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Endocrine > Endocrine Ettinger > Flashcards

Endocrine Ettinger Flashcards

1
Q

What is primary hyperPTH?

A

Excessive synthesis and secretion of PTH by abnormal, autonomously functioning parathyroid “chief” cells

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2
Q

What is the classic biochemical triad of hyperPTH?

A

Hypercalcemia, hypophosphatemia, hyperphosphaturia

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3
Q

Which breeds are noted to have hyperPTH?

A

Keeshond (genetic predisposition), Poodles, GSD, Retrievers

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4
Q

What does the owner see with hyperPTH?

A

Mild to nothing!

o 42% sought vet care for other reasons when hyperCa found (yearly exams, dental bloodwork)

o 50% urinary signs (urolithiasis, UTIs)

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5
Q

What are the hallmarks on a chemistry for hyperPTH?

A

HyperCa!!!!!

Low to normal Phos (PTH inhibits renal tubular resorption of phos - you pee it out!)

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6
Q

What are the hallmarks on a chemistry for hyperPTH?

A

HyperCa!!!!!

Low to normal Phos (PTH inhibits renal tubular resorption of phos - you pee it out!)

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7
Q

Why are patients with hyperPTH isothenuric?

A

HyperCa = Reversible form of nephrogenic DI (interferes with ADH) = Isosthenuria

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8
Q

What % of hyperPTH dogs had UTIS?

A

o Sediments: Hematuria, pyuria, bacteruria, crystalluria (29% with UTIs)

o Uroliths!!! (about 25%)

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9
Q

What would you see on a PTH/PTHrp/Vit D panel in hyperPTH?

A

iCa high = PTH should be or approach undetectable!
“Normal” PTH in hyperCa animal = ABNORMAL and considered excessive!

PTHrp - undetectable
Vit D: Normal to increased

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10
Q

If the phosphorus is low to normal how does this help with DDx for hyperCa animal?

A

If serum phos low or normal: LESS likely renal failure, Vit D toxicosis, or Addisons; MORE likely primary hyperPTH or malignancy associated hyperCa

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11
Q

How many HyperCa have LSA?

A

About 40%, check for mediastinal mass

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12
Q

What is recommended for acute hyperCa?

A

saline (0.9%) diuresis +/- Lasix

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13
Q

What is recommended for acute hyperCa?

A
  1. Rehydrate (increased GRF to increased Ca loss in urine)
  2. saline (0.9%) diuresis (promotes renal loss of Ca, Na competes with Ca for reabsoprtion = Ca lost!)
  3. +/- Lasix (inhibits Ca reabsorption in thick ascending LOH)
    NOTE: Thiazides = Decreased Ca excretion in distal tubule
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14
Q

How are steroids helpful for hyperCa?

A

Reduce bone resorption of Ca, decrease intestinal Ca absorption, and increase renal Ca excretion

Cytotoxic to neoplastic lymphocytes, inhibit growth of neoplastic tissue

Counteract effects of Vit D and granulomatous dz

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15
Q

What are the major bisphosphonates and how do they work?

A

etidronate, clodronate, pamidronate)

Structurally related to pyrophosphates (metabolic by-product) → Inhibitory effect on osteoclast function and viability

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16
Q

What is calcitonin?

A

· Reduces osteoclast activity and formation of new osteoclasts
· Considered to be “weak and short acting” in humans

Salmon calcitonin (Calcimar) = MOST POTENT

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17
Q

What is plicamycin?

A

(aka mithramycin)
· Cytotoxic compound = Potent inhibitor of RNA synthesis in osteoclast

Significant Toxicity: Thrombocytopenia, hepatic necrosis, renal damage, hypoCa

Works within 24-48hrs

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18
Q

What is plicamycin?

A

(aka mithramycin)
· Cytotoxic compound = Potent inhibitor of RNA synthesis in osteoclast

Significant Toxicity: Thrombocytopenia, hepatic necrosis, renal damage, hypoCa

Works within 24-48hrs

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19
Q

How would bicarbonate help with hyperCa?

A

· Ionized fraction of Ca determined by acid-base status

Creating a slight alkalosis (bicarbonate tx) shifts iCa to protein bound fraction (less harmful)
= Mild effect

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20
Q

How would a Ca receptor agonist work with hyperCa?

A

· Ca sensing receptor on parathyroid cells (down regulates synthesis and secretion of PTH)

Molecules that mimic Ca can activate this receptor and inhibit parathyroid function too
R-5658

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21
Q

After sx for hyperPTH, does recurrence happen?

