External Ozone Therapy:
Wound Healing, Antimicrobial Action, and Skin Repair Explained
Ozonated oils and glycerin are topical applications of one of the most researched alternative therapies in dermatology. An overview of the mechanisms of action, the scientific substantiation and the applications in dogs, cats and humans.
By Stefan Veenstra DVM
What is ozone therapy and how does it work externally?
Ozone (O₃) is a molecule made up of three oxygen atoms. Unlike regular oxygen (O₂), ozone is unstable and easily releases one oxygen atom, giving it a powerful oxidative effect. In medical and veterinary ozone therapy, this oxidative potential is used for disinfection, wound healing and immune modulation.
In external application, ozone is not used as a gas but in a stabilized form: by passing ozone gas through oils or glycerin, the unsaturated compounds in those substances react with the ozone and form stable ozone compounds, mainly ozonides and hydroperoxides. These compounds slowly release their oxidative potential on contact with the skin and thus exert their effect locally.
This is the fundamental principle behind all ozonated products: they are not irritating like ozone gas, but deliver the active ozone compounds to the tissue where they are needed in a controlled manner.
Mechanism of action 1: wound healing and tissue regeneration
One of the most studied effects of topical ozone therapy is the stimulation of wound healing. Ozone stimulates the release of growth factors such as PDGF (platelet-derived growth factor) and TGF-beta that activate fibroblast proliferation for faster tissue closure. At the same time, it increases the local oxygen supply by stimulating microcirculation, which promotes aerobic metabolism in the wound bed tissue.
In infected wounds, this effect is doubly relevant: ozone eliminates the pathogens that hinder healing while stimulating cell growth. Studies show that ozonated oils significantly increase the amount of new blood vessels in wound tissue, a process that is essential for the supply of oxygen and nutrients to the repairing tissue.
Clinical review · Journal of Natural Science, Biology and Medicine 2011
Elvis and Ekta showed in an extensive clinical review that ozone promotes wound healing via increasing oxygen supply, activation of growth factors and direct inhibition of infections. The researchers described ozone therapy as a promising alternative or adjunct to chronic and infected wounds.
Mechanism of action 2: antimicrobial activity — also in resistant bacteria
The antimicrobial activity of ozone is broad-spectrum and mechanistically different from that of antibiotics. Ozone works via direct oxidation of the cell wall, DNA and proteins of microorganisms. Bacteria, fungi, yeasts and viruses do not have a protective mechanism that works specifically against oxidative attack, unlike the enzyme systems that antibiotics are directed against.
This is why ozonated oils are also effective against resistant strains of bacteria such as MRSA: resistance develops via modification of enzyme targets or efflux pumps, but those mechanisms do not protect against oxidative cell wall damage caused by ozone. Resistance to ozone has therefore never been demonstrated in the literature.
Study · Martínez-Sánchez et al. 2005 · Antibacterial effect of ozonated oil
Martínez-Sánchez and colleagues showed that ozonated sunflower oil has a broad spectrum of antibacterial, antifungal and antiviral effects, including against resistant strains of bacteria. The study confirmed that the antimicrobial activity is directly related to the peroxide index of the ozonated product: a higher index correlates with stronger antimicrobial activity.
Mechanism of action 3: dermatological applications
Ozonated oils have been extensively studied in a wide range of skin conditions. In addition to infectious skin problems, there is growing evidence for the effect on eczema, psoriasis-like skin problems and chronic dermatitis. The mechanism here is twofold: on the one hand, direct antimicrobial action on secondary infections that exacerbate eczema, on the other hand, direct modulation of the inflammatory response in the skin via Nrf2 activation.
Ozonated oils activate the Nrf2 signaling pathway, the same pathway also activated by curcumin and resveratrol, and thus stimulate endogenous antioxidant enzyme production in keratinocytes. This protects skin cells from oxidative damage and reduces the inflammatory response.
Study · Journal of Investigative Dermatology 2005 · Skin wound healing
Valacchi et al. showed that topical ozone treatment promotes cutaneous wound healing and is effective in eczema and psoriasis-like skin problems. The investigators described the stimulation of vascular endothelial growth factors as a key mechanism for the enhanced tissue repair response.
Mechanism of action 4: gums and oral health
Gum disease in dogs and cats has a bacterial basis: pathogenic bacteria in the subgingival space cause inflammation, bleeding gums, and breakdown of the periodontal ligament. Ozonated oils have been studied as adjunct in the treatment of periodontal disease due to their ability to lower the bacterial load in the oral microbiome without destroying the commensal microbiome.
In dogs and cats, topical application of ozone ointment or oil to the gums is a practical way to harness the antimicrobial effect of ozone in gum disease. The product is applied with a cotton swab to the affected gums, where the ozone compounds locally reduce the bacterial load and support inflammation in recovery.
Clinical research · Indian Journal of Dental Research 2010
Kshitish and Laxman showed in a clinical and microbiological study that ozone treatment in patients with periodontitis led to significant reductions in bacterial pathogens and improvement in clinical periodontal parameters. The research suggested ozone therapy as a valuable adjunct to conventional periodontal treatment.
