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Flehmen response in horses: Is it an odour or is it the stomach?

Tanja Dietz


3 Min. Lesezeit

Horses usually exhibit flehmen when they have detected an odour that they want to identify more closely. When a horse flehmens, it stretches its head forwards and pulls up its upper lip. This closes the horse's nostrils and the odour is directed into the vomeronasal organ, an additional olfactory organ with which horses can filter out and identify sexual attractants in particular.

Disclaimer: The following text has been translated from German. It is important to note that if you have any inquiries regarding the feeding of your horse, it is always recommended to consult your veterinarian first.

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However, flehmen does not always mean that a horse has perceived a particular odour. It can also be a sign of discomfort and pain, especially in the gastrointestinal tract. Many horses suffering from stomach ulcers or colic exhibit this symptom.

Find out why your horse is exhibiting flehmen!

Most horse owners know their horses well and are therefore able to judge whether their horse is currently reacting more strongly to unfamiliar smells with flehmen or whether something else is the trigger for this behaviour. As horses are better able to filter out sexual attractants through flehmen, it can be observed that stallions in particular flehmen frequently. This is how they determine whether a mare is in heat or not. However, if the horse flehmens conspicuously often, which is otherwise rather atypical for your horse and the situation or the surroundings do not give any indication of a reason, your alarm bells should ring, as this is usually a sign that your horse is in pain.

Flehmen as a symptom of a stomach ulcer

If your horse flehmens due to a stomach ulcer, this is usually accompanied by other symptoms that indicate a stomach ulcer. These include, for example, increased yawning, empty chewing, dull coat or defensive behaviour when saddling and girthing. You should also be able to observe clear changes in your horse's behaviour. In general, there is a very wide range of behaviour here, ranging from horses that are exhausted, depressed and withdrawn into themselves to horses that react aggressively.

Stomach patients flehmen noticeably often and in very different situations - for example, when standing in the box or in the pasture, when grooming, but this symptom can also be observed when riding. If you notice any abnormalities in combination with flehmen, you should definitely contact your vet.

We also recommend our Stomach Diary app, which we provide free of charge. There you can regularly enter unusual behaviour you have observed in your horse. Of course, this can also be done by the people who look after your horse when you are not there.

Gastroscopy provides information about stomach ulcers

If it is clear from the list that your horse is frequently showing flehmen response for no recognisable reason, this is a solid indication that this may be a symptom of gastric ulcers in the horse. Of course, only your vet can give you certainty here. However, you can avoid false alarms in this way, after all, a single observed flehmen does not necessarily mean a stomach ulcer. However, if the horse exhibits increased symptoms that confirm the suspicion of "gastric ulcers", a gastroscopy should be carried out to find out whether the horse is suffering from gastric ulcers or not. You should not wait too long before performing a gastroscopy so that any gastric ulcers can be treated quickly and specifically so that they can heal and cause the horse no further pain.

More on the topic

You can find lots more information and links on the topic of symptoms and signs of gastric ulcers in horses on our topic page.

Symptoms of gastric ulcers - the most important symptoms that horses show when they suffer from a gastric ulcer.


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