External Application of Essential Oils in Animals Jürgen Reichling Institute of Pharmacy and Molecular Biotechnology, Department of Biology, University of Heidelberg Mentha x piperita Rosmarinus officinalis Thymus vulgaris Matricaria recutita Beautifulboy

Outline Phytotherapeutical use of essential oils in animals Antifungal effect of tea tree oil (TTO) on Malassezia pachydermatis isolated from canines suffering from cutaneous disease Topical use of a 10% TTO-containing cream against canine localized pruritic dermatitis Species specific differences and toxicolo- gical aspects Conclusion

Phytotherapeutical use of essential oils in animals Wounds and other problems of the skin Respiratory ailments Nervous system disorders Ailments affecting the loco motor apparatus like rheumatism and arthritis Repellents and antiparasitics Antimicrobials and antibiotics Digestion system and diarrhea Control of pet odor

Phytotherapeutical use of selected essential oils in animals PLANT ESSENTIAL OIL USE Calendula officinalis Pot marigolds Otitis, gastritis, cuts, wounds, inflamed skin, dermatitis Matricaria recutita German chamo-mile oil Wounds, burns, itching, dermatitis, inflamed skin Melaleuca alternifolia Tea trea oil Flea treatment, insect repellant, dermatitis Mentha pulegium Pennyroyal oil Bacterial infections, flea treatment Artemisia absinthium Absinthe oil Wormer Eucalyptus globulus Eucalyptus oil Wounds, inflammations, cuts, insect repellent, flea treatment

Phytotherapeutical use of selected essential oils in animals PLANT ESSENTIAL OIL USE Pelargonium roseum Geranium oil Insect repellent, itching Helichrysum italicum Helichrysum oil Paw cuts, dermatitis, irritated skin, wounds Lavandula angustifolia Lavender oil Paw cuts, dermatitis, itching, insect repellent Cymbopogon citratus Lemongras oil Insect repellent, fungal infection Thymus vulgaris Thyme oil Eczema, bacterial infections Commiphora myrrha Myrrh oil Wounds, ear and teeth care, repellent for fleas and ticks

Treatment of fleas For treatment of flea infested animals an USA patent propagates a mixture of pennyroyal oil, eucalyptus oil, cedar oil, citronella oil and rue oil inserted into apricot kernel oil, olive oil or almond oil in concentrations up to 7%. In the market you will find different essential oil-containing preparations, such as herbal flea shampoos, herbal flea collars or herbal flea drops for dogs

Acaricidal effect of Tea Trea Oil (TTO) In an in vitro experiment the acaricidal effect of TTO on nymphs of Ixodes ricinus was examined. It was found that 8 to 10µl of TTO was lethal for more than 80% of the ticks when TTO was inhaled. The acaricidal effect correlated very well with the duration of exposure of ticks to TTO.

Parasitic mite infection control in honeybee colonies Selected essential oils Mites: Varroa destructor (V) and Acarapis woodi (T) Lemon oil V and T Lemongras oil Thyme oil Eucalyptus oil V Oregano oil Rosemary oil

Malassezia pachydermatis

Dog paw of a Labrador Retriever infected by Malassezia pachdermatis

MFC of Terb.-HCL [µg/ml] Antifungal effect of Tea Trea Oil (TTO) on Malassezia pachydermatis isolated from canines suffering from cutaneous disease Clinical isolates MFC of TTO [µg/ml] MFC of Terb.-HCL [µg/ml] B 7097 1120.0 0.8 – 1.6 B 7104 560.0 0.8 B 7124 0.4 – 0.8 B 7139 0.4 B 7148

Staphylococcus species Antibacterial activity of Tea Tree Oil (TTO) against different Staphylococcus species Staphylococcus species MIC [µg/ml] Staphylococcus aureus 2500 Staphylococcus capitis 1200 – 2500 Staphylococcus epidermidis 2500 – 5000 Staphylococcus haemolyticus Staphylococcus hominis 1200 Staphylococcus saprophyticus 2500 -5000 Staphylococcus xylosus

Topical use of a 10% TTO-containing cream against canine localised pruritic dermatitis

Topical use of a 10% TTO-containing cream against canine localised pruritic dermatitis

Species specific differences and toxicological aspects 1. Dogs can utilize carotinoids from plants to synthesize retinol, but cats require preformed Vitamin A from animal tissue. 2. Dogs can use either fish or plant sources of omega-3-fatty acids, whereas cats require fish because they lack in delta-6-desaturase. Cats can synthesize neither eicosapentaenoic acid from α-linolenic acid nor arachidonic acid from linoleic acid.

Species specific differences and toxicological aspects 3. Cats are highly sensitive to essential oils because they are lacking in glucuronyl transferase activity. 4. In most cases of reported adverse side effects, the essential oils were used to treat dermatological conditions at inap-propriate high doses.

Species specific differences and toxicological aspects 5. The most common clinical signs after dermal exposure of inappropriate high concentrations of essential oils include ataxia, muscle weakness, depression, and behavioral abnormalities. 6. Some essential oils are phototoxic (e.g. bergamot oil) and can burn skin badly if exposed to sunlight.

Conclusion Evidence-based veterinary phytotherapy is still in its infancy. At present, the use of essential oils in animals is exclusively based on anec- dotal reports and experiences of aroma therapists and pet owners. So called aroma therapists are mostly laymen and subsequently lacking in a medicinal background.

Conclusion Our first clinical trial with TTO in dogs have shown that an evidence-based use of essential oil in animals is possible. When using essential oils in animals species specific differences have to be taken into account. Essential oils are powerful biological agents which should be used in appro- priate doses, indicated ailments, during a limited time period and with care.

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