A

Yes, 16/187 dogs

Esp in keehounds (!!! Need to monitor this breed) = 7/187 dogs

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22
Q

Besides sx what other options are there for hyperPTH dogs?

A
  1. Heat Ablation

2. Ethanol Ablation

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23
Q

What is the biggest complication with any tx for hyperPTH?

A

Hypocalcemia (post-tx) - Atrophied other parathyroid glands
Risk = Higher pretx Ca, longer duration (Ca >15) = Greater risk of hypoCa NOW study that shows that iCa or PTH levels prior to tx do NOT predict hypoCa after!!!!!

Vit D prior to after did not prevent the decreased in Ca

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24
Q

What is used to tx hypoCa after treating hyperPTH?

A

Calcitriol (Vit D)

GOAL: Keep Ca low to low normal (wake up those other parathyroid glands)

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25
Q

What is the prognosis for hyperPTH?

A

Excellent!!!

After tx 33% will develop hypoCa but treatable!!

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26
Q

What is the prognosis for parathyroid carcinomas?

A

Excision of parathyroid carcinomas = Resolution of hyperCa and Excellent tumor control

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27
Q

What are the most common CS in hyperCa cat?

A

Poor appetite, weight loss, weakness (less common PU/PD)

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28
Q

What is different in dogs than cats with hyperPTH?

A

Cervical mass that CAN be palpated in cats!!! Not true in dogs (need ultrasound)

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29
Q

How is primary hypoPTH diagnosed?

A

Low iCa with low or low normal PTH

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30
Q

What is the mechanism of hypoCa in ethylene glycol?

A

Marked increased in phos = decreased in Ca

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31
Q

What can be seen with nutritional HyperPTH?

A

· Improper diet = Low Ca to Phos ratio (beef heart or liver) → Ca deficiency = transient decrease in serum Ca → Increase in PTH = Reduction in bone mass from Ca mobilization to replace Ca that is lacking in diet

Normally Ca and Phos are in RR (some can have hypoCa)

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32
Q

What is considered ER tx for hypoCa?

A

IV Ca gluconate (slow)

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33
Q

What is considered long term tx for hypoCa?

A

Vitamin D (calcitriol) and Oral Calcium (calcium carbonate)

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34
Q

What is seen on histopath for hypoPTH?

A

Lymphocytic parathyroiditis

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35
Q

What is the prognosis for hypoPTH?

A

Excellent with tx (depends on owner - Lots of monitoring)

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36
Q

What are the hallmark CS for hypoPTH?

A

Seizures (50%), tremors, fasiculations, muscle cramping, stiff gait, tetany

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37
Q

What are the major types of primary acquired hypoT4?

A

· Primary Acquired Hypothyroidism (deficiency of T4/T3):
o 1. Lymphocytic Thyroiditis (50% cases)
§ Multifocal/diffuse infiltrate of lymphocytes, plasma cells, MPs → Fibrosis
§ Immune Mediated (unclear process)
§ Antithyroglobulin antibodies: 36-50% hypoT4 dogs (unclear role); varies with breed
· Association of DLA Class II Haplotype DQA1*00101: Dobermans, English Setters, Rhodesian Ridgebacks
§ Heritable Thyroiditis: Beagle, Borzoi
o 2. Idiopathic Thyroid Atrophy
§ Loss of thyroid tissue, replacement with adipose (may be a final stage of thyroiditis)
o 3. Bilateral Thyroid Neoplasia (thyroid or mets)
§ Remain euthyroid until 75% thyroid destroyed
§ Risk Factor: Lymphocytic thyroiditis
o 4. Reversible from high doses of potentiated sulfonamides

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38
Q

What is secondary acquired hypoT4?

A

(deficiency of TSH) - rare (~5% of cases)
o Pituitary malformation
o Pituitary neoplasia

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39
Q

What is tertiary hypoT4?

A

· Tertiary Hypothyroidism (deficiency of TRH): NOT documented in vet med

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40
Q

What is primary congenital hypoT4?

A

Cretinism: Rare in dogs
o Iodine deficiency, thyroid dysgenesis, dyshormonogenesis
o Thyroid peroxidase deficiency: Autosomal recessive Rat terrier, Toy Fox (DNA test for carriers)

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41
Q

What is secondary congenital hypoT4?

