By Heather Bjornebo, DVM, DABVP(Reptile-Amphibian Practice), CertAqV
One of the things I love about exotic pet medicine is how rapidly things are advancing and progressing. It seems every year we are getting new advanced treatment options for our patients which is so exciting. One medication that I am excited about is Capromorelin.
Recent studies on capromorelin, sold by the trade names Entyce® (dogs) and Elura® (cats), have shown promise as a medication to help stimulate appetite in sick exotic pets. Classified as a ghrelin agonist mimics the hunger hormone ghrelin where in the brain it acts on the hypothalamus resulting increased growth hormone release by the pituitary gland causing increased hunger and food intake. In addition, capromorelin also increases insulin-like growth factor-1, which increases lean muscle mass.
One recent promising study published in the Journal of Exotic Pet Medicine and Surgery on hedgehogs showed significant increases in food intake when the medication was administered. Seventy percent of the hedgehogs in this study administered this medication showed an increase over those recieving the placebo consuming on average 11% more food.1
A study showed capromorelin decreased stress induced weight loss in laboratory mice. The only study group where no benefit was seen with this medication was when patients were receiving the long acting opioid pain medication Buprenorphine-XR.2
Another recent study in rabbits compared the efficacy of capromorelin versus Mirtazapine on improving appetite. Mirtazapine is another meidcation often used in veterianry medicine to increase appetite in sick animals. It is available as a topical gel that can be applied to the ear lobe. While previous studies in rabbits showed mirtazapine increases fecal output, it did not improve appetite. In this study it showed a positive effect on appetite with healthy rabbits increasing their intake after 2 days. Normal patients given capromorelin also showed significant increase in appetite, though not as profound as those given mirtazapine. Conversely, patients recovering from neuter surgery didn’t demonstrate any significant improvement in appetite on either medication. The overall take home was both medications help appetite, with mirtazapine being more effective and less stressful for the patient due to being topical and not oral. However, both did show promise in treatment of GI stasis.2
Capromorelin has also been studied in birds. In a study in chickens the medication not only biochemically increased their blood insulin levels, it increased their appetite demonstrated by increased pecks per hour.4
Definitely, more studies are needed to fully evaluate the use of this medication in exotic pets. So far the initial studies show a lot of promise, even if the results in rabbits suggest topcial Mirtazapine may be the medication of choice in this species. While less effective, it still gives practitioners another tool to treat GI stasis in this species. Hopefully, in the years to come more studies covering its efficacy and use in many other types of exotic pets, including reptiles.
If you have questions about Capromorelin, contact your family veterinarian.
References:
- Huckins, G.L., Mans, C. and Doss, G.A., 2025. Effects of oral capromorelin on food intake and body weight in healthy, four-toed hedgehogs (Atelerix albiventris). Journal of Exotic Pet Medicine, 52, pp.1-3.
- Punger, E.M., Norris, S.L., Stevens, S.C., Santos, K.H. and Christy, A.C., 2024. Investigating the Effect of Enterally Administered Capromorelin on Body Weight in Mice (Mus musculus). Comparative Medicine, 74(5), pp.327-335.
- Draper, J.M., Savson, D.J., Lavin, E.S., Feldman, E.R., Singh, B., Martin-Flores, M. and Daugherity, E.K., 2022. Comparison of effects of capromorelin and mirtazapine on appetite in New Zealand white rabbits (Oryctolagus cuniculus). Journal of the American Association for Laboratory Animal Science, 61(5), pp.495-505.
- Ceron-Romero, N., Taofeek, N., Thomas, A., Vroonland, E., Sanmartin, K., Verghese, M., Heinen, E. and Vizcarra, J.A., 2021. Capromorelin, a ghrelin receptor agonist, increases feed intake and body weight gain in broiler chickens (Gallus gallus domesticus). Poultry science, 100(8), p.101204.