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Nutrition: sick horse

ISSN 2398-2977

Podcast: Nutrition: sick horse

Trauma/sepsis and renal disease


  • Higher protein Nutrition: protein (12-16%) ensuring essential amino acid Amino acids requirements are met, vitamins B, E and C Nutrition: vitamins, selenium and energy Nutrition: energy requirements to ensure wound healing, immune response and reduce tissue catabolism.
  • A compound feed containing 14% protein given with timothy and lucerne hay has shown to bring about better blood characteristics and weight gains in sick horses than one containing 9% protein.
  • Malnutrition increases morbidity and mortality in these situations.
  • Lack of appetite may be a problem and this may be stimulated with carrots, apples and fresh green grass.
  • Poor teeth may indicate a need for wet mashes and chop or chaff.
  • Use concentrated nutrient sources to provide a balanced diet in a small volume of feed.

Renal disease

  • Low protein, calcium and phosphorus, but with a Ca:P ratio >1:1 required, although important to ensure essential amino acid requirements are met by using an amino acid balancer.
  • Based on low protein hay.
  • Avoid legume hays and alfalfa (high calcium and protein content) and wheat bran (high phosphorus content).

Hepatic disease and enterolithiasis

Hepatic disease

  • Feed little and often, 6 times daily.
  • The appetite may be poor - stimulate with grass, morning and evening.
  • Offer cereals high in starch low in protein, eg maize, as an additional energy source.
  • Avoid feeds that are high in fats or oils.
  • Give good quality protein Nutrition: protein sources, such as soybean or linseed, that are low in amino acids Amino acids, phenylalanine, tyrosine and tryptophan, and high in short branched chain amino acids, valine, leucine and isoleucine.
  • Feed plenty of low protein grass hay.
  • Give supplementary vitamins B complex and E Nutrition: vitamins.
  • Require low sodium, high starch diet.


  • Development of enteroliths Gastrointestinal: enterolith is prevented by reducing the cecal pH to 6.5 or less.
  • Add apple cider vinegar to the diet (approximately 120 ml to each of two feeds daily or 250 ml to a single feed).
  • Increasing the grain content of a diet so that the hay:grain ratio is 1 or less will also reduce the cecal pH but this may be associated with wood chewing Behavior: crib-biting and wind-sucking and loose droppings, or even colic Abdomen: pain - adult.
  • Calculate and monitor base excess of the ration, so that it is not excessively high.

Cardiac disease and diarrhea

Cardiac disease

  • Maintain lean body mass.
  • If fluid retention occurs, restrict salt and deny access to a salt lick unless on potassium-sparing drugs, eg spironolactone or catopril.
  • Hay and unprocessed grain are naturally low in salt, but commercial feeds may have salt added in excess of 1%. If feeding straight cereals supplement providing vitamins Nutrition: vitamins and minerals Nutrition: minerals should be provided.
  • Potassium levels are high in most forages and supplementation is not therefore necessary even if on diuretics; provided forage intakes are adequate, at least 1% BW.


  • High protein low fiber diet will reduce large bowel activity but maintain nutrition via small intestine.
  • Feed very small meals at frequent intervals to maximize absorption in the small intestine.
  • Complete resting of the large bowel by fasting for more than 24 h may → colonization by anaerobic bacteria and hypoproteinemia Hypoproteinemia.
  • Ensure that any cereals fed are cooked/micronized to increase starch absorption in the small intestine.
  • If abnormal fermentation is suspected following diarrhea or antibiotic treatment:
    • Diet high in digestible fiber.
    • Supplement with yoghurt.
    • Including feces from a healthy horse used to be recommended but more effective measures are now available.
    • Proprietary probiotics Nutrition: probiotics and prebiotics.
  • May need electrolyte treatment - see fluid therapy for diarrhea Fluid therapy: diarrhea.

Horses in poor condition and obese horses

Horses in poor condition

  • Feed small meals at frequent intervals - 6 times/day if possible.
  • Gradually increase quality and quantity of feed over several weeks to maintenance level +30% and feed forage ad lib.
  • Always use highly digestible feed stuffs.
  • Treat inciting cause.
  • If using a compound feed, use one designed to promote weight gain. A smaller volume of a more concentrated feed is better for maintaining the health of the digestive system.
  • Regular gentle exercise.

Print-off the Owner Factsheet on Nutrition - keeping your horse on top form Nutrition - keeping your horse on top form and Feeding the older horse Feeding the older horse to give to your client.

Obese horses

Do not withhold food → hypoproteinemia Hypoproteinemia, hyperlipemia, boredom, death.

