Major Uses

Tetracycline is a broad-spectrum antibiotic used primarily to treat Lyme disease, Rocky Mountain spotted fever, upper respiratory infections, infectious anemia, and other conditions in cats and dogs. It may also be used to treat certain immune-mediated disorders, such as discoid lupus erythematosus, due to its ability to modulate the immune system of animals. Tetracycline works by inhibiting protein synthesis in susceptible bacteria.

One important benefit of tetracycline is its effectiveness against infections of the prostate gland; most antibiotics are unable to fully penetrate the prostate. It is also useful in the treatment of intracellular parasites.

Common Precautions

Tetracycline may cause side effects in some animals undergoing treatment with the medication. Vomiting and nausea are the two most commonly reported adverse effects, and these may be worse in cats than in dogs. Lack of appetite and diarrhea are also possible. If given to immature animals, the medication has the potential to permanently stain teeth.

The bitter taste of the medication may cause drooling and vomiting in some animals, especially cats. If fever or depression develops in cats during treatment with tetracycline, the drug should be stopped and a veterinarian should be consulted. Tetracycline should not be used in animals with existing kidney or liver disease unless absolutely necessary. It should not be given to pregnant animals due to the possibility of fetal abnormalities.

Rarely, use of tetracycline may induce urinary stones consisting of tetracycline. Additionally, the drug may cause a false positive urine test for glucose. This is not harmful, but it should be noted.

Tetracycline should not be given with food; food binds to the medication and prevents proper absorption by the body. Tetracycline is known to interact with a variety of other medications and supplements, including antacids, iron supplements, insulin, digoxin, and theophylline.

Tetracycline 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.


Tetracycline should be stored in its original packaging, at room temperature, and away from children and animals. It should be kept in a light-resistant container.


Tetracycline is available as an oral suspension and as 250 mg and 500 mg capsules. In dogs, tetracycline is typically dosed at 10 mg/lb (20 mg/kg) three times daily. In cats, the medication is dosed at 5 to 7 mg/lb (10 to 15 mg/kg) three times daily.

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 tetracycline is missed, it should be given as soon as possible. If it is almost time for the next dose, the missed dose should be skipped and the normal schedule resumed. Two doses of this medication should not be given at once.

A pet's veterinarian should be contacted with any questions about the administration of or response to any medication.

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.