<i>N</i> -Acetylcysteine in Dogs and Cats <b/>

N -acetylcysteine (NAC), a derivative of the amino acid cysteine, is widely recognised for its diverse pharmacological properties, including antioxidant, anti-inflammatory, and mucolytic effects. As a precursor to glutathione, NAC plays a critical role in maintaining redox balance and mitigating oxidative stress, thereby preventing cellular damage caused by reactive oxygen species. While NAC has been extensively studied in human medicine, its application in veterinary medicine, particularly in dogs and cats, has gained growing interest in recent years. Beyond its antioxidant action, NAC exhibits clinically relevant anti-inflammatory and mucolytic effects, positioning it as a valuable therapeutic agent for managing hepatic, respiratory, and toxicological conditions in small animals. This review aims to synthesise the current knowledge on the pharmacokinetics, therapeutic applications, and species-specific considerations of NAC in canine and feline medicine, highlighting its potential to fill important gaps in oxidative stress management and supportive therapy in veterinary practice.