This article has not yet been professionally approved. The information is based on the sources listed below.
Horse not gaining weight: check ration and feed intake
What information you can gather on weight, forage and actual intake, and when the causes need to be investigated by your vet.
The short answer
A horse that is not gaining weight or keeps losing weight needs its cause investigated. Feed quantity and energy supply are possible starting points; health problems and dental problems must also be checked 1. Gather weight trends, the amounts actually eaten and product information. With persistent or marked weight loss, the next step is a veterinary investigation, not a blanket increase in concentrates.
When does investigating the cause take priority?
The University of Minnesota recommends investigating the cause of underweight with veterinary and nutritional support before a weight-gain plan is drawn up. This applies especially to severe underweight: refeeding is then a separate task that needs professional planning 1.
- Since when has the trend changed?
- Is there less appetite, difficulty chewing or noticeable feed left over?
- Which findings, medication and examinations are already known?
- Which changes to housing, pasture or work came beforehand?
How do you keep weight and body condition apart?
Note the measuring method and date so that you do not compare different figures without thinking. A measuring tape estimate is an estimate. The body condition score assesses fat deposits in specific regions of the body; it does not automatically tell you anything about the musculature 2.
- Use the same measuring method over time wherever possible.
- Record which values are estimated and which are weighed.
- Discuss body condition in the context of the whole horse.
- Record your muscle observations separately from weight.
What is actually being eaten?
Start your feeding log with what is offered and what is left over. The nutrient calculation needs a daily intake amount. A full hay rack or a scoop of concentrates is not yet a known amount in kilograms; unknown intake remains an uncertainty in the calculation 3.
- Weigh out hay and other feeds that can be weighed and document leftovers.
- Observe access to feed and possible displacement within the group.
- Weigh cubes before soaking and record added water separately.
- Describe pasture access and mark unknown grass intake as an estimate.
- Note all other supplements with product name and daily amount.
How do you check energy and protein?
Assess the amounts eaten using current feed values and the estimated requirement. Maintenance and work belong in the same calculation; missing hay values should remain visible. A result based on table values is not a measurement of your hay batch 3.
Do not check protein in isolation. The amino acid literature describes weight loss despite protein intake when energy intake is insufficient. An extra portion of protein may therefore miss the actual gap 4.
Which causes can a ration analysis not detect?
Dental problems, parasites or disease can contribute to a lack of weight gain; investigating them is a job for your vet. The feeding log helps in the conversation but does not replace an examination 1.
A suspected gastric ulcer cannot be confirmed from weight loss or a feed list either. Clinical signs are non-specific, and diagnosis requires a suitable veterinary examination 5.
- Take existing findings and your feeding log to the appointment.
- Agree the goal, amounts and progress checks together.
- Agree which changes require a further examination.
- Do not judge weight gain on a single weight estimate alone.
Key takeaways
Frequently asked questions
Why is my horse not gaining weight despite lots of feed?
This may be a question of the energy actually taken in; but health or dental problems are also possible. The amount offered alone does not explain the cause. Discuss the progress with your vet and a feeding adviser 1.
Should I give more concentrates straight away?
An unchecked increase does not answer the question of the cause. Clarify intake, forage and health status and have the change planned professionally. Large or abrupt ration changes are not suitable general advice 6.
What if my horse is not building muscle either?
Look at energy and usable amino acids together and have noticeable muscle loss investigated. More crude protein alone does not reliably make up for an energy undersupply 4.
Sources & studies
The content is based on the references listed below. It does not replace individual veterinary or feeding advice.
Show list of sources (6)
- University of Minnesota Extension: Caring for the underweight horseInstitutional practice guide, checked on 29 September 2026: identifying causes with a vet and feeding advice, body condition, access to feed and dental problems; severely emaciated horses need a supervised refeeding plan. American ration examples are not adopted as a standard dose for Germany.
- Henneke DR, Potter GD, Kreider JL, Yeates BF (1983): Relationship between condition score, physical measurements and body fat percentage in mares. Equine Veterinary Journal 15(4):371–372Original publication on the body condition score; bibliographically checked. Its application and limits are additionally supported by horse-specific specialist reviews.
- Bayerische Landesanstalt für Landwirtschaft (LfL): Gruber Tabelle zur PferdefütterungPractical reference table with requirement and feed values based on the GfE recommendations; the basis of many ration calculations in German-speaking countries. Chapter 9.3, Table 39: most common poisonous plants for horses with habitat, toxicity and risk level (after Kamphues et al. 2014)
- Mok CH, Urschel KL (2020): Amino acid requirements in horses (Invited Review). Asian-Australasian Journal of Animal Sciences 33(5):679–695Review of amino acid requirements: in horses essentially only lysine is quantitatively established; there are no robust requirement figures for methionine/threonine
- Merck Veterinary Manual: Gastric Ulcers in HorsesStandard veterinary reference work: a definitive diagnosis requires gastroscopic visualisation of the empty stomach; clinical signs alone are not sufficient
- Liburt NR (2026): Nutritional Diseases of Horses and Other Equids. Merck Veterinary ManualSpecialist overview, as of February 2026: energy surplus, non-specific signs of deficiency and risks of oversupplementation; no basis for a remote diagnosis.