A

· Secondary Congenital Hypothyroidism (isolated loss of TSH or TRH deficiency)
o Family of giant Schnauzers and 1 boxer

Feature of panhypopituitarism

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42
Q

Which breed are overrepresented with hypoT4?

A

Goldens and Dobermans

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43
Q

What is a myxedma coma?

A

Profound mental dullness or stupor, with nonpitting edema, hypothermia with lack of shivering, bradycardia, weakness, inappetence
· Deposition of glycosaminoglycans
· Concurrent infection may precipitate hypoT4 crisis

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44
Q

What dz is associated with lar par, megaesophagus, Myanthenia gravis, and DCM?

A

HypoT4

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45
Q

What polyendocrinopathies are noted with hypoT4?

A

Addison’s and DM (hypoT4 = insulin resistance)

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46
Q

Does T4 supplementation improve survival in euthyroid sick patients?

A

NO!

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47
Q

How is the TSH response test performed?

A

§ Test of thyroid gland reserve (standard for diagnosis of hypoT4)
§ Protocol: human recombinant TSH (rhTSH): 75-100ug TSH collection in 4-6 hrs
o HypoT4: Pre and post TSH serum T4 below RR ( 2.5 ug/dl and increase at least 1.5X basal T4
§ Can’t be used in dogs on l-thyroxine (thyroid atropy)
o Need to stop for 6-8 wks before testing

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48
Q

ow is the TRH response test performed?

A

§ Dose: 0.01-0.1 mg/kg TRH
§ Protocol: 200 ug TRH/dog IV; collect blood before and 30 mins, then 4 hrs after
o TT4 measured at 0 and 4 hrs; TSH measured at 0 and 30 mins
o Euthyroid: Post TRH TT4 > 2 ug/dl and if relative increased in TSH greater than 100% at 30 mins after TRH administration
o HypoT4: Post TRH TT4

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49
Q

What % of hypoT4 dogs have anti-thyroglobulin antibodies?

A

38-50%

Can be transiently increased with vaccination

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50
Q

Which feline breeds get congenital hypoT4?

A

DSH and Abyssinians

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51
Q

What human disease does hyperT4 resemble?

A

Human toxic nodular goiter (Grave’s Dz): Autoimmune dz circulating antibodies (thyroid stimulating immunoglobulins (TSIs) bind to throtropin (TSH) receptors and mimic TSH)

BUT TSIs NOT seen in cats

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52
Q

Which breeds are at a lower risk of hyperT4?

A

Siamese and Himalayan, purebred cats

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53
Q

What are risk factors of hyperT4?

A

Entirely canned food (esp flavored
Goitrogenic Compounds
§ Metabolized by glucuronidation (SLOW in cats)
· Goitrogenic soy isoflavones (genistein and daidzein) – In commercial cat food

Living indoors, using cat litter, sleeping on floor = Increase risk

These + eating seafood or fish flavored canned food → Increased exposure to polybrominated diphenyl ethers (PBDEs) = Endocrine disruptors in cats

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54
Q

What is the mechanism of intermittent vomiting with hyperT4?

A

Triggers chemoreceptor trigger zone

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55
Q

What is an apathetic hyperT4 cat?

A

~ 10% of cats, anorexia & depressed; need to r/o CHF and other illness

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56
Q

Which counterregulator hormones are the most important for increasing glucose?

A

Glucagon and catecholamines

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57
Q

What molecule is secreted with insulin that in humans and CATS assumes a B-pleated shape?

A

Islet amyloid polypeptide

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58
Q

What are the two big issues with Type 2 DM?

A

Insulin Resistance

B Cell Dysfunction (accounts for progressive nature)

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59
Q

Which adipokine is anti-inflammatory?

A

Adiponectin: High levels in lean!

Obesity: Drop in adiponectin and rise in leptin - pro-inflammatory cytokines

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60
Q

Have anti-islet antibodies (Type 1 DM) been described in cats?

A 
NO! Type I DM is very rare
Lymphocytic infiltration (only in a few cats)
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61
Q

Which breed of cat is more likely to get DM?

A

Burmese (4X) higher!

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62
Q

How likely are obese cats to get DM?

A

3.9X more likely

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63
Q

What are the risk factors for cats getting DM?

