Pancreas & Endocrine Disease PDF

Animal Disease -- Lecture 11 **A Refresher of Endocrine System** - Oversees & integrates functions all over the body using hormones - Glands -- to maintain homeostasis Pituitary, thyroid, parathyroid, adrenals, pancreas & gonads - Brain Control secretions of endocrine glands & hy...

Animal Disease -- Lecture 11 **A Refresher of Endocrine System** - Oversees & integrates functions all over the body using hormones - Glands -- to maintain homeostasis Pituitary, thyroid, parathyroid, adrenals, pancreas & gonads - Brain Control secretions of endocrine glands & hypothalamus also assists with water balance, metabolism, & body temp - Diseases of these glands often stem from autoimmune attacks, or the organ malfunctioning (over or under production of hormones or response to them) Thyroid Gland - Ventral cervical region, lateral margins of trachea - Not palpable in healthy animals - Produce hormones T3 T4 Function together to control metabolism Produces calcitonin Deposits calcium in bone, reduces free calcium in blood Underactive & overactive **Hypothyroid Disease** - Hypothyroidism common disease of dogs - Genetic predisposition -- goldens, labs, Dobermans, irish setters, mini schnauzers, spaniels, dachshunds etc - 6-10 yrs of age, females more prone than males Is a dysfunction anywhere in the hypothalamic-pituitary-thyroid axis may result in thyroid hormone deficiency - More than 95% of cases are dogs and is from destruction of gland itself termed "primary hypothyroidism" or thyroid atrophy Leads to decreased metabolic rate , anestrus Causes -- lymphocytic thyroiditis (autoimmune disease) and idiopathic atrophy of the thyroid gland - Secondary is uncommon but may be from tumor, or congenital Clinical Signs - Metabolic & dermatologic signs = lethargy, weight gain, altered skin/coat:alopecia, excessive shedding, loss of hair on tail is common, sun seeking, recurrent skin infections, anestrus Diagnosis - Clinical signs - +/- hypercholesterolemia - Low T3, free T4 - Serum thyroid hormone testing (thyroid stimulating hormone (TSH) = high Treatment - Lifelong support with thyroid hormone replacement - Human options make treatment fairly inexpensive - Orally BID, good success - Monitor dosage frequently Too high = hyperthyroid Once stabilized -- recheck 1-2x year **Hyperthyroid Disease** - Common disease of cats - Middle aged -- older cats most common - Excess T3 & T4 due to thyroid adenoma, thyroid carcinoma possibly - Screening & early detection T4 blood tests esp in senior cats Can sometimes palpate enlarged thyroid - If T4 comes back normal & without clinical signs recheck in 6 months or when clinical signs develop Clinical Signs - Weight loss - Hypertension - Polyphagia - Blindness + retinal detachment - Occasional vomiting - increased vocalization, especially at night - Increased appetite - Tachycardia +/- murmur Diagnosis - Increased T4 in serum chem, if high and no clinical signs recheck in 2 weeks - Palpate enlarged thyroid - DI Treatment - Radioactive Iodine -- 131 -- curative treatment of choice -- simple & effective Diseased tissue absorb it = destruction of cells Hospitalization until radioactive material becomes absent from body Specialized procedure - Antithyroid Drug Therapy -- palliative approach Daily, life-long Block thyeoid hormone synthesis Oral, transdermal, caution when touching Routine blood, BP, physical exam monitoring - Diet Lifelong, iodine deficient diet (no iodine = thyroid cant produce hormone) Indicated if not a candidate for radioiodine/thyroidectomy Most effective if only moderate increase in T4 Cant eat any other food than this (no treats, sraps ect) - Surgery -- Thyroidectomy Potentially curative but with anesthetic risks Removal of thyroid glands = removal of hormone = cure Unilateral or bilateral Requires competent surgeon who will spare parathyroid glands Supplement with thyroid hormone orally Complications - Secondary disorder can arise Thyrotoxic hypertrophic cardiomyopathy Systemic hypertension Chronic kidney disease **Adrenal Glands** Outermost zone synthesizes & secretes mineralocorticoids -- aldosterone Middle zone produces glucocorticoids -- cortisol & corticosterone Inner zone secretes sex steroids **Addisons Disease -- Hypoadrenocorticism** - Lack of glucocorticoids, mineralocorticoids, or both - Think Addisons & absence of steroids -- small, skinny, weak Predispositions - Young to middle ages - Nova scotia duck tolling retrievers, great danes, poodles, west highland white terrier, bearded colie, Portuguese water dog Cause - Primary adrenocortical failure - Immune mediated, cytotoxic drugs, neoplasia, granulomatous disease, adrenal gland hemorrhage Diagnosis -- ACTH stimulation (blood) test -- cortisol concentration is measured before and after the administration of exogenous ACTH - Draw blood, administer ACTH, set timer, draw blood again (1hr post, prep & send to lab) - Levels in samples are compared and then interpreted Clinical Signs - Vaque, nonspecific, wax & wane - Anorexia - Dehydration - Poor appetite - Bradycardia - Vomiting & diarrhea - intolerance for heat - PU/PD - Hypoalbuminemia, hypocholesterolemia, & mild/moderate ionized hypercalcemia Treatment - IV fluid therapy - Correction of hypoglycemia - Antiemetic, antinausea & nutritional supportive care - Glucocorticoid & mineralocorticoid replacement - Dogs in an Addisonian crisis should be treated in an emergent basis -- present in shock **Cushing's - Hyperadrenocorticism** - Elevated cortisol concentrations - Adrenocortical hormone of any cause - A collection of disorders ('umbrella term") Most cats with Cushing's syndrome have concurrent diabetes mellitus that's poorly regulated - Type 1 -- pituitary dependent (Cushing's) (PHD) - Type 2 -- adrenal dependent (from adrenal tumor) (ADH) - Think -- Cushing & cushions -- big & round Predispositions - Middle to older aged canines - Poodle, esp miniature poodle - Dachshund, boxer, Boston terrier - Yorkshire terrier - Staffordshire terriers Cause - 85% have pituitary dependent hyperadrenocorticism (PDH) & 15% have a cortisol-producing adrenal tumor Diagnosis - History, physical exam, clinicopathological testing, endocrine testing, & diagnostic imaging - Low dose dexamethasone suppression test (LDDST) is a screening test of choice for Cushing's syndrome because of its high sensitivity and its ability not only to confirm the presence of hyperadrenocorticism but able to differentiate between PDH & ADH - ACTH -- shorter, simpler dynamic test for the diagnosis of various disorders, including iatrogenic hyperadrenocorticism & spontaneous hyperadrenocorticism of adrenal or pituitary origin - High -- dose dexamethasone suppression test Clinical Signs - Pot belly -- distended belly, abdominal enlargement, sway back - PU/PD, polyphagia - Panting in dogs - Muscle wasting - Dermatological changes -- hair loss, skin/coat changes, pyoderma - Weakness, lethargy - Recurrent UTI's - Bruising & hyperpigmentation Treatment - Medical treatment -- mitotane or trilostane - Surgery - Radiotherapy - Treatment options available for Cushing's in dogs include medical treatment, surgery & radiotherapy. All three have been used with varying amounts of success Prognosis - Mean survival of 2 years with or without treatment - Dogs with early hyperadrenocorticism that have no comorbidities can live much longer when treated **Pancreatitis** - Inflammation of the pancreas - Most common exocrine disorder in dogs & cats - Acute or chronic - Can be very severe -- necrotizing - Pancreatic secretions decrease, which causes pancreatic enzymes to increase - Enzymes begin "auto digesting" pancreas Widespread damage to pancreas Inflammation +/- necrosis Causes - Sometimes unknown - High fat diet, inappropriate foods, obesity - High cholesterol - High triglycerides - Trauma, tumors - Meds -- furosemide, azathioprine, sulfonamides, tetracyclines - Hypoadrenocorticism - Genetic (Mini schnauzers, yorkies, cocker spaniels, poodles, dachshunds) Clinical Signs - Nausea - Abdominal Pain (praying pose) - Anorexia - dehydration - Vomiting & diarrhea - +/-pyrexia - Weakness Can be less severe & only cause anorexia, lethargy & diarrhea Diagnosis - Snap test in clinic - Canine pancreatic lipase immunoreactivity - Rads - Chem panel -- increased liver enzymes (ALT,ALP), hypocalcemia, hyperlipidemia, +/- increased amylase, lipase - CBC -- leukocytes, increased PVC d/t dehydration Treatment - Fluid therapy + KCl if needed, NPO 3-4 days, depending on severity - Antibiotic therapy - Analgesia +/- plasma or albumin therapy - Low fat diet long term - Fairly good prognosis with prompt & proper treatment, & owner compliance - Can result in death **Exocrine Pancreatic Insufficiency (EPI)** EPI -- decreased production of digestive enzymes by the pancreas - Insufficient synthesis and secretion of digestive enzymes by the exocrine portion of the pancreas - Recall normal functions = secretions from the pancreas are carried to the SI by the pancreatic duct - EPI = failure to produce enough pancreatic enzymes to digest fats, carbs & proteins - Leads to poor absorption of nutrients - Genetics -- German shepherd, collie, chow chow, cavalier king Charles spaniel - Congenital -- present from birth, although sometimes undiagnosed until later - Secondary to chronic pancreatitis -- progressive loss of cells Clinical Signs - Evidence of maldigestion & malabsorption - Weight loss, normal appetite - Nutrients remaining in the intestinal lumen leads too loose, voluminous feces, pale & steatorrhea - Chronic diarrhea a - +/- vomiting Treatment -- digestive enzymes, cobalamin, & improve gut microbiome - Pancreatic enzyme replacement - Powder more effective than tabs - Viokase - Pancrazyme - Fresh raw pancreas may be a viable alternative - Vitamins -- esp B12 (cobalamin) - Pre & probiotics - +/- antibiotics with diagnosis d/t +++ bacteria Diagnosis - Serum trypsin like immunoreactivity concentrations - Clinical signs - Assay that measures fecal elastase in dogs has been validated