Aromatherapy & essential oils in animals

What is aromatherapy in animals?

Aromatherapy uses volatile plant compounds — essential oils — via inhalation, dispersion into the air (diffuser) or diluted topical application. In animals, it is used primarily for behavioural problems such as anxiety and travel sickness-related stress, but also for skin conditions and as an adjunctive agent for infections or parasite prevention.

For which complaints is it used?

• Anxiety and stress (travel anxiety, firework phobia, separation anxiety)
• Skin irritations and wound care
• Respiratory support
• Flea and tick prevention

What does the evidence say?

Scientific research into the effectiveness of aromatherapy in animals is scarce. The most frequently cited study is a narrative review on lavender inhalation in dogs with travel sickness-related excitement [3] — a study design that is methodologically too limited to allow causal conclusions. Randomised controlled trials (RCTs) are completely lacking.

The evidence grade is therefore Insufficient: there is no demonstrable evidence that aromatherapy works in animals, but also no well-designed research that definitively answers the question. This distinguishes the situation from modalities where studies have been conducted but yielded negative results.

Safety: significant, documented risks

While the evidence base for effectiveness is minimal, the toxicological risks in animals are well documented — and this justifies caution regardless of whether a remedy works or not.

Cats are particularly vulnerable. Cats lack the liver enzymes — specifically glucuronyltransferase — required to break down many compounds in essential oils (phenols, monoterpenes, aldehydes). Exposure can lead to liver damage, neurological symptoms and respiratory difficulties [4].

Tea tree oil poses a documented poisoning risk. A case series of 443 dogs and cats showed that 77% developed clinical signs of toxicity after exposure to concentrated tea tree oil, ranging from muscle tremors and ataxia to depression, hypothermia and coma [5].

Other oils with documented risk (non-exhaustive) [4]:

• Peppermint, eucalyptus, wintergreen (methyl salicylate)
• Clove oil (eugenol)
• Cedar, juniper, pine oil
• Citrus oils

Diffuser use is also not risk-free. Indirect exposure via a diffuser can cause respiratory irritation in cats. Birds are even more sensitive than mammals and can experience serious problems even at low concentrations [6]. Always ensure adequate ventilation and the possibility for the animal to leave the room.

Practical safety rules

• Never use undiluted essential oils directly on or near animals
• Always allow animals an escape route when using a diffuser
• Store essential oils out of reach of animals
• Consult a veterinary surgeon before use in animals with known liver, kidney or respiratory problems