A

· Old age
· Obesity
o Fat cats are 3.9x more likely to develop DM
o Drop in insulin sensitivity has been documented after weight gain in cats
o GLUT4 expression is lower in muscle and fat of fat cats vs. lean cats
o GLUT1 is unchanged (not insulin sensitive)
o Decreased adiponectin and increased leptin and TNF-a
· Male gender
· Neutered
· Physical inactivity
· Glucocorticoid or progestin administration

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64
Q

What is the structure of insulin?

A

polypeptide chains
§ A chain: 21 aa
§ B chain: 30 aa
o Both chains are connected by 2 disulfide bridges

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65
Q

How does insulin differ bwtn species?

A

o Feline insulin differs from bovine by only 1 aa
o Differs from canine and human in 3 and 4 positions

	          A8 A10	A18	B30
Human	Thr	Ile	Asn	Thr
Pig/Dog	Thr	Ile	Asn	Ala
Cattle	Ala	Val	Asn	Ala
Cat	        Ala	Val	His	Ala
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66
Q

Why does oral glucose release more insulin than IV?

A

o Oral glucose causes more severe insulin release than IV
§ Due to the actions of incretins, release by endocrine cells in the GI tract = Stimulate insulin release
· Glucagon-like-peptide-1 (GLP-1)

Glucose dependent insulinotropic polypeptide (Gastric inhibitory peptide)

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67
Q

In which organs is glucose entry not affected by insulin concentration?

A

brain, kidney, and erythrocytes are not affected by lack of insulin

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68
Q

What are lente insulins?

A

o Based on the fact that insulin effect can be delayed by simply adding zinc in excess
§ Approx 10x the amount in NPH
o Other factor affecting onset of action: physical condition
§ Amorphous
· 1 mm n diameter
· Faster onset and short duration than crystalline zinc
§ Crystalline
o Lente insulins are mixtures of 30% short-acting amorphous with 70% long-acting crystalline
§ Rapid onset
§ Prolonged duration
o Vetsulin/Caninsulin

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69
Q

What is a major negative of using sulfonylureas in cats?

A

Glipizide:
§ may have negative effects on islets and may accelerate β-cell loss
· experiments have documented increased amyloid deposition

		o Stimulate secretion of insulin 
			§ Some b cell function required
		o Glipizide should only be used in diabetic cats that are in good physical condition, are nonketotic, and have only mild to moderate signs of diabetes
		o Several drawbacks    
			§ treatment is successful in only about 30% of cats
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70
Q

What are in the intrinsic defense and preventative mechanisms in pancreas?

A

Protect from auto-digestion:
§ Production of proteins as zymogens
§ Segregation from lysosomes
§ Presence of enzymatic inhibitors
o PSTI ( SPINK 1)– pancreatic secretory trypsin inhibitor
§ Unidirectional flow of pancreatic duct
§ Protease inhibition
o α2 macroglobulin – non specific, irreversibly binds, cleared by RES and most important
§ Class specific
o α1 protease inhibitor & α1 antitrypsin – reversible bind, transport to α2 macroglobulin

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71
Q

What are 2 circumstances that cTLI would be normal but patient would have EPI?

A

· Isolated pancreatic lipase deficiency (reported in one dog)
· Obstructed pancreatic duct

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72
Q

What is the most common breed with primary hyperPTH in dogs?

A

Keeshond

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73
Q

What is a major difference in cats with hyperPTH compared to dogs?

A

Cats have a palpable mass (Cervical region)

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74
Q

What are bisphosphonates used for idiopathic hyperCa in cats?

A

Alendronate (erosive esophagitis, osteonecrosos of jaw)

Zoledronate (more necrosis)

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75
Q

What is used ot manage post-op hypoCa in parathyroidectomies?

A

Calcitriol

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76
Q

Which breed has a high incidence of recurrence?

A

Keeshound! (10%, regardless of path)

All histopath have similar behavior

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77
Q

Can HAC lead to increase in PTH?

A

Yes, Hypercortisolemia can result in increased PTH BUT NOT increase in total or iCa
Improves with tx of Cushing’s dz

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78
Q

What is Hungry Bone Syndrome?

A

HypoCa NOT related to low PTH = Uptake of Ca by bones after longstanding HyperPTH or HyperT4
*calcitriol, but also bisphoshpnates to try to inhibit osteoclasts from taking up Ca

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79
Q

What electrolyte is important for PTH secretion?

A

Mg!!

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80
Q

What is the main defect with primary congenital HypoT4?

A

Thyroid peroxidase def = Cretinism

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81
Q

Which breeds get primary congenital HypoT4?

