Veterinary Medicine - March 2009 - (Page 121)

lucocorticoids are some of the most common drugs prescribed in practice because they have a variety of therapeutic effects. Although cats appear to not experience as many side effects with glucocorticoids as other species do, adverse reactions can occur, including skin atrophy and fragility, poor wound healing, and a predisposition to diabetes mellitus and congestive heart failure. Cats do not seem to develop steroid hepatopathy as dogs do, but this condition may just occur less frequently or be more difficult to detect in cats. A recent article in Veterinary Dermatology reviews what is known about glucocorticoids in cats, explaining how glucocorticoids produce their therapeutic effects and what processes are thought to result in the side effects mentioned above. Overall, the metabolically active drug prednisolone seems to be the preferred glucocorticoid in cats (antiinﬂammatory dose 0.55 to 1.1 mg/kg/day divided once or twice a day; immunosuppressive dose 2.2. to 8.8 G Exploring the use and effects of glucocorticoids in cats mg/kg/day divided once or twice a day). Many authors recommend that cats be given doses twice that of dogs to achieve anti-inﬂammatory effects. Contrary to previous study ﬁndings, subsequent larger studies have documented episodic cortisol secretion with no circadian rhythm, so the time of day is probably not important in glucocorticoid dosing in cats. Using shortto intermediate-acting glucocorticoids is recommended to monitor for adverse effects and quickly discontinue the drug if any adverse effects occur. Repositol glucocorticoids should be reserved for cats in which oral dosing is not possible. At therapeutic doses, cats receiving glucocorticoids should be able to produce normal antibody responses to antigens, including vaccines. Because of glucocorticoid’s association with diabetes mellitus and congestive heart failure, careful administration is warranted in cats at risk for diabetes or with preexisting heart disease. Lowe AD, Campbell KL, Graves T. Glucocorticoids in the cat. Vet Dermatol 2008;19(6):340-347. Using renal tubular enzymes to identify renal damage earlier bout 66% to 75% of nephrons are no longer functioning by the time traditional blood and urine test results reveal renal abnormalities in dogs. So an earlier method to detect kidney tubular damage would be of great beneﬁt. Researchers have proposed using the renal tubular enzymes N-acetyl-beta-D-glucosaminidase (NAG) and gamma-glutamyl transpeptidase (GGT) as indicators of early renal disease. A recent study in the American Journal of Veterinary Research sought to establish reference ranges in adult dogs for these two enzymes so that abnormal results can be identiﬁed. The researchers collected urine samples from 38 client-owned healthy dogs by using antepubic cystocentesis and measured NAG and GGT activities. A The results: • Reference range for GGT activity in dogs: 1.93 to 28.57 U/g • Reference range for NAG activity in dogs: 0.02 to 3.63 U/g (males); 0.02 to 2.31 U/g (females) No difference was found between males and females for GGT activity. No differences were seen with changes in body surface area, but the GGT reference ranges were higher in dogs with a urine pH of 7 or above. The researchers concluded that GGT and NAG activities above these reference ranges may indicate renal tubular damage earlier than normal blood and urine testing. Urine GGT and NAG assays are available through most commercial laboratories and are cost-effective. Their use in detecting early renal tubular injury could prompt management changes that decrease morbidity and mortality in affected patients. Brunker JD, Ponzio NM, Payton ME. Indices of N-acetyl-beta-Dglucosaminidase and gamma-glutamyl transpeptidase activities in clinically normal adult dogs. Am J Vet Res 2009;70(2):297-301. Hot Literature is a weekly Web department. To read more of these study recaps, go to dvm360.com and click on “Medicine.” VETERINARY MEDICINE March 2009 121 http://www.dvm360.com http://www.dvm360.com

Table of Contents Feed for the Digital Edition of Veterinary Medicine - March 2009

Veterinary Medicine - March 2009 Contents Letters Correction Author Guidelines Hot Literature Idea Exchange A Challenging Case Local and Regional Anesthesia Techniques The Latest Scoop on Litter Product Preview CE Form/Advertiser Index Marketplace/Classifieds Mind Over Miller

Veterinary Medicine - March 2009

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.