This study has been designed to examine the effect on cardiovascular enzymes, testosterone and semen characteristics of the Yucca schidigera extract (YSE), used as a feed additive in commercial cat food for the purpose of decreasing faecal odour in male cats. In eighteen healthy male cats, while the biomarker cardiac troponin I (cTnI), known as the "gold standard" for cardiovascular assessment in cats was used, creatin kinase-MB (CK-MB), total cholesterol and triglyceride levels were also investigated as aiding parameters. The level of cTnI was 0.16 +/- 0.03 ng/ml before feeding without YSE. It was found 0.20 +/- 0.04 ng/ml after feeding with YSE. Similarly, results of the study demonstrated that there was no difference statistically in cardiovascular or lipidic parameters after feeding on this type of cat food for 12 weeks. The level of testosterone was 0.29 +/- 0.01 ng/ml before feeding without YSE. It was found 0.21 +/- 0.02 ng/ml after feeding with YSE. (P>0.05). Therefore, semen analysis revealed a statistically significant increase in sperm motility alongside a significant decrease in sperm abnormalities. The mean volume, concentration, motility and total sperm defect rates were 118.61 +/- 8.55 mu l, 197.78 +/- 12.83x10(6)/ml, 83.33 +/- 1.06% and 27.22 +/- 1.33% before feeding without YSE, respectively. These values were 213.06 +/- 21.29 mu L, 300.56 +/- 16.59x10(6)/ml, 90.00 +/- 1.07% and 18.67 +/- 0.59% after feeding with YSE, respectively. The differences between these values were statistically significant (P<0.001). It was concluded at the end of the study that the commercial cat food containing Yucca schidigera extract could be beneficial effects of the sperm volume, concentration, motility and total morphological defect rates in healthy male cats.