What is the best peptide for a horse losing weight?

Two different problems share this question

Start by working out which horse you have, because the advice is opposite. An overweight horse is at risk of laminitis. A horse losing condition may be ill, in pain or not getting what it needs from its feed. Neither problem has a peptide answer.

My horse is overweight: what do vets worry about?

The main worry is laminitis. Equine metabolic syndrome (EMS) means your horse's insulin is out of balance. The Merck Veterinary Manual says insulin-linked laminitis makes up about 90% of laminitis cases in the general horse population. Fat along the neck crest, behind the shoulder and at the tailhead is common. Obesity is not required, though. A lean form of EMS is described, so your vet tests insulin and does not go by looks alone.

Diet comes first. Merck calls it the most important part of managing EMS. That usually means severe limits on grazing, no grain or treats, and low-sugar hay, sometimes soaked, given in a slow feeder or several small meals. Spring and autumn grass carry extra risk. Do not crash diet. Severe restriction can do harm and raises the risk of hyperlipemia, which is too much fat in the blood.

Exercise builds muscle and reduces fat, but only once any laminitis has settled. Merck says no drug is labeled for insulin problems in horses and that none should be used without a proper diet. If diet and exercise are not enough, your vet may add a medicine.

My horse is losing condition: what will the vet look for?

Weight loss in a well-managed horse is abnormal, and age alone does not explain it. The MSD Veterinary Manual advises a full medical and dental workup, plus a review of the diet, before you make big changes to the ration. These are common causes:

• Teeth. Broken or uneven teeth are a common cause of poor appetite and weight loss. Look for slow eating, dropped wads of part-chewed food, bad breath and reluctance to drink cold water.
• Worms. Small strongyles infect all grazing horses to some extent, and long-running cases can bring weight loss. A low egg count does not rule this out, because the AAEP says egg counts do not track the disease-causing stages.
• Ulcers. Poor appetite, weight loss and a change in attitude can point to gastric ulcers. Only a gastroscopy confirms them.
• PPID (Cushing's). Mostly seen in older horses. A long coat that does not shed, poor muscle tone and more drinking are typical. Your vet can test for it, and FDA-approved pergolide tablets are available on prescription.
• Feed. The MSD manual also names simple feeding mistakes. An older horse with worn teeth may need soaked feed or easily chewed hay cubes.

When should I call the vet today?

Call the same day for any of the signs below. Colic, or a horse that will not put weight on a leg, needs a vet visit now. Slow weight loss with none of these still needs a booked visit, because the cause does not fix itself. If you are unsure how urgent it is, a video call with a licensed vet can help you decide, but your own vet still needs to examine your horse.

• Your horse stops eating or drinking
• Colic signs, even mild ones
• Fever, diarrhea or a dull, quiet horse
• Warm feet, a pounding pulse at the foot, or a horse that does not want to move, which can mean laminitis
• Weight falling away in days or a few weeks

What is known about peptides and weight in horses?

Nothing that would help you choose one. No clinical trial of BPC-157, TB-500, GHK-Cu or KPV in horses appears in PubMed, and BPC-157 returns no PubMed results at all for horses. All four are not officially tested in horses and not FDA-approved for animals. Nobody can say whether any of them changes weight, appetite or condition.

Exenatide, a prescription GLP-1 type drug, is a separate matter and is not one of these four. Merck says trials of it in horses gave variable results and that recommendations cannot yet be made.

The practical risk is delay. While you try a product, a sore tooth, a worm burden or a pituitary problem stays untreated. Read what is and isn't known about safety before you consider anything, and see the competition rules if your horse competes.

Questions to ask your vet

Your vet can only help with what they know, so tell them about every feed, supplement and product your horse gets. Then ask:

• Is this a fat problem, a muscle problem or both?
• Should we test insulin, and should we test for PPID?
• When were the teeth last checked, and how often does this horse need it? Merck suggests at least twice a year for stabled horses and yearly for horses at grass.
• What would a fecal egg count tell us, and what would it miss?
• Would a gastroscopy change what we do?
• How slowly should I change the diet? The MSD manual says over at least two weeks.