Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: Lynn Schmeitzel x
  • Refine by Access: All Content x
Clear All Modify Search

Summary

Clinical status, skin biopsy specimens, and endocrine function were evaluated in normal-coated Pomeranians (n = 12) and Pomeranians affected with growth hormone (gh)-responsive dermatosis (n = 7), then were compared with values in mixed-breed dog controls (n = 19). All Pomeranians were clinically normal; however, the Pomeranians with gh-responsive dermatosis had bilateral alopecia and hyperpigmentation of the trunk, caudal portion of the thighs, and ventral neck region.

Skin biopsy specimens from the affected Pomeranians had decreased-to-normal epidermal thickness and follicular atrophy, compared with normal-coated Pomeranians. Numerous elastin fibers were observed in the skin biopsy specimens of unaffected and affected Pomeranians.

Both groups of Pomeranians had normal results of thyrotropin-releasing hormone (trh) and thyrotropin (tsh) response, adrenocorticotropin (acth) stimulation, and dexamethasone suppression testing. There was no significant increase in serum gh concentration in either group of Pomeranians after xylazine or human GH-releasing factor (ghrf) administration, whereas control dogs had significant (P ≤ 0.05) increase in serum gh concentration after administration of either agent.

Baseline plasma acth concentration in unaffected and affected Pomeranians was increased above the normal range (40 to 90 pg/ml). Post-acth administration serum progesterone, 17-hydroxyprogesterone, and androgen (dehydroepiandrosterone sulfate or androstenedione) concentrations were consistently high in unaffected and affected Pomeranians, compared with values in control dogs.

High baseline plasma acth concentration and increased production of progesterone, 17-hydroxyprogesterone, and dehydroepiandrosterone sulfate or androstenedione after acth administration suggested disregulation of adrenocortical hormone synthesis in both groups of Pomeranians, possibly attributable to partial deficiency of the 21-hydroxylase enzyme. Although all 3 treated dogs developed normal coat in response to supplementation with human gh, gh-responsive dermatosis in Pomeranians may not be entirely attributable to hyposomatotropism, but may also involve adrenocortical hyperprogestinism and/or hyperandrogenism.

Free access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate adrenal sex hormone concentrations in neutered dogs with hypercortisolemia.

Design—Case series.

Animals—11 neutered dogs with hypercortisolemia.

Procedure—Serum samples obtained before and 1 hour after administration of ACTH were evaluated for concentrations of cortisol, progesterone, testosterone, dehydroepiandrosterone sulfate or androstenedione or both, and 17-hydroxyprogesterone.

Results—For all dogs, concentrations of 1 or more adrenal sex hormones were substantially greater than reference range values before or after administration of ACTH. Testosterone concentration was not greater than reference range values in any of the dogs.

Conclusions and Clinical Relevance—Results emphasize the importance of ruling out hypercortisolemia before measuring adrenal sex hormone concentrations as a means of diagnosing adrenal hyperplasia syndrome (alopecia X) in dogs. (J Am Vet Med Assoc 2001;218:214–216)

Full access
in Journal of the American Veterinary Medical Association

Summary

Changes in platelet indices (platelet count and platelet size) and pcv associated with thyroid disease were studied in 7 dogs with hypothyroidism and 21 cats with hyperthyroidism that were admitted to the veterinary teaching hospital. Compared with control (euthyroid) dogs, dogs with hypothyroidism had higher platelet count (P = 0.003), smaller platelet size (P = 0.01), and lower pcv (P = 0.02). Comparison of the group of hyperthyroid cats with a group of similarly aged, clinically normal cats with normal thyroxine values indicated that the group of hyperthyroid cats had significantly (P = 0.03) higher mean platelet size than did control cats, but differences were not found in mean platelet count or pcv. Results of this investigation indicate that the changes in platelet size reported in human beings with thyroid endocrinopathies also are found in animals so-affected. Although the pathogenesis of platelet abnormalities in animals with thyroid derangement is unclear and likely is multifactorial, the observed relation between platelet and erythrocyte production in this group of dogs is consistent with reports of an inverse relation between thrombocytopoiesis and erythropoiesis in iatrogenically hyperthyroid mice and in mice exposed to hypoxia.

Free access
in American Journal of Veterinary Research

Objective

To determine the effect of oral melatonin (MT) administration on serum concentrations of sex hormones, prolactin, and thyroxine in dogs.

Design

Prospective study.

Animals

8 male and 8 female adult sexually intact dogs.

Procedure

5 male and 5 female dogs were treated with MT (1.0 to 1.3 mg/kg [0.45 to 0.59 mg/lb] of body weight), PO, every 12 hours for 28 days; the other 6 dogs were used as controls. Blood samples were collected on days 0, 14, and 28, and serum concentrations of estradiol-17β, progesterone, testosterone, androstenedione, 17-hydroxyprogesterone (17-HP), dihydroepiandrostenedione sulfate (DHEAS), prolactin, and thyroxine were determined. On day 5, serum MT concentrations were measured before and periodically for up to 8 hours after MT administration in 4 treated dogs.

Results

Female dogs treated with MT had significant decreases in serum estradiol, testosterone, and DHEAS concentrations between days 0 and 28. Male dogs treated with MT had significant decreases in serum estradiol and 17-HP concentrations between days 0 and 28. Serum MT concentrations increased significantly after MT administration and remained high for at least 8 hours. Prolactin and thyroxine concentrations were unaffected by treatment.

Conclusions and Clinical Relevance

Melatonin is well absorbed following oral administration and may alter serum sex hormone concentrations. (J Am Vet Med Assoc 1999;215:1111–1115)

Free access
in Journal of the American Veterinary Medical Association