Hypoadrenocorticism in an aged cat

Acute adrenal necrosis in a young female cat

CASE DESCRIPTION

An 18-month-old spayed female domestic short haired cat was presented for poor appetite, lethargy, exaggerated swallowing, and regurgitation 2 weeks after endoscopic retrieval of gastric foreign material.

CLINICAL FINDINGS

The cat was quiet with tacky mucous membranes on physical examination. Point-of-care blood testing identified mild azotemia, moderate hypercalcemia, and a sodium-to-potassium ratio of 26. An ultrasound examination the next day identified moderate to marked bilateral adrenomegaly. Cytology of a fine needle aspirate of the adrenal glands was consistent with necrosis and associated inflammation. Hypoadrenocorticism was diagnosed by a confirmatory adrenocorticotropic hormone stimulation test.

TREATMENT AND OUTCOME

The cat normalized both clinically and biochemically after treatment with prednisolone and desoxycorticosterone pivalate.

CLINICAL RELEVANCE

Acute adrenal necrosis has been well documented in human medicine after anesthetic events. To our knowledge, hypoadrenocorticism caused by cytologically confirmed acute adrenal necrosis has not been previously reported in dogs and cats.

Clinical features and long-term management of cats with primary hypoadrenocorticism using desoxycorticosterone pivalate and prednisolone

BACKGROUND

Primary hypoadrenocorticism (PH) is rare in cats and knowledge about treatment is sparse.

OBJECTIVE

To describe cats with PH with a focus on long-term treatment.

ANIMALS

Eleven cats with naturally occurring PH.

METHODS

Descriptive case series with data on signalment, clinicopathological findings, adrenal width, and doses of desoxycorticosterone pivalate (DOCP) and prednisolone during a follow-up period of >12 months.

RESULTS

Cats ranged from 2 to 10 years (median 6.5); 6 cats were British Shorthair. Most common signs were reduced general condition and lethargy, anorexia, dehydration, obstipation, weakness, weight loss, and hypothermia. Adrenal glands on ultrasonography were judged small in 6. Eight cats could be followed for 14 to 70 months (median: 28). Two were started on DOCP doses ≥2.2 mg/kg (2.2; 2.5) and 6 < 2.2 mg/kg (1.5-2.0 mg/kg, median 1.8) q28 days. Both high-dose cats and 4 low-dose cats needed a dose increase. Desoxycorticosterone pivalate and prednisolone doses at the end of the follow-up period were 1.3 to 3.0 mg/kg (median: 2.3) and 0.08 to 0.5 mg/kg/day (median: 0.3), respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Desoxycorticosterone pivalate and prednisolone requirements in cats were higher than what is currently used in dogs; thus, a DOCP starting dose of 2.2 mg/kg q28 days and a prednisolone maintenance dose of 0.3 mg/kg/day titrated to the individual need seems warranted. Small adrenal glands (width < 2.7 mm) on ultrasonography in a cat suspected of hypoadrenocorticism can be suggestive of the disease. The apparent predilection of British Shorthaired cats for PH should be further evaluated.

Hypoadrenocorticism in two cats successfully treated with desoxycorticosterone pivalate

Two cats were presented with lethargy and anorexia. Clinically, the cats showed hypothermia and dehydration. Blood examination in both cats showed hyponatraemia, hyperkalaemia and additionally azotaemia in case 1 and hypercalcaemia in case 2. In both cats, an adrenocorticotropic hormone (ACTH) stimulation test showed an insufficient stimulation of the adrenal glands. In case 1, markedly elevated endogenous ACTH was additionally measured. Both cats were successfully treated with a combination of desoxycorticosterone pivalate (DOCP) and prednisolone (0.15 mg/kg daily). Case 1 received a final concentration of 2.6 mg/kg DOCP every 30 days, while case 2 was successfully managed with 2.2 mg/kg every 28 days. These rare cases of feline hypoadrenocorticism demonstrate that DOCP can be used similarly as in dogs.