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  • Author or Editor: Ad Rijnberk x
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SUMMARY

In 6 cats, mean ± sem baseline plasma concentrations of cortisol, corticotropin, and α-melanocyte-stimulating hormone (α-msh) were 87 ± 16 nmol/ L, 73 ± 14 ng/L, and 129 ± 12 ng/L, respectively. The cats were subjected to: handling and subsequent skin testing without anesthesia; anesthesia with 50 mg of ketamine HCl and 2.5 mg of diazepam given IV, immediately followed by handling and skin testing; and anesthesia and handling as previously described, but without skin testing. Significant (P <0.05; multivariate analysis for repeated measures) increase in plasma cortisol, corticotropin, and α-msh concentrations was observed until 20 minutes after the start of the experiments in cats undergoing physical restraint and subsequent skin testing with or without preceding anesthesia. These responses were largely abolished when anesthesia with ketamine and diazepam was only followed by handling.

We conclude that, during stress in cats (in contrast to dogs), the pituitary intermediate lobe is activated to secrete α-msh. In addition, the cortisol response after skin testing of cats under anesthesia may be a reasonable explanation for the reported weak skin test reactivity in cats.

Free access
in American Journal of Veterinary Research

SUMMARY

Nephrotomography and ultrasonography were used in 11 dogs with hyperadrenocorticism to assess the value of these techniques for the localization of biochemically diagnosed hyperfunctioning adrenocortical tumors. Both techniques enabled accurate localization of a unilateral adrenal mass in each of the dogs. Cross-sectional diameters of the masses ranged from 1 to 4 cm. In 1 dog, expansion of tumor into the caudal vena cava was revealed by caudal venacavography and ultrasonography. Mineralization in the tumor mass in 2 dogs was easily recognized by nephrotomography, but not by ultrasonography.

Paracostal laparotomy confirmed the presence of an adrenocortical tumor in each dog, and expansion of tumor into the caudal vena cava in 1 dog. Cross-sectional diameters of the tumors ranged from 1.2 to 4.5 cm and corresponded well with cross-sectional measurements by nephrotomography and ultrasonography.

It was concluded that nephrotomography and ultrasonography have similar diagnostic accuracies for the detection and localization of hyperfunctioning adrenocortical tumors.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine plasma concentrations of adrenocorticotrophic hormone (ACTH) and α-melanocyte stimulating-hormone (α-MSH) in healthyferrets and ferrets with hyperadrenocorticism.

Animals—16 healthy, neutered, privately owned ferrets, 28 healthy laboratory ferrets (21 sexually intact and 7 neutered), and 28 ferrets with hyperadrenocorticism.

Procedures—Healthy ferrets were used for determination of reference plasma concentrations of ACTH and α-MSH. Diagnosis of hyperadrenocorticism was made on the basis of history, clinical signs, urinary corticoid-to-creatinine ratios, ultrasonography of the adrenal glands, and macroscopic or microscopic evaluation of the adrenal glands. Blood samples were collected during isoflurane anesthesia. Plasma concentrations of ACTH and α-MSH were measured by radioimmunoassay.

Results—Plasma concentrations of ACTH in 23 healthy neutered ferrets during the breeding season ranged from 4 to 145 ng/L (median, 50 ng/L). Plasma concentrations of α-MSH in 44 healthy neutered or sexually intact ferrets during the breeding season ranged from < 5 to 617 ng/L (median, 37 ng/L). Reference values (the central 95% of the values) for ACTH and α-MSH were 13 to 100 ng/L and 8 to 180 ng/L, respectively. Plasma concentrations of ACTH and α-MSH in ferrets with hyperadrenocorticism ranged from 1 to 265 ng/L (median, 45 ng/L) and 10 to 148 ng/L (median, 46 ng/L), respectively. These values were not significantly different from those of healthy ferrets. Plasma ACTH concentrations of sexually intact female ferrets in estrus were significantly higher than those of neutered females.

Conclusions and Clinical Relevance—Ferrets with hyperadrenocorticism did not have detectable abnormalities in plasma concentrations of ACTH or α-MSH. The findings suggest that hyperadrenocorticism in ferrets is an ACTH and α-MSH-independent condition.—(Am J Vet Res 2002;63:1395–1399)

Full access
in American Journal of Veterinary Research

Summary

Results of abdominal survey radiography and x-ray computed tomography (CT) were compared in 13 dogs with hyperadrenocorticism histologically attributed to adrenocortical tumors. X-ray computed tomography enabled accurate localization of the tumor in all 13 dogs. Apart from 2 poorly demarcated irregular-shaped and mineralized carcinomas, there were no differences between adenoma (n=3) and carcinoma (n= 10) on CT images. In 1 dog, invasion of the caudal vena cava by the tumor was suggested on CT images and was confirmed during surgery. Suspicion of adhesions between tumors of the right adrenal gland and the caudal vena cava on the basis of CT images was confirmed during surgery in only 2 of 6 dogs.

Survey radiography allowed accurate localization of the tumor in 7 dogs (4 on the right side and 3 on the left). In 6 of these dogs, the tumor was visible as a well-demarcated soft tissue mass and, in the other dog, as a poorly demarcated mineralized mass. The smallest tumor visualized on survey radiographs had a diameter of 20 mm on CT images. Six tumors with diameter ≤ 20 mm were not visualized on survey radiographs. In 1 of these dogs, a mineralized nodule was found in the left adrenal region, without evidence of a mass.

In a considerable number of cases, survey radiography can provide presurgical localization of adrenocortical tumors in dogs with hyperadrenocorticism; CT is redundant in these instances. In the absence of positive radiographic findings, CT is valuable for localization of adrenocortical tumors.

Free access
in Journal of the American Veterinary Medical Association