Herbs that calm and soothe

Herbs have been an abundant medical resource since ancient times, and a huge body of knowledge has been amassed on their methods of extraction and use in both humans and animals.

Scarce scientific data

Some herbs with calming effects have been proven to be safe for animals, whereas others are known to be toxic to them. For many herbs that are traditionally known for their calming and sedative actions, however, there is a considerable lack of scientific data about their efficacy and safety for pets. Likewise, a herb regarded as toxic may not be harmful in small quantities; the toxicity depends on the amount of the herb ingested.

Herbs regarded as safe

The herbs valerian (Valeriana officinalis), purple passionflower (Passiflora incarnata) and lemon balm (Melissa officinalis) are considered safe and are widely used for their calming properties.

Valerian root is rich in valepotriates, which are the main sedative components, and also in actinidine – a cat attractant similar to nepetalactone, which is the active compound found in catnip (Nepeta cataria). Valerian is available in various dosage forms, such as tea, powder, tablets, capsules and drops. Meanwhile, the main anxiolytic components in passionflower are considered to be flavonoids like chrysin. Liquid extracts are prepared from all parts of the passionflower: flowers, stems and leaves. Both of these herbs are used to relieve anxiety, insomnia and even to control seizures. Lemon balm is known to have antimicrobial, antiparasitic and sedative properties. Its leaves are used to prepare infusions (tea) and liquid extracts.

The safety of valerian and purple passionflower was studied in a preclinical study in dogs, both acutely and chronically, for 180 days. There were no observed adverse effects of their use, so they are regarded as safe. Nonetheless, it would be useful to have more clinical data on their efficacy – such as the dose and the dosage regimen for standardized extracts to achieve adequate sedation. Interestingly, while lemon balm is regarded as being safe for use in animals, only its antimicrobial and antiparasitic actions have been studied in dogs (mostly in combinations with other essential oils). Its sedative effect was actually only confirmed in rodents.

Potentially dangerous herbs for pets

Perhaps surprisingly, chamomile (Chamaemelum nobile) is less safe for dogs and cats, since its components – volatile oil bisabolol, chamazulene, anthemic and tannic acid – can cause poisoning. According to the American Society for the Prevention of Cruelty to Animals (ASPCA), symptoms include contact dermatitis, allergic reactions, vomiting, diarrhea and anorexia, while long-term use can lead to bleeding tendencies.

Another sedative plant called Humulus lupulus can cause a dangerous increase in the body temperature of pets, along with panting, increased heart rate and digestive disturbances. Its flowers, which are known as hops, are used as a flavoring and stability agent in beer. And while lavender (Lavendula angustifolia) is widely used in aromatherapy for humans thanks to its soothing scent, its active chemical components – linalool and linalyl acetate – can cause nausea and inappetence in dogs and cats.

Unexplored by modern science

Numerous calming herbs are still unexplored by modern science from a pet perspective. For example, leaves of bastard balm (Melittis melissophyllum) and sweet chestnut (Castanea sativa) are traditionally regarded as effective and non-toxic. Nonetheless, studies are quite scarce, so this could be an interesting opportunity from both a scientific and a commercial perspective.

And even if a herb is regarded as safe, it is still wise to be prudent. Therefore, when considering herbal options for their pets, owners should check with veterinarians whether the herbs are safe or toxic in their specific situation.