Endocrine System Diseases Flashcards
What is the main trigger of the Endocrine System?
hypothalamus
What are Endocrine Glands?
- basic units of the endocrine system
- secrete hormones directly into the bloodstream
- ductless
What are Exocrine Glands?
units that secrete their products onto epithelial surfaces through tiny tubes called ducts
What are Hormones?
chemical messengers produced by -endocrine glands and secreted directly into blood vessels
-produce effects when they find their receptors in or on cells
What is Negative Feedback?
- endocrine glands stimulated to produce more hormone when it drops below a certain level
- if hormone level is adequate, gland either slows or stops production
What is Direct Stimulation of Nervous System?
secretion of some hormones is stimulated by sympathetic nerve impulses when an animal feels threatened
What are the 2 diseases of the Thyroid Gland?
hyperthyroidism
hypothyroidism
Where is the Thyroid Gland located?
ventral cervical region along lateral margins of trachea
What hormones are produced by the Thyroid Gland?
T3 (triiodothyronine)
T4 (tetraiodothyronine thyroxine)
Calcitonin
What cells in the Thyroid Gland produce T3 and T4?
follicular cells
What cells in the Thyroid Gland produce Calcitonin?
parafollicular cells
What are T3 and T4?
iodine containing hormones
What is the function of Calcitonin?
causes calcium deposition in bone which decreases blood calcium concentration
What is Hypothyroidism?
clinical state associated with deficency of T4, which causes low cell metabolism in most tissues of the body
What % of dogs acquire Hypothyroidism?
90%
What is Primary Acquired Hypothyroidism caused by?
idiopathic follicular atrophy
lymphocytic thyroiditis
iodine deficiency, neoplasia, infection
What is the cause of Secondary Acquired Hypothyroidism?
RARE
anterior pituitary dysfunction or destruction from neoplasia
What is the most common Endocrine Disease in Dogs?
Hypothyroidism
What breeds does Hypothyroidism commonly affect?
golden retrievers, doberman, irish setter, schnauzer, cocker spaniel, dachshund
What is the signalment for Hypothyroidism?
4-10 yrs old
females
What are the common c/s of Hypothyroidism?
weight gain w/out diet change skin changes cold intolerance lethargy/sleeping exercise intolerance
What Skin Changes can occur with Hypothyroidism?
bilaterally symmetric truncal alopecia alopecia of tail, neck, axillae and other areas of friction seborrhea superficial pyoderma dry, lustless haircoat hyperpigmentation
What are less common c/s of Hypothyroidism?
neuropathies (generalized weakness, ataxia, facial paralysis/paresis, seizures) GI (constipation, regurgitation caused by megaesophagus) bloodwork abnormalities ( hyper lipemia, gross lipemia, hyper cholesterolemia) eye(hyperlipidemia, corneal lipidosis)
How do you diagnose Hypothyroidism?
blood tests
hypothyroid dogs have lowered levels of T4
What are some considerations with Hypothyroidism?
sick animals and animals on certain meds may have low T4 levels (euthyroid sick syndrome)
What breed of dog has naturally low T4 levels?
greyhound
How do you treat Hypothyroidism?
thyroid supplement (l-thyroxine) oral, synthetic levothyroxine
What is client info for Hypothyroidism?
supplement for life
daily dosing required
overdose=hyperthyroidism
reduced fat diet (if overweight)
What is Hyperthyroidism?
pathologic, sustained, high overall metabolism caused by high circulating concentrations of thyroid hormone
What is the pathophysiology of Hyperthyroidism?
autonomously hyperfunctioning nodules
no physiologic controls (functional thyroid adenoma)
secrete T3 and T4
What are c/s of Hyperthyroidism?
weight loss polyphagia vomiting/diarrhea PU/PD tachypnea/dyspnea hyperactivity aggression tachycardia hypertension poor body condition thickened nails unkempt appearance large palpable gland
How do you diagnose Hyperthyroidism?
palpate enlarged thyroid gland
elevated T4, FT4
x rays for associated heart disease
How do you treat Hyperthyroidism?
methimazole (tapazole)
radioiodine treatment (#1)-emitted radiation destroys functioning follicular cells
surgical removal of gland
What are complications of Hyperthyroidism?
renal disease/failure unveiled when thyroid levels controlled (2-3 months after meds)
tapazole may not be effective after 2-3 years of treatment
What is the prognosis for Hyperthyroidism?
excellent if uncomplicated
if labs show azotemia prior to treatment, prognosis is guarded
What is client info for Hyperthyroidism?
cause is unknown
surgery and radiation only cures
cat may become hypothyroid following Rx
after tapazole, blood pressure and kidneys should be checked
What are the 2 diseases of the Parathyroid Glands?
hyperparathyroidism
hypoparathyroidism
What is secreted from the Parathyroid Gland?
parathyroid hormone (PTH)
What is the primary cause of Hyperparathyroidism?
