Folic Acid

What is folic acid?

Folic acid (also known as folate or folacin) is a B vitamin (B9) used to treat folic acid deficiency in dogs, cats, horses, and other animal species. Folic acid deficiencies usually occur due to small intestinal disease or pancreatic insufficiency but can also occur due to chronic use of certain medications, such as trimethoprim. Folic acid is necessary for normal metabolic functions such as DNA synthesis and red blood cell production.

The U.S. Food and Drug Administration (FDA) does not review non-drug health products (e.g., herbals, nutraceuticals, 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 folic acid given?

• Folic acid comes in capsule and tablet forms. An injectable form is available for your veterinarian to use in hospital.
• All forms administered at home are given orally (by mouth). 
• Oral forms may be given with or without food.
• Follow your veterinarian’s instructions on administering this medication and give for the entire time prescribed by your veterinarian, even if your pet is feeling better.

This medication should take effect within 1–2 hours, although outward improvements 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?

Folic acid may cause the following side effects:

• Mild gastrointestinal upset 

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

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

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 liver and/or kidney disease.

Are there any risk factors for this supplement?

DO NOT USE folic acid in

• Pets that are allergic to any component of the medication
• Pets with anemia (low red blood cell count) of unknown cause
• Pets that have not had their folate and cobalamin blood levels determined

Are there any drug interactions I should be aware of?

The following medications should be used with caution when given with folic acid:

• Barbiturates (e.g., phenobarbital)
• Cholestyramine
• Certain antimicrobials (e.g., chloramphenicol, nitrofurantoin, sulfa/trimethoprim)
• Fluorouracil
• Methotrexate

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.

Is any monitoring needed with this supplement?

• Folate and cobalamin blood tests are recommended before and during treatment.
• 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 folic acid?

• Store at room temperature between 68°F and 77°F (20°C and 25°C).
• Protect from light and moisture. Do not freeze.
• Keep medication 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.