Overview of Minocycline for Canines and Felines

Minocycline, also known as Minocin® or Dynacin®, is an antibiotic for dogs and cats of the tetracycline class. This drug is related to other tetracyclines such as doxycyline, chlortetracycline and oxytetracycline. It has recently been used more often and in place of doxycyline because of a substantial increase in the price of that product.

Minocycline will inhibit the synthesis of protein within susceptible organisms (bacteria, etc.), resulting in their death.

Minocycline is often used for infections caused by bacteria and by microorganisms that are not susceptible to common antibiotics. 

Minocycline is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.

This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug.

Brand Names and Other Names of Minocycline

This drug is registered for use in humans only.

Human formulations: Minovin®, Dynacin® (and various generic preparations.

Veterinary formulations: None

Uses of Minocycline for Dogs and Cats

Minocycline is an antibiotic used to treat infections in animals caused by susceptible bacteria. 

Examples of these infections include urinary tract infections, respiratory infections, blood-borne infections and wound infections. 

Minocycline is especially useful for treating tick-borne bacterial diseases such as Rocky Mountain spotted fever, ehrlichiosis and water-borne infections such as leptospirosis. 

Minocycline is also used to treat Wolbachia, an organism that infects heartworms, in an effort to treat heartworm disease.

Minocycline is not effective for treating infections caused by a virus or fungus.

Precautions and Side Effects

While generally safe and effective when prescribed by a veterinarian, minocycline can cause side effects in some animals.

Minocycline should not be used in animals with known hypersensitivity or allergy to the drug.

Minocycline may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with minocycline. Such drugs include certain antacids, iron supplements, kaolin, bismuth subsalicylate, isotretinoin, warfarin and certain antibiotics such as penicillins.

The most common side effects include gastrointestinal disturbances. Occasionally nausea and/or vomiting has been observed, especially when high doses are administered. 

Rarely, animals may develop diarrhea or loose stools from oral minocycline. This is related to a change in the bacterial population in the animal’s intestine. If diarrhea is observed, your veterinarian should be notified, and a change in medication may be indicated.

Minocycline may bind to calcium in teeth and cause discoloration. Therefore, the administration of minocycline to animals younger than seven months of age is discouraged without first consulting with a veterinarian. Minocycline is less likely to cause bone and teeth abnormalities then other tetracyclines.

Minocycline should not be administered orally with calcium or calcium-containing medications because they may inhibit oral absorption of the antibiotic.

How Minocycline is Supplied

Minocycline is available as oral tablets as follows: 50 mg, 75 mg and 100 mg. Extended release 45 mg, 65 mg, 115 and 135 mg.

Available in oral capsules in 50, 75 and 100 mg.

Oral suspension 50 mg/5 ml in 60 mL.

Available in powder for injection in 100 mg vials.

Dosing Information of Minocycline for Dogs and Cats

Medication should never be administered without first consulting your veterinarian. 

The typical dose for dogs is 2.2 to 5.4 mg per pound (5 to 12 mg/kg) every 12 hours to 24 hours orally. Doses can be higher to treat some infections.

The typical dose for cats is 2.2 to 5.4 mg per pound (5 to 12 mg/kg) every 12 hours orally. Doses may be higher to treat some infections.

The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.