Cephalexin for Fish (Fish Ceph)
Quick answerCephalexin is a first-generation cephalosporin. Like penicillins, it weakens bacterial cell walls, but it is stable against some enzymes that break penicillins down. Strongest against gram-positive bacteria, with activity against some gram-negative species.
What cephalexin is commonly used for
- Fin rot and body wounds
- Skin and ulcer infections
- Bacterial infections that follow injury
Things to know
- Not effective against parasites, fungi or viruses.
- Cephalosporins and penicillins are related, so people with penicillin allergies should take care when handling.
- Treat in a hospital tank where possible to protect the biofilter.
How it compares with other options
Cephalexin is one of several classes of antibiotic used by keepers. Our comparison guide lays out which class suits which problem, and our treatment packs combine complementary classes so you have a backup ready.
Products containing cephalexin
Cephalexin FAQ
What is cephalexin used for in aquariums?
It is commonly used for bacterial problems on the skin and fins, such as fin rot, ulcers and wounds.
How is cephalexin different from amoxicillin?
Both attack the bacterial cell wall. Cephalexin is a cephalosporin and can remain effective against some bacteria that have learned to break down penicillins, which is why some keepers switch between them.
Responsible use. For ornamental aquarium fish only. Not for human use or fish intended for food. Follow the label and consult a veterinarian when unsure.