Background and aimThis study aimed to explore the clinical potential of Withania somnifera/ashwagandha root extract (ARE) to mitigate age‐related changes in healthy geriatric dogs. We hypothesized that ARE can reduce the effects of advancing age, including physiological changes, immune response decline and susceptibility to diseases, by its immunomodulatory effects.MethodsA randomized, double‐blind, placebo‐controlled trial was conducted in Telangana, India, from July 2022 to September 2022. Twenty apparently healthy dogs, aged 8 years or older, were enrolled. The dogs were divided into two groups to receive ARE (15 mg/kg, once daily, orally) or a placebo control. Various parameters, including serum cortisol levels, haematological profiles, biochemical markers, antioxidant indicators and anti‐inflammatory responses, were assessed at the initiation of study, day 30, and day 60.ResultsThe erythrocyte count and haemoglobin levels were significantly increased with ARE (p < 0.001), whereas leukocyte count decreased (p < 0.05). Moreover, significant decreases in important markers of liver function (alanine aminotransferase, aspartate aminotransferase, albumin and globulin; p < 0.001 at day 60), as well as kidney function markers (creatinine and blood urea nitrogen; p < 0.001 at days 30 and 60), were observed in ARE‐treated dogs compared to the placebo control group. In addition, the levels of markers of oxidative stress (superoxide dismutase, catalase, glutathione and malondialdehyde) were significantly modulated by ARE intervention, indicating strong antioxidant effects. Interestingly, serum cortisol levels reduced significantly with ARE (p < 0.001). Compared to baseline, ARE significantly decreased key inflammatory markers, including interferon‐γ, tumour necrosis factor‐α, nuclear factor kappa light chain enhancer of activated B cells and interleukin‐10 (p < 0.001) levels at day 60.ConclusionIn conclusion, the findings of this study suggest that ARE has adaptogenic properties in healthy geriatric dogs by improving haematological and biochemical profiles, enhancing antioxidant defence, reducing stress and modulating inflammatory responses.