Diabetes Mellitus
List common clin path findings with DM
chem: hyperglycemia, hypercholesterolemia, mild/mod ALP and ALT elevation
CBC: no specific findings
UA: glycosuria, maybe UTI. always culture!
List clinical signs of HAC
polyphagia
PU/PD
pot belly
muslce weakness
panting
lethargy
fat redistribution
alopecia
calcinosis cutis (not common but diagnostic finding)
comedomes
anestrus or testicular atrophy
what are the electrolyte derangements with addison's and why?
Hyperkalemia (aldosterone promotes excretion of K in DCT)
hyponatremia (aldosterone promotes reabsorption of Na in PCT and DCT)
hypochloremia (aldosterone promotes reabsorption of Cl in PCT)
acidosis (aldosterone promotes renal tubular H+ secretion)
Who does hyperthyroidism most commonly occur in and what are the clinical signs?
cats over 8 years old
polyphagia, weight loss, poor coat, PU/PD, V/D, panting, restlessness/hyperactive
rare: lethargy, hyporexia, obesity
can also have no clinical signs
signalment and clinical signs of hypothyroidism
middle aged dogs
lethargy, weight gain, alopecia, pyodemra, seborrhea, rat tail, hyperpigmentation, secondary infections
**derm signs are the most commonly noticed by owner**
uncommon: neuromuscular, infertility, myxedema (tragic face), ocular disorders (secondary to hyperlipidemia), cretinism (puppies)
Which insulins use a U40 syringe?
Prozinc and Vetsulin
list clin path findings of HAC
nRBCs
mild erythrocytosis in females with androgens
increased ALP and ALT
increased triglycerides, cholesterol, glucose, Na
normal to decreased K, BUN
UA: hyposthenuria or isosthenuria. mildly elevated UPC, silent UTI (good idea to culture), mild proteinuria
signalment and clinical signs of addison's
young/middle aged dogs. females>males
lethargy, anorexia, weight loss, v/d, dehydration, collapse, PU/PD
less common: neuro, regurg, exercise intolerance, melena, abdominal pain
Clin path findings for hyperthyroidism
mild polycythemia, heinz bodies, stress leukogram, increased ALT and ALP without bilirubin increase
variable UA results
high blood pressure!
clin path findings with hypothyroidism
50% have anemia, normal to high platelets, increased cholesterol, increased triglycerides, mildly elevated liver enzymes
What diet is recommended for DM dogs and cats?
Dogs: increase fiber! allows for delayed gastric emptying and slower absorption of glucose (less peak)
cats: high protein, low carb! canned!
list the screening vs differentiation tests for HAC
screening: ACTH stim, LDDST
differentiation: LDDST, HDDST, endogenous ACTH, maybe abdominal ultrasound
what will you give a patient in a hypoadrenal crisis?
fluids- NaCl best, LRS fine too. give in 1/4 shock doses and reassess- do not want to increase Na too quickly.
dextrose if severely hypokalemic. can give Ca gluconate to protect heart if K >8.5
IV glucocorticoids (dexamethasone)
what would a low or low-normal TT4 with high fT4 indicate?
euthyroid sick syndrome
what is a T4 best used for?
if it is low, need another test (fT4, TSH, T4AA)
If you have already increased an insulin dose twice and patient is still insulin resistant, what will you do next?
look for concurrent problems!
endocrine- acromegaly, hyperthyroid, cushings, hypothyroid
medications- steroids, progestins
inflammation, infection, neoplasia
explain the difference between PDH and FAT
PDH= pituitary making excess ACTH. much more common!! both adrenals enlarged. decreased CRH.
FAT= adenoma or carcinoma on the adrenal gland secreting cortisol independent of pituitary control. CRH and ACTH will be suppressed. contralateral adrenal will be atrophied. episodic, random cortisol secretion
what is addison's frequently confused with and why?
the great imitator! most frequently confused with AKI due to depleted Na in renal medulla, inability to concentrate urine, hypovolemia, hypotension, decreased CO.
describe when you would use the following tests: TT4, fT4
TT4: best test for hyperthyroidism! if high, treat. if normal, can retest in 3-4 weeks.
fT4: run if you get normal T4 but still suspect illness. this CAN be elevated in non-thyroidal illness (diabetes, pancreatitis, lymphoma), so never run this by itself. will be high with hyperthyroidism.
what is the best testing combo for sensitivity? for specificity?
best sensitivity: TT4, fT4, TSH
best specificity: fT4, TSH
What are some complications associated with diabetes in dogs and cats?
cats: UTI, neuropoathy, DKA, hyperosmolar non-ketotic acidosis (HONK)
dogs: UTI, cataracts (high conc of aldose reductase in lens leads to sorbitol accumulation), uveitis, DKA, HONK
List the pros/cons for each treatment option for HAC. Which is preferred PDH vs FAT?
Mitotane= breaks down adrenal gland. requires intense monitoring with ACTH stim and electrolytes. GI upset common. expensive, daily medication required. **Preferred for FAT
Surgery= ***recommended for FAT. before sx, need to determine metastasis and extensive pre-op evaluation. cons: up front cost
Trilostane= vetoryl= ***treatment of choice for PDH. competitive inhibitor of steroid synthesis by inhibiting 3-B-hydroxysteroid dehydrogenase. cons: can cause hypoadrenocorticism
what is a normal progression for steroid replacement in a newly diagnosed addisonian?
start with injectable glucocorticoid. switch to oral when eating/drinking (prednisone). taper dose. increase dose if sick or stressed.
transition to mineralocorticoid replacement once through initial crisis.
- fludrocortisone is mineralocorticoid + glucocorticoid, so do not need prednisone. often causes PU/PD. oral.
- DOCP is mineralocorticoid only, so needs concurrent prednisone (lowest effective dose). injectable every 28 days ideally. first dose may fail, but adverse effects uncommon.
list the pros and cons for treatment options for hyperthyroidism. which is the treatment of choice if concurrent CKD? which are potentially curative?
methimazole: blocks thyroid hormone synthesis. reversible. oral or transdermal options. expensive, can have severe side effects (vomiting if oral form, facial pruritus, hepatopathy, thrombocytopenia, leukopenia, immun emediated anemia, bleeding
**this is the best choice with concurrent CKD**
I-131: potentially curative, no anesthesia required, very successful, well tolerated. not widely available, up front cost, radioactive handling, may become hypothyroid.
iodine restricted diet: thyroid is the only organ in the body that needs iodine, so no side effects! just difficult with owner compliance or multi-cat households.
surgery: potentially curative. anesthetic risk, may leave thyroid tissue behind (nuclear scintigraphy recommended pre-op), parathyroid damage can lead to hypocalcemia, nerve damage possible
What is the treatment for hypothyroidism? How should we monitor therapy?
levothyroxine
Check T4 4-6 hours post-pill (after 2 weeks of tx?)