adenoma or carcinoma
What is the secondary cause of Hyperparathyroidism?
poor diet;low Ca intake
What are c/s for Hyperparathyroidism?
many animals show no c/s urinary/renal calculi cardiac arrhythmias, tremors anorexia, vomiting, constipation weakness
How do you diagnose Hyperparathyroidism?
chemistry panel (increased blood calcium, decrease phosphorus) PTH assay (elevated) ultrasound of neck (enlarged glands, abdomen-uroliths)
How do you treat Hyperparathyroidism?
surgical removal of dz parathyroid gland
ultrasound guided chemical (ethanol)
ultrasound guided heat (laser) ablation
What is post op care for Hyperparathyroidism?
hospitalize for 1 wk
calcium therapy
vitamin D supplements
What are causes of Hypercalcemia?
neoplasia renal failure hypoadenocorticism vitamin D rodenticide poisioning drugs or artifacts
What are c/s of Hypercalcemia?
PU/PD anorexia lethargy vomiting weakness stupor/coma uroliths
How do you diagnose Hypercalcemia?
elevated serum calcium levels
low to low-normal phosphorus concentrations
How do you treat Hypercalcemia?
fluids (0.9% NaCl)
diuretics (furosemide)
steroids
What are complications associated with Hypercalcemia?
irreversable renal failure
soft tissue calcifications
What are causes of Hypocalcemia?
parathyroid disease (removal of parathyroid gland accidentally #1) chronic renal failure puerperal tetany (eclampsia)
What are c/s of Hypocalcemia?
restlessness, muscle tremors, tonic-clonic contractions, seizures tachycardia with excitement bradycardia in severe cases hyperthemia stiffness, ataxia
How do you diagnose Hypocalcemia?
total serum <6.5 mg/dl
How do you treat Hypocalcemia?
iv infusion of 10% Ca gluconate solution
diazepam (iv) to control seizures
oral supplements of Ca
improve nutrition
What is the function of Insulin?
moves glucose into cells to be used for energy
decreases blood glucose
What is the function of Glucagon?
raises blood glucose
stimulates liver to release glucose
stimulates gluconeogenesis
What is Hyperglycemia?
excessively high blood glucose levels
What is the normal glucose level in dogs?
60-120 mg/dl
What is the normal glucise level in cats?
70-150 mg/dl
What is Diabetes Mellitus?
disorder of carbs, fats and protein metabolism caused by an absolute or relative insulin deficiency
What is Type 1 DM?
insulin dependent
very low or absent insulin secretory ability
What is Type 2 DM?
non insulin dependent
inadequate or delayed insulin secretion relative to the needs of the patient
What are the causes of DM?
chronic pancreatitis
immune mediated diseases (beta cell destruction)
What are predisposing/risk factors of DM?
cushing's acromegaly obesity genetic predisposition drugs (steroids)
What age/sex does DM affect most?
dogs: 4-14, females 2x more likely
cats: all ages, but 75% are 8-13yrs, neutered males
What breeds does DM affect most?
poodles, schnauzers, keeshonds, cairn terriers, dachshunds, cockers, beagles
When do c/s of DM develop?
exceeds capacity of renal tubular cells to reabsorb
dogs: BG > 180-220 mg/dl
cats: BG >200-280 mg/dl
What systems does DM affect?
endocrine/metabolic hepatic opthalamic renal/urologic nervous musculoskeletal
What are c/s of DM?
polyuria polydipsia polyphagia weight loss dehydration cataract formation (dogs) plantigrade stance (cats)
What is Diabetic Ketoacidosis?
true medical emergency secondary to absolute or relative insulin deficiency causing hyperglycemia, ketoemia, metabolic acidosis, dehydration and electrolyte depletion
How is Diabetic Ketoacidosis diagnosed?
ketones in urine or in blood
What are c/s of Diabetic Ketoacidosis?
all of the DM signs depression weakness tachypnea vomiting odor of acetone on breath
How do you treat Diabetic Ketoacidosis?
IV fluids 0.9% NaCl
regular insulin to decrease BG
monitor BG q 2-3hrs
when BG is normal, switch to long acting insulin
How do you diagnose Diabetic Ketoacidosis?
