Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: Vets prescribe antibiotics for cats with bacterial infections, such as abscesses, some urinary or skin infections, dental infections, and certain respiratory infections. Common choices include amoxicillin-clavulanate, doxycycline, clindamycin, and a long-acting injection (cefovecin). The right drug and dose depend on the infection and your cat’s weight and health, so only use antibiotics your vet prescribes. Many cat colds and most cases of cystitis aren’t bacterial and don’t need antibiotics.
This guide doesn’t give doses. Your cat’s dose must come from your vet.
Commonly used antibiotics
- Amoxicillin-clavulanate: used for skin, wound, urinary, and respiratory infections.
- Doxycycline: often used for respiratory infections involving Mycoplasma or Chlamydia, and some tick-borne diseases.
- Clindamycin: used for dental infections, abscesses, bone infections, and toxoplasmosis.
- Cefovecin (Convenia): a single injection that lasts about 2 weeks, helpful for cats that are hard to pill. It can’t be stopped once given.
- Fluoroquinolones (such as marbofloxacin or pradofloxacin): reserved for specific infections, ideally based on a culture.
- Metronidazole: used for some gut and anaerobic infections.
When antibiotics aren’t needed
- Upper respiratory infections (“cat colds”): usually viral. Guidelines suggest antibiotics only if there’s fever, lethargy, poor appetite, and thick discharge, or signs lasting more than about 10 days.
- Feline idiopathic cystitis: the most common cause of urinary signs in young cats, and not an infection.
- Most mild diarrhea.
Unnecessary antibiotics cause side effects and resistance without helping.
Side effects
- Vomiting, diarrhea, drooling, or poor appetite
- Esophageal damage: doxycycline and clindamycin tablets or capsules can stick in a cat’s esophagus and cause serious narrowing. Always follow pills with a small amount of water or food.
- Enrofloxacin: at higher doses it can cause sudden, permanent blindness in cats. Vets generally choose other options for cats.
- Metronidazole: high doses or long courses can cause wobbliness or other neurological signs.
- Allergic reactions: facial swelling, hives, or trouble breathing (emergency).
Call your vet if side effects appear or your cat isn’t improving within a few days.
Giving antibiotics to cats
- Ask about a flavored liquid, compounded treat, or injection if pilling is a struggle.
- Use the syringe provided for liquids.
- Follow every pill with water or a treat.
- Give every dose on schedule for the full course prescribed.
What to avoid
- Human antibiotics or a dog’s prescription: strengths and formulations differ, and some ingredients or doses are unsafe for cats.
- Leftover antibiotics from a previous illness.
- Stopping early without your vet’s advice.
- Crushing bitter tablets into food without asking, which can cause drooling and food refusal.
Frequently asked questions
Can I give my cat amoxicillin from my doctor?
No. Human products may be the wrong strength or combination, and your cat may not need an antibiotic at all.
How long until antibiotics work?
Many cats improve within 2–3 days. If not, call your vet.
Is the long-acting injection better than pills?
It’s convenient, but it can’t be stopped if there’s a reaction and isn’t the right choice for every infection. Discuss the options with your vet.
Sources
- Lappin MR, et al. Antimicrobial use guidelines for treatment of respiratory tract disease in dogs and cats: ISCAID. J Vet Intern Med. 2017
- Weese JS, et al. ISCAID guidelines for the diagnosis and management of bacterial urinary tract infections in dogs and cats. Vet J. 2019
- Gelatt KN, et al. Enrofloxacin-associated retinal degeneration in cats. Vet Ophthalmol. 2001
- German AJ, et al. Oesophageal strictures in cats associated with doxycycline therapy. J Feline Med Surg. 2005
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.