Evaluation of the low-dose dexamethasone suppression test and ultrasonographic measurements of the adrenal glands in cats with diabetes mellitus

Abstract

The objectives of the study were to evaluate the low-dose dexamethasone suppression (LDDS) test and the size of the adrenal glands via ultrasonography in cats with diabetes mellitus. Twenty-two cats were enrolled in the study. In 19 cats, suppression of cortisol concentrations below 5.5 nmol/litre occurred four and eight hours after intravenous administration of dexamethasone (0.1 mg/kg). In one other cat, the cortisol concentration was also below 5.5 nmol/litre at eight hours but was 11.0 nmol/litre at four hours. The results were in agreement with those of healthy cats in a previous study. The cortisol concentrations four and eight hours after administration of dexamethasone did not differ between cats with good glycemic control (n = 8) and those with moderate to poor control (n = 12). The adrenal glands of the diabetic cats were not enlarged compared with those of healthy cats. In two diabetic cats, the LDDS test results were abnormal. One cat had a pituitary adenoma and adrenal glands of normal size as determined by ultrasonography. The size of the adrenal glands of the other cat clearly differed; histological examination of the larger adrenal gland revealed an adrenocortical adenoma. Based on our findings, the results of the LDDS test using 0.1 mg/kg of dexamethasone are normal in cats with diabetes mellitus independent of the quality of glycemic control. In addition, diabetes mellitus does not lead to a measurable increase in the size of the adrenal glands in cats. Further studies are needed to evaluate if the dexamethasone dosage used in this study is useful to diagnose mild form of hypercortisolism.

Feline Diabetes Mellitus

“…The results did not differ between cats with good glycemic control and those with moderate to poor control. In two cats, the test was abnormal and hyperadrenocorticism was confirmed by histopathology (Kley et al, 2007). Based on our results, the dexamethasone test appears to be a suitable part of the diagnostic work-up in diabetic cats suspected of having hyperadrenocorticism.…”

Hyperadrenocorticism in Cats

“…Correct discrimination has been documented consistently in about 80% to 90% of cats with FCS (Duesberg and Peterson, 1997;Kley et al, 2007;Valentin et al, 2014). It is an excellent discrimination test for separating cats with ATH from those with PDH.…”

“…Increasing the dose to 0.1 mg/kg was consistently effective in suppressing healthy cats but not cats with FCS (Smith and Feldman, 1987;Hoenig, 2002;Kley et al, 2007). Increasing the dose to 0.1 mg/kg was consistently effective in suppressing healthy cats but not cats with FCS (Smith and Feldman, 1987;Hoenig, 2002;Kley et al, 2007).…”

Skin fragility syndrome in a cat with multicentric follicular lymphoma

“…Furthermore, ultrasound scan measurements showed that both adrenal glands were similar in size to those of healthy cats. 4,5 Post-mortem examination and histological analyses of the adrenal and pituitary glands identified no abnormality of corticotrophs or adrenocortical cellsdefinitively ruling out this disease.…”