Page 2534 - Cote clinical veterinary advisor dogs and cats 4th

Polyuria and Polydipsia: Differential Diagnosis Preputial Discharge 1271

(Continued from previous page)

VetBooks.ir Differential Diagnosis Item Key Feature(s)
Behavioral or physiologic
Risk factors include overfeeding, gluttony/high satiety threshold, highly palatable food, response to a stressful event, low-calorie
food, high activity level, and pregnancy/lactation.
Hyperthyroidism Common in adult cats, rare in dogs; weight loss, thyroid nodule palpable in ≈90% of hyperthyroid cats; measure serum T 4 and
if inconclusive, serum free T 4 by equilibrium dialysis.
Gastrointestinal infiltration Increased suspicion if intestinal wall thickening on palpation and/or ultrasound; biopsy is confirmatory.
Sudden acquired retinal degeneration Concurrent acute visual deficits/blindness +/− HAC; mechanism unknown
Uncommon/Rare
Lesion of hypothalamic satiety center Other neurologic deficits expected
Cold ambient temperature Environmental history
Acromegaly Concurrent diabetes mellitus almost always present
HAC, Hyperadrenocorticism; T 4, thyroxine; TLI, trypsin-like immunoreactivity.
Modified from the third edition in unabridged form.

THIRD EDITION AUTHOR: Christine Savidge, DVM

Polyuria and Polydipsia: Differential Portosystemic Shunts
Diagnosis

Breeds
More commonly single, intrahepatic in large-breed dogs
Disorder Diagnostic Aids More commonly single, extrahepatic in small-breed dogs and cats Differentials, Lists, and Mnemonics
Diabetes mellitus Fasting blood glucose, urinalysis Multiple Shunts
Multiple shunts are extrahepatic and are most commonly acquired rather
Renal glycosuria Fasting blood glucose, urinalysis
than congenital. They occur secondary to portal hypertension induced by
Chronic kidney disease BUN, creatinine, Ca:P, urinalysis chronic hepatopathies or surgical intervention in an animal with hepatic
Postobstructive diuresis History, monitoring urine output microvascular dysplasia.
Location on Portogram
Pyometra History, CBC, abdominal radiography,
abdominal ultrasonography If shunt is cranial to T13, more likely intrahepatic
If any part of the shunt is caudal to T13, more likely extrahepatic
Escherichia coli septicemia Blood, urine, or other bacterial cultures
Hypercalcemia Serum calcium
Hepatic insufficiency Biochemistry panel, bile acids, ammonia
tolerance test, abdominal radiography and
ultrasonography
Hyperadrenocorticism History, ACTH stimulation test, dexamethasone Preputial Discharge
suppression test, urine cortisol/creatinine ratio
Primary hyperaldosteronism Serum sodium and potassium, BP, abdominal
ultrasonography, ACTH stimulation test
(aldosterone) Urine
PU/PD
Bacterial pyelonephritis Urine culture, abdominal ultrasonography, Ectopic ureters
excretory urography Urethral sphincter mechanism incompetence
Hypokalemia Serum potassium UTI
Urolithiasis
Hyponatremia Serum sodium
Hemorrhagic
Hypoadrenocorticism Na:K, ACTH stimulation test Bleeding disorder (thrombocytopenia, coagulopathy, vessel wall disruption)
Hyperthyroidism Serum thyroxine Neoplasia (bladder, urethra, prostate, testicle)
Inflammation/infection (bladder, urethra, prostate, testicle, penis/prepuce
Diabetes insipidus Trial treatment; modified water deprivation test [balanoposthitis])
Psychogenic PD Modified water deprivation test Foreign body (bladder, urethra, prepuce)
Trauma
Polycythemia/erythrocytosis CBC
Urolithiasis
Acromegaly Serum GH and IGF-1, CT scan Mucopurulent
Paraneoplastic disorders: Penile and preputial inflammation/infection (balanoposthitis)
Neoplasia
Intestinal leiomyosarcoma Abdominal ultrasonography, biopsy
Foreign body (preputial, urethral)
Iatrogenic disorders History Phimosis
Very low-protein diet History
PU/PD, Polyuria/polydipsia; UTI, urinary tract infection.
ACTH, Adrenocorticotropic hormone; BP, blood pressure; BUN, blood urea nitrogen; CBC, complete
blood count; GH, growth hormone; IGF-1, insulin-like growth factor 1; PD, polydipsia.
From Feldman E, Nelson R: Canine and feline endocrinology and reproduction, ed 3, St. Louis,
2004, Saunders.
www.ExpertConsult.com