Steroids & immune Dogs & Cats

Chlorambucil (Leukeran) for dogs and cats

Treats some cancers, such as lymphoma, and immune diseases like inflammatory bowel disease. [1]

Last reviewed: October 2026 · 2 sources · see sources

Quick answerChlorambucil is a prescription medicine for dogs and cats. It damages the DNA of fast-dividing cells, including cancer and immune cells. The most common side effects: coat changes and fur loss.

Key facts

Generic nameChlorambucil
Common brand namesLeukeran
Used inDogs & Cats
TypeSteroids & immune
Prescription?Prescription
Typical US priceNot listed (no reliable public source)

What it's used for

Treats some cancers, such as lymphoma, and immune diseases like inflammatory bowel disease. [1]

How it works

It damages the DNA of fast-dividing cells, including cancer and immune cells. [1]

Side effects and cautions

Common side effects: Coat changes and fur loss. Serious: low blood counts, bleeding or infections. [1]

Use with care: It is a chemotherapy drug: wear gloves and follow your vet's handling rules. Regular blood counts are needed. [1]

Call your vet right away if your pet has trouble breathing, facial swelling, hives, collapse, or any side effect that is severe or getting worse.

About dosingDosing is your vet's call. We don't list doses because the right amount depends on your pet's weight, age, health and other medicines. Don't change a dose or stop a medicine without asking your vet, and never give a pet medicine meant for people unless your vet tells you to [2].

What it costs

We don't list a price for this one because we couldn't find a reliable public source. Ask your vet or pharmacy for a quote; prices depend on your pet's size, the dose and where you fill it.

Chlorambucil FAQ

What is Chlorambucil used for in dogs and cats?

Treats some cancers, such as lymphoma, and immune diseases like inflammatory bowel disease.

What are the side effects of Chlorambucil?

Coat changes and fur loss. Serious: low blood counts, bleeding or infections.

Does Chlorambucil need a prescription?

Yes. It needs a prescription from a veterinarian.

How much Chlorambucil should I give my pet?

Only your veterinarian can tell you. The right dose depends on your pet's weight, health and other medicines, so we don't list doses. Never give a pet a medicine prescribed for a person or another animal without asking your vet.

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This page is general information for pet owners, not veterinary advice. Talk to your vet about your own pet.

Sources (2) — tap to show
  1. VCA Animal Hospitals – Chlorambucil (veterinary drug handout)
  2. FDA – Frequently asked questions about animal drugs