Marshmallow root (Althaea officinalis) has been used for thousands of years for health care. Its medicinal use was first recorded in the 9th century BC. The scientific name is derived from the Greek altho, meaning to cure, a strong statement for its health benefits. Historically it has been used for health problems related to the mucous membranes. Mucous membranes are the moist, inner lining of some organs and areas of the body like the digestive, respiratory and urinary tissues. This means it has indications for a wide range of problems that include diarrhea, coughs and urinary bladder disorders. Marshmallow root is the focus for use, but, in some situations, the leaf is used. Do not confuse the herb marshmallow root with the sweet marshmallow treat that no longer contains the marshmallow root herb.

Marshmallow root has many different actions depending on the amount of the herb given, frequency of administration and preparation. These actions include diuretic, antimicrobial, anti-inflammatory, expectorant, blood glucose lowering and immune boosting effects. The way the marshmallow root is processed can have an impact on the amount of the active constituent present. For example, marshmallow root contains a gelatinous material known as mucilage. This mucilage plays an important role in soothing and protecting irritated or inflamed tissue. Making a decoction (heating or boiling) will damage the mucilage, while a cold infusion (soaking in water) is best for the mucilage. This means that the method of preparation should be considered along with its intended use.

Specific health challenges experienced by dogs and cats that marshmallow root may benefit include problems with diarrhea, nausea and vomiting. These issues may be associated with chronic problems like inflammatory bowel disease or acute issues like stress-related diarrhea or upset from food changes. Marshmallow root also has benefits for urinary tract inflammation and infections as a result of its anti-inflammatory and antimicrobial effects along with its diuretic action. These same effects can be helpful for respiratory issues like bronchitis and laryngitis. In addition to its anti-inflammatory effects and mucous membrane protective actions, marshmallow root is an antitussive (relieves or prevents coughs). Historically, marshmallow has also been used topically for management of wounds.

Marshmallow root is often mixed with other herbs like licorice, mullein leaf or wild cherry bark. The goal is to use herbs that work together to more effectively address the range of symptoms associated with the illness being addressed. Before using these combinations, it is important to understand each of the ingredients and make sure that they are safe for pets.

Marshmallow root is considered safe to use for dogs and cats. However, it should be avoided in individuals that show sensitivity to marshmallow root. Marshmallow root can also lower blood glucose levels; therefore, use with caution in diabetic pets, especially if they are receiving insulin. Due to the high mucilage content, marshmallow root can potentially interfere with absorption of some medications. Timing of administration can be important.

As with all health issues for pets, it is essential to get a clear understanding of the illness and diagnosis before starting on any therapy. There are many illnesses that appear similar but have very different therapies. For example, vomiting can indicate that there is simply an upset stomach or intestine that just needs a conservative approach to soothing the inflammation. However, vomiting can indicate many other issues that can be more serious, like liver disease, pancreatitis or a foreign object like a ball in the stomach creating a blockage or severe irritation. Issues like a foreign object may require surgery for removal and cannot effectively be managed by marshmallow alone. In a similar manner, a cough could be caused by irritation in the airways requiring an approach that reduces the inflammation or the cough could be caused by a heart problem that requires management of the heart issue as the primary care. Keep in mind that marshmallow root may play a role in management of a health issue even when it is not the primary focus of therapy.

If you have questions about your pet’s health, contact your veterinarian. If you have questions about the use of herbs in your pet, contact a veterinary herbalist.

Ron Carsten, DVM, PhD, CVA, CCRT was one of the first veterinarians in Colorado to use the integrative approach, has lectured widely to veterinarians, and has been a pioneer in the therapeutic use of food concentrates to manage clinical problems. He is also the founder of Colorado Animal Rescue (CARE). In addition to his Doctor of Veterinary Medicine, he holds a PhD in Cell and Molecular Biology and is a Certified Veterinary Acupuncturist and Certified Canine Rehabilitation Therapist. He practices integrative veterinary medicine in Glenwood Springs.