Endocrine Flashcards

Question

What are the contraindications for hypophysectomy?

Answer 1

* Risk-averse owners * Large pituitary tumors * Comorbidities that may interfere with anesthesia or recovery ## Footnote Anesthetic risks include hypothermia, hypotension, bradycardia, and airway obstruction.

Answer 2

853 days ## Footnote In one study, 95% of surviving cats had improved diabetic control.

Answer 3

* Uncertainty of clinical improvement * Uncertainty of timing, magnitude, and duration of insulin reduction * Lack of consistent normalization of IGF-1 concentrations ## Footnote Myocardial hypertrophy often persists despite treatment.

Answer 4

They lower serum IGF-1 and reduce mean blood glucose levels ## Footnote However, their effectiveness may be limited due to variable receptor expression.

Answer 5

* Proportionate dwarfism * Disproportionate dwarfism * Retained deciduous teeth * Dull hair coat * Corneal edema * Weakness and lethargy * Hypoglycemia ## Footnote These signs typically manifest by 1–2 months of age.

Answer 6

* IGF-1 Testing * GH Assay * Other biomarkers like P3P and Ghrelin ## Footnote ELISA and radioimmunoassay are validated for IGF-1 testing.

Answer 7

* High insulin doses * Use long-acting formulations like glargine or ProZinc * Monitor with continuous glucose monitoring ## Footnote The initial approach mirrors that for uncomplicated diabetes.

Answer 8

ALIVE Diabetic Clinical Score ## Footnote This score helps assess the overall health status of diabetic cats.

Answer 9

Fluoxetine ## Footnote Fluoxetine may help manage excessive hunger in diabetic cats.

Answer 10

Hypersomatotropism ## Footnote Recognizing this condition can be critical for appropriate treatment.

Answer 11

Single-chain polypeptide composed of 190 amino acids.

Answer 12

Canine and porcine.

Answer 13

Pituitary gland.

Answer 14

Mammary gland.

Answer 15

* GHRH (stimulatory) * Somatostatin (inhibitory)

Answer 16

Secreted by the stomach.

Answer 17

Increases GH secretion, food intake, gastric/intestinal motility.

Answer 18

Mediated anabolic effects such as protein synthesis and body size regulation.

Answer 19

Pituitary GH secretion.

Answer 20

* Luteal phase of estrous cycle * Exogenous progestins * Mammary GH-secreting tumors

Answer 21

* Soft tissue swelling * Snoring, dyspnea * Stiffness, neck rigidity * Polyuria, polydipsia, polyphagia * Thick skin folds * Abdominal enlargement

Answer 22

German Shepherd Dogs.

Answer 23

Failure to increase GH after GHRH supports acromegaly diagnosis.

Answer 24

Discontinue PG treatment and consider ovariectomy.

Answer 25

Juvenile hyposomatotropism.

Answer 26

Autosomal recessive.

Answer 27

German Shepherd Dogs.

Answer 28

LHX3 mutation.

Answer 29

* Proportional growth retardation * Retention of lanugo hairs * Truncal alopecia * Hyperpigmented skin

Answer 30

Low plasma IGF-1.

Answer 31

* Porcine GH * Progestins * Levothyroxine

Answer 32

Can occur after hypophysectomy or due to traumatic brain injury.

Answer 33

* Pomeranian * Miniature Poodle * Chow Chow * Keeshond

Answer 34

Localized to trunk, caudal thighs, perineum, neck.

Answer 35

Normal GH response in 1/3 of affected dogs.

Answer 36

Varies; some respond to GH therapy, others to castration.

Answer 37

No significant GH increase in either group ## Footnote This includes both affected Pomeranians and unaffected controls.

Answer 38

Poor to moderate success ## Footnote This reflects the variability in treatment effectiveness across different cases.

Answer 39

Inconsistent improvement ## Footnote This indicates that while some dogs may benefit, results are not reliable across the board.

Answer 40

Hypophysectomy or trauma ## Footnote This highlights potential causes of acquired growth hormone deficiency.

Answer 41

Speculatively linked to GH deficiency ## Footnote This suggests a possible connection, though further research is needed to confirm it.

Answer 42

* Normal IGF-1 * Inconsistent GH stimulation results * Unreliable treatment responses ## Footnote These factors collectively indicate that the condition might not be solely due to GH deficiency.

Answer 43

Multifactorial, genetically influenced, and/or hormonally complex ## Footnote This suggests that AGHD may involve multiple interacting factors rather than a single deficiency.

Answer 44

Antidiuretic hormone (ADH) ## Footnote AVP is critical for water balance regulation.

Answer 45

Magnocellular neurons of the paraventricular and supraoptic nuclei in the hypothalamus

Answer 46

* AVP * Neurophysin-2 * Copeptin

Answer 47

Along the hypothalamic-neurohypophyseal tract

Answer 48

* Osmoreceptors detecting a 1–2% increase in plasma osmolality * Decrease in blood volume or pressure by 10–15% * Stress, nausea, pain, hypoglycemia * Exercise, dry food ingestion * Certain drugs

Answer 49

~5.9 minutes

Answer 50

Increases water reabsorption by binding to basolateral V2 receptors

Answer 51

Triggers insertion of aquaporin-2 (AQP2) channels into the apical membrane

Answer 52

USG increases as urine volume decreases proportionally to water reabsorbed

Answer 53

* Cause vascular smooth muscle contraction * Stimulate platelet activation * Promote hepatic glycogenolysis and gluconeogenesis

Answer 54

Thirst and AVP secretion are triggered by osmoreceptor activation

Answer 55

Natriuretic peptides

Answer 56

Complete or partial AVP deficiency

Answer 57

* Pituitary neoplasia

Answer 58

* Phase 1: Axonal shock → central DI * Phase 2: Excessive AVP release → transient antidiuresis * Phase 3: Permanent or transient DI after AVP store depletion

Answer 59

* 53% develop CDI lasting >2 weeks * 22% develop permanent CDI

Answer 60

* Hyperadrenocorticism * Pyometra * Liver disease

Answer 61

Mutations in AVPR2 (V2 receptor) or AQP2 (aquaporin-2)

Answer 62

* Severe polydipsia * Polyuria * Water intake up to 5–20× normal

Answer 63

<90–100 mL/kg/day

Answer 64

* Seizures * Obtundation * Behavior change * Tremors

Answer 65

To distinguish between Central Diabetes Insipidus, Nephrogenic Diabetes Insipidus, and Primary Polydipsia

Answer 66

Marked reduction in water intake and increase in USG

Answer 67

Central DI

Answer 68

Hypernatremia and dehydration signs

Answer 69

DDAVP trial therapy

Answer 70

* Pulsatile, variable secretion * Technical sample handling requirements * Limited availability of validated assays

Answer 71

Low AVP response

Answer 72

AVP response to 20% NaCl infusion

Answer 73

Low AVP response

Answer 74

Normal/high AVP, no USG increase

Answer 75

Normal AVP, appropriate USG response

Answer 76

AVP activity in healthy dogs

Answer 77

No, it is a research tool only

Answer 78

A stable AVP surrogate used in humans

Answer 79

MRI and CT

Answer 80

Consistent with central DI

Answer 81

Desmopressin (DDAVP) Therapy

Answer 82

Synthetic analog of AVP; selective V2 receptor agonist

Answer 83

Minimal effect; no associated hypertension

Answer 84

Nearly all respond

Answer 85

Improper administration, use of oral tablets with low bioavailability

Answer 86

Low-sodium, low-protein diet

Answer 87

Reduces sodium reabsorption in distal tubules, leading to mild volume depletion

Answer 88

Often long-term manageable with DDAVP

Answer 89

Poorer prognosis due to progressive neurologic decline

Answer 90

~50% show reduced urine output

Answer 91

Variable response to treatment; long-term management can be difficult

Answer 92

* Intracellular signaling * Nerve conduction * Neuromuscular transmission * Muscle contraction * Blood coagulation * Hormone secretion * Hepatic glycogen metabolism ## Footnote Disruptions in calcium homeostasis can adversely affect multiple organ systems.

Answer 93

The Calcium-Sensing Receptor (CaSR) ## Footnote CaSR detects extracellular calcium concentrations and adjusts PTH secretion accordingly.

Answer 94

~50% ## Footnote Ionized calcium is biologically active.

Answer 95

* 50% = Ionized (iCa) * 40% = Protein-bound (mostly to albumin) * <10% = Complexed with anions (e.g., bicarbonate, citrate) ## Footnote Understanding calcium fractions is important for accurate diagnosis.

Answer 96

* Parathyroid Hormone (PTH) * Parathyroid Hormone-Related Protein (PTHrP) * Vitamin D (Calcitriol/1,25-dihydroxycholecalciferol) * Calcitonin ## Footnote CaSR suppresses PTH during hypercalcemia and stimulates it during hypocalcemia.

Answer 97

An 84-amino acid polypeptide ## Footnote PTH is synthesized and secreted by chief cells in the parathyroid glands.

Answer 98

Decreases serum phosphate levels ## Footnote PTH increases serum calcium levels while decreasing phosphate.

Answer 99

Inverse sigmoidal relationship ## Footnote PTH secretion is modulated by serum calcium levels.

Answer 100

A protein that mimics PTH, increasing calcium and decreasing phosphate, elevated in humoral hypercalcemia of malignancy (HHM) ## Footnote PTHrP is crucial for fetal calcium regulation but is virtually undetectable postnatally in healthy animals.

Answer 101

PTH via 1-alpha hydroxylase ## Footnote Calcitriol promotes intestinal calcium absorption and inhibits PTH synthesis.

Answer 102

Helps reduce postprandial hypercalcemia by inhibiting bone resorption and enhancing renal calcium excretion ## Footnote Calcitonin functions to oppose PTH but has a minor physiologic role.

Answer 103

Solitary adenoma ## Footnote Other causes include carcinoma and adenomatous hyperplasia.

Answer 104

Affected gland(s) secrete PTH independently of serum calcium, causing persistent elevation of PTH and hypercalcemia ## Footnote In secondary hyperparathyroidism, all four glands typically become hyperplastic.

Answer 105

Evaluates CASR, MEN1, and HRPT2 mutations ## Footnote Genetic syndromes may involve sporadic or familial cases of hyperparathyroidism.

Answer 106

MEN1 mutations ## Footnote Sporadic cases may involve somatic MEN1 mutations in ~35% of patients.

