Question
I own a six-year-old Quarter Horse mare—1,200 lb (545 kg) with a body condition score of 4. I ride her five days a week, but I work her only moderately. She is kept stalled 12 hours a day and is turned out the remainder of the day. She tested positive (N/H) for hyperkalemic periodic paralysis (HYPP) and polysaccharide storage myopathy (PSSM1). Her current ration includes 2 lb (0.9 kg) of a low-starch feed, 4 lb (1.8kg) timothy pellets, free-choice alfalfa/grass hay during turnout, 6-9 lb (2.7-4.1 kg) alfalfa/grass hay in stall, and vitamin E and ulcer supplements. I have tried other diets for my mare, but I cannot seem to find the right combination to return her to "normal." My mare is losing weight and no longer has a shiny coat. She seems very stiff and unwilling to collect and drive from behind. She does not refuse work but is less energetic. She also seems touchy or sensitive. What are your thoughts?
Answer
Based on the diet information provided, there are a few diet modifications that can help facilitate weight gain while managing your mare’s metabolic conditions. These include providing a balanced diet and increasing the amount of digestible energy (calories) provided by the diet through feeding dietary fat.
Veterinary researchers at University of California, Davis, recommend feeding a diet between 0.6-1.5% potassium. Having a forage analysis of your current alfalfa/grass hay for its potassium content, plus starch and sugar content, will determine if it is suitable for your mare or if switching to a straight grass hay would be more appropriate.
If you find that your hay is too abundant in potassium and sugar, and you are not able to purchase more appropriate hay, soaking it can reduce both potassium and sugars. One review study revealed that one hour of soaking reduced potassium concentrations from 2.2% to 1.3% for orchardgrass hay and soaking for 12 hours reduced it even more to 0.65%. While you are searching for low-potassium forage, would it be possible to soak the current hay before feeding to your mare? If soaking is not feasible, another option is to increase the amount of timothy pellets fed and reduce the amount of hay you’re currently feeding.
A high-calorie, low-starch, low-sugar feed, such as Re-Leve, would be appropriate for your horse. RE-LEVE was developed specifically for horses with PSSM as the first feed that helped reduce clinical signs of PSSM. Re-Leve Concentrate is recommended for performance horses with lower energy requirements, such as those fed less than 6 lb (2.7) of concentrate feed. Based on the current feed intake of 2 lb (0.90) of low-starch feed, Re-Leve Concentrate is a suitable way of providing complete and balanced nutrition as well as boosting dietary fat levels. Re-Leve can be ordered and shipped direct to you from the manufacturer.
