# Cephalexin for Fish (Fish Ceph)

> Cephalexin 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.

Source: https://petremedyusa.com/medications/cephalexin-for-fish/ · PetRemedyUSA

## 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.

## Products

- [Fish Ceph 250mg 30-Capsules](https://petremedyusa.com/products/fish-ceph-250mg-30-capsules/): from $35.99
- [Fish Ceph 500mg 60-Capsules](https://petremedyusa.com/products/fish-ceph-500mg-60-capsules/): from $51.99
- [Fish Ceph 500mg 100-Capsules](https://petremedyusa.com/products/fish-ceph-500mg-100-capsules/): from $63.99
- [Fish Ceph 250mg 100-Capsules](https://petremedyusa.com/products/fish-ceph-250mg-100-capsules/): from $55.19

## Frequently asked questions

### 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.