Last Updated on April 5, 2022 by Allison Price
|As a horse owner of EMS or laminitic horses, one of the first things you will be told is “no treats,” ..”. Sometimes, a grape or prune can be used to hide pergolide tablets. However, owners might be advised not to use an apple or a slice of carrot for the same purpose. What’s the science behind all this?|
On the SELF nutrition website, we compared the analyses of carrots and apples, plums as well as grapes and raisins – any fruits/veg that could be given to horses to treat or hide their medication.
Both on an as fed basis and dry matter basis, the carrot is the best choice because it contains less sugar/starch. A 500-kg horse needs 15,000 IU/day. 100g fresh raw carrots provides more. Horses that graze will have plenty of vitamin, but horses who eat all hay, particularly hay that isn’t green or older than six months, might be deficient in vitamin A. Carrots are a great source of vitamin A. Carrots are also anti-inflammatory.
How does carrot sugar/starch compare to other common feeds like hay?
A 500-kg horse would need to eat 2% of his bodyweight. This would translate into a dry weight of 10 kg, or approximately. 11.2kg as fed weight hay per day. If we stick to the fed figures, hay contains 7.15% ESC (simple sugar) with starch (or 8% DM), which would mean that 800 g of sugar/starch can be consumed in a single day. Taken over 16 hours, that’s 700 g hay per hour, it would equal 50 g sugar/starch for each 16-hour period.
If 700g of 7.15% sugar/starch/hay is fed, it will give 50 grams sugar/starch.
100g of hay would yield 7.1g sugar/starch if it were fed.
100g carrots as feed gives you 6.1g sugar/starch
– so a carrot doesn’t look quite so evil now!
Fair enough, 100g of hay provided some fibre, protein, and fat. The carrot provided mostly water but also valuable vitamin A.
Compare a carrot with Spiller’s High Fibre Cubes, which were approved in 2019 by the Laminitis Trust. (NB: The Laminitis Trust Feed Authorization Mark does not indicate that a feed is safe. It contains 10% starch and 4.5% Sugar ***,. 100g of High Fibre Cubes would yield 14.5 g sugar/starch – more sugar/starch than the same weight carrots.
Glycaemic index (GI), a measure of how common foods affect human diabetes, has been developed. Glycaemic index (GI) ranks common foods on a scale of 0 to 100 based on how fast and how much blood sugar is raised after healthy people have consumed a certain amount of food (to ensure a controlled intake of carbohydrates). The University of Sydney has given 80g of raw diced carrots a GI of 35 (2017). Glycaemic load might be more useful – it takes into consideration the effects on blood glucose from eating a typical amount. Carrots, which are high in water content, have a low GLA (less than 10 is considered low). 80g of raw diced carrots has a GL of 2 according the University of Sydney (2017). Debunkin the Carrot Myth – Glycemic Index Foundation. These figures are for humans and not horses.
Clare Macleod, an equine nutritionist, dispels the myth that carrots should not be fed to horses suffering from laminitis. She also explains that while carrots may have a high sugar content on a dry matter basis, fresh weight data shows that they are very low in sugar. A fresh carrot has around 7.5% sugar. For older horses, she recommends carrots because of their betacarotene (vitamin A precursor).
Common sense must prevail. If a horse has insulin levels that are too high or is suffering from active laminitis, then it should be restricted to carrots. Once insulin levels and other symptoms are under control, a carrot or two per day is unlikely to cause any harm, especially if it’s sliced and eaten throughout the day.
You can find more information on feeding horses with laminitis and EMS, as well as PPID, at The Laminitis Site’s Diet page.
* Laminitis Trust Approval mark for horse feeds
4. NSC (%) should not exceed 40% of dry matter. NSC is used to estimate hydrolysable or rapidly fermentable carbohydrate feed components.
** ACVIM Consensus statement Equine Metabolic Disorder (2010)
NSC should be calculated by adding starch percentages and WSC percentages together. This value should ideally not exceed 10% of dry matter when giving horses or ponies EMS.
*** Spillers High Fiber Cubes nutrition analysis
(First published March 2013, updated February 2019).
In February 2019, a new ECEIM consensus document on the equine metabolic disorder was posted online. It stated that “grains and cereal-based complementary foods, fruits, vegetables, carrots, apples, and treats should not be included in the diet due to their high NSC content.”
The Laminitis Site shared the statement and suggested that carrots have a 6% combined sugar-starch ratio, which is less than some hays or feeds that are “safe for laminitics”.
ECEIM replied to this comment by saying that carrots may contain more sugar than starch on a dry matter basis. They are also clearly high-NSC feed items (Brokner and al 2012), which is different from most hays. While we accept that one fresh carrot may contain less sugar than other items, such as sugar lumps, we still recommend that they be avoided in insulin-dysregulated horses. We consider feeding high-sugar foods such as carrots and sugar lumps to horses with laminitis a poor practice. Carrots are not natural food for horses, and do not add nutritional value to a balanced diet as stated in the consensus statement. The ECEIM comment is available.
