Doxycycline for Cats

Written By Emily Gantt
Published: 07/30/2021Updated: 07/30/2021
Doxycycline for Cats

Doxycycline is a broad-spectrum oral antibiotic that comes from the tetracycline family. This medication is approved by the FDA for use in humans, though not for animals. Still, vets sometimes prescribe this medication for use in animals, including cats. Doxycycline treats sorts of bacterial infections in cats, including urinary tract infections, respiratory infections, and toxoplasmosis, to name a few. 


A prescription for doxycycline averages between $25 and $40 for a bottle, depending on the amount prescribed and the pharmacy. 


The dosage of doxycycline the vet prescribes your cat will depend on your cat's weight and age. The typical rule of thumb is 2 milligrams of doxycycline per pound of body weight.

Dosage instructions

When giving this medication, you may crush it and mix it into wet cat food, or you can put the pill directly down the cat's throat. When giving a tablet or capsule directly, make sure you give them at least 6 milliliters of broth or water afterward. Do not use the dry-pilling method for administering this medication since doxycycline in particular can cause esophageal irritation and damage.

Liquid doxycycline is a little easier to give. Like the pills, you can mix liquid doxycycline in food to hide the flavor or give the medication directly with a syringe. 


Though there are very few studies of the efficacy of doxycycline for cats, we did find a German study with some promising results. In this study, researchers treated 43 felines with chlamydophila felis or mycoplasma infections with either doxycycline or pradofloxacin for 42 days. Doxycycline was more effective than pradofloxacin against chlamydophila, eliminating 100% of the bacteria in all cats in the study group. On the other hand, 4 felines treated with pradofloxacin alone were still positive for infection after the study's end.

Side effects 

Like most medications, doxycycline may come with side effects. Side effects are usually mild, but using doxycycline in combination with other drugs may exacerbate the side effects. Here are the most common side effects of doxycycline for cats:

  • Nausea

  • Vomiting

  • Discoloration of teeth

  • Diarrhea

  • Throat irritation (from dry pilling methods)

  • Liver failure


There are some things to consider when giving doxycycline to cats. First and foremost, you should avoid giving your cat dairy or foods with high iron or calcium content since these can inhibit the absorption of doxycycline. 

Secondly, keep your cat out of the sunlight when taking this medication since it can make some animals more susceptible to sunburn, especially on the ears and nose. 

This medication should be used cautiously in felines with liver or kidney problems. Ask your vet before giving this medication if your cat has either of these conditions.

Lastly, this medication is not recommended for pregnant cats since it can cause discoloration of the teeth in their offspring. 

Drug interactions

Doxycycline has some known contraindications that pet parents should be aware of. Antacids can decrease the absorption of this medication. Also, doxycycline can interfere with the effectiveness of certain epilepsy medications. Talk to your vet if your cat is currently taking any of the below medications:

  • Antacids (Pepto, bismuth subsalicylate)

  • Oral iron supplements

  • Certain seizure medications (phenobarbital)

  • Certain blood thinners (warfarin)

  • Certain antibiotics (penicillin)

  • Ulcer medications (sucralfate)

Allergic reactions and sensitivity 

Allergic reactions are uncommon with doxycycline for cats, though they aren't impossible. Gastrointestinal issues normally characterize allergic responses to this medication, but more serious anaphylactic reactions are possible. Signs of anaphylaxis include:

  • Swelling of the face, tongue, paws, or throat

  • Hives

  • Trouble breathing

  • Collapse

  • Pale gums

Frequently asked questions

How should I store doxycycline?

You should store doxycycline tablets and capsules in the original bottle at room temp in a dark, dry place. Refrigerate liquid formulations of doxycycline after opening.

How long is doxycycline liquid suspension good for?

Liquid doxycycline has a short shelf-life. You should dispose of this medication after 2 weeks.

What should I do if I forget to give my cat a dose of doxycycline?

If it's close to the next scheduled dose, wait until that time to give your cat the medication. If you remember an hour or two after the usual dosage time, give the medication and resume your normal dosing schedule. Refrain from giving your cat two doses at once to make up for missed doses; this could cause an overdose or increase the possibility of side effects. 

How long does it take for doxycycline to start working?

This medication starts working within a couple of hours, though it can take several days before pet parents notice the effects.

Need pet insurance?
Need pet insurance?

Learn more in the Wag! app

Five starsFive starsFive starsFive starsFive stars

43k+ reviews


© 2023 Wag Labs, Inc. All rights reserved.

© 2023 Wag Labs, Inc. All rights reserved.