Weight loss in horses
Most horses in the UK are overweight, but if your horse is too thin, they may be suffering from an underlying health condition.
Is my horse too thin?
The short answer is probably not! In the UK the majority of pleasure horses are overweight, so take care when comparing your horse to others on your yard.
There are many health concerns related to obesity and it can be much more challenging to get your horse to lose weight than to gain weight. If you are concerned that your horse may be too thin or is losing weight rapidly then please ask your vet to check them over and assess their condition.
Seasonal weight fluctuations
Winter weight loss is completely normal, and in fact should be encouraged. Horses are naturally designed to store fat over the summer months and then use these fat stores during the winter months.
When should I be worried about my horse's weight?
Weight loss occurs when calorie output exceeds calorie input, so is either caused by an increased calorie demand (i.e. increased amount of exercise, pregnancy, cold weather) or by reduced calorie intake (i.e. not enough food, poor quality food or gut disease reducing absorption of nutrients from gut).
If your horse has suddenly started losing weight without any changes to diet or exercise it would be advisable to consult your vet. Some common causes of weight loss include:
Dental disease
Chewing food and spitting it out (quidding) or reduced intake of food tends to only occur once dental disease is very severe. Many people think that it would be obvious if there horse had dental issues but some horses will still appear to be eating normally despite dental pathology and pain.
These horses may still be eating a normal volume of food, but if they have insufficiently chewed it then they will not be able to digest it effectively. It may be possible to see these undigested long pieces of fibre in the faeces. All horses should have their teeth checked at least once a year and more regularly if they have known dental problems.
Worm burden affecting weight loss
We now recommend performing regular faecal worm egg counts (FWEC) rather than a blanket worming programme, this is to try to reduce resistance of the worms to the wormers. It must also be combined with good pasture management including regular poo picking.
Tapeworm and encysted small red worm do not show up on FWECs so horses should still be wormed at least once a year against these worms. In cases of weight loss it may be sensible to give a wormer if the horse has not been wormed in the last six months as tapeworm can contribute to weight loss.
Gastric Ulcers
A wide range of symptoms can be seen in horses suffering from stomach ulcers. These include, but are not limited to: weight loss, poor quality coat, mild colic, grumpy or aggressive behaviour, pain as girth is tightened and poor performance.
A gastroscope examination can be performed which involves popping a camera up the horses nose and down into it’s stomach to check for ulcers. Treatment includes medication to reduce acid in the stomach and dietary management.
Gastrointestinal disease ie IBD
Weight loss due to gastrointestinal disease is usually accompanied by diarrhoea. There are many potential causes of diarrhoea in horses and can range from a simple upset of the normal gut bacteria to life threatening disorders such as cancer. The gut is full of lots of ‘good bacteria’, which are kept in a delicate balance, this balance can be disrupted by sudden changes in diet or by eating very rich foods such as haylage.
There are lots of very good probiotic supplements available that can help restore the bacterial balance. If diarrhoea persists then your vet will perform blood tests and possibly gut biopsies to check for Inflammatory bowel disease (IBD) and alimentary lymphoma (cancer). These are thankfully rare causes of weight loss but can be very serious.
Liver disease
Blood tests are often performed when the cause of weight loss is unknown, these tests would include a check for liver function. A liver biopsy is often performed after blood results indicate liver disease is present
Heart disease
Weight loss as a consequence of heart disease only tends to occur in cases of severe heart disease causing heart failure. Other symptoms would usually also be present in these cases, ie heavy breathing, exercise intolerance, fluid build up under belly and around sheath (oedema).
Cushings Disease (PPID)
Cushings disease (aka PPID) can also contribute to mild weight loss, particularly in older horses. A simple blood test can be carried out to diagnose PPID and it can usually be well managed with a tablet in food.
Monitoring your horse's weight
We recommend that you weigh your horse and record their measurements on a biweekly basis so that notice any subtle changes. Whilst weigh tapes are not always 100% accurate they do offer an excellent guide and you will quickly realise if you horse’s weight is fluctuating.
There are many excellent reputable feed helplines and we would encourage people to discuss their horses dietary requirements, but if you are at all concerned then do call us on 01577 841010 – even if it is for a chat.
Health Horse Club members benefit from 10% off a Remote Nutritional Consultation with Independent Equine Nutritionist Donna Case.
If you would like any additional information please call us on 01577 841010.