A

Rat Terrier, Toy Fox Terrier, Tenterfield terrier

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82
Q

What is secondary congenital HypoT4?

A

Loss of TSH or TRH = Panhypopitutarism

Seen in Giant Schnauzer, Boxer

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83
Q

What can be normal in 13-38% of hypoT4 dogs?

A

TSH

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84
Q

What is the mechanism that sulfonamides results in hypoT4?

A

Block iodination of thyroglobulin

Clinical HypoT4 that is reversible

85
Q

Which breeds will have a decreased TT4?

A

Sighthounds and sled dogs

86
Q

What happens to TT4 in neonates?

A

3-5X adult for 3 weeks and then decreased

87
Q

Can TSH be increased in euthyroid dogs?

A

YES, TSH increased in 7-18% euthyroid dogs

88
Q

Which are more common in dogs AntiT3 or AntiT4 antibodies?

A

AntiT3 - 5.7% dogs with CS, 34% hypoT4 dogs

AntiT4 - 1.7% dogs with CS, 15% dog hypoT4

89
Q

What is considered the gold standard for testing thyroid function? How is it performed?

A

TSH response test - thyroid gland reserve
rhTSH 75-100ug (cats 25ug)
If hypoT4: T4 low post TSH!

90
Q

Can the TSH response test be used in dogs on l-thyroxine?

A

NO!! They have thyroid atrophy

Need to stop supplementation for 6-8weeks

91
Q

What is the TRH test and how is it performed?

A

Give TRH (IV) 200ug/dog - samples at 30 mins and 4 hrs for TSH and TT4

If hypoT4 post TSH will be

92
Q

What is the problem with TRH test?

A

Some dogs fail to respond to TRH!

93
Q

What can transiently affect ATAbs?

A

Drugs
Viral infection
Vaccination
Nonspecific protein binding

94
Q

Do ATA interfere with thyroid supplementation?

A

NO!

95
Q

What should be considered in a dog with GI dz that is hypoT4?

A

Supplementation with T3, but high risk of hyperT4, need to monitor closely

96
Q

What should you consider if there is tx failure in HypoT4 dog?

A 
Wrong DX!!
Owner compliance
Inadequate dose
Poor PO absorption
Defective T4 to T3 conversion (but not reported in dogs)
97
Q

What would you expect with hypoT4 in cats?

A

Low TT4/low fT4
Can use K9 TSH test in cats

CS: Inappetant

98
Q

What are causes of hypoT4 in cats?

A
  1. Iatrogenic - I131
  2. Congenital HypoT4 - DSH and Abyssinian
  3. Lymphocytic thyroiditis
  4. Secondary hypoT4 - head trauma
99
Q

If you have normal T4/fT4 and normal TSH…..

A

Normal dog

If strong suspicion test more

100
Q

If you have Low/borderline T4/fT4 and normal TSH…..

A
  1. HypoT4
  2. Normal variant
  3. Concurrent illness

Consider: thyroid ABs, provocative testing, therapeutic trial

101
Q

If you have normal T4/FT4 and HIGH TSH……

A
  1. Early subclinical hypoT4
  2. Recovery from illness

Consider rechecking in 1-3 months, or if strong suspicion check for thyroiditis (ATAs)

102
Q

What % of dogs have anti-thyroglobulin ABs?

A

30-50% hypoT4 dogs

BUT 10-20% euthyroid dogs do too!!

103
Q

If you have low/borderline T4/fT4 and HIGH TSH….

A

HYPOT4 - Need supplementation life long :)

104
Q

Why do hyperT4 cats vomit?

A

Thyroid hormone thought to stimulate CRTZ

105
Q

Why are hyperT4 cats PU/PD?

A

Thyroid hormone thought to inhibit aquaporins

106
Q

Is there evidence that hyperT4 damages kidneys?

A

Direct evidence is lacking!

107
Q

What happens with fructosamine with hyperT4?

A

Decreased!!! dt high protein turnover

108
Q

What % of hyperT4 can have normal TT4?

A

10% of HyperT4 cats

109
Q

If you have mid-range-high TT4 and increased fT4 in cat…..

A

HyperT4

110
Q

If you have low TT4 and increased fT4 in cat……

A

Nonthyroid illness

111
Q

How can you use TSH in cats with hyperT4?

A

Only 45% success with using canine TSH

Used to eliminate hyperT4 if TSH is detectable

112
Q

Was there a significant difference in MST in cats that developed azotemia after I131?

