Page 267 - Problem-Based Feline Medicine

15 – THE CAT WITH POLYURIA AND POLYDIPSIA 259

The cat with an estradiol- and testosterone-secreting
CYSTIC ENDOMETRIAL
tumor, had bilaterally enlarged adrenal glands, and
HYPERPLASIA/PYOMETRA COMPLEX
basal estradiol and testosterone concentrations were
markedly elevated.
Classical signs
A skin biopsy shows changes consistent with an
● Low-grade inappetence and lethargy.
endocrinopathy.
● Vaginal discharge or distended uterus
palpable.
● ± Fever.
Differential diagnosis
● ± Polyuria, polydipsia.
Hyperadrenocorticism is the most likely differential
diagnosis and may appear identical clinically and on See main reference on page 269 for details of acute
hormonal testing to a progesterone-secreting tumor, pyometra/metritis (The Cat With Depression, Anorexia
except for the absence of markedly increased basal or Dehydration).
progesterone concentrations.
Other causes of poorly controlled diabetes need to be
considered, e.g. excessive insulin dose, too short a Clinical signs
duration of action of insulin, hyperthyroidism and
acromegaly. Chronic cystic endometrial hyperplasia/pyometra
complex presents with vaginal discharge, and cats
Other causes of a poor hair coat need to be considered. may have polyuria and polydipsia as a presenting sign.
Pyrexia is rare.
Treatment Stump pyometra is rarely a cause of polyuria, poly-
dipsia; it more often presents as vaginal discharge.
Aminoglutethimide (AGT; approximately 6 mg/kg q
12 h PO) was used successfully for 1–2 months in some Chronic cystic endometrial hyperplasia/pyometra com-
cats to control signs prior to surgery. plex occurs in intact cats of any age, regardless of
● Aminoglutethimide inhibits the enzyme, which whether they have previously had kittens.
converts cholesterol to prenenolone during synthe- Copious vaginal discharge (watery or thick) is most
sis of adrenocortical steroids. common.
● Mammary gland enlargement following treatment
has been reported in a male cat. Low-grade inappetence may be present for weeks or
months.
Trilostane resulted in a temporary improvement in the
cat with the estradiol- and testosterone-secreting Weight loss, lethargy, unkempt appearance and
tumor. mild dehydration may be evident.
Surgical removal of the adrenal tumor is the treat- Depression, listlessness, ± mild dehydration. Cats are
ment of choice once signs have been controlled usually not pyrexic.
medically. Surgery resulted in long-term survival Polyuria, polydipsia occurs in some cats.
and resolution of clinical signs including diabetes
mellitus.

Diagnosis
Prognosis
Clinical signs that are highly suggestive of cystic
Prognosis is good for cats that respond to medical ther- endometrial hyperplasia/pyometra complex are vaginal
apy and undergo successful surgical removal of the discharge and listlessness in an intact cat, plus a dis-
adrenal mass. tended uterus on radiograph. Radiographically,