Endocrinological (PDF)

Endocrine  Substance produced by one organ has a target effect on another organ Endocrine System Feedback loops of hormones target and refulate distant organs Fat, Fuzzy and Foundered Equine Metabolic syndrome Insuli...

Endocrine  Substance produced by one organ has a target effect on another organ Endocrine System Feedback loops of hormones target and refulate distant organs Fat, Fuzzy and Foundered Equine Metabolic syndrome Insulin Resistance PPID Pituitary pars intermedia dysfunction “Cushings Disease” PPID & EMS overlap PPID Primarily found in older horses Life-long disease Cannot be cured only managed 20-33% of all horses will develop before the age of 20 Approximately 30% of PPID horses also have IR so always test for both Normal Brain to Adrenal Function Anatomy Brain Hypothalamus Pituitary Pars intermedia lobe Anterior lobe Posterior lobe Normal Brain to Adrenal Function Hypothalamus produces dopamine Dopamine causes pituitary to produce ACTH Normal Brain to Adrenal Function Adrenal gland Located on kidneys Produce Cortisol Cortisol Cortisol stress hormone controls blood sugar levels Activate fight or flight Role in detoxification Antioxidation Infection fighting Normal Hypothalamus Adrenal Function Increased Cortisol levels negatively feedback to hypothalamus to decrease dopamine and therefore ACTH Dopaminergic neurons inhibit pars intermedia therefor limit release of ACTH PPID Pathophysiology Slow degenerative disease of dopamine producing neurons in hypothalamus (similar to Parkinson’s disease in humans) Secondary to the degeneration of the hypothalamus Loss of inhibition of pars intermedia Benign overgrowth of pars intermedia in pituitary gland Pars intermedia grows producing excessive amounts of ACTH PPID PPID Advanced CS: Once showing distinct clinical signs, disease is advanced Generalized Hypertrichosis Fatty bulge over eyes Pendulous abdomen Muscle wasting Dullness/depression Abnormal sweating patterns Recurrent infections (hoof abscesses, skin infections, corneal ulcers) Increased drinking Increased urination PPID Early CS: slow to shed in spring Have patchy shedding, guard hairs Laminitis Inappropriate lactation Infertility Regional adiposity Tendon laxity PPID Testing: Do not test unless have PPID suspect Baseline for ACTH elevation TRH stimulation test Include insulin testing PPID Practical Clinical Research Results to Consider When Testing for PPID in Horses John C. Haffner, DVM*; Rhonda M. Hoffman, PhD, PAS, DACAN; Steven T. Grubbs, DVM, PhD, DACVIM; Kayla N. Shepard, MS; Dwana L. Neal, MBA; and Greg L. Pearce Authors’ address: Middle Tennessee State University Horse Science Center, 314 W. Thompson Lane, Murfreesboro, TN 37129 PPID testing Be aware of: Time of year Stressors (sedation, trailering) Pain (laminitis) Laboratory differences PPID Tx: Pergolide Possible side effects Inappetence Brain fog Drug handling Compounding 3 months for full effect Life long treatment Continued monitoring Subset of horses do not respond Chasteberry? PPID Management Dentistry Hoof care Clipping Blanketing Parasite control Aggressiely treat infections Blue light therapy?? PPID Management Nutrition First determine BCS Palpate through the hair! Consider muscle loss Exercise if plameness may prevent) Good quality protein Consider dental condition Consider social aspects Vitamin C & E supplementation (antioxidants) PPID Nutrition If also has EMS or high BCS Low NSC 15 YO No sex predelection Diagnosis Bloodwork (fasted) High circulating glucose levels High insulin levels Oral sugar test Sedatives can alter results Thyroid normal Common misconception Killing with kindness Often hampered by client Approach like a substance abuser Food is the drug Intervention must be staged Watch the treats!! Nutritional Management 1.5% of body mass in forage Slowly decrease over 2-4 weeks to target body weight Mature grass hay, unimproved field hay Low glycemic index varieties Hay soaking (not reliable) Goal to decrease body weight by one BCS in 60-90 days If goal not reached, decrease intake again by 10-15%If also has EMS or high BCS Low NSC 6 Monitor high risk breeds Take care with spring or stressed pastures Sugars in pasture grass highest in Spring during rapid growth When temperatures are cool From midmorning onward Use grazing muzzle Dry lots Monitor for laminitis Coexisting Disease PPID EMS Test for both