Hypercholesterolemia in 75% of cases, Hypertriglyceridemia, Hyponatremia
*what is a big hint towards hypothyroidism pertaining to tests you can do?
chem panel--> **Hypercholesterolemia
what are 2 thyroid function tests and what are their results with hypothryroidism? which thyroid fxn test is not useful in the dog?
(1) Low T4 and fT4 (2) High TSH....... TT3 and fT3 considered unreliable in the dog
would you rather look at T4 of fT4 levels?
fT4 correlates directly with availability to tissues, Less influenced by medication conditions and other drugs. Must measure by ED (equilibrium dialysis)
is it common to see high TSH in 1* hypothyroidism?
75-80% in 1* hypothyroidism
what is Euthyroid sick syndrome?
low serum T4 levels with normal thyroid function
5 common causes of Euthyroid sick syndrome?
(low serum T4 levels with normal thyroid function) (1) Hyperadrenocorticism (2) Diabetes mellitus (3) Other systemic illnesses (4) Estrus, pregnancy (5) Medications (glucocorticoids, potentiated sulphonamides, phenobarbital, carprofen)
is it high or low adrenal fxn that can lead to euthyroid sick syndrome?
two distinctly female things which can cause euthyroid sick syndrome?
estrus and pregnancy
**4 medications which can cause euthyroid sick syndrome?
glucocorticoids, potentiated sulphonamides, phenobarbital, carprofen (she said ppl forget about carprofen all the time)
how do you tx hypothyroidism? how do you check-in/reassess treatment? How do you know if you need to recheck sooner?
L-thyroxine (T4): 0.01-0.02 mg/kg PO BID. After 4 weeks, 4-6 h post-pill T4 should be measured and the dose adjusted if needed. When stable, reevaluation q 6-12 months. Recheck sooner if clinical signs have not resolved, relapse, or thyrotoxicosis
what are Serum biochemistry abnormalities you'd see with cushing's?
***inc ALP (80%), inc ALT~, Hypercholesterolemia (the major marker for hypothyroid, so look out), Mild hyperglycemia (DM in 5-10% cases)
*what is a big hint towards cushings pertaining to tests you can do?
chem panel--> ***inc ALP (80%), inc ALT~ (bc dont see this one with hypothyroid, whereas there is crossover with hypercholesterol)
how is urine affected by cushings?
Hyposthenuria - USG <1.015, proteinuria
what is the Screening test you use to start to dx cushings? what should you know about the efficacy of this test?
Urine cortisol:creatinine test. Must know this test has very low specificity (specificity is trust the positive, so if low, in this case, not awesome positives so gotta move to next test) If negative, 99% ruled out Cushing’s. If positive, proceed to next test
3 main diagnosis tests for cushings?
(1) Urine cortisol:creatinine (the screening test-- low specificity) (2) ACTH stimulation test (inc specificity) (3) Low Dose Dexamethasone Suppression test (inc sensitivity)
ACTH stimulation test--> what can this test tell you, and what can you use this test to do?
Can differentiate between iatrogenic and spontaneous Cushing’s and to monitor response to treatment
aside from the 3 main diagnostic tests for cushings, what are some other tests you can do which can help aid in diagnosis?
Ultrasound evaluation of both adrenal glands (size and morphology), High dose dexamethasone suppression test, CT and MRI of the pituitary gland, Basal ACTH level (available only in a few labs in the world)
what is the most common cause of cushings in cats?
80% PDH ( pituitary adenoma)
how does cushing's usually present in cats? (clinical signs)
Vague clinical signs, Diabetes mellitus, Skin fragility, Curling of the pinnal tips
how do you treat cushing's if it is caused by PDH (pituitary adenoma)? (4)
who does Sertoli cell tumour affect? who is more prone? where is the tumor? Why does it cause alopecia?
Testicular neoplasm, so it affects Intact males. More common in cryptorchid dogs. Excess estrogen secreted by tumour cells--> alopecia
3 major clinical signs of a sertoli cell tumor?
(1) Asymmetrical testicles on palpation (enlargement and atrophy) (2) Prostatomegaly / prostatitis (3) Feminization (Gynecomastia, Pendulous prepuce)
Dermatologic signs of sertoli cell tumor? (6)
(1) Bilaterally symmetrical alopecia (2) Primary hair follicles of the cervical region, trunk, perianal skin and posterior thighs are most sensitive to estrogen levels (3) Absence of pruritus (4) Hyperpigmentation (5) Otitis externa (6) Comedones
which locations' hair follicles are most sensitive to estrogen (thus, the distribution of alopecia...?)
Primary hair follicles of the cervical region, trunk, perianal skin and posterior thighs
does sertoli cell tumor--> hyperestrogenism cause pruritus?
what other dz/problem can come about because of hyperestrogenism?
what lesions aside from alopecia might you see on the skin bc sertoli tumor--> hyperE?
what are other (non skin) clinical signs you can see with sertoli tumor--> hyperE?
Mental dullness, Anemia, Thrombocytopenia, Bone marrow suppression, Attractiveness to other male dogs (things associated with hyperE, basically)
how do you dx sertoli cell tumor?
Physical + dermatologic examination and Ultrasound (testicles / abdomen)
Pathogenesis not characterized (affects certain breeds tho so maybe a genetic thing)
breed disposition for alopecia X? Sex predilection?
Affects plush-coated breeds like Pomerian (coat funk / black skin dz), Mini Poodles, Malamutes. males more affected than females
average age of onset for alopecia X?
Distribution of alopecia in alopecia X?
Alopecia circumferentially around cervical region (under the collar), rat tail, truncal. Head and extremities are spared!!!
clinical signs of alopecia X?
Bilateral symmetrical alopecia, Hyperpigmentation, No systemic illness
is there systemic illness with alopecia X?
nope...basically just alopecia and some hyperpigmentation
2 ways to dx alopecia X?
(1) Rule out hypothyroidism and Cushing’s (2) Biopsy: flame follicles! (Excessive tricholemmal keratinization of hair follicles)
what is an identifying feature histopathologically which helps you dx alopecia X? explain what is going on with this
look for flame follicles which is Excessive tricholemmal keratinization of hair follicles
how do you tx alopecia X?
Not needed! This is a cosmetic disease (sweater therapy- ie put clothes on the dog to cover its bald spots). If intact, castration (might make a diff?). Can attempt Trilostane, Melatonin at 3mg/dog BID
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