equine Influenza is a far more serious viral infection, which is highly contagious. A stringent vaccination programme is followed in the UK, which has kept the disease at bay. However, any suspected cases should immediately be isolated and barrier nursing put into place.
Signs include a clear nasal discharge, loss of appetite, fever, and a dry, deep cough. Just like humans, some horses experience muscle pain, and can be reluctant to walk, with swollen legs. Infection lasts from 2 to 10 days, and the horse can still be contagious for a week after he appears to have recovered. As it is a virus, it cannot be treated with anti-biotics (unless secondary bacterial infections occur). Good nursing care is all that is required, while time allows the horse to heal.
There are various strains of EHV, 1 and 4 are linked with respiratory disease. Strains 2 and 5 sit latently in many horses but rarely cause disease. They can, however, make the horse more susceptible to other infections.
EHV-1 also leads to neurological disease, abortion and death of newborn foals. EHV-4, although severe, is non-fatal. Small outbreaks of EHV-1 have been seen in the UK, but stringent isolation has kept them at bay.
Horses are infected by inhalation of the virus, but the good news is that the virus does not live long outside of a host body. Fever, loss of appetite, depression, clear nasal discharge and a deep dry cough are all symptoms, extremely similar to those of Equine Influenza.
Vaccination does not prevent the disease but can limit its severity. As with ‘flu, the horse is treated with supportive nursing and isolation, and must be given adequate time to recover fully.
Equine Viral Arteritis
Although a condition that causes inflammation of the blood vessel, signs of respiratory disease are common, as is abortion. It’s contracted by inhalation or by sexual contact. The disease can incubate for up to 14 days, and signs include the normal respiratory symptoms, as well as red nasal tissue and excessive tears.
Isolation, supportive care and sufficient recuperation time are required. There is not normally any long term issues, but keep an eye for secondary bacterial infections, and foals do occasionally die if they contract EVA.
Pneumonia means inflammation of the lung, and any respiratory infection can lead to this secondary infection. It can be viral or bacterial, and it is important if your horse is suffering from a respiratory disease to rest him well. Coming back into work too soon, or any stressful situation, can lead to pneumonia.
Diagnosing Viral Infections
As you can tell from this list, many of these diseases have very similar symptoms. As the care is ultimately the same, the main reason to discover the cause of the respiratory infection is to help prevent it spreading.
Nasal swaps are the most common method of determining viral infections, alongside studying antibodies found in blood samples. As these tests take time, several samples each week are needed to confirm the disease. The vet will also not declare the viral infection has cleared until he has taken several clear swaps in succession.
If in doubt, call your vet. If it is just a common cold, there will be no harm done (apart from to your wallet!) but a speedy response to a more serious condition can prevent it spreading further.
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