A

NO!!! :)

113
Q

In I131 cats what did decreased survival in azotemic cats?

A

HypoT4 status!!

114
Q

Can normal housemates eats y/d?

A

Yes, but they need to even iodine in other food

115
Q

Can cats develop a goiter on y/d?

A

YES!

116
Q

What are the effects of y/d on I131?

A

Unknown, stop about 2 weeks ahead

117
Q

Has hypoT4 been reported in cats with hyperT4 and healthy cats on y/d?

A

NO! When feed 0.3ppm iodine for 1 year

118
Q

What is the critical hormone for DKA?

A

Increase in glucagon

119
Q

If you have IM insulinitis what are your Abs directed against?

A

Beta cells and GAD (glutamic acid decarboxylase) - seen in some dogs

120
Q

How many diabetic dogs have uncomplicated ketonuria?

A

About 66%

121
Q

What % of dogs and cats get EPI with diabetes?

A

Dogs 25%

Cats 10%

122
Q

How does kinostat work in DM?

A

Aldosterone reductase inhibitor that stops cataract formation

123
Q

What is the cut off for Beta hydroxybutyrate in DKA?

A

Cut off 3.8 but highly specific when >4.8

124
Q

What is HONKDM?

A

Hyperosmolar nonketotic DM
Extreme hyperglycemia >600
Hyperosmolarity > 350
No ketones - some functioning beta cell remain and thus ketones are not made

125
Q

What are the ranges for fructosamine in dogs?

A

> 500 poor glycemic control
450-500 fair control
400-450 good control
350-400 good control

126
Q

What can falsely lower fructosamine?

A 
Hypoalbuminemia
Hyperlipidemia
Azotemia
Room temp
Hypert4
127
Q

What is the prognosis for DM in dogs?

A

2-3 years after sx

128
Q

Is there day to day variation in BG curves?

A

Yes! When preferred at home vs at hospital there were differences too
60% same decision
40% different decision and in 3% dogs and 8% cats if was contrary decision

129
Q

What are the three mains factors resulting in DKA?

A
  1. Absolute or relative lack of insulin= hyperglycemia
  2. Increased glucagon
  3. Increase EPI, cortisol, GH
130
Q

What are the four main outcomes of DKA?

A

Increased hepatic glycogenolysis and gluconeogensis
Decreased peripheral use of glucose
Increased lipolysis
Increased hepatic ketogenesis

131
Q

What is the prognosis for DKA?

A

Guarded
Mortality
Dogs 29%
Cats 26%

132
Q

What are the goals for insulin tx in DKA?

A

Decrease bg by 50-70 mg/Dl/hr
Above 250 for first 4-6 hrs
Once lower than 250 add dextrose

133
Q

What are the insulin cri rates in dogs and cats?

A

Dog 0.09 u/kg/hr

Cat 0.045 u/kg/hr

134
Q

Are fat cats at risk of DM?

A

Yes 3.9x more likely to get DM
Decrease in insulin sensitivity
Decrease GLUT4 Muscle and fat
Decreased apidonectin and increased leptin and TNFa

135
Q

What are the risk factors for DM in cats?

A

Obesity
Male
Neutered

136
Q

What % cats go into remission with glargine and high protein,low carb diet?

A

> 80-90%

137
Q

What is key to diabetic remission in cats?

A

Need functioning beta cells

138
Q

What type of diet is ideal for cats with DM for remission?

A

Low carb and high protein

139
Q

What were remission rates in cats with DM?

A

> 80-90% with glargine and diet
60% with PZI
20-30% diet alone

140
Q

What factors make remission in DM unlikely?

A

Increased cholesterol
Plantigrade stance
Increased insulin dose

141
Q

What is insulin resistance?

A

> 1.5 u/kg q 12hrs

142
Q

How long can somogyi response last?

A

Release of EPI, glucagon
Can last 24-72hrs
Marked hyperglycemia > 400

143
Q

What is considered Whipple’s triad?

A

Related to insulinoma

144
Q

In what disease can a glucagon cri be used?

A

With an insulinoma

145
Q

What % of insulinoma develop DM after sx?

A

About 10%

146
Q

What are medical management options of insulinoma?

A

Diet increased freq high protein
Prednisone
Diazoxide inhibits stop and blocks insulin secretion
Octerotide somatostatin analog that inhibits insulin secretion

147
Q

What cat breed gets insulinomas?