It would be interesting to compare total sugar and starch on an “as fed” basis (as horses eat that amount) of sugar cubes and raw carrot. We also recommend Spillers High Fibre Cubes (until 2019-see above).
Sugar: Two cubes of sugar were 5.15 g each on a gram scale. Sugar cubes contain 100% sucrose, on an as fed or dry matter basis. (Sucrose is half glucose and half fructose).
Carrot: A 83.5g serving of raw carrot has approximately 5.15g of sugar and starch.
The USDA Nutrient Database numbers for raw carrot show a sugar content of 4.74% (0.55% glucose, 3.59% surose, and 0.59% glucose) and starch content at 1.43% = 6.17%. This is 6.17 g sugar and starch per 100 g. 83.5 grams of carrot x 61.77% sugar/starch = 5.15 G sugar/starch. Our carrot was 83g in thickness at 15+ cm.
Spillers High Fibre Cubes : 35.5g High Fibre cubes contain approximately 5.15g sugar and starch. According to the website and feed label, the sugar content is 4.5% and starch content is 10%. This means that 100g contains 14.5g sugar and starch.
So, let’s take a look at the statement of ECEIM:
1. Carrots aren’t fed dry matter, they are fed as-fed. Their combined sugar and starch levels are very low: 5.15 g for an average 83g carrot and 6.17 g for a 100g carrot. For this discussion, it doesn’t matter if carrots are fed on an as-fed or dry matter basis. A 100g carrot is equivalent to 6.17g sugar and starch when it’s fed. The same 100g carrot has 88.3g of water. It also contains 11.7g dry matter. Its sugar and starch percentage is (6.17 / 1.1.7 = 52.7%). You are feeding a carrot with 52.7% sugar/starch, but only 11.7g (since you don’t count the water), which is surprising, because it contains 6.17g sugar and starch. ).
Clare MacLeod, Equine Nutritionist, commented (on The Laminitis Site’s Facebook page 14 February 2019), “Carrots do not have high levels of NSC when fed as a meal.” Period. It is a fundamental mistake to attribute the characteristics of a feed product DM in its fresh state.
Brokner et al. Brokner et al. (2012) analysed freeze-dried carrots – The DM content was 89.1%, sugar 58.1% (glucose 124%, fructose 12.5%, and sucrose 33.2%), fiber 27.8%, protein 7.4%, and starch negligible – all figures are given on a dry matter base. The photo shows the water content of fresh carrots at 11.7g per 100g. These freeze-dried carrots would have 6.8g of sugar per 100g if they were rehydrated to their original weight.
EquiAnalytical shows lower numbers for carrots than USDA figures (figures as of February 2019).
Average WSC 31.05% x DM Content of 13.18% = 4.09% As Fed, average ESC 20,.6% = 2.72% As Fed, average starch 2.18% = 0.29% As Fed, total sugar and starch (using the WSC = 4.38%)
2. The photo below illustrates that you can feed twice as many fresh carrots as High Fibre Cubes and 16x as many carrots as 2 sugar lumps for the same amount sugar and starch. We’re talking about 5.15 grams of sugar and starch for a horse weighing 500 kg. He should be eating 2% of his bodyweight, and keep the total sugar and starch intake below 10%.
3. Although carrot feeding is considered “unnecessary” and poor discipline, slivers can be useful training aids. They can encourage horses that are in pain or fearful to cooperate with you. For more information on the benefits of rewarding horses with food rewards, see Hand-Feeding Treats for Horses by Dale Rudin February 2019
A piece of carrot can be used as a hiding place for Prascend tablets. Also, a horse with EMS or laminitis may have already been subject to restrictions and less friendly management. He may not be allowed out on the field with his mates, and may be kept in a stable for hours, eating boring soaked hay from a tiny holed haynet. He is not naughty. He may be used to getting a carrot when he behaves well, or maybe last thing at night. But he should not lose that one pleasure. You can put yourself in the shoes of your horse. You want to manage your horse’s risk of developing laminitis and speed his recovery. But not so strict that you give him nothing to live with. It all comes down to looking at the numbers and thinking about your horse’s needs and wants.
4. “Carrots should not be used as a natural food item for horses.” What is a natural feed item? Something a wild horse would find? No unmolassed sugarbeet, no soya maashes, and no mineral balancers …. Feral horse may not be able to find a carrot in the wild, but it’s possible. !
5. To make up shortfalls in their forage, some owners add vitamins and minerals to their horses’ diets. Carrots are a great source of vitamin A. Although the ECEIM might argue that carrots have “no nutritional value”, it is not true that they are of no nutritional value. However, all horses should be fed a balanced diet that contains vitamin A. A carrot contains a small amount of protein (7.9% DM), fibre (24% DM), minerals, and oil – compared with a sugar lump that has no other nutrients (energy).
The ECEIM authors may deal with owners who feed their horses kilos of carrots when they are told that ID horses can have carrots. However, this is not our experience. Many owners of horses suffering from EMS or laminitis give their horses a small amount (generally less that 100 g per day) and have no problems.
I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!