Calendula

What is calendula?

Calendula (Calendula officinalis), also known as pot marigold, is most used as a topical anti-inflammatory and antiseptic. It contains antioxidants, flavonoids, and terpenoids that likely contribute to its anti-inflammatory effects. Its antiseptic effects are not as reliable. It has also been used less often to treat and prevent gastric ulcers, and to help lower blood sugar. Calendula is most often used in dogs, cats, and horses.

The U.S. Food and Drug Administration (FDA) does not review non-drug health products (e.g., herbals, nutraceutaicals, shampoos, and other supplements) for safety or effectiveness before they are sold to the public. Manufacturers of non-drug health products must ensure their products are safe and labeled accurately. The FDA requires that these non-pharmaceuticals contain a disclaimer that says, “This product is not intended to diagnose, treat, cure or prevent any disease.” Health Canada licenses “veterinary health products” after reviewing safety, efficacy, and manufacturing information provided by the manufacturer. These products are not tested by Health Canada.

Your veterinarian is the best source of information about the safety of non-drug health products in pets. Just because a product is natural does not mean it is safe. All medicines and medicinal plants are potentially toxic if used inappropriately or given at high doses. Supplements can also have side effects, like pharmaceuticals. Few supplements and herbs have been subjected to rigorous scientific trials to determine their efficacy.

Although the information in this handout may be helpful, it also may be incomplete and may not represent the full range of effects the supplement could have on your pet.

How is calendula given?

• Calendula comes in liquid, cream, salve, and ointment form.
• Liquids are given orally (by mouth). All other forms are given topically (directly onto the skin).
• Oral forms are best given with food.
• Follow your veterinarian’s instructions on administering this medication carefully and give for the entire time prescribed by your veterinarian, even if your pet is feeling better.

This supplement should take effect within a few hours, although outward effects may not be noticeable.

What if I miss giving my pet the supplement?

If you miss a dose, give it as soon as you remember. However, if it is almost time for the next scheduled dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once.

Are there any potential side effects?

Calendula may cause the following side effects:

• Mild gastrointestinal upset
• Mild skin irritation if applied topically

Serious adverse reactions may occur. If any of the following signs develop, stop giving calendula and contact your veterinarian immediately:

• An allergic reaction such as irregular breathing, rash, fever, puffiness and swelling around the face

Drug sensitivities can develop over time with repeated exposure. Your pet may have no reaction after the first few doses, but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment.

Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This short-acting medication should stop working within 24 hours, although effects may last longer in pets with kidney and/or liver disease.

Are there any risk factors for this supplement?

DO NOT USE calendula in:

• Pets that are allergic to any component or to similar plants (e.g., ragweed, chrysanthemums, marigolds, daisies)

USE WITH CAUTION in:

• Pets that are pregnant or nursing
• Pets with low blood pressure (hypotension)
• Pets that are diabetic

Are there any drug interactions I should be aware of?

The following medications should be used with caution when given with calendula:

• Antifungals
• Blood pressure medications (e.g., amlodipine)
• Sedatives (e.g., benzodiazepines, barbiturates)
• Insulins

Vitamins, herbal therapies, and supplements have the potential to interact with each other, as well as with prescription and over-the-counter medications. It is important to tell your veterinarian about any medications (including all vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.

Is any monitoring needed with this supplement?

• Follow your veterinarian’s directions for follow-up visits and diagnostics.
• At home, monitor for any abnormal changes. If any occur, discontinue the medication and contact your veterinarian.

How do I store calendula?

• Follow the manufacturer’s label directions for storage.
• Keep the container out of reach of children and pets.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet’s weight and symptoms. Report any adverse effects to the FDA or Health Canada.