A

Siamese

148
Q

What should be considered if concurrent pituitary and adrenals rumors noted?

A

Transition from adrenal hyperplasia to adrenal nodular hyperplasia

149
Q

Which part of the pituitary makes ACTH?

A

Pars distalis mainly

Little from beta cells in pars intermedia

150
Q

Since it is recommended to perform pituitary imaging in all dogs with PDH, what could be used to help?

A

POMC and pro ACTH levels to determine if imaging needed

151
Q

Is there a correlation of ALP with severity of HAC?

A

No!

152
Q

Can you have an abnormal bile acids in dogs with HAC?

A

Yes they can be increased

153
Q

What % of HAC dogs have proteinuria?

A

60-80%

It does not always normalize with tx

154
Q

What effects does HAC have on thyroid status?

A

HAC can decrease TSH leading to low TT4 in 20-57%

155
Q

What is the protocol for ACTH stim?

A

Cosyntropin at 5ug/Kg

156
Q

Which HAC screening test is very affected by systemic disease ?

A

UCCR

LDDST

157
Q

What is the protocol for LDDST in dogs?

A

0.01 mg/kg dex sp IV

158
Q

What many HAC are dexamethasone resistant?

A

40% PDH

100% adrenal tumors

159
Q

What is the protocol for HDDST in dogs?

A

0.1 mg/kg dec sp iv

160
Q

How many cases will be differentiated with HDDST?

A

Only 12% of PDH cases, in general FAT and 15-50% PDH esp large tumors do not suppress!

161
Q

What is the name of the syndrome that described progression of neurological signs in dogs that have HAC with treatment?

A

Nelsons syndrome

162
Q

Is there a difference btwn trilostane and mitotane?

A

No! Trilostane 662 days and mitotane 708 days

163
Q

What the MST difference with q12 vs q24 dosing of trilostane?

A

Q12 900 days vs q24 662 days

164
Q

What electrolyte change can be seen with trilostane?

A

Mild increase in K

165
Q

What % dogs relapse on mitotane?

A

50% relapse within 12 months

166
Q

How does selegiline work?

A

Increased Dopamine which inhibits secretion of ACTH from pars intermedius

167
Q

What % of dogs that underwent radiation tx for PDH needed medical management?

A

30-60%

168
Q

In FAT cases is there a difference btwn trilostane and mitotane?

A

No significant difference btwn MST

169
Q

What is ectopic ACTH syndrome?

A

Marked increase in ACTH
hypokalemia- severe cortisol activated mineralocorticoid receptors
No suppression even with HDDST
No evidence of pituitary tumor

170
Q

Which dog breeds have ectopic ACTH syndrome been seen?

A

Dachshunds

GSD with pancreatic and hepatic masses

171
Q

How do you do ectopic ACTH syndrome?

A

Give CRH, if PDH ACTH and cortisol will increase

If ectopic no change

172
Q

What is food dependent glucocorticoid excess?

A

When gastric inhibitory polypeptide (GIP) from duodenum activated ectopic GIP receptors on adrenal glands
High cortisol with bilateral adrenomegaly
Low ACTH

173
Q

What is the tx for food dependent glucocorticoid excess?

A

Octerotide to down regulate somatostatin receptors on GIP cells
Trilostane
Mitotane

174
Q

What are the dynamic thyroid function tests to consider in hyperT4 cats?

A

Used when CS of hyperT4 but TT4 equivocal and fT4 not helpful
1. TSH response test (give TSH and measure TT4 = BUT abnormal thyroid gland can respond too)
2. TRH Response Test (give and measure TT4) = BUT indistinguishable btwn sick euthyroid and hyperT4 with illness)
3. T3 suppression Test (give liothyronine for 7 doses and then check TT4 and TT3) - In hyperT4 additional T4 does NOT change TT4 since already decreased TSH; if euthyroid >50% suppression
Test is more useful to confirm euthyroid (rule out hyperT4)

175
Q

What is the most reliable to confirm hyperT4 in sick cats?

A

Thyroid scintigraphy, may even help prior to increase in TT4

176
Q

Is it known in hyperT4 cats if anti-thyroid drugs affect uptake for thyroid scintigraphy?

A

Unknown, but in healthy cats methimazole can alter uptake

177
Q

Do thyroid nodules continue to grow on methimazole?

A

YES

178
Q

What is the ideal dosing with methimazole?

