Natural Antimicrobial Compounds in Veterinary Medicine: Focus on Companion Animals

Companion animals, including dogs and cats, share close living environments with humans, making antimicrobial stewardship essential to prevent zoonotic transmission of resistant pathogens. The overuse and misuse of conventional antibiotics in veterinary medicine have accelerated the emergence of multidrug-resistant (MDR) microorganisms, prompting the need for alternative strategies. Natural compounds, such as antimicrobial peptides (AMPs), phytochemicals, chitosan-based polymers, and nutraceuticals, offer promising solutions due to their broad-spectrum activity, low resistance potential, and additional health-promoting properties. This review provides a comprehensive analysis of recent advances of the aforementioned compounds for companion animals, including their mechanisms of action, applications in feed and nutraceuticals, and therapeutic use in dermatological, gastrointestinal, and systemic infections. We discuss the current challenges related to bioavailability, safety, standardization, and regulatory frameworks, as well as future perspectives for integrating these agents into veterinary practice. Emphasis is placed on clinical evidence in dogs and cats, highlighting how natural antimicrobials can contribute to sustainable infection control and antimicrobial resistance mitigation under the One Health paradigm.