Answer 107

Familial hypocalciuric hypercalcemia (FHH) ## Footnote FHH is characterized by very low urinary calcium clearance.

Answer 108

< 0.01 in 80% of cases

Answer 109

* CASR * MEN1 * HRPT2

Answer 110

* CASR mutations (majority) * AP2S1 mutations * GNA11 mutations

Answer 111

* Polyuria and polydipsia (PU/PD) * Urinary incontinence * Stranguria * Hematuria * Urinary tract infections * Urolithiasis

Answer 112

* Inappetence * Vomiting * Constipation

Answer 113

Stones, Bones, Abdominal Groans, Thrones, and Psychiatric Moans

Answer 114

14.5 mg/dL

Answer 115

Cervical Ultrasound

Answer 116

Pamidronate: 1.3–2 mg/kg in 150 mL saline over 2 hrs

Answer 117

GI upset and hypocalcemia if overdosed

Answer 118

Hypercalcemia can contribute to CKD, though some dogs may not develop it.

Answer 119

* Excess filtered calcium exceeds renal reabsorption → hypercalciuria * Increased phosphate excretion contributes to urinary supersaturation * Elevated intestinal calcium absorption increases oxalate absorption

Answer 120

Theoretically indicates risk, but poor predictive value in practice

Answer 121

<1% ## Footnote Poor oral bioavailability indicates that less than 1% of the drug is available in the bloodstream after oral administration.

Answer 122

1.3–2 mg/kg in 150 mL saline over 2 hrs ## Footnote This dosing regimen ensures adequate delivery of the drug.

Answer 123

Up to 3 weeks ## Footnote The duration of effect is significant for treatment planning.

Answer 124

100–850× more potent ## Footnote This indicates a significantly stronger effect, warranting careful dosing.

Answer 125

* Expensive * Can cause vomiting and anorexia * Resistance may develop ## Footnote Understanding these limitations is essential for effective treatment planning.

Answer 126

25 µg/kg IV in 5% dextrose over 2–4 hours ## Footnote This dosing is infrequent due to its rarity of use.

Answer 127

Calcium-sensing receptor (CaSR) ## Footnote This interaction helps control calcium, phosphate, and PTH levels.

Answer 128

Surgical Parathyroidectomy ## Footnote This is indicated especially when parathyroid nodules exceed 10 mm.

Answer 129

PTH levels pre-, intra-, and post-op (although not realistic given send out test) ## Footnote This technique aims to confirm successful excision.

Answer 130

* Early reports: 72% success * Later series (30 dogs): >90% success ## Footnote This method requires general anesthesia and careful operator technique.

Answer 131

Capsular invasion ## Footnote Identifying these features is crucial for accurate diagnosis.

Answer 132

Begin calcium + vitamin D supplementation 12–24 hours pre-op if calcium is significantly elevated ## Footnote This may help prevent post-operative hypocalcemia.

Answer 133

Calcium gluconate ## Footnote It is the least caustic and preferred for intravenous use.

Answer 134

Excellent in all breeds for short-to-mid-term prognosis ## Footnote Long-term prognosis is generally good, except in Keeshonds.

Answer 135

50% recurrence ## Footnote This highlights the genetic predisposition of the breed.

Answer 136

Most common cause of feline hypercalcemia, recognized since the 1990s ## Footnote Diagnosis is often one of exclusion.

Answer 137

* High-fiber diets * Renal diets * Calcium oxalate stone-prevention diets ## Footnote These dietary adjustments can help manage calcium levels.

Answer 138

Surgical excision ## Footnote Prognosis post-op is generally good.

Answer 139

Decreased bone resorption and intestinal absorption

Answer 140

Reduced renal phosphate excretion

Answer 141

Deficiency causes neuronal hyperexcitability

Answer 142

Seizures, muscle tremors, stiff gait, jaw clamping, restlessness, anxiety, aggression

Answer 143

6 weeks to 13 years

Answer 144

* Miniature Schnauzers * Poodles * German Shepherds * Terriers * St. Bernards (in Australia/New Zealand)

Answer 145

Lethargy, poor appetite, similar neuromuscular signs to dogs

Answer 146

Hypocalcemia and hyperphosphatemia

Answer 147

Prolonged ST segment and QT interval

Answer 148

Calcitriol (active vitamin D3)

Answer 149

Initial: 20–40 ng/kg/day for 2–4 days; Maintenance: 10–20 ng/kg/day

Answer 150

Maintain serum total calcium in the range of 8.0–9.5 mg/dL

Answer 151

Calcinosis cutis

Answer 152

Not always decreased despite its role in PTH secretion

Answer 153

Every 2 to 3 days

Answer 154

Idiopathic destruction

Answer 155

General estimates range from 0.2% to 0.8%.

Answer 156

Swedish Giant Schnauzers and Hovawarts: up to 15%.

Answer 157

The thyroid gland consists of two lobes, located on either side of the trachea, composed of microscopic follicles lined by thyroid epithelial cells.

Answer 158

A large glycoprotein that contains the precursors for thyroid hormones.

Answer 159

TPO catalyzes several steps in hormone synthesis.

Answer 160

* T4: 10–16 hours * T3: 5–6 hours

Answer 161

T3 is approximately 3 to 5 times more potent than T4.

Answer 162

The hypothalamus releases thyrotropin-releasing hormone (TRH), stimulating the anterior pituitary to release thyroid-stimulating hormone (TSH).

Answer 163

* Primary hypothyroidism: disease of the thyroid gland * Secondary hypothyroidism: disease of the pituitary gland * Tertiary hypothyroidism: disease of the hypothalamus

Answer 164

* Thyroid hypoplasia/aplasia * Thyroid dysgenesis * Dyshormonogenesis (defective hormone synthesis)

Answer 165

* Pituitary neoplasia * Surgical hypophysectomy * Intracranial trauma or hemorrhage * Adenohypophysitis

Answer 166

* Lymphocytic thyroiditis * Thyroid atrophy

Answer 167

A destructive autoimmune process characterized by multifocal or diffuse infiltration of the thyroid by lymphocytes, macrophages, and plasma cells.

Answer 168

Approximately 7 years.

Answer 169

* Lethargy * Weight gain * Exercise intolerance * Mental dullness * Cold intolerance * Generalized weakness

Answer 170

* Hair thinning * Dry, coarse hair coat * Alopecia * Dry, scaly skin * Seborrhea

Answer 171

* Neuropathies * Central vestibular disease * Myxedema coma

Answer 172

Thyroid hormones are critical for hair growth maintenance and immune response.

Answer 173

Hypothyroidism can lead to bradycardia and possible association with atherosclerosis.

Answer 174

Approximately 50% of hypothyroid dogs have circulating TGAAs, correlating with lymphocytic thyroiditis.

Answer 175

Hypothyroidism ## Footnote Demodicosis refers to a skin condition caused by the Demodex mite, often seen in dogs.

Answer 176

* Neuropathies * Central vestibular disease * Myxedema coma * Subclinical myopathies

Answer 177

* Puffy appearance to skin * Skin is pale, cool to touch, non-pitting * Thickened lips * Thickened forehead skin * Drooping eyelids

Answer 178

* Predominance of hair follicles in telogen phase * Kenogen follicles * Hyperpigmentation * Atrophic or dystrophic follicles * Thickened dermis * Vacuolated arrector pili muscles

Answer 179

True ## Footnote The clinical importance of this impairment is controversial.

Answer 180

* Reduced heart rate * Low voltage R and P waves * Sinus bradycardia * First- or second-degree AV block

Answer 181

Atherosclerosis is rare in dogs, but when present, hypothyroidism is often implicated.

Answer 182

* Neuropathies * Central vestibular dysfunction * Rarely, seizures

Answer 183

A rare, life-threatening condition characterized by profound mental dullness, severe weakness, hypothermia, hypoventilation, bradycardia, and hypotension.

Answer 184

Aggressive behavior ## Footnote There is little evidence to support this belief.

Answer 185

* Gait abnormalities * Weakness * Exercise intolerance

Answer 186

* Corneal lipid deposits * Reduced tear production

Answer 187

* Decreased fertility * Parturition problems

Answer 188

gallbladder mucocele

Answer 189

Decreased glomerular filtration rate (GFR) ## Footnote The significance of this finding is unknown.

Answer 190

* Disproportionately wide skull * Macroglossia * Delayed dental eruption * Square trunk and short limbs

Answer 191

A rare autosomal recessive disorder characterized by chronic mucocutaneous candidiasis, hypoparathyroidism, and adrenal insufficiency.

Answer 192

* Mild, normocytic, normochromic anemia * Increased red cell distribution width (RDW) * Increased white blood cell count is extremely unusual

Answer 193

Higher, but with significant overlap.

Answer 194

* Increases in platelet count * Small platelet size * Decrease in vWF concentrations with thyroid treatment.

Answer 195

Approximately 75%.

Answer 196

Lipid degradation is severely impaired, leading to lipid accumulation.

Answer 197

* Low-density lipoproteins (LDL) * Very low-density lipoproteins (VLDL) * High-density lipoproteins (HDL)

Answer 198

Reduced protein turnover.

Answer 199

* Alkaline phosphatase (ALP) * Gamma-glutamyltransferase (GGT)

Answer 200

Mildly increased in approximately 30–50% of hypothyroid dogs.

Answer 201

Approximately 75% higher.

Answer 202

They may be affected by hemolysis, lipemia, and hyperbilirubinemia.

Answer 203

Equilibrium dialysis (ED) followed by highly sensitive RIA.

Answer 204

Non-thyroidal illness (NTI) can lead to non-thyroidal illness syndrome (NTIS).

Answer 205

Presence of T3 and T4 autoantibodies.

Answer 206

Both decline with age.

Answer 207

Greyhounds.

Answer 208

Short-term exercise has limited effect.

Answer 209

Total T3 values are within or above the reference range in up to 90% of hypothyroid dogs.

Answer 210

Excellent; it is the most frequently recommended screening test.

Answer 211

Low total T3 values are common in many breeds, in non-thyroidal illness, and with various drugs.

Answer 212

T4 autoantibodies

Answer 213

Poor diagnostic specificity

Answer 214

Assays that employ a separation step (e.g., equilibrium dialysis)

Answer 215

A significant portion of hypothyroid dogs have normal TSH.