A

2.5 mg PO q12hrs (87%) compared to 5 mg PO q24hrs (54%) in 2 wks

179
Q

Why are B-blockers used in hyperT4?

A

In humans inhibit peripheral T4 to T3 conversion

180
Q

In I131, what results in damage and tissue destruction?

A

Beta rays!

181
Q

How many cats are euthyroid with one dose of I131?

A

90%!!

182
Q

How many are hypoT4 after I131 tx?

A

About 30% > 3 months post I131, but tx not needed in all

183
Q

What is the relapse rate after I131?

A

Rare,

184
Q

What can be given prior to I131 that has the potential to decrease dose by 30%?

A

rhTSH (25ug/cat)

185
Q

What are the guidelines for adrenal insufficiency or critical illness related corticosteroid insufficiency in dogs?

A
  1. Normal or elevated cortisol but ACTH cortisol
186
Q

What can decreased renin?

A

Aging and neutering

187
Q

Why would you perform a fludrocortisone test for hyperaldosteronism?

A

Rule out false + from Screening tests (aldosterone:renin), idea that it should decreased aldosterone production (based on urine aldosterone: creatinine ratio)

188
Q

What disease result in secondary hyperaldosteronism?

A

When increased renin and increased aldosterone
Renal Disease
Cardiac disease
Liver Failure

189
Q

What is medical management of primary hyperaldosteronism?

A

Spironolactone
K supplementation
Hypertension tx (amlodipine)

190
Q

What are two main differences of feline and canine cushing’s?

A

Cats have no increased in ALP and No LOW USG

191
Q

What are the main effects of steroids that result in insulin resistance?

A
  1. Decreased GLUT4
  2. Decrease insulin secretion from B cells
  3. Increased hepatic gluconeogenesis
192
Q

What is different about UCCR in cats?

A

Higher RR than dogs

193
Q

How is the LDDST different in cats than dogs?

A

Higher dose of steroids given (0.1 mg/kg dex sp)
Really just looking at 8 hr (unknown if 4 hr is helpful to detect PDH)

Can combined LDDST with UCCR after 2-3 days of dex PO

194
Q

IN which type of cushigns are ACTH precursors high in cats?

A

PDH has increased POMC and proACTH

195
Q

How is the HDDST performed in cats?

A

1 mg/kg Dex SP - Like a coin toss, only 50% PDH cats will suppress

196
Q

What % of cats with PDH have normal head CT scans?

A

45% - microadenomas

197
Q

What drug inhibits 11-B hydroxylase and has been used in cats with HAC prior to adrenalectomy?

A

Metyrapone

198
Q

Is mitotane good in cats with cushings?

A

no, cats appear to be resistant

199
Q

Why is ACTH stim not good in cushing cats?

A

low sensitivity - 2/3 cats within RR with Cushings

200
Q

What are the major forms of acromegaly in dogs?

A

Luteal phase/exogenous progestins (GH from mammary tissue)
HypoT4
Primary somatotroph adenoma (rare)

201
Q

What radiation for acromegaly o the GH and IGF-1 return to normal?

A

NO! Even in animals that care clinically improved

contrast to sx

202
Q

What is pasierotide?

A

Somatostatin that resulted in decreased IGF-1 and decreased insulin needs (2 cats DM remission) in acromgealy cats

203
Q

In acromegaly cat why can you have a false - IGF-1?

A

Based on insulin duration, since insulin needed to make IFG-1 in liver - Need to be on insulin for 6-8 weeks

204
Q

What are the IGF-1 and GH ranges that diagnose Acromegaly?

A

IGF-1> 1000 ng/ml
GH > 10 ng/ml
Best when combined

205
Q

How do you diagnose pituitary dwarfism?

A

Since normal animals can have decreased GH need stim test
GHRH or alpha adrenergic (xylazine) - Pre GH and 20-30 post GH
Ghrelin Stim

206
Q

What breed gets congenital nephrogenic DI?

A

Huskies

207
Q

What are major comlications with hyperlipidemia?

A

Increased LEs
Insulin resistance
Pancreatitis
Renal injury

208
Q

What is the profile of idiopathic hyperlidpidemia in Mini Schnazuers?

A

Excessive VLDL +/- hyperchylomicronemia

Mild increased in cholesterol

209
Q

What are the main stays in tx of hyperlipidemia?

A 
Low fat and moderate protein diet
Fish OIl (omega 3)
Niacin (B3)
Gemfibrozil
(statins)

Endocrine (4 decks)

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