Major Uses

Doxycycline is a tetracycline antibiotic used to treat bacterial infections in dogs and cats. It is not approved by the Food and Drug Administration for use in animals, but it is prescribed legally by veterinarians for extra-label use in dogs and cats.

This medication provides broad antibacterial protection against a wide variety of infectious agents by inhibiting bacterial protein synthesis. Doxycycline is most commonly used to treat toxoplasmosis, leptospirosis, Rocky Mountain spotted fever, psittacosis, mycoplasma, and Lyme disease. It may also be used in the treatment of certain upper respiratory infections and in cases of methicillin-resistant Staph intermedius (MRSI) in animals. Additionally, doxycycline is sometimes used in combination with other medications when treating heartworm infections.

Common Precautions

The most commonly reported side effects associated with the use of doxycycline in dogs and cats are nausea and vomiting. Administering the medication with food is beneficial. Diarrhea is also sometimes observed in animals being treated with doxycycline.

When given to immature animals, doxycycline may permanently stain teeth. The drug is also known to irritate the esophagus if allowed to become stuck during swallowing. This can potentially cause scarring and difficulty swallowing. Following administration of tablets with at least 6 cc of water is helpful.

Animals may erroneously test positive for glucose on urine dipstick tests when taking doxycycline. Doxycycline should not be used in animals undergoing treatment with digoxin, as tetracyclines are known to make digoxin act stronger. Doxycycline is also known to interact with supplements that contain calcium and/or iron. When these medications are given at the same time, there is a risk that neither will be absorbed properly.

Administering doxycycline in combination with theophylline, such as in the treatment of kennel cough, may result in nausea. Other drugs known to interact with doxycycline include anticoagulants, barbiturates, insulin, bismuth subsalicylate, aminophylline, methoxyflurane, kaolin/pectin, cathartics, certain other bactericidals, and others.

Doxycycline should be used cautiously in young, pregnant, or lactating animals, and in pets with severe liver disease. The teeth should not be brushed for two full weeks following administration of Doxirobe.

Doxycycline should not be used in animals with a known allergy or hypersensitivity to the drug. Any known or suspected overdose should be reported to a veterinarian right away.


Doxycycline should be stored in a tightly sealed container, at room temperature, and out of the reach of animals and children. Capsules and tablets should be stored away from light sources. Unreconstituted and reconstituted oral gel should be refrigerated.


Doxycycline is available as an oral syrup or suspension, in tablet and capsule form, and as a solution for injection.

Typical dosing of doxycycline in dogs and cats is 2.5 mg per pound (5 mg/kg) every 12 hours by mouth. Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.

If a dose of this medication is missed, it should be given as soon as possible. It is important not to give two doses of this medication at once.

This information is for general reference only and should not be used for the diagnosis or treatment of any condition of your pet. It's intended as a general reference, this information may not include all possible uses, precautions, directions, reactions (including allergic), drug interactions, or withdrawal times. Always consult your local veterinarian and have your pet examined for any advice concerning the diagnosis and treatment of your pet, including which products and doses are most appropriate. Any trademarks are the property of their respective owners. VetDepot is not a pharmacy. All prescription products are dispensed by our Pharmacy Partner. Article last updated 2/2014.