Following the introduction of the
symmetric dimethylarginine (SDMA) immunoassay, cases were reported where the SDMA concentration was markedly increased above the reference interval (RI) with neither concurrent increases in serum
creatinine (Cr) concentrations nor clinical signs of
kidney disease. Many of these animals were also concurrently diagnosed with
cancer, most commonly
lymphoma. The purpose of the study was to evaluate the association of increased SDMA in dogs and cats with
lymphoma and other
cancers as compared with age- and breed-matched non-tumour controls. In this retrospective case-control study, serum chemistry results from 1804 tumour cases, and age- and breed-matched non-tumour control animals were used. Matched-pair odds ratios between animals diagnosed with
neoplasms and non-tumour controls for dichotomized SDMA values were determined by tumour type. SDMA concentrations were significantly higher in dogs and cats with
lymphoma (p < .0001) compared with non-tumour controls. The odds ratio for increased SDMA concentrations in dogs with
lymphoma was 10.0 (95% CI, 5.98-16.72) and for cats with
lymphoma was 3.04 (95% CI 1.95-4.73). A significant number of canine and feline
lymphoma cases had an increased SDMA concentration not associated with an increased Cr concentration (p < .001). Canine and feline
lymphoma patients have an increased odds of having a SDMA concentration above the RI at diagnosis. Further characterization and evaluation of dogs and cats with
lymphoma is required to help understand the mechanism(s) and the clinical significance of these alterations.