Minocycline for Dogs and Cats

PetMD’s medications content was written and reviewed by veterinary professionals to answer your most common questions about how medications function, their side effects, and what species they are prescribed for. This content shouldn’t take the place of advice by your vet.

What Is Minocycline?

Minocycline is a prescription antibiotic used in dogs, cats, and horses for specific bacterial infections. Minocycline may be used to treat tick-borne diseases of the blood including Borrelia (Lyme disease), Ehrlichia, Anaplasma, Rickettsia, and in the treatment protocol for heartworm disease in dogs as an alternative to doxycycline, the preferred treatment for these diseases, if doxycycline is not available.

Minocycline is also effective against Mycoplasma, spirochete bacteria, Chlamydia, and a variety of other susceptible bacteria. Minocycline is not used for the treatment of urinary tract infections or prostate infections in animals because it does not reach these areas in high enough concentrations to treat these infections.

Minocycline is FDA-approved for human use under several brand names including Minocin®, Minolira® extended-release, and Solodyn® extended-release, and as generic minocycline. Extended-release formulations of minocycline are not used in animals. Minocycline may also be given by intravenous infusion for certain medical conditions under direct veterinary supervision in a hospital setting.

Minocycline is currently not FDA-approved as a veterinary medication. However, it is readily utilized in the veterinary field, and veterinarians can legally prescribe certain human drugs in animals in certain circumstances. This is called extra-label or off-label use because this use isn’t described on the drug label.

In certain circumstances, your vet may recommend a compounded formulation of minocycline. Compounded medications are prescribed if there’s a specific reason your pet’s health can’t be managed by an FDA-approved drug, such as if your pet has trouble taking pills in capsule form, the dosage strength is not commercially available, or the pet is allergic to an ingredient in the FDA-approved medication.

Compounded medications are not FDA-approved. They are created by either a veterinarian or a licensed pharmacist on an individual basis to best suit a patient’s particular needs. You can learn more about compounded medications here

Minocycline Considerations

Minocycline should not be used in pets who are hypersensitive to it. Giving minocycline with certain medications and supplements can result in health risks to your pet or interfere with the absorption of minocycline, so it is important to discuss your pet’s medications, including vitamins and supplements, with your veterinarian.

Minocycline should be used with caution in pets that are pregnant, nursing, or younger than 6 months of age, since minocycline and other medications in the class of tetracycline antibiotics can cause birth defects and problems with teeth and bone development in growing animals. Speak with your veterinarian about whether your pet is still in its growth stage and if minocycline is right for them.

How Minocycline Works

Minocycline is classified as a tetracycline antibiotic. Minocycline works by preventing susceptible bacteria from making the essential proteins required for growth and survival. Without these proteins, the bacteria's cell wall becomes compromised, along with their ability to properly replicate and grow.

Minocycline Directions

Follow the directions on the drug label or as provided by your veterinarian.

Your veterinarian will instruct you to give your pet a specific amount of water immediately after giving the medication, to ensure the minocycline moves into the stomach properly and the medication does not become stuck in the esophagus.

Minocycline is best absorbed on an empty stomach. If gastrointestinal upset occurs, giving with a small amount of food may help, but this can decrease the amount of medication absorbed.

Certain medications and supplements can interfere with the absorption of minocycline. It is important to give your veterinarian a complete list of medications and supplements that your pet is currently taking.

Missed a Dose?

Speak with your veterinarian about what to do if you forget to give a dose of minocycline. Generally, they may instruct you to give it when you remember, or if it is almost time for your pet’s next dose, to skip the missed dose and resume your normal dosing schedule. Do not give extra or double doses.

Minocycline Possible Side Effects

Side effects of minocycline include:

• Gastrointestinal upset (vomiting, diarrhea)

• Reduced appetite

• Loss of hearing

• Yellowing of the eyes

• Lethargy

• Increased risk of sunburn of the hairless areas (nose, eyelids, ears, and abdomen)

Rare symptoms that may indicate severe side effects include low energy, weakness, severe or bloody diarrhea, loss of appetite (anorexia), yellowing of the whites of the eyes, gums, and skin (jaundice), bleeding, seizures, or severe changes in behavior.

If an oral minocycline capsule or tablet becomes stuck in the esophagus, it can cause painful damage and ulceration to the throat and esophagus (esophagitis), including symptoms of trouble swallowing, loss of appetite, and vomiting.

Long-term minocycline use can alter the balance of healthy bacteria in the body and increase the risk of fungal infection.

Human Side Effects

Minocycline is also a prescription medication for humans, frequently with dosages that are different from those prescribed for your pet by a veterinarian. Due to possible side effects, humans should never use medicine dispensed for their pets and pets should not be given any medicine dispensed for a human’s use.

Medications classified as tetracycline antibiotics are avoided for use in pregnant women because they can cause permanent growth defects and discoloration in the bones of the developing baby. If you are pregnant, wear disposable gloves when administering the medication and wash your hands afterward.

If you accidentally ingest this medication, immediately seek medical attention. Call your physician or the national Poison Control Center hotline at 800-222-1222.

Call Your Vet If:

• Severe side effects are seen (see above)

• Your pet’s condition worsens or does not improve with treatment

• You see or suspect an overdose

• You have additional questions or concerns about the use of minocycline

Minocycline Overdose Information

An overdose of minocycline can cause loss of appetite, severe vomiting, and diarrhea, sometimes severe enough to cause dehydration and electrolyte imbalances.

If you suspect an overdose, immediately contact your veterinarian, seek emergency veterinary care, or call an animal poison control center. Consultation fees often apply.

Pet Poison Helpline (855) 764-7661

ASPCA Animal Poison Control (888) 426-4435

Minocycline Storage

Minocycline should be stored at controlled room temperatures from 68 to 77 F.

Always confirm storage requirements by reading the prescription label.

Keep the container tightly closed in order to protect its contents from moisture and light.

Compounded medications should be stored according to the compounding pharmacy’s label.

Keep out of reach of children and pets.