Geriatric horses and horses with rectal lacerations/vaginal surgery

Geriatric horses

  • Problems in ageing horses are associated with poor teeth Teeth: abnormal wear, inadequate chewing.
  • Fibre digestion also often less efficient.
  • There may also be reduced ability to absorb protein Nutrition: protein, phosphorus Phosphorus and calcium Nutrition: minerals.
  • Vitamin C Nutrition: vitamins levels also tend to be low in geriatric mares Nutrition: geriatric.
  • Feed short chops if long-stem forage cannot be chewed efficiently.
  • Dampen commercial pelleted feeds to reduce chewing.
  • Cereal meals are available that can be fed as a mash to ease chewing - they tend to be low in oil so are suitable if liver failure suspected.
  • For preference use micronized cereals.
  • Restrict calcium supplements and alfalfa due to the possibility of renal disease.
  • Renal calculi are associated with alfalfa hay diets.
  • Cushing's syndrome Pituitary pars intermedia dysfunction (PPID), with hyperglycemia, predisposes to laminitis Foot: laminitis - may require low starch diet.
  • If losing condition there are feeds produced specifically for older horses that typically contain:
    • 12-16% protein.
    • 11-12 MJ/kg DE.
    • Calcium to phosphorus ratio of 1.5:1.
    • Feeding a more concentrated feed will keep the volume of feed required low which is beneficial for gut health.

Print-off the Owner Factsheet on Feeding the older horse Feeding the older horse to give to your client.

Rectal lacerations and vaginal surgery

  • Complete pelleted feed → small fecal balls easily passed and avoids straining.
  • A highly digestible, liquid diet may be used to minimize fecal volume post-surgery.

Laminitis and Equine Rhabdomyolysis Syndrome (ERS)


  • Overweight horses and ponies are predisposed to laminitis Foot: laminitis.
  • Access to grazing may have to be restricted to reduce fructan intake.
  • Horses that are prone to laminitis or at risk of laminitis should be turned out very late at night or early morning and brought in by mid-morning as this is when fructan levels are lowest.
  • Do not allow horses to graze pastures when low temperatures are followed by warm, bright weather.
  • If access to pasture is limited, provide alternative forage. Overweight individuals can have oat straw or fibrous hay.
  • Both the forage and concentrates should be fed in frequent small meals to reduce the time the gut is empty and to reduce the amount of starch that reaches the hind gut.
  • Provide a balanced diet of essential amino acids Amino acids, minerals Nutrition: minerals and vitamins Nutrition: vitamins to maintain health and promote hoof growth. Including alfalfa in the diet is advocated as it contains relatively high levels of the nutrients required for hoof growth.
  • Horses in work or that are underweight can be given a high fiber and fats and oils diet alongside a balance of minerals, vitamins and essential amino acids. The forage used should be good quality and fed to appetite.
  • A probiotic Nutrition: probiotics supplement may be beneficial after a laminitis episode to try and re-establish a healthy population of micro-organisms in the hind gut.

Equine Rhabdomyolysis Syndrome (ERS)

  • Also known as azoturia, tying-up, Monday morning disease, set fast Muscle: myopathy - exertional rhabdomyolysis.
  • Etiology not fully understood.
  • Adjustments to the diet can help reduce episodes in some individuals.
  • Cause may not be related to diet.
  • Aim is to reduce starch content of diet and ensure that mineral Nutrition: minerals, vitamin Nutrition: vitamins and electrolyte requirements are met.
  • Feed plenty of good quality forage so that the proportion of concentrates fed can be kept to a minimum.
  • A balanced supply of vitamins Nutrition: vitamins, minerals Nutrition: minerals and essential amino acids Amino acids should be provided that is appropriate for the level of work Nutrition: work the horse is doing.
  • A high fiber, low energy and low cereal compound feed is recommended, to which additional nutrients can be added if the horse is in harder work. Cube rations usually have a lower starch content than mixes with comparable nutrient levels.
  • Fats and oils can be added to the diet to increase the energy Nutrition: energy content of the diet. High fat supplements are available which usually have additional vitamin E Vitamin E and selenium Selenium added and so are preferable to adding straight oil.
  • Electrolyte supplements should be used routinely to counteract any losses that occur when working and traveling.

Print-off the Owner Factsheet on Azoturia - Tying-up Azoturia - 'Tying-up' to give to your client.

Further Reading


Refereed papers

Other sources of information

  • Frape D (2004) Equine Nutrition and Feeding. 3rd edn. Blackwell Publishing Ltd, Oxford, England. ISBN: 1405105984.
  • Bercier D L (2003) How to Use Parenteral Nutrition in Practice. In: Proc 49th AAEP Convention. pp 268-273.
  • Longland A C & Cairns A J (2000) Fructans and their implications in the aetiology of laminitis. In: Proc 3rd Dodson & Horrell Int Conference on Feeding Horses.
  • Harris P A (1999) Feeding and management advice for 'tying-up', azoturia, Monday morning disease, equine rhabdomyolysis syndrome, etc. In: Proc BEVA Specialist Day on Behaviour and Nutrition.