CBC biochem panel UA low electrolytes blood gases fructosamine levels
What diet should a dog with DM be placed on?
high fiber, complex carbs
slows digestion, reduces post prandial glucose spike, promotes weight loss, reduces risk of pancreatitis
What diet should a cat with DM be placed on?
high protein, low carbs
What oral hypoglycemics should be used in treatment of DM?
sulfonylureas-glipizide (cats)
alpha glucosidase inhibitors (dogs)
What is client info for DM?
lifelong insulin replacement therapy
refridgerate insulin, mix gently
if animal doesn’t eat - no insulin
What is Hypoglycemia?
low blood glucose levels
What are causes of Hypoglycemia?
neonatal and juvenile septicemia neoplasia starvation iatrogenic - insulin overdose portosystemic shunt
What are causes of Insulin Shock?
insulin overdose
too much exercise
anorexia
What are c/s of Insulin Shock?
weakness
incoordination
seizures
coma
How do you prevent Insulin Shock?
consistant diet/consistent exercise
monitor urine/blood glucose at same time each day
feed 1/3 insulin, the rest 8-10hrs later
have sugar supply handy
What is the cause of Insulinoma?
tumor of beta cells, secreting excess insulin
What are c/s of Insulinoma?
prolonged hypoglycemia weakness ataxia muscle fasiculations posterior paresis brain damage seizures coma death
How do you diagnose Insulinoma?
chem panel (low glucose, high insulin) observations (symptoms occur after fasting or exercise)
How do you treat Insulinoma?
removal of tumor
acute at home (administer glucose)
acute at hosp ( adm. glucose 50% dextrose)
chronic care (3-6 small meals/day, glucocorticoid therapy, diazoxide, octreotide injections)
What is EPI?
exocrine pancreas insufficiency
inability to process nutrients efficiently due to lack of production of enzymes from pancreas
What breeds is EPI most commonly found?
german shepherds
rough collies
Where is EPI most commonly a result of in cats?
chronic pancreatitis
When is EPI usually evident?
when 85%-90% of pancreas is unable to secrete enzymes
What are c/s of EPI?
weight loss, no change in diet or appetite
persistant tarry diarrhea
flatulence
poor haircoat
How do you test for EPI?
TLI ( trypsin-like immunoreactivity)
detects trypsin and trypsinogen
How do you treat EPI?
enzymatic supplements
viokase powder
What is client info for EPI?
life long treatment
expensive
can be well controlled
should not be bred
What are the 2 diseases of the Adrenal Glands?
cushing’s (hyperadrenocorticism)
addison’s (hypoadrenocorticism)
What is Cushing’s Disease?
hyperadrenocorticism
disorder caused by deleterious effects of high circulation cortisol concentrations on multiple organ systems
What organ systems are affected by Cushing’s?
renal skin cardiovascular respiratory endocrine/metabolic musculoskeletal nervous reproductive
What are the effects of excess glucocorticoids?
suppress inflammation
suppress immune system
inhibit cartilage growth, development and repair
What are c/s of Cushing’s?
bilaterally symmetrical alopecia pot belly pyoderma PU/PD muscle wasting thin coat calcinosis cutis abnormal gonadal function
Where is Calcinosis Cutis usually seen?
dorsal midline
ventral abdomen
inguinal region
skin is usually thin and atrophic
How do you diagnose Cushing’s?
chem panel ( increased ALP, ALT, CHOL, BG, decreased BUN, lipemia, low USG) urine cortisol/creatinine ratio (normal = no cushings, elevated = cushings)
What are the 3 tests to diagnose Cushing’s?
ACTH stimulation test
low dose dexamethason suppression test
high dose dexamethasone suppression test
What is the ACTH stimulation test?
normal pt. show increase of plasma cortisol
pituitary dependant diseases : excess ACTH release
adrenal tumors (exaggerated cortisol response)
doesn’t differentiate between pit disease and adrenal tumor
What is the Low Dose Dexamethasone Suppression Test?
inject low dose of steroid
measure plasma cortisol at 0, 4, 8 hrs
Interpretation: normal= decrease, pit and adrenal tumors = no affect @ 8hrs
What is the High Dose Dexamethasone Suppression Test?
0.1 mg/kg IV
collect plasma cortisol at 0,4,8 hrs
Interpretation: pit. disease= 70-75% show decrease at 4 or 8hr, adrenal tumor=no change
How do you treat Cushing’s?
sugical removal (not pituitary) medical treatment: lysodren (necrosis of z fasiculata, z reticularis)
What is an alternative to Lysodren?
trilostane
less side effects
What is Addison’s Disease?
hypoadrenocorticism
disorder caused by deficient production of glucocorticoids (cortisol) or mineralocorticoids (aldosterone) or both
secondary disease caused by chronic admin of corticosteroids
What are c/s of Addison’s?
due to mineralcorticoid (aldosterone) deficiency lethargy, weakness, anorexia, wt. loss vomiting/diarrhea PU/PD, dehydration bradycardia
How do you diagnose Addison’s?
Na:K ratio
increased BUN, CREA and Ca++
decreased blood glucose and albumin
ACTH stimulation (normal = increase cortisol, abnormal= low, unchanged cortisol levels)
How do you treat Addison’s?
acute crisis ( normal saline, glucorticoid replacement: dexamethasone or prednisone, mineralocorticoid replacement: florinef, percortin)
How do you treat chronic Addison’s?
glucocorticoid replacement : prednisone, predisolone
mineralocorticoid replacement : florinef, percortin V
monitor electrolytes, BUN/CREA, c/s
