By Dr Phil Sacks
I have treated 100’s of Mast cell tumours in dogs in private veterinary practice as they are one of the most common tumors in dogs and in my experience extremely common especially in Staffies, Pit bulls, Boxers.
Mast cells are tissue cells that live for about 40 days , and they come from the Bone marrow
Mast cells are filled with histamine –cause the allergic reaction; and Heparin makes them bleed a lot, attractive to