Introduction and Objective

A successful breeder not only has to worry about pedigrees, structure, and temperament, but must also be concerned with the overall health of their dogs. Blood tests are an integral part of ascertaining health. Selective breeding has resulted in purebred dogs with relatively constricted gene pools compared with mixed breed dogs, which may influence physiologic variables that determine "normal" blood test results. Breed specific reference intervals for hematologic or serum biochemical testing have been published for several breeds, including Greyhounds, Belgian Tervurens, Akitas, Shiba Inus, and Scottish Terriers. To ensure optimal interpretation of laboratory test results, we constructed reference intervals for routine serum biochemical parameters for Siberian Huskies, Alaskan Malamutes, Golden Retrievers, and English Setters.

Materials and Methods

Healthy AKC registered Siberian Huskies, Alaskan Malamutes, Golden Retrievers and English Setters were recruited to participate in a study of breed specific reference intervals for thyroid hormone values. Dogs were required to be sexually mature and under 9 years of age, non-pregnant, and not taking medication other than heartworm preventative, flea/tick medication or nutritional supplements. Physical examinations were performed along with serum biochemical profiles (Olympus AU400e, Center Valley, PA), automated complete blood counts (Cell-Dyne 3500, Abbott Park, IL), and manual urinalysis. Dogs were excluded if they had abnormal CBC data that could not be accounted for by the effects of a transient stress response, suspicious urinalysis results (WBC >0-5 low power field (10x) OR bacteria >20 low power field (10x)), or physical abnormalities. Dogs were also excluded if they were hypercholesterolemic due to the potential for post-prandial effects on other analytes, or if data suggested compromised sample quality.

Results

Samples were obtained from 78 Siberian Huskies ranging in age from 12-96 months (mean, 48.1 months) including 41 sexually intact females, 32 sexually intact males, 2 castrated males, and 3 spayed females. Samples were obtained from 59 Alaskan Malamutes ranging in age from 13-112 months (mean, 47.4 months) including 25 sexually intact females, 12 sexually intact males, 11 castrated males, and 11 spayed females. Samples were obtained from 90 Golden Retrievers ranging in age from 10-103 months (mean, 44.0 months) including 42 sexually intact females, 37 sexually intact males, 7 castrated males, and 4 spayed females. Samples were obtained from 77 English Setters ranging in age from 11-102 months (mean, 38.9 months) including 40 sexually intact females, 32 sexually intact males, 4 castrated males, and 1 spayed female. See Table 1 for the 95% reference intervals that were generated by using JMP 4 Statistical Discovery Software, (Cary, NC).

Conclusion

Breed specific differences in reference intervals are not apparent for BUN, Cr, Ca, Phos, Mg, Alb, Na, Cl, K, HCO3, Tbil, GGT, Glu, and Chol . However, there are noticeable differences between the breeds in the upper limit of the reference intervals of some serum enzyme activities (ALP, ALT, AST, AMY), with Siberian Huskies and English Setters having higher upper limits for ALP, ALT, and AST compared with Alaskan Malamutes, Golden Retrievers, and general canine reference intervals developed at the University of Minnesota . These differences in serum enzyme activities may impact clinical interpretation and recommendations for further testing. Additional statistical analysis of this data is pending to further clarify the significance of the breed-related differences.

Table 1. University of Minnesota Clinical Pathology Laboratory reference intervals (UMRI) were based on 70 mixed breed and purebred dogs of various breeds.

Siberian Husky(SH), Alaskan Malamute(AM), Golden Retriever(GR), English Setter(ES).

This work was supported by the AKC and OFA (AKC Grant 372: Determination of breed-specific reference intervals for assessing thyroid function in several breeds) and the University of Minnesota 2007 Summer Scholars Program.