Information for Veterinarians

Prevalence of PPID

Pituitary pars intermedia dysfunction (PPID) is the most common disease of the endocrine system affecting horses and ponies.1 Recently conducted studies suggest that PPID is more common than previously thought. One in 7 horses or ponies 15 years of age or older has PPID.2 In aged horses, researchers have found the prevalence to be as high as 30%.3Although generally associated with geriatric horses, PPID has been diagnosed in horses as young as 4 years of age.4 Both genders and all breeds are equally susceptible.5-7

PPID is now recognized as one of the more common conditions that challenge equine owners who want to keep their horses active and healthy into their 20s and 30s. By raising awareness of clinical signs of disease and implementing the latest diagnosis and treatment protocols, we have the opportunity to help both our equine patients and their devoted owners.

Identifying early clinical signs

One of your biggest challenges with PPID is to increase awareness among horse-owning clients of the early, hard to spot, clinical signs. Diagnosing PPID as early as possible is a critical step, because it gives owners the option to begin treatment programs before clinical signs reach advanced stages.

Horse owners often fail to recognize the early signs of PPID and assume that their horse is going through the normal aging process. If you treat a horse with one or more of the following conditions, it is likely that they are experiencing early signs of PPID.

  • Hirsutism (hypertrichosis)
  • Laminitis
  • Muscle wasting
  • Weight loss
  • Abnormal sweating
  • Abnormal fat distribution
  • Excessive thirst
  • Lethargy
  • Weight loss
  • Polyuria/polydispsia (PU/PD)

Science behind PPID and PRASCEND® (pergolide mesylate)

The intermediate lobe of the pituitary gland (pars intermedia) is affected in PPID. Hormones produced in the intermediate lobe include alpha melanocyte-stimulating hormone (alpha-MSH), beta endorphin, and adrenocorticotropin hormone (ACTH). In the healthy horse, the production of hormones from the intermediate lobe is inhibited by dopamine. Dopamine binds with a receptor and then inhibits the production and release of the hormones.

In the healthy horse, there is enough dopamine available to keep hormone production at a low, baseline level. A horse with PPID does not produce enough dopamine. The end result may be a much greater immunosuppressive level of the hormone cortisol, as compared to a healthy horse. The intermediate lobe of the pituitary gland becomes grossly enlarged, up to 2 to 5 times its normal size, which further compresses the other lobes.3

PRASCEND mimics natural dopamine, acting to replace the reduced levels of dopamine in horses with PPID. By binding to the dopamine receptor, it decreases the secretion of hormones. Horses treated with PRASCEND show improvement in signs of disease, such as improved hair coat, muscle mass, and attitude.8 See the How it works video below for more details.

Watch a video featuring a leading veterinarian discussing the science of PPID and the mechanism of action for PRASCEND.

Important safety information

PRASCEND is for use in horses only. Treatment with PRASCEND has been observed to cause inappetance, with most cases being transient. Weight loss, lethargy, and behavioral changes may be observed in some horses. If severe, a temporary reduction of dose may be necessary. PRASCEND has not been evaluated in breeding, pregnant, or lactating animals. As PRASCEND is a dopamine agonist, it may interfere with reproductive hormones involved in these groups of animals. The concurrent use of dopamine antagonists should be avoided since these agents may diminish the effectiveness of PRASCEND. PRASCEND should not be used in horses with hypersensitivity to pergolide mesylate or other ergot derivatives. Refer to the package insert for complete product information.

References:

  1. Donaldson MT, Jorgensen AJ, Beech J. Evaluation of suspected pituitary pars intermedia dysfunction in horses with laminitis. J Am Vet Med Assoc. 2004;224(7):1123-1127.
  2. McGowan TW, Hodgson DR, McGowan CM. The prevalence of equine Cushing's syndrome in aged horses. In: Proceedings from the 25th American College of Veterinary Internal Medicine Forum; June 6-9, 2007; Seattle, WA. Abstract 603.
  3. McFarlane D. Equine pituitary pars intermedia dysfunction. Vet Clin North Am Equine Pract. 2011;27(1):93-113.
  4. Donaldson MT, LaMonte BH, Morresey P, Smith G, Beech J. Treatment with pergolide or cyproheptadine of pituitary pars intermedia dysfunction (equine Cushing's disease). J Vet Intern Med. 2002;16(6):742-746.
  5. Schott HC. Pars pituitary intermedia dysfunction: challenges of diagnosis and treatment. In: Proceedings from the 52nd American Association of Equine Practitioners Annual Convention; December 2-6, 2006; San Antonio, TX.
  6. Schott HC. Pituitary pars intermedia dysfunction: equine Cushing's disease. Vet Clin North Am Equine Pract. 2002;18(2):237-270.
  7. Oke S. Equine Cushing's disease [fact sheet]. Beech J, ed. The Horse: Your Guide to Equine Health Care. Lexington, KY: Blood-Horse Publications; 2010. Available at: http://www.southmountainequine.net/educational/documents/cushings.pdf. Accessed August 12, 2011.
  8. PRASCEND® (pergolide mesylate) [Freedom of Information Summary]. St. Joseph, MO: Boehringer Ingelheim Vetmedica, Inc.; 2011.