Lower urinary tract dysfunction (LUTD) is a commonly seen problem in cats. This chronic condition with no specific underlying cause remains a challenge for achieving effective treatment. Glycosaminoglycans (GAGs) are linear polysaccharides possessing characteristic repeated disaccharide sequences, thought to be involved in the pathogenesis of feline LUTD. The aim of the present study is to evaluate feline-specific serum sulphated glycosaminoglycan (S-GAG) and serum dermatan sulphate (DS) levels in cats with non-obstructive LUTD versus healthy controls. Eighteen client-owned cats suffering non-obstructive LUTD and 16 client-owned healthy cats were enrolled in this case-control study. Pre-treatment serum samples from cats in both the study (non-obstructive LUTD cats) and control (healthy cats) groups were analysed with "Quantitative Sandwich ELISA method" using feline-specific S-GAG and DS kits. The mean serum S-GAG and DS levels of the study group were measured against the control group. Measurements for study males were compared to the control males, and the neutered cats in the study group were compared to the intact ones in control group. Cats in study group had lower serum S-GAG concentrations (3.52 +/- 0.26 ng/mL) than the control ones (3.93 +/- 0.27 ng/mL). Cats in study group had higher serum DS levels (27.20 +/- 6.62 ng/mL) than control cats (16.79 +/- 5.21 ng/mL). This study reports serum S-GAG and DS data in cats with non-obstructed LUTD and in healthy cats for the first time.