The NGD Care ozone product line: basis and choice
The NGD Care ozone product line is formulated on the basis of three different carriers, each with its own properties that determine the application. The carrier is not only a means of transport but also determines the texture, contact time, applicability and the additional nourishing properties for skin and mucous membranes.
Rich semi-solid ointment based on organic extra virgin olive oil. 36 hours ozonated for high peroxide index. Naturally rich in antioxidants and oleocanthal. Widely applicable for larger skin surfaces, wounds, eczema and gums.
Unique wax character: a stable balm for local dry zones in the event of intensive ozonation. In milder ozonation, liquid as an ear drop. Does not clog pores and is stable. Ideal for paws, ear canal and specific skin folds.
Water-soluble and non-greasy. Highest peroxide index in full strength (Skin Gel). More pleasant smell than olive oil. Diluted in physiological salt for mild application to the nose (5%) and eyes (5%). Broad spectrum from strongest skin treatment to gentle mucous membrane care.
Relevance for dogs and cats
The antimicrobial and wound-healing mechanisms of ozonated oils are not species-specific: bacterial cell walls, fungal structures and viral envelopes respond identically to oxidative attack in all mammals. The veterinary application of ozone therapy is therefore the same as the human one, with the application form adapted to the practical situation.
In dogs, hot spots, wounds, interdigital infections (intertoe skin), skinfold dermatitis, otitis externa and gum disease are the most common areas of application. In cats, skin infections, wounds after fights, eye care and gum disease are the most relevant indications. In humans, in addition to skin inflammations, wounds and eczema, we also use it for minor burns, insect stings, warts and impetigo. The ozone product line of NGD Care is formulated for external use only and is safe when used correctly in humans and all animal species.
External ozone products treat the symptom on the skin. In the case of chronic skin problems, recurrent infections or conditions with a systemic cause, internal approach via supplements is essential. Ozone products and the NGD Care Skin Protocol are complementary: external cleaning and disinfection, internally restoring the gut-skin axis.
Safety and use
Ozonated oils and glycerin are safe when used externally. In gaseous form, ozone is an irritant to the respiratory tract, but the ozone compounds in the stabilised products are non-volatile and non-irritating. The smell can be pungent for some animals, particularly at the olive oil base. The jojoba and glycerin gel have a more pleasant smell and are usually better tolerated. Nevertheless, the olive oil base remains the most commonly used ozone oil.
Do not use internally in higher concentrations. The nasal spray and eye drops are deliberately kept at 5% for safe use on mucous membranes. Avoid contact with the eyes with the Ozone Ointment and Skin Balm, as this can irritate. In case of serious infections, deep wounds or persistent problems, always consult a veterinarian or doctor for diagnostics.
Ozone ointment OzonCare: ozonated organic olive oil
Ozone Jojoba Skin Balm: semi-solid balm for local areas
Ozone Jojoba Ear Drops: mild ear drops
Ozone Glycerin Skin Gel: strongest antimicrobial action
Ozone Glycerin Nasal Spray: mild nasal care
Ozone Glycerin Eye Drops: Mild Eye Care
Conclusion
Ozonated oils and glycerin are scientifically substantiated external preparations with a broad efficacy profile: antimicrobial via direct oxidation of pathogens, wound healing via stimulation of growth factors and blood flow, and inflammation-modulating via Nrf2 activation. They are effective against bacteria, fungi, yeasts and viruses, including resistant strains.
The wearer determines the application: olive oil for wide skin treatment, jojoba for local areas and the ear, glycerin for the strongest effect or mild mucous membrane care. External ozone products are most effective as a complement to internal treatment for chronic skin problems involving the gut-skin axis.
Do you also want to apply ozone therapy internally to your dog or cat?
Stefan Veenstra DVM explains how rectal, subcutaneous and intravenous ozone therapy works for intracellular infections, tumors, renal insufficiency in cats and joint complaints via prolozone.
Literature
- Elvis AM, Ekta JS. Ozone therapy: a clinical review. J Nat Sci Biol Med. 2011; 2(1):66–70.
- Martínez-Sánchez G, et al. Antibacterial activity of ozonized sunflower oil (Oleozon®). Phytother Res. 2005; 19(11):914–920.
- Valacchi G, et al. Ozone treatment promotes cutaneous wound healing. J Invest Dermatol. 2005; 125(6):1217–1224.
- Kshitish D, Laxman UK. The use of ozonated water and 0.2% chlorhexidine in the treatment of periodontitis patients. Indian J Dent Res. 2010; 21(3):341–348.
- Martínez-Sánchez G, et al. Ozonated oils as antimicrobial systems in topical applications: characterization, current applications, and advances. Antioxidants. 2020; 9(6):486.
- Ozonized glycerin: benefits, uses, and safety explained. 2025. Review article.
This information is educational in nature and based on available scientific literature. External ozone products are intended to support and do not replace a veterinary consultation. In case of severe or persistent complaints, always consult a veterinarian or doctor.