The aim of this study was to assess the beneficial effects of oral supplementation of Lepidium meyenii (Maca) on improving and keeping sperm quality in dogs during storage, and to investigate its effect on changes in testosterone concentrations. Forty male dogs were enrolled in the study and divided into four groups of ten dogs each: two subfertile (control and treatment) and two normofertile (control and treatment) groups. The dogs in the treatment groups received Maca in a capsule formulation (75 mg/kg), while the control groups received placebo. The spermiogram and testosterone levels were assessed at three times of the sperm cycle: 0 (T0), 31 (T31), and 62 (T62) days. Ejaculates were processed for storage at 5 °C and evaluated for total and progressive motility and membrane integrity at 3 (T3h), 24 (T24h), 48 (T48h), and 72 h (T72h) post storage. The oral supplementation of 75 mg/kg of Maca extract in dogs can improve sperm parameters and increase serum testosterone concentrations, leading to improved reproductive capacity. The semen of subjects treated with oral Maca supplementation maintained its parameters stable for a longer period when stored compared to the semen of control subjects, demonstrating the beneficial effect of the use of this extract on male fertility.