Lavender essential oil may exert its anxiolytic effects through its impact on the central nervous system. Lavender contains compounds such as linalool and linalyl acetate that have been shown to have sedative effects on the nervous system. For example, a study by Kim et al. (2011) found that inhalation of lavender essential oil significantly reduced anxiety-like behaviour in mice, possibly through the modulation of the GABAergic system.

GABA (gamma-aminobutyric acid) is a neurotransmitter that has been linked to the regulation of anxiety and stress. Research has shown that lavender essential oil can increase GABA levels in the brain, which may contribute to its anxiolytic effects. For example, a study by Umezu et al. (2006) found that inhalation of lavender essential oil increased GABA levels in rat brains, leading to a decrease in anxiety-like behaviour.

Lavender essential oil diffused at a dog shelter also was found to have a calming effect.  In a study by Graham et al. (2005), when lavender was diffused in the kennels, dogs spent more time resting, less time moving around and they were less vocal.

Peru balsam essential oil contains a number of compounds that may contribute to its therapeutic effects, including cinnamic acid, benzoic acid, and vanillin. Cinnamic acid has been shown to have anti-inflammatory and neuroprotective effects, which could potentially help reduce anxiety in dogs. Benzoic acid has been shown to have anxiolytic effects in animal models, although more research is needed to determine its mechanism of action. Vanillin has been shown to have sedative effects in animal models, which could contribute to Peru balsam’s calming properties.

A few studies have investigated its potential therapeutic effects in other areas. For example, a study by Tsai et al. (2013) found that Peru balsam essential oil had antibacterial and anti-inflammatory effects in vitro, suggesting a potential mechanism for its therapeutic effects in a variety of conditions. Another study by Costa et al. (2019) found that Peru balsam essential oil had antioxidant and anti-inflammatory effects in rats, suggesting a potential role in the management of oxidative stress and inflammation.

Sandalwood essential oil has been shown to have a positive effect on the limbic system, with some studies suggesting that it can increase alpha waves in the brain, which are associated with relaxation and calmness. A study by Xiong et al. (2008) found that inhalation of sandalwood essential oil reduced anxiety-like behaviors in mice, suggesting a potential mechanism for its calming effects.

In addition, sandalwood essential oil has been shown to have anti-inflammatory properties, which could potentially help reduce anxiety in dogs. Chronic inflammation has been associated with the development of anxiety and other mood disorders in both humans and animals, and reducing inflammation may be a potential strategy for managing anxiety. A study by Srivastava et al. (2010) found that sandalwood essential oil had anti-inflammatory effects in vitro and in vivo, suggesting a potential mechanism for its therapeutic effects in anxiety.

Ylang ylang essential oil contains several bioactive compounds, including linalool and benzyl acetate, which have been shown to have sedative effects on the central nervous system. These compounds may help reduce anxiety and promote relaxation when inhaled by dogs.

In addition, ylang ylang essential oil has been shown to have a positive effect on the cardiovascular system, which could contribute to its calming effects. A study by Hongratanaworakit and Buchbauer (2006) found that inhalation of ylang ylang essential oil decreased heart rate and blood pressure in human subjects, suggesting a potential mechanism for its calming effects.

Sweet marjoram essential oil contains several bioactive compounds, including terpinen-4-ol, which has been shown to have sedative effects on the central nervous system (Duru et al., 2003). These compounds may help reduce anxiety and promote relaxation when inhaled by dogs.

In addition, sweet marjoram essential oil has been shown to have a positive effect on the cardiovascular system, which could contribute to its calming effects. A study by Park et al. (2014) found that inhalation of sweet marjoram essential oil reduced heart rate and blood pressure in rats, suggesting a potential mechanism for its calming effects.

One of the active components of Roman chamomile essential oil is chamazulene, which has been shown to have anti-inflammatory and anxiolytic effects in animal models (Koulivand et al., 2013). Another component, bisabolol, has been shown to have sedative and anxiolytic effects in animal models (Galdino et al., 2012). These compounds may contribute to Roman chamomile essential oil's anxiolytic effects.

A study by Sarris et al. (2015) found that a combination of essential oils, including Roman chamomile, lavender, and bergamot, reduced anxiety in patients with generalized anxiety disorder. Another study by Moss et al. (2006) found that exposure to Roman chamomile essential oil vapor reduced anxiety in healthy volunteers. While these studies did not specifically investigate the effects of Roman chamomile essential oil on dogs, they suggest that it may have anxiolytic effects in humans.

One study by Umezu et al. (2006) investigated the anxiolytic effects of Roman chamomile essential oil in rats and found that inhalation of the oil significantly reduced anxiety-related behaviour.

A few studies have investigated its potential therapeutic effects in other areas. For example, a study by Cho et al. (2013) found that topical application of Roman chamomile essential oil reduced skin inflammation in dogs, suggesting a potential role in the management of skin allergies.

In a study by Kritsidima et al. (2011), dogs exposed to lavender and chamomile essential oils in a veterinary waiting room exhibited reduced signs of anxiety compared to dogs exposed to no essential oils.