Answer 216

Lymphocytic thyroiditis

Answer 217

No direct information

Answer 218

50–70 µg per dog, or 100 µg for dogs >20 kg

Answer 219

High diagnostic sensitivity (~100%)

Answer 220

Excludes hypothyroidism

Answer 221

Decreased echogenicity

Answer 222

0.03–0.26%

Answer 223

* Increased risk of thyrotoxicosis * Requires multiple daily administrations * May result in T4 deficiency in critical organs.

Answer 224

Inappropriate T4:T3 ratio leading to excessive T3.

Answer 225

About four times the normal daily secretion.

Answer 226

* Intraluminal contents * Dietary components * GI bacterial binding.

Answer 227

Bioavailability is almost halved when T4 is given with food.

Answer 228

Q24h is widely accepted.

Answer 229

Approximately 10%.

Answer 230

Within 1 month.

Answer 231

9–15 hours.

Answer 232

Values <2.7 µg/dL.

Answer 233

* Poor compliance * Inadequate supplementation.

Answer 234

* Polyuria and polydipsia * Polyphagia * Panting * Weight loss * Hyperactivity * Tachycardia * Hyperthermia.

Answer 235

IV T4 administration at 5 µg/kg every 12 hours.

Answer 236

~30 hours.

Answer 237

Idiosyncratic skin reactions to inactive ingredients.

Answer 238

Can decrease total T4 concentrations.

Answer 239

A rare clinical entity with a small number of reported cases involving congenital or adult-onset hypothyroidism.

Answer 240

Non-thyroidal illness syndrome.

Answer 241

* Lymphocytic thyroiditis * Diffuse follicular hyperplasia * Idiopathic causes

Answer 242

A condition documented in two cats and suspected in an additional five based on scintigraphic findings.

Answer 243

Dyshormonogenesis.

Answer 244

* Thyroid dyshormonogenesis * Thyroid hypoplasia or aplasia * TSH resistance * Thyroiditis * Iodine deficiency

Answer 245

Dyshormonogenesis.

Answer 246

A condition where a colony of cats developed thyroiditis at 40–60 days of age, with early hormone supplementation reducing severity.

Answer 247

Iatrogenic hypothyroidism following treatment for hyperthyroidism.

Answer 248

* Radioactive iodine (I-131) therapy * Bilateral thyroidectomy * Administration of antithyroid drugs (e.g., methimazole) * Stereotactic radiation therapy

Answer 249

* Clinical signs * Low total T4 * Elevated serum TSH concentrations

Answer 250

* Lethargy * Inappetence * Mental dullness * Dermatologic abnormalities * Obesity * Polyuria and polydipsia

Answer 251

* Disproportionate dwarfism * Large head * Short, wide neck * Short, thick limbs * Facial dysmorphism * Palpable bilateral goiter

Answer 252

* Normocytic, normochromic anemia * Hypercholesterolemia * Elevated creatine kinase (CK) * Azotemia

Answer 253

It is highly specific for diagnosing hypothyroidism when associated with low total T4.

Answer 254

Measurement of serum T3 is not recommended due to its variability.

Answer 255

* Decreased activity * Weight gain

Answer 256

Increased risk of azotemia.

Answer 257

~20% developed decreased free and/or total T4 and increased TSH.

Answer 258

25 µg IV ## Footnote This is lower than the dose used in dogs.

Answer 259

2–3 fold increase after 6–8 hours ## Footnote This indicates the normal response of the thyroid gland to TSH stimulation.

Answer 260

111–300% ## Footnote This shows a significant response in healthy cats.

Answer 261

146–414% ## Footnote This indicates a heightened response in these cats despite their illness.

Answer 262

<11% ## Footnote This minimal response suggests a diagnosis of hypothyroidism.

Answer 263

Technetium-99m (99mTc) ## Footnote This isotope helps visualize thyroid function and morphology.

Answer 264

1:1 ratio ## Footnote This indicates normal thyroid function.

Answer 265

Thyroid lobes are bilaterally enlarged with homogeneous uptake ## Footnote This is indicative of congenital hypothyroidism.

Answer 266

No thyroid tissue can be identified ## Footnote This suggests severe thyroid atrophy.

Answer 267

10–20 µg/kg PO every 12–24 hours ## Footnote This dosage is critical for effective treatment.

Answer 268

4–6 weeks ## Footnote This allows sufficient time for the medication to take effect.

Answer 269

* Resolve clinical signs * Maintain serum total T4 and TSH within reference ranges * Avoid overt hyperthyroidism ## Footnote These goals guide effective management of the condition.

Answer 270

16 µg/kg PO Q12H ## Footnote This reflects the dosing needed for effective management.

Answer 271

32.7 µg/kg/day ## Footnote This indicates the differences in treatment needs based on age and condition.

Answer 272

Excellent prognosis; normal life expectancy ## Footnote This emphasizes the effectiveness of treatment.

Answer 273

Severity of skeletal changes and neurologic status at treatment initiation ## Footnote These factors can affect long-term outcomes.

Answer 274

456 days ## Footnote This statistic highlights the serious implications of untreated hypothyroidism.

Answer 275

905 days ## Footnote This shows a better prognosis for euthyroid cats.

Answer 276

85% ## Footnote This indicates a common finding in these cases.

Answer 277

14% ## Footnote This highlights the distinction between hypothyroid and euthyroid states.

Answer 278

* Weight loss * Polyphagia * Vomiting * Hyperactivity * Polyuria and polydipsia (PU/PD) * Panting * Poor grooming habits * Behavioral changes

Answer 279

9 years of age or older, with a mean age around 13 years

Answer 280

* Muscle wasting: 77% * Weight loss: Key early detection sign * Dehydrated appearance: Due to decreased skin elasticity * Thin body condition: 35% * Dental disease: 45% * Tachycardia: 31% * Heart murmur: 29%

Answer 281

It has direct positive inotropic and chronotropic effects and indirect effects through peripheral vasodilation

Answer 282

Approximately 10–30%

Answer 283

* Increased alanine aminotransferase (ALT) activities: >80% * Increased alkaline phosphatase (ALP) activities: >50%

Answer 284

Randomly obtained serum total T4 concentration

Answer 285

Abnormal in ~98% of hyperthyroid cats

Answer 286

* Anti-thyroid medications (oral or transdermal) * Iodine-restricted diet * Thyroidectomy * Radioactive iodine therapy (¹³¹I)

Answer 287

Diagnosed in about 1–2% of cases

Answer 288

Tumor growth through routine cervical palpation

Answer 289

* Dietary influences such as iodine or selenium deficiency * Chronic exposure to thyroid-disrupting compounds

Answer 290

Almost all hyperthyroid cats have undetectable TSH concentrations

Answer 291

Apathetic hyperthyroidism (likely clinical signs are from concurrent illnesses)

Answer 292

Offers excellent sensitivity and specificity for diagnosis

Answer 293

Aggressive thyroid tumors that may require specialized treatment strategies

Answer 294

Thin body condition observed in 35%

Answer 295

Mild-to-moderate liver enzyme elevations are typically secondary to hyperthyroidism

Answer 296

Warrants repeat scintigraphy to assess for carcinoma

Answer 297

They block hormone synthesis, allowing the thyroid tumor to continue growing. ## Footnote Anti-thyroid drugs do not treat the tumor itself.

Answer 298

A marked increase in thyroid nodule size.

Answer 299

Increased severity of clinical signs, formation of large thyroid masses, multifocal thyroid disease, development of intrathoracic thyroid masses, increased risk of thyroid carcinoma.

Answer 300

* Normalize thyroid hormone concentrations without causing iatrogenic hypothyroidism * Improve clinical signs and quality of life * Monitor and address concurrent disease.

Answer 301

* Methimazole * Carbimazole.

Answer 302

They block thyroid hormone synthesis by inhibiting thyroid peroxidase.

Answer 303

Quality and stability are highly variable, choose a pharmacy with a history of producing high-quality formulations.

Answer 304

Daily medication required, mild and severe adverse effects possible, risk of iatrogenic hypothyroidism.

Answer 305

Continue therapy for a few days, reduce dose temporarily, or discontinue until signs resolve.

Answer 306

* Toxic hepatopathy * Neutropenia * Agranulocytosis * Thrombocytopenia.

Answer 307

Amlodipine.

Answer 308

Gastrointestinal upset and erythema of pinna (transdermal)

Answer 309

Switching to the other is not helpful. Discontinuation of the medication and consider another treatment option

Answer 310

They have lower bioavailability and a delayed onset compared to oral forms.

Answer 311

Decrease antithyroid drug dosage by 25–50%.

Answer 312

5% to >20%.

Answer 313

Hypertension resolves with hyperthyroidism treatment. Some cats will become hyperthyroid after hyperthyroid treatment

Answer 314

* Initially less expensive * Easy for owners to administer * No anesthesia, surgery, or hospitalization required.

Answer 315

* Low palatability in approximately 25% of cats * Requires strict dietary adherence * Suboptimal control of hyperthyroidism is common.

Answer 316

Alternative treatment should be recommended.

Answer 317

Radioactive iodine (¹³¹I) therapy.

Answer 318

3–14 days.

Answer 319

Pre-treatment with antithyroid drugs (during waiting period). Removal about 1 week before treatment though

Answer 320

Effective cure and avoidance of iatrogenic hypothyroidism.

Answer 321

Radiation thyroiditis.

Answer 322

Hypocalcemia due to iatrogenic hypoparathyroidism.

Answer 323

Increased cardiac output, intrarenal vasodilation, decreased muscle mass, increased GFR.

Answer 324

Pre-existing renal azotemia was associated with shorter survival.

Answer 325

1–4% ## Footnote Thyroid cancer is the most common neuroendocrine tumor in dogs.

Answer 326

10–30% benign adenomas ## Footnote The majority of thyroid tumors in dogs are malignant.

Answer 327

Carcinomas (about 70% of cases) ## Footnote These tumors stain positively for thyroglobulin.

Answer 328

Calcitonin ## Footnote These cells account for about 30% of canine thyroid tumors.

Answer 329

Usually carcinoma. Functional adenomas are rarely reported ## Footnote Iatrogenic causes are more common.

Answer 330

Excessive L-thyroxine supplementation or consumption of raw foods containing thyroid tissue ## Footnote Thyrotoxicosis can occur from raw or dried beef-based diets.

Answer 331

Excess TSH stimulates thyroid cell mitogenesis and hormone synthesis ## Footnote It may also lead to neoplastic transformation.

Answer 332

Point mutations in RAS genes and abnormalities in the PI3K-AKT pathway ## Footnote These pathways involve cell surface receptors like tyrosine kinases.

Answer 333

9–11 years ## Footnote Some studies suggest 10–15 years.

Answer 334

Dysphagia, dysphonia, coughing, upper airway dyspnea, edema ## Footnote Clinical signs often result from space-occupying effects.

Answer 335

Ultrasound ## Footnote It can evaluate vascularity and invasion into surrounding structures.

Answer 336

Histologic examination ## Footnote Excisional biopsy may be both diagnostic and curative.

Answer 337

Primary tumor size, regional lymph node involvement, presence of distant metastasis ## Footnote Staging helps determine treatment options and prognosis.

Answer 338

Approximately 3 years ## Footnote Surgical excision is recommended for solitary, well-encapsulated tumors.

Answer 339

Extensive hemorrhage ## Footnote Thyroid carcinomas are highly vascular.

Answer 340

Methimazole ## Footnote Dosage is typically 2.5–5 mg PO q12–24h.

Answer 341

To manage thyrotoxic hypertension ## Footnote Monitoring blood pressure is essential.

Answer 342

Parathyroid glands ## Footnote This helps in preventing hypocalcemia.

Answer 343

Enlarged lymph nodes ## Footnote Other differentials include salivary gland enlargement and abscess.

Answer 344

Medullary thyroid carcinoma ## Footnote Specific breed predispositions include Labrador Retrievers and Golden Retrievers.

Answer 345

0.1–0.5 mg/kg PO q24h ## Footnote Telmisartan is an angiotensin receptor blocker.

Answer 346

0.5–1 mg/kg PO q24h ## Footnote Alendronate can cause esophageal irritation and needs serum calcium monitoring.

Answer 347

Vitamin D analog ## Footnote Used to treat postsurgical hypocalcemia.

Answer 348

* Non-movable, invasive tumors unsuitable for surgery * Local control or tumor shrinkage to enable later surgery

Answer 349

24.5 months ## Footnote 4 of 8 dogs died from metastatic disease.

Answer 350

* Esophagitis * Tracheitis * Laryngitis * Skin erythema or alopecia

Answer 351

12 to 34 months ## Footnote Best outcomes were seen when used adjunctively after surgery.

Answer 352

Bone marrow suppression ## Footnote This is a serious and irreversible complication.

Answer 353

Cisplatin ## Footnote Median survival time was approximately 11 months.

Answer 354

* Polyuria and polydipsia (PU/PD) * Hyperactivity * Weight loss despite polyphagia * Systemic hypertension * Tachycardia

Answer 355

Antithyroid drug to control thyrotoxicosis ## Footnote Typical dose is 2.5–5 mg PO q12–24h.

Answer 356

0.25–1 mg/kg PO q12h ## Footnote Administered the night before and morning of anesthesia.

Answer 357

* ACE inhibitors (e.g., enalapril, benazepril) * Amlodipine (calcium channel blocker)

Answer 358

A neoplasm of the pancreatic beta cells that synthesizes and secretes excessive quantities of insulin, often causing clinical signs of hypoglycemia. ## Footnote It is uncommon in dogs and rare in cats.

Answer 359

Approximately 70%

Answer 360

Approximately 80%

Answer 361

Most often located in either the right or left limb of the pancreas.

Answer 362

Ranges from 45% to 64%

Answer 363

T1N0M0 — primary tumor without regional lymph node or distant metastasis

Answer 364

T1N1M0 — primary tumor with regional lymph node metastasis

Answer 365

T1N1M1 or T1N0M1 — presence of distant metastasis

Answer 366

* Glucagon * Catecholamines (epinephrine and norepinephrine) * Growth hormone * Glucocorticoids

Answer 367

* Mental dullness * Disorientation * Weakness * Ataxia * Visual disturbances or apparent blindness * Collapse * Seizures

Answer 368

Concurrent normal or elevated serum insulin concentrations despite hypoglycemia.

Answer 369

High-quality, dual-phase, thin-section multi-detector CT

Answer 370

Low fructosamine can support a diagnosis of insulinoma.

Answer 371

* Fasting * Exercise * Excitement

Answer 372

Some dogs may be overweight due to insulin's anabolic effects.

Answer 373

* Presence of compatible clinical signs * Persistent fasting hypoglycemia * Concurrent normal or elevated serum insulin concentrations

Answer 374

Serum to assess insulin concentration

Answer 375

Glycosylated hemoglobin (HbA1c)

Answer 376

76%. A second test increases it to 91%

Answer 377

High-quality dual-phase, thin-section multi-detector CT

Answer 378

Surgical resection of the primary tumor and any metastases

Answer 379

Diabetes mellitus

Answer 380

Cytotoxic treatment aimed at destroying insulin-secreting beta cells

Answer 381

Response to treatment for hypoglycemia

Answer 382

12 to 14 months

Answer 383

* Young dogs * Persistent postoperative hypoglycemia

Answer 384

* Siamese * Domestic Shorthairs * Domestic Longhairs * Maine Coon

Answer 385

Increases blood glucose via gluconeogenesis and decreases tissue glucose uptake

Answer 386

* Mild injection site pain * Nausea * Vomiting * Abdominal pain * Constipation * Steatorrhea

Answer 387

Stimulates glycogenolysis and gluconeogenesis, raising blood glucose

Answer 388

* Anorexia * Weight loss * Episodic weakness or falling * Mental dullness * Lethargy * Hypothermia * Bradycardia * Limb and facial twitching * Seizures ## Footnote Clinical signs vary with the severity of hypoglycemia and co-morbidities

Answer 389

* One mass identified on abdominal ultrasound * Two masses discovered during exploratory laparotomy ## Footnote These findings indicate the importance of imaging in diagnosis

Answer 390

* 6 tumors in the left pancreatic lobe * 3 tumors in the right lobe * 1 tumor at the angle of the pancreas ## Footnote Tumor size ranged from 0.4 to 3 cm

Answer 391

Prompt surgical extirpation ## Footnote This is critical for managing the condition effectively

Answer 392

Transient diabetes mellitus due to suppression of insulin secretion from residual atrophied pancreatic beta cells ## Footnote Postoperative monitoring is essential for early detection of complications

Answer 393

* Small, frequent meals * Oral prednisone therapy at 0.5 mg/kg PO every 12 hours ## Footnote Glucocorticoids enhance hepatic gluconeogenesis and glycogenolysis while reducing peripheral glucose uptake

Answer 394

* Disease stage at diagnosis * Malignant behavior of the mass * Completeness of surgical resection * Timing of diagnosis ## Footnote The prognosis may also be related to overexpression of glucokinase 1 in neoplastic beta cells

Answer 395

Survival times ranged from 1 day to 18 months ## Footnote More recent cases report survival up to 32 months post-surgery

Answer 396

* Severe hyperglycemia * Hyperosmolality * Dehydration without significant ketosis

Answer 397

* Decreased net effective action of circulating insulin * Increased circulating counter-regulatory stress hormones

Answer 398

* Acidemia * Osmotic diuresis * Loss of electrolytes * Volume depletion

Answer 399

Insulin deficiency, along with excess counter-regulatory hormones, worsens insulin resistance, hyperglycemia, and ketonemia

Answer 400

Rapid metabolic changes due to insulin deficiency and ketone body formation

Answer 401

* Increased gluconeogenesis * Altered glycogen metabolism * Decreased peripheral glucose uptake

Answer 402

DKA can have absolute or relative insulin deficiency, while HHS typically has relative insulin deficiency (enough to prevent lipolysis)

Answer 403

* Infection * Pancreatitis

Answer 404

* Acute pancreatitis * Bacterial pneumonia

Answer 405

Typically >600 mg/dL

Answer 406

It forms the basis of DKA diagnosis, as urine reagent strips detect ketones

Answer 407

* Replace fluid and electrolyte deficits * Administer insulin * Correct acidosis * Identify and treat concurrent diseases

Answer 408

They are unsuitable for correcting sodium and water deficits and can cause cerebral edema

Answer 409

Cerebral edema ## Footnote Increased extracellular osmolality can lead to significant neurological complications.

Answer 410

* Overhydration * Pulmonary edema * Third-space losses ## Footnote Close monitoring is essential to avoid these complications.

Answer 411

* Prolonged hypoperfusion * Tissue hypoxia * Prerenal azotemia ## Footnote Insufficient fluid therapy can lead to severe complications.

Answer 412

Fluid deficit (mL) = Percent dehydration (as decimal) × Body weight (kg) × 1000 ## Footnote Example: 10% dehydration = 0.10.

Answer 413

Administer fluid boluses of 5–10 mL/kg over 20 minutes ## Footnote Reassess heart rate and blood pressure after each bolus.

Answer 414

All pets with DKA should be assumed to be potassium depleted ## Footnote Acidosis can mask total body potassium deficits.

Answer 415

Every hour during the first 24 hours ## Footnote Close monitoring is essential to manage BG levels effectively.

Answer 416

Do not decrease the insulin dose when adding dextrose ## Footnote This is crucial to prevent hypoglycemia and large osmotic shifts.

Answer 417

12–24 hours ## Footnote Insulin promotes ketone utilization, helping to correct acidosis.

Answer 418

When plasma bicarbonate concentration <11 mEq/L after several hours of therapy ## Footnote Bicarbonate therapy carries risks and should be used cautiously.

Answer 419

Bicarbonate deficit (mEq) = Body weight (kg) × 0.4 × (12 − Patient’s bicarbonate) ## Footnote Only enough bicarbonate to bring levels up to 12 mEq/L should be given.

Answer 420

* Inhibits lipolysis * Suppresses hepatic gluconeogenesis * Promotes glucose utilization * Enhances ketone body metabolism ## Footnote These effects are crucial for managing DKA.

Answer 421

When ketosis and acidemia have resolved, hydration status is adequate, and serum electrolytes are normal ## Footnote The pet should also be eating voluntarily.

Answer 422

* Rapid onset of action * Quickly metabolized ## Footnote These characteristics allow for swift adjustments and improved safety.

Answer 423

* Variable absorption * Delay in onset * Prolonged duration of action * Increased risk of hypoglycemic events ## Footnote IV administration is preferred for rapid control.

Answer 424

Insulin binds to plastic tubing and syringes ## Footnote Precondition the line to minimize loss.

Answer 425

Always supplement unless the patient has anuric kidney failure ## Footnote Delay if urine production has not started or if hyperkalemia persists.

Answer 426

* Lethargy * Muscle weakness * Seizures * Arrhythmias ## Footnote Monitoring is important to prevent complications.

Answer 427

* Hyperphosphatemia * Hypercalcemia * Anuria * Tissue necrosis ## Footnote Careful assessment is required before supplementation.

Answer 428

Administration of digitalis or cardioglycosides ## Footnote These medications can interact negatively with magnesium.

Answer 429

Mortality rates have dropped from 25–35% to <10% ## Footnote This improvement is due to vigilant monitoring and therapy.

Answer 430

* Severe underlying medical conditions (pancreatitis, hormonal disorders, sepsis, AKI, CHF) * Financial limitations leading to euthanasia * Not typically metabolic complications of DKA itself ## Footnote Understanding these causes can help in prevention strategies.

Answer 431

Possible after DKA resolution, particularly in cats with: * Concurrent pancreatitis * Glucocorticoid treatment at the time of DKA diagnosis ## Footnote These factors are linked to the potential for remission.

Answer 432

HHS animals are critically ill and may present with acute renal failure, leading to death or euthanasia ## Footnote This highlights the severity of HHS.

Answer 433

Isotonic 0.9% saline ## Footnote This fluid helps restore hydration status safely.

Answer 434

Serum potassium and phosphate must be monitored closely ## Footnote Correcting these electrolytes is vital for patient safety.

Answer 435

Delay insulin until plasma volume is restored ## Footnote This approach minimizes risks associated with rapid insulin administration.

Answer 436

BG should not decrease more than 50 mg/dL per hour ## Footnote This limit helps prevent complications such as cerebral edema.

Answer 437

Generally guarded to poor, worse than for DKA ## Footnote This highlights the seriousness of HHS.

Answer 438

* Fluid replacement rate: 60–80% deficit over first 12h, rest over 24h * Initial insulin administration: Start 2–4h after fluids if K⁺ normal * BG reduction target: 50–75 mg/dL/hour * Dextrose supplementation: Start when BG <250 mg/dL * Prognosis: Good with close monitoring (<10% mortality) ## Footnote These targets are essential for effective DKA management.

Answer 439

* Fluid replacement rate: Gradual over 24–48h * Initial insulin administration: Delay until plasma volume restored * BG reduction target: <50 mg/dL/hour * Dextrose supplementation: Start when BG <250 mg/dL * Prognosis: Guarded to poor ## Footnote These targets differ from DKA due to the nature of HHS.

Answer 440

About 0.3% in first-opinion practices and about 1% in referral/institutional practices.

Answer 441

* Type 1 Diabetes Mellitus (T1DM) * Type 2 Diabetes Mellitus (T2DM)

Answer 442

It resembles human Type 1 diabetes.

Answer 443

* Reduced size and number of pancreatic islets * Reduced number of beta cells * Beta cell vacuolization, enlargement, and degeneration.

Answer 444

* Genetic Predisposition * Immune-Mediated Mechanisms * Juvenile Onset * Pancreatic Abnormalities

Answer 445

* Insulin-Deficient Diabetes Mellitus (IDDM) * Insulin-Resistant Diabetes Mellitus (IRDM)

Answer 446

* Endocrine influences * Obesity * Drugs * Inflammatory mediators * Disorders of receptor function

Answer 447

Histologically identifiable pancreatitis is reported in 30–40% of diabetic dogs.

Answer 448

It is characterized by excellent glycemic control with small insulin doses.

Answer 449

* Decreased tissue utilization of glucose, amino acids, and fatty acids * Accelerated hepatic glycogenolysis and gluconeogenesis * Hyperglycemia * Glucosuria

Answer 450

Middle-aged and older dogs (5–12 years) with a peak prevalence between 7–10 years.

Answer 451

* Australian Terrier * Standard Schnauzer * Miniature Schnauzer * Bichon Frise * Spitz

Answer 452

60–90 days.

Answer 453

As soon as diabetes is diagnosed.

Answer 454

* Reduce or eliminate clinical signs * Prevent short-term complications (hypoglycemia, DKA) * Maintain good quality of life

Answer 455

Hypoglycemia.

Answer 456

* Hyperglycemia * Hypercholesterolemia * Hypertriglyceridemia (lipemia) * Mild increases in ALT (<500 U/L) and ALP (<500 U/L)

Answer 457

* Water intake * Urine output * Appetite * Body weight changes

Answer 458

* Address contributing factors * Start insulin therapy * Manage diet

Answer 459

* Intermediate-acting (e.g., Vetsulin, NPH) * Long-acting (e.g., PZI, glargine) * Ultra-long-acting (not yet approved)

Answer 460

Lowers blood glucose by increasing insulin absorption and improving blood flow.

Answer 461

* Increased frequency of defecation * Constipation * Obstipation

Answer 462

0.5 U/kg once daily.

Answer 463

Carry a glucose source.

Answer 464

It provides owners with more control over their dog's management.

Answer 465

Decrease the per-injection dose by ~30%.

Answer 466

Freezing or heating inactivates insulin.

Answer 467

Yes, but it is safest to store insulin in the refrigerator.

Answer 468

Monthly replacement is not necessary if insulin is properly stored and handled.

Answer 469

Gently rolling is suggested for consistency with most products.

Answer 470

Insulin glargine. (pH based)

Answer 471

Without needles attached to prevent air entry and dilution.

Answer 472

Prime the pen by loading and expelling 1–2 units upright.

Answer 473

Vetsulin VetPen.

Answer 474

It was more accurate at low doses compared to syringes.

Answer 475

5 seconds.

Answer 476

1–3 days after starting insulin.

Answer 477

It reduces progesterone-driven insulin resistance.

Answer 478

* Inflammatory diseases (e.g., pancreatitis) * Infectious diseases * Neoplastic conditions * Metabolic diseases (e.g., Cushing’s disease)

Answer 479

1–2 weeks.

Answer 480

Mean blood glucose over the preceding 2–3 months.

Answer 481

* Extreme hypertriglyceridemia * Hyperbilirubinemia * Prolonged erythrocyte lifespan.

Answer 482

Each laboratory should generate its own reference intervals.

Answer 483

Slightly above the reference range.

Answer 484

80–250 mg/dL.

Answer 485

Dose changes should be limited to 10–25%.

Answer 486

Measures interstitial glucose continuously and records data every minute.

Answer 487

Correlation coefficient (ρ) = 0.94 ## Footnote Indicates a strong correlation between the glucose sensor readings and actual blood glucose levels.

Answer 488

* Incorrect insulin type * Incorrect dose or frequency * Technical issues * Concurrent diseases ## Footnote Understanding these causes is crucial for effective management of diabetes in dogs.

Answer 489

≤1 U/kg/injection subcutaneously every 12 hours ## Footnote This dosage helps maintain stable blood glucose levels.

Answer 490

Wide glucose excursions between hyperglycemia and hypoglycemia within a day or across days ## Footnote High variability can complicate diabetes management.

Answer 491

* Standard deviation (SD) of BG values * Coefficient of variation (CV) ## Footnote These metrics help assess the stability of blood glucose levels.

Answer 492

Change insulin type; for example, switch from Vetsulin to insulin detemir or glargine ## Footnote Different insulin types may offer better control.

Answer 493

* Inactive insulin * Improper administration technique * Inadequate dose * Impaired insulin absorption ## Footnote Identifying these causes is essential for effective diabetes management.

Answer 494

Accumulation of sorbitol and galactitol in the lens leading to osmotic swelling and fiber rupture ## Footnote This process can result in significant vision impairment.

Answer 495

Generally have a life expectancy similar to non-diabetic dogs of the same age, sex, and breed ## Footnote Effective management and owner engagement are key to improving outcomes.

Answer 496

Occasionally reported but its clinical relevance remains unclear; observed microscopic changes include membranous glomerulopathy ## Footnote Chronic kidney disease is often independent of diabetic nephropathy.

Answer 497

A syndrome characterized by hyperglycemia due to defects in insulin secretion, insulin sensitivity, or both.

Answer 498

A state of abnormally increased blood glucose concentrations that do not yet meet the criteria for DM.

Answer 499

Type 2 diabetes mellitus (T2DM).

Answer 500

Up to 25%.

Answer 501

Blood glucose >270 mg/dL with classical signs of hyperglycemia and one of the following: * Increased glycosylated proteins * Glucosuria on multiple occasions OR Blood glucose between 125–270 mg/dL plus two of the following: * Classical signs of hyperglycemia * Increased glycosylated proteins * Glucosuria on multiple occasions.

Answer 502

Ranges from 0.5% to 2%.

Answer 503

Domestic shorthair and longhair cats.

Answer 504

Most cats are diagnosed after 8 years of age, with a peak incidence between 10–13 years.

Answer 505

Obesity causes insulin resistance and significantly increases the risk of diabetes.

Answer 506

Impaired insulin secretion and peripheral insulin resistance.

Answer 507

A state of euglycemia without the need for insulin therapy for at least four weeks after prior insulin administration.

Answer 508

Reducing insulin resistance and decreasing carbohydrate load.

Answer 509

Glucotoxicity refers to chronic hyperglycemia damaging beta cells, while lipotoxicity refers to hyperlipidemia damaging beta cells.

Answer 510

Incretins stimulate insulin secretion in a glucose-dependent manner and inhibit glucagon secretion.

Answer 511

They may improve metabolic outcomes but did not significantly increase remission rates in studies.

Answer 512

* Mild or early diabetes * Absence of hyperlipidemia * Shorter duration of clinical signs * Older age * History of glucocorticoid therapy.

Answer 513

* Protamine zinc insulin (PZI) * Lente insulin * Glargine (U100) * Detemir.

Answer 514

Various dietary strategies have been used, but evidence for superiority of any particular diet is insufficient.

Answer 515

It may allow medications and dietary interventions to be more successful in inducing remission.

Answer 516

No significant difference in remission rates between glargine (U100) and PZI, combined with a low-carbohydrate diet.

Answer 517

* Low-carbohydrate (3.5 g/100 kcal), low-fiber (0.1 g/100 kcal) diet * Moderate-carbohydrate (7.6 g/100 kcal), high-fiber (3.1 g/100 kcal) diet

Answer 518

68% remission

Answer 519

41% remission

Answer 520

Tight glycemic control with a target BG of 60–160 mg/dL.

Answer 521

* Tightly controlled group: 78% remission * Traditional group: 14% remission

Answer 522

It significantly improves remission rates.

Answer 523

* Disease progression * Increased carbohydrate intake * Worsening insulin resistance

Answer 524

* Minimizing insulin resistance * Minimizing dietary carbohydrate load * Optimizing beta cell function

Answer 525

* Complex nature of glycemic control * Pharmacologic limitations of insulin formulations * Caregiver burden and compliance

Answer 526

* Avoiding hypoglycemia * Preventing diabetic ketoacidosis (DKA) * Preventing excessive weight loss * Reducing polyuria and polydipsia (PU/PD)

Answer 527

Starting with a low insulin dose.

Answer 528

* No perfect insulin formulation * Variability in pharmacologic properties * Consideration of owner preferences and compliance

Answer 529

* Humans: 2–4 hours * Dogs: 6–9 hours * Cats: 6–12 hours

Answer 530

1.5–3-fold increase in cats, compared to 5-fold in humans and 5-7-fold in dogs.

Answer 531

Multiple small meals.

Answer 532

* No need for resuspension * More consistent absorption * Lower risk of hypoglycemia

Answer 533

Soluble at pH 4 and precipitates at neutral pH.

Answer 534

* Glargine U100 (e.g., Lantus) * Glargine U300 (e.g., Toujeo)

Answer 535

* Highly predictable action * Minimal variability * Often requires q12h dosing in cats

Answer 536

They must be evenly resuspended through gentle rolling and inversion.

Answer 537

Typically too short for once-daily use; q12h dosing usually required.

Answer 538

It has a lower biological potency due to albumin binding in plasma.

Answer 539

Ultra-long-acting basal insulin coverage in humans.

Answer 540

About 12 hours.

Answer 541

* NPH * NPH-Regular mixes * Lente * PZI * Glargine U100 * Detemir

Answer 542

Aim for blood glucose nadirs between 80–100 mg/dL.

Answer 543

Aim for blood glucose peaks between 250–350 mg/dL.

Answer 544

Differences between required and delivered doses can cause substantial intraday glycemic variability.

Answer 545

Porcine lente and NPH have shorter durations compared to PZI, glargine U100, detemir, and degludec.

Answer 546

Once-daily high doses of PZI, glargine U100, or detemir may achieve acceptable clinical control.

Answer 547

Lasting 8–24 hours with evenly distributed time-action profiles and no distinct peak.

Answer 548

* Owner concerns about quality of life * Burden of responsibility * Injection discomfort

Answer 549

q12h or longer.

Answer 550

Monitor for ketosis.

Answer 551

Potentiates insulin secretion during hyperglycemia and promotes weight loss. GLP-1 agonist

Answer 552

Mild hyperglycemia.

Answer 553

Excessive weight gain may signal insulin overdose.

Answer 554

Impair counter-regulatory responses.

Answer 555

Increase renal glucose excretion.

Answer 556

Greater risk of overdose ## Footnote Heavier cats have a higher risk of overdose due to their body mass and insulin requirements.

Answer 557

* Financial strain * Caregiver fatigue * Concurrent diseases in the cat ## Footnote These challenges can lead to unsustainable treatment plans.

Answer 558

Overall insulin deficiency ## Footnote Weight loss indicates that the cat may not be receiving enough insulin.

Answer 559

Avoid further insulin increases ## Footnote This is to reduce the risk of hypoglycemia.

Answer 560

Early disease management or as adjuncts to insulin ## Footnote These agents can help improve glycemic control.

Answer 561

Favorable safety profiles ## Footnote They are particularly promising in the treatment of diabetes.

Answer 562

If no improvement is observed after increasing insulin dose ## Footnote This may necessitate a restart of the titration process.

Answer 563

* Further decrease the insulin dose * Consider that the signs may not be due to hypoglycemia ## Footnote This approach helps avoid unnecessary insulin increases.

Answer 564

* Clinical signs * Fructosamine levels * Persistent negative glucosuria ## Footnote These factors help determine if insulin can be gradually decreased.

Answer 565

Do not capture short-term hypoglycemic episodes ## Footnote High concentrations of glycosylated proteins do not rule out hypoglycemia.

Answer 566

Measures interstitial glucose and helps expedite insulin titration ## Footnote CGMs provide valuable trend data.

Answer 567

* Diabetic neuropathy * Urinary tract infections (UTIs) * Chronic kidney disease (CKD) ## Footnote These complications can arise due to chronic hyperglycemia.

Answer 568

Obesity predictably causes insulin resistance ## Footnote Weight gain should be expected with insulin initiation.

Answer 569

* Life-threatening * Leads to long-term consequences ## Footnote Repeated mild hypoglycemia can impair counter-regulatory responses.

Answer 570

Lowers the threshold for activation of warning signs ## Footnote This results in fewer early signs before severe hypoglycemia occurs.

Answer 571

Progressive dysfunction of the central and autonomic nervous systems ## Footnote This dysfunction leads to a lower threshold for activation of warning signs.

Answer 572

Fewer warning signs, sudden seizures, coma, and even death due to neuroglycopenia.

Answer 573

About one-third exhibited only mental dullness, lethargy, weakness, and ataxia.

Answer 574

* Vocalization * Twitching * Seizures * Bradycardia * Hypothermia * Vomiting * Panting * Decreased appetite * Inappropriate urination * Diarrhea * Drooling

Answer 575

Interstitial glucose.

Answer 576

Reported glucose concentrations are lower than actual blood glucose.

Answer 577

They often show no clinical signs for several hours.

Answer 578

Proposes that hypoglycemia induces a counter-regulatory hormone surge, causing rebound hyperglycemia and insulin resistance.

Answer 579

It does not support the hypothesis; no consistent correlation between hypoglycemic episodes and subsequent hyperglycemia was found.

Answer 580

* Worsened hyperglycemia * Diabetes-related complications

Answer 581

Poorer glycemic control.

Answer 582

Reduced glycemic variability was associated with higher remission rates.

Answer 583

Hypoglycemia.

Answer 584

The body’s ability to sense and respond to future hypoglycemia.

Answer 585

It negatively impacts glycemic control and possibly long-term outcomes.

Answer 586

Strategies that reduce both hypoglycemia and hyperglycemia.

Answer 587

* Iatrogenic causes: long-term administration of exogenous glucocorticoids * Naturally occurring causes: excessive endogenous cortisol production

Answer 588

* ACTH-dependent hypercortisolism: Pituitary-dependent hypercortisolism (PDH) and ectopic ACTH syndrome * ACTH-independent hypercortisolism: Functional adrenocortical tumors and primary ACTH-independent adrenocortical hyperplasia

Answer 589

Pituitary-dependent hypercortisolism (PDH) ## Footnote Diagnosed in approximately 80–85% of cases.

Answer 590

Glucocorticoids (cortisol)

Answer 591

Primarily by plasma potassium and angiotensin II levels; ACTH has acute effects

Answer 592

Stimulates the secretion of pro-opiomelanocortin (POMC) in the anterior pituitary

Answer 593

False ## Footnote Unlike humans, dogs lack a consistent circadian rhythm for ACTH or cortisol secretion.

Answer 594

Negative feedback suppressing CRH and ACTH secretion

Answer 595

* Large tumor size * Peripheral fibrosis * Capsular invasion * Trabecular growth pattern * Hemorrhage * Necrosis * Increased Ki-67 proliferative index

Answer 596

To predict postoperative outcomes in adrenal tumor cases

Answer 597

Cortisol secretion occurs only after food intake

Answer 598

5% of all dogs with hypercortisolism; up to 10% of dexamethasone-resistant cases

Answer 599

Dogs exhibiting clinical signs consistent with hypercortisolism but normal endocrine test results

Answer 600

* Miniature Poodles * Dachshunds * Terriers * Boxers * Standard Schnauzers

Answer 601

Approximately 11 years

Answer 602

0.2% ## Footnote Based on several studies.

Answer 603

Middle-aged to older dogs, with diagnosis ranging from 6 months to 20 years, and a mean age of approximately 11 years.

Answer 604

* Miniature Poodles * Dachshunds * Terriers * Boxers * Standard Schnauzers ## Footnote Breed associations should be interpreted cautiously due to variations in breed popularity across geographic regions.

Answer 605

Yes, it affects both sexes, with a slight female predisposition suggested.

Answer 606

Neutering appears associated with an increased risk of hypercortisolism.

Answer 607

* Cortisol-induced inhibition of vasopressin action at renal tubules * Increased neurohypophyseal vasopressin release threshold * Central diabetes insipidus from large pituitary tumors.

Answer 608

Bilaterally symmetrical alopecia (endocrine alopecia).

Answer 609

Characterized by irregular plaques of dystrophic calcium deposits within or beneath the skin, considered a pathognomonic finding.

Answer 610

Increased alkaline phosphatase (ALP).

Answer 611

It helps determine whether cortisol levels remain elevated in dogs with hypercortisolism despite dexamethasone administration.

Answer 612

* Sensitivity: 85–100% * Specificity: 44–73%.

Answer 613

It represents an integrated cortisol measure over several hours and is used in combination with suppression testing.

Answer 614

* Hyperphosphatemia * Mild hypernatremia * Hypokalemia ## Footnote Hyperkalemia severity may correlate with the severity of hypercortisolism.

Answer 615

* Shortened prothrombin time (PT) * Increased fibrinogen concentrations * Elevated thrombin-antithrombin complexes.

Answer 616

To confirm increased cortisol production and decreased sensitivity of the hypothalamic-pituitary-adrenal axis.

Answer 617

Adrenocortical responsiveness to exogenous ACTH.

Answer 618

ACTH Stimulation Test.

Answer 619

Does not assess negative feedback sensitivity.

Answer 620

Lower specificity, requires multiple samples.

Answer 621

Suppression of cortisol by >50% from baseline.

Answer 622

Pituitary enlargement.

Answer 623

* Microadenomas * Macroadenomas

Answer 624

* Heterogeneous echotexture * Vascular invasion * Adrenal diameter >2 cm

Answer 625

Potential cure if complete excision is achieved.

Answer 626

Transient or permanent central diabetes insipidus.

Answer 627

Does not eliminate the source of hormone excess.

Answer 628

Up to 24% of dogs with invasive adrenal tumors exhibit vascular invasion.

Answer 629

* Hemorrhage (minor to severe) * Hypertension or hypotension * Bradycardia * Tachycardia * Death

Answer 630

* Pancreatitis * Thromboembolism

Answer 631

* Adrenal tumor regrowth * Functional metastasis * Development of new pituitary-dependent hypercortisolism (PDH)

Answer 632

778 to 953 days.

Answer 633

Tumors <3 cm are associated with significantly better survival than tumors ≥3 cm.

Answer 634

Increases perioperative mortality.

Answer 635

1,030 days.

Answer 636

Competitively inhibits the enzyme 3β-hydroxysteroid dehydrogenase.

Answer 637

* Transient hypocortisolism * Hypoadrenocorticism * Risk of permanent adrenal necrosis

Answer 638

Reflects adrenal reserve capacity.

Answer 639

Consider dose reduction to preserve adrenal reserve.

Answer 640

102–476 days.

Answer 641

* Anorexia * Lethargy * Weakness * Diarrhea

Answer 642

MC2R Antagonists

Answer 643

One of the most common comorbidities.

Answer 644

* Induces insulin resistance * Increases hepatic gluconeogenesis * Decreases insulin secretion * Blunts the incretin effect * Causes direct beta-cell cytotoxicity

Answer 645

1.6–23% ## Footnote Indicates the frequency of gallbladder mucocele among dogs diagnosed with hypercortisolism.

Answer 646

3.4–23% ## Footnote Shows the overlap between gallbladder mucocele and hypercortisolism in dogs.

Answer 647

2-fold increase ## Footnote Indicates a significant increase in surgical risk for these dogs.

Answer 648

* Higher concentrations of unconjugated bile acids * Increased bile hydrophobicity * Injury to biliary epithelium * Mucinous hyperplasia ## Footnote These factors contribute to the development and complications of mucocele.

Answer 649

Increased basal and post-ACTH dehydroepiandrosterone (DHEA) concentrations ## Footnote Suggests issues with DHEA secretion or transport.

Answer 650

Higher doses ## Footnote This is likely due to decreased bile secretion affecting the absorption of lipid-soluble drugs.

Answer 651

~3% ## Footnote Indicates a specific occurrence of urolithiasis in this population.

Answer 652

Calcium oxalate stones ## Footnote Indicates the specific composition of uroliths in this condition.

Answer 653

Extremely rare ## Footnote This indicates a low occurrence rate in this population.

Answer 654

Hypercoagulability ## Footnote This is associated with several underlying mechanisms related to hypercortisolism.

Answer 655

* Increased fibrinogen concentration * Decreased fibrinolysis * Thrombocytosis * Changes on thromboelastography ## Footnote These factors contribute to a hypercoagulable state.

Answer 656

37–86% ## Footnote This shows a significant correlation between hypercortisolism and hypertension.

Answer 657

Worse prognosis in cats ## Footnote Feline HAC carries more serious consequences than canine HAC.

Answer 658

* Diabetes mellitus * Skin hyperfragility syndrome * Other complicating comorbidities

Answer 659

Pituitary-dependent hyperadrenocorticism (PDH) ## Footnote Accounts for approximately 85% of feline cases.

Answer 660

Represents about 15% of feline cases, typically caused by an autonomously functioning adrenal cortical adenoma or carcinoma.

Answer 661

* Alopecia * Unkempt hair coat * Thin, hyperfragile skin * Pendulous abdomen * Muscle wasting * Hepatomegaly * Weight changes

Answer 662

* Diabetes mellitus * Polyuria/polydipsia (PU/PD) * Polyphagia more likely related to DM than HC

Answer 663

* Immunosuppression from cortisol excess * Skin fragility * Diabetes mellitus * Concurrent CKD

Answer 664

* Glucosuria * Hypercholesterolemia * Proteinuria * Anemia * Neutrophilia * Lymphopenia

Answer 665

To assess cortisol response; >21.7 µg/dL post-ACTH is suggestive of HAC.

Answer 666

Helps identify adrenal or pituitary enlargement, invasion, or metastasis.

Answer 667

9.5 to 13 years.

Answer 668

79% (same a prevalence of DM)

Answer 669

* Severe infections * Skin hyperfragility * Other serious complications

Answer 670

To assess major vessel invasion and metastatic disease

Answer 671

Hypoadrenocorticism requiring prednisolone replacement

Answer 672

Transsphenoidal Hypophysectomy

Answer 673

Competitive inhibitor of 3β-hydroxysteroid dehydrogenase

Answer 674

17 out of 20 cats survived longer than 3 months

Answer 675

11β-hydroxylase

Answer 676

Pre-surgical stabilization

Answer 677

Pituitary irradiation

Answer 678

* Adrenal adenomas * PDH undergoing appropriate definitive treatment

Answer 679

* Staged wound closure * Use of tissue glue for recent lesions

Answer 680

Focal enlargement of the adrenal gland in a pet with no clinical suspicion of adrenal gland disease ## Footnote It is commonly found during routine abdominal ultrasound.

Answer 681

Approximately 4% of dogs ## Footnote The incidence is higher with CT scans, at about 9%.

Answer 682

* Nodular hyperplasia * Cysts * Abscesses * Hematomas * Granulomas

Answer 683

14%–30% ## Footnote This statistic highlights the importance of evaluating incidental adrenal masses.

Answer 684

Poor glandular demarcation and irregular contrast enhancement ## Footnote Additionally, vascular invasion is a strong indicator of malignancy.

Answer 685

Adrenalectomy ## Footnote This is advised if the mass is enlarging or if clinical signs of hormone excess develop.

Answer 686

29.8 ± 8.9 months ## Footnote Larger tumor size is associated with shorter survival.

Answer 687

A principal mineralocorticoid produced in the zona glomerulosa of the adrenal cortex ## Footnote It regulates serum sodium and potassium concentrations.

Answer 688

Autonomous aldosterone secretion with suppressed renin concentrations ## Footnote This is due to negative feedback mechanisms.

Answer 689

Promotes sodium reabsorption and excretion of potassium and hydrogen ions ## Footnote This action helps conserve water and increases blood volume and pressure.

Answer 690

Most cats are >10 years old, with a median of ~13 years ## Footnote Cases have been reported in cats as young as 5 years.

Answer 691

A high-normal or elevated PAC with a low PRA suggests autonomous aldosterone production ## Footnote This can be useful in the initial screening for hyperaldosteronism.

Answer 692

In cats, adrenocortical carcinomas are more common than adenomas or bilateral hyperplasia ## Footnote In humans, bilateral zona glomerulosa hyperplasia is more prevalent.

Answer 693

Not widely available, require large blood volumes, rapid processing, and frozen plasma. ## Footnote There is no established feline PRA reference range.

Answer 694

Autonomous aldosterone production, even in the absence of RAS stimulation.

Answer 695

Does not exclude primary hyperaldosteronism (PHA) in cats.

Answer 696

Aldosterone secretion over time.

Answer 697

* No special handling or cooling required * Owners can collect urine at home

Answer 698

* Difficult to measure aldosterone in cat urine * Wide reference range * Basal concentrations often fail to identify PHA

Answer 699

Oral fludrocortisone suppresses aldosterone secretion in healthy cats.

Answer 700

Reduced UACR by a median of 78%.

Answer 701

* Elevated PAC * Imaging confirmation of an adrenal mass

Answer 702

Aldosteronoma.

Answer 703

Unilateral adrenalectomy.

Answer 704

* Hemorrhage * Acute kidney injury * Thromboembolism * Sepsis

Answer 705

1,297 days (range: 2–1,582 days).

Answer 706

Amlodipine.

Answer 707

7 months to 984 days in 4 cats.

Answer 708

Solitary adrenal adenoma or carcinoma.

Answer 709

* Lethargy * Anorexia * Weakness * Polyuria and polydipsia

Answer 710

* Increased baseline aldosterone concentration * Suppressed plasma renin activity

Answer 711

Fludrocortisone acetate or desoxycorticosterone pivalate (DOCP).

Answer 712

Excellent prognosis.

Answer 713

* Fragile skin * Aggression * Vulvar enlargement in spayed females * Mammary enlargement in males

Answer 714

Varies based on pre-op health, metastatic status, and surgical success.

Answer 715

Frequent serum electrolyte monitoring.

Answer 716

Polyphagia, polyuria, and polydipsia.

Answer 717

2 ## Footnote Only two cases have detailed treatment data available.

Answer 718

Mitotane ## Footnote The dosage was 47 mg/kg PO daily for approximately 20 days.

Answer 719

* PU/PD * Polyphagia * Panting * Weight gain * Abdominal distention ## Footnote These signs help in the clinical suspicion of the disease.

Answer 720

Progesterone ## Footnote Hyperprogesteronemia is a key feature.

Answer 721

Markedly suppressed cortisol despite signs of Cushing’s ## Footnote This finding is critical in evaluating potential adrenal tumors.

Answer 722

Wide; random basal elevations common ## Footnote This variability can complicate diagnosis.

Answer 723

Baseline + post-ACTH stimulation hormone panel ## Footnote This approach aids in confirming the diagnosis.

Answer 724

Poor response reported after 20 days ## Footnote Medical management has limited and poorly documented success.

Answer 725

Cushingoid signs, suppressed cortisol, exclusion of iatrogenic steroid use ## Footnote These factors are crucial in forming a clinical suspicion.

Answer 726

* Short duration of therapy * Dosage possibly suboptimal * General resistance of adrenal tumors to Mitotane treatment ## Footnote These factors contribute to the poor outcomes observed.

Answer 727

Zona glomerulosa

Answer 728

Autoimmune disease

Answer 729

It is a steroidogenic enzyme targeted by autoantibodies in autoimmune hypoadrenocorticism.

Answer 730

* Leonbergers * Pomeranians * Great Danes * Standard Poodles * Bearded Collies

Answer 731

CTLA-4 gene

Answer 732

Primary is due to adrenal cortex failure; secondary is due to pituitary or hypothalamic dysfunction.

Answer 733

* Typical primary HA (deficiencies in glucocorticoids and mineralocorticoids) * Atypical primary HA (deficiency of glucocorticoids only)

Answer 734

* Anorexia * Weight loss * Vomiting * Diarrhea * Lethargy * Weakness * Polyuria/Polydipsia

Answer 735

3–4 years

Answer 736

* Lower neutrophil counts * Higher lymphocyte and eosinophil counts

Answer 737

ACTH stimulation test

Answer 738

* Hypophysectomy * Abrupt withdrawal of glucocorticoids

Answer 739

Dehydration

Answer 740

Bradycardia

Answer 741

85% specific for diagnosing hypoadrenocorticism.

Answer 742

* Hyponatremia reduces renal medullary concentration gradient * Osmotic effect of sodium losses impairs urine concentrating ability

Answer 743

* Sodium-to-potassium ratio (reflecting aldosterone function) * Lymphocyte count (reflecting glucocorticoid function)

Answer 744

≥30 mEq/L (or mmol/L)

Answer 745

Abdominal ultrasound

Answer 746

* Shortened to absent P waves * Prolonged PR intervals * Widened QRS complexes * Short R waves * Tall, peaked T waves * Ectopic beats

Answer 747

IV administration

Answer 748

* Basal cortisol measurement * Cortisol-to-endogenous ACTH ratio * IM administration of long-acting synthetic ACTH * Plasma aldosterone-to-renin activity ratio

Answer 749

* Normal sodium and potassium concentrations * Low endogenous ACTH concentrations

Answer 750

Dogs with illnesses mimicking HA, particularly regarding electrolyte derangements

Answer 751

Aggressive IV fluid resuscitation

Answer 752

0.9% Sodium chloride (NaCl)

Answer 753

8–12 mEq/L

Answer 754

IV glucose

Answer 755

0.5 mg/kg PO q12h for 2–3 days after crisis stabilization

Answer 756

Decrease DOCP dose by ~10%

Answer 757

Abrupt steroid withdrawal

Answer 758

Pseudo-hypoadrenocorticism

Answer 759

* Abrupt steroid withdrawal * Neoplastic invasion of the adrenal glands ## Footnote Pseudo-hypoadrenocorticism is also characterized by hyponatremia and hyperkalemia.

Answer 760

* Hyponatremia * Hyperkalemia * Hypoglycemia ## Footnote These findings help differentiate HA from other disorders.

Answer 761

It must be tailored appropriately for cats ## Footnote The protocol specifics can vary significantly between species.

Answer 762

* Acute stabilization * Glucocorticoid supplementation * Mineralocorticoid supplementation ## Footnote These principles are similar to those used in dogs.

Answer 763

Worse prognosis for cats ## Footnote Delayed diagnosis and rarity of the condition likely contribute to less favorable outcomes.

Answer 764

The gastrointestinal (GI) tract ## Footnote It produces over 30 hormones that regulate digestion, metabolism, motility, and appetite.

Answer 765

Endocrine, paracrine, and neurocrine ## Footnote These modes of action affect various physiological processes.

Answer 766

Tissue-specific gene expression, alternative mRNA splicing, and post-translational modifications ## Footnote These factors contribute to the unique functions of hormones.

Answer 767

Hormone excess and hormone deficiency ## Footnote An example of hormone excess is functional neuroendocrine tumors.

Answer 768

G cells of stomach antrum and duodenum ## Footnote Gastrin is a key hormone involved in gastric acid secretion.

Answer 769

Protein intake, gastric distension; inhibited by low gastric pH ## Footnote These stimuli help regulate gastric functions.

Answer 770

Stimulates gastric acid and pepsinogen secretion; promotes gastric mucosal growth and motility; contributes to pancreatic enzyme secretion ## Footnote Essential for digestion and gastrointestinal health.

Answer 771

Zollinger-Ellison syndrome ## Footnote This condition results from gastrin-secreting tumors.

Answer 772

I cells in duodenum and jejunum ## Footnote CCK plays a role in fat and protein digestion.

Answer 773

Luminal fats, amino acids, and H+ ## Footnote These nutrients signal the need for digestive enzymes.

Answer 774

Stimulates gallbladder contraction, pancreatic enzyme secretion, relaxes sphincter of Oddi; inhibits gastric emptying ## Footnote CCK coordinates digestion processes.

Answer 775

S cells of duodenum ## Footnote Secretin plays a vital role in neutralizing gastric acid.

Answer 776

Acidic chyme (H+) ## Footnote This response helps regulate pH levels in the intestine.

Answer 777

Stimulates bicarbonate secretion; inhibits gastric acid production and motility ## Footnote Important for maintaining intestinal environment.

Answer 778

Glucagon, GLP-1, GLP-2, GIP ## Footnote These hormones are crucial for glucose metabolism.

Answer 779

Promotes gluconeogenesis and glycogenolysis ## Footnote It opposes the action of insulin.

Answer 780

Potentiates glucose-dependent insulin secretion; inhibits gastric emptying and increases satiety ## Footnote GLP-1 plays a significant role in glucose homeostasis.

Answer 781

D cells in GI tract, pancreatic islets (δ-cells), hypothalamus ## Footnote Somatostatin has broad inhibitory effects on various hormones.

Answer 782

Inhibits gastric acid, pancreatic secretion, bile release, insulin/glucagon release, and GI motility ## Footnote It regulates multiple digestive processes.

Answer 783

Regulates migrating motility complexes (MMCs) in fasting; coordinates GI secretions in fed state ## Footnote Essential for digestive rhythm.

Answer 784

Stomach ## Footnote Ghrelin is known as the hunger hormone.

Answer 785

Stimulates appetite and GH release ## Footnote It links energy balance with the pituitary axis.

Answer 786

Enterochromaffin cells and enteric neurons ## Footnote Serotonin is important for regulating GI motility.

Answer 787

Stimulates GI motility and secretion ## Footnote Plays a critical role in digestive function.

Answer 788

Insulinoma ## Footnote It causes episodic hypoglycemia due to unregulated insulin secretion.

Answer 789

Episodic hypoglycemia ## Footnote This occurs due to inappropriate insulin levels.

Answer 790

Pancreas (often right limb) ## Footnote This tumor is rare in dogs and cats.

Answer 791

Elevated serum gastrin; gastric pH <2.5 + gastrin >1000 ng/L ## Footnote The secretin stimulation test can also aid in diagnosis.

Answer 792

Pancreatic α-cells ## Footnote This tumor can lead to diabetes mellitus.

Answer 793

Diabetes mellitus, weight loss, necrolytic migratory erythema (NME) ## Footnote These symptoms result from glucagon excess.

Answer 794

Hyperglucagonemia; low serum amino acids ## Footnote Imaging can help confirm the presence of a pancreatic mass.

Answer 795

Enterochromaffin cells ## Footnote These tumors secrete serotonin and kinins in humans.

Answer 796

Diarrhea, abdominal cramping, flushing ## Footnote These symptoms are more common in humans.

Answer 797

Surgical excision when feasible ## Footnote These tumors have a high metastatic rate.

Answer 798

PP-producing cells ## Footnote This tumor is rare and often non-functional.

Answer 799

Vomiting, ulcers, diarrhea, hypertrophic gastritis ## Footnote These symptoms result from excessive polypeptide production.

Answer 800

Difficult—PP is often co-expressed with other hormones ## Footnote Histopathology is required for confirmation.

Answer 801

GLP-1 ## Footnote It has a significant role in glucose regulation.

Answer 802

True ## Footnote It inhibits various digestive processes.

Answer 803

A neuroendocrine tumor arising from chromaffin cells of the adrenal gland medulla.

Answer 804

Tumors originating from non-adrenal chromaffin cells located in sympathetic and parasympathetic paraganglia.

Answer 805

Modified postganglionic sympathetic neurons, devoid of axons and dendrites, derived from neural crest cells during early prenatal development.

Answer 806

Approximately 0.01% to 0.1%.

Answer 807

Typically have an average diameter of 5 cm, but may grow up to 15 cm.

Answer 808

More than 90%.

Answer 809

Local invasion occurs in 66% of cases.

Answer 810

Reported in 20% of cases.

Answer 811

* Regional lymph nodes * Liver * Spleen * Kidneys * Pancreas * Lungs * Heart * Bone * Central nervous system

Answer 812

Chromaffin cells.

Answer 813

Tyrosine → DOPA → Dopamine → Norepinephrine → Epinephrine.

Answer 814

Phenylethanolamine N-methyltransferase (PNMT), stimulated by cortisol.

Answer 815

* Metanephrine (from epinephrine) * Normetanephrine (from norepinephrine) * Vanillylmandelic acid (VMA)

Answer 816

Autonomously by diffusion, independent of nerve impulses.

Answer 817

Approximately 7%.

Answer 818

* RET * NF1 * TMEM127 * VHL * SDH (especially SDHB and SDHD)

Answer 819

Reported in 50% of cases.

Answer 820

* Epistaxis * Retinal bleeding or detachment * Acute blindness * Seizures

Answer 821

* Glucocorticoid-producing adrenocortical tumors * ACTH-producing pituitary tumors

Answer 822

* Mild to moderate anemia * Leukocytosis * Increased liver enzyme activity * Azotemia * Decreased urine-specific gravity * Proteinuria

Answer 823

High-performance liquid chromatography (HPLC) assays measuring catecholamines or metanephrines.

Answer 824

≥4× the upper limit of normal (ULN).

Answer 825

Contrast-enhanced CT.

Answer 826

* Cells arranged in epithelial-like aggregates * Presence of bare nuclei * Inconsistent nuclear features * Cytoplasm with fine chromatin granules

Answer 827

Complication rate for FNA is approximately 10%.

Answer 828

* Hemorrhage * Hypertensive crisis * Tumor seeding * Death

Answer 829

* Cardiac ultrasound * Electrocardiogram (ECG)

Answer 830

* Hypertension * Tachycardia * Arrhythmias * Hemorrhage

Answer 831

A non-competitive, non-selective, long-acting alpha-adrenergic blocker

Answer 832

0.25 mg/kg PO q12h

Answer 833

Continuous monitoring (ECG, blood pressure) for 48 hours postoperatively

Answer 834

Phenoxybenzamine

Answer 835

* Large, round to polygonal cells * Nested, trabecular, or solid arrangements * Round to oval nuclei with possible pleomorphism

Answer 836

Evaluating tumor invasiveness, growth patterns, cytologic features, and mitotic activity

Answer 837

* Advanced age * Poor general condition * Serious concurrent diseases

Answer 838

6–16 cm in diameter

Answer 839

* Dysphagia * Dyspnea * Circulatory disturbances

Answer 840

Approximately 0.2% of all canine tumors

Answer 841

* Sympathetic PGL * Parasympathetic PGL

Answer 842

Parasympathetic PGL

Answer 843

It helps differentiate pheochromocytomas from adrenocortical tumors

Answer 844

May help reduce phenoxybenzamine dose

Answer 845

Nonspecific and vague, similar to those in dogs