From Dog

Chlorambucil (Leukeran) is an orally-available nitrogen mustard alkylating agent.

This drug achieves effects gradually and often can be used in animals with compromised bone marrow. It can cause bone marrow suppression, but this is usually late in onset and rapidly reversible. This drug is given orally and is most commonly used in treatment of chronic, well-differentiated cancers; it is considered ineffective in rapidly proliferating tumours.

Chlorambucil is indicated for:

  • Immune mediated skin diseases (Pemphigus)
  • Chemotherapy in dogs with various forms of lymphoma
  • Chronic inflammatory diseases such as irritable bowel disease and chronic periodontitis.

The most common adverse side-effects seen with chlorambucil are gastrointestinal toxicity and myelosuppression. A less common side-effect of high-dose chlorambucil is neurotoxicity. Seizures and myoclonus have been reported. These signs may be due to chloroacetaldehyde, a neurotoxic metabolite of chlorambucil[1]. The risk of neurotoxicity is reduced by ensuring a 24-hour interval between successive doses or by using low-dose chlorambucil every 49 hours.

Dose rates for use in dogs:

- Lymphoma - 2 mg / dog orally, once or twice weekly +/- 5mg prednisolone orally once a day
- Irritable bowel disease - 0.1 - 0.5 mg/kg orally every 2 - 3 days


  1. Barrs, VR & Beatty, JA (2010) Diagnosis and treatment of low-grade alimentary lymphoma. In August, JR (Ed) Consultations in feline internal medicine. Vol 6. pp:187-199