Blood seen at a horse’s nostrils can originate from any number of locations along the respiratory tract – from the lungs and throat, to the sinuses and nasal passages. While a one-off trickle of blood from a single nostril may not trigger the ringing of alarm bells, severe nosebleeds are not unheard of and can even be fatal when they occur.
What can cause nosebleeds in horses?
There are many reasons why your horse or pony may develop a nosebleed. The most obvious cause would be trauma. Could your horse have banged his head in the horsebox or stable? Wounds or swellings to the head and neck can indicate that trauma is a likely cause.
Infection and inflammation in the air-filled sinuses of the skull can also cause nosebleeds. This can occur secondary to respiratory problems or problems with the teeth. Often these horses have a history of nasal discharge (which can be very smelly), coughing, quidding, enlarged glands or smelly breath.
Nosebleeds can also occur as a result of masses in the nasal passages. Ethmoid haematomas are growths which originate in the region of the sinuses. As they grow, they can damage the surrounding tissue, usually causing intermittent, mild nosebleeds.
Arguably the scariest and most serious cause of nosebleeds in horses is guttural pouch mycosis. Horses and ponies have an outpouching of the airways in the back of the throat known as the guttural pouches. These pouches have little known function but are an important site for several major blood vessels and nerves. Occasionally, fungal spores in the environment are inhaled into the airways and enter the pouches. The fungi preferentially locate themselves next to the arteries, sometimes damaging the walls of these blood vessels. This can lead to a profuse nosebleed from one or both nostrils.
Extremely strenuous exercise can also trigger nosebleeds. This is most common in racehorses and occurs due to the rupture of tiny blood vessels within the lungs.
What to do if your horse has a nosebleed…
- Don’t clean up the blood before your vet arrives. It is really useful for us to be able to assess how much blood your horse or pony has lost as it can give us a clue as to the possible cause involved and the most important line of treatment.
- Keep your horse or pony as calm and quiet as possible. This can be extremely tricky and owners and vets alike can feel extremely helpless just watching the blood flow. Horses cannot breathe through their mouths and so obstructing the nostrils to stem the flow is not advised.
- While your vet is en route, think about how you would describe the nosebleed. What was your horse doing just before it happened? Was this the first time it has happened? Was it from one nostril or both? Was the blood a bright cherry red or more reddish-brown? How much blood do you think was lost?
Managing your horse’s nosebleed…
If your horse’s nosebleed is very mild and stops quickly, treatment may not be necessary and your vet may simply ask you to monitor him closely for recurrence.
If the nosebleed was severe, your horse may need intravenous fluids to replace the blood that he has lost. To make this decision, your vet will be looking for clues such as a high heart rate, pale, tacky gums and a depressed or lethargic attitude. If the bleeding is not stopping, or if your horse needs to be transported to the vet clinic, sedatives may be used to alter his blood pressure and to keep him calm.
Once supportive treatment is in place, your vet can begin investigating the problem in more detail. This will involve a full examination of your horse and, usually, further imaging such as x-rays or endoscopy. Passing an endoscope (a long, thin camera) up the horse’s nose is possibly the most useful tool for visualising the source of the problem. However, in some cases, your vet may advise waiting a day or two before doing this. Passing the camera too early could risk dislodging the newly formed clot that has formed over the bleeding point and so it is often best to give this time to settle before proceeding.
Ultimately, the aim is to identify the cause of the nosebleed so that more targeted treatment can begin. While some causes can be treated medically, guttural pouch mycosis, for example, requires surgical intervention.
If your horse has been suffering from nosebleeds or if you have any questions or queries on the matter, contact your vet for advice.
If you have any questions about any aspects of your horses’s health, or indeed your pet, farm or smallholding animals, please do not hesitate to contact us on 01892 835456. Putlands Veterinary Surgery is based in Paddock Wood in Kent, and offers a friendly, proffessional and personal service for all species of animal. We have four dedicated large animal vets with a wealth of equine experience between us, and are always happy to help