PU/PD

Question 1

What is the difference between central and nephrogenic diabetes insipidus?

Answer 1

(Central → complete or partial lack of vasopressin secretion from the hypothalamus; nephrogenic → plenty of vasopressin secretion from the hypothalamus but it has decreased action within the kidneys)

Question 2

Central diabetes insipidus, primary nephrogenic diabetes insipidus, hyperadrenocorticism, hypercalcemia, and primary polydipsia more commonly cause marked hyposthenuria, what USG value would indicate marked?

Answer 2

(USG < 1.006)

Question 3

How does an animal’s response to a desmopressin trial differ if they have central diabetes insipidus versus primary nephrogenic diabetes insipidus?

Answer 3

(Central → water intake will decrease and USG will increase; primary nephrogenic → no response)

Question 4

What values define polydipsia in dogs?

Answer 4

(Water intake greater than 90-100 ml/kg/day; in cats is water intake greater than 50 ml/kg/day)

Question 5

What are differentials for primary polydipsia?

Answer 5

(Physiologic response (increased temperature, dry food diet), psychogenic/behavioral, and other medical conditions (hyperthyroidism, fever, GI dz, and neurological dz))

Question 6

What are the two main causes of primary polyuria?

Answer 6

(Diabetes insipidus and osmotic diuresis; other category is misc.)

Question 7

Does hyperadrenocorticism or hypoadrenocorticism cause secondary nephrogenic diabetes insipidus?

Answer 7

(Both)

Question 8

Does hyperthyroidism or hypothyroidism cause secondary nephrogenic diabetes insipidus?

Answer 8

(Hyperthyroidism)

Question 9

Does hyperaldosteronism or hypoaldosteronism cause secondary nephrogenic diabetes?

Answer 9

(Hyperaldosteronism)

Question 10

Dogs with a pyometra can have secondary nephrogenic diabetes insipidus, why?

Answer 10

(Because of associated E. coli endotoxemia)

Question 11

Does hyperkalemia or hypokalemia cause secondary nephrogenic diabetes insipidus?

Answer 11

(Hypokalemia)

Question 12

What neoplasm is associated with causing secondary nephrogenic diabetes insipidus?

Answer 12

(Leiomyosarcoma)

Question 13

What drugs can cause secondary nephrogenic diabetes insipidus?

Answer 13

(Glucocorticoids and phenobarbital)

Question 14

What signalment is associated with primary nephrogenic diabetes insipidus?

Answer 14

(Puppy and/or kitten)

Question 15

What is the most common form of central diabetes insipidus and what are the other possible causes?

Answer 15

(Most common form is idiopathic, other causes are head trauma, neoplasia, and hypothalamic-pituitary malformations)

Question 16

What is psychogenic polydipsia?

Answer 16

(An idiopathic disease where an animal, vast majority dogs, ingests excess water resulting in compensatory polyuria to prevent water intoxication)

Question 17

What are the six steps of working up PU/PD?

Answer 17

(1. Ensure presence of PU/PD, 2. Get a thorough signalment, history, and PE, 3. Get a complete UA, culture as needed, 4. CBC/chem, 5. Additional testing (long fucking list), 6. Modified water deprivation test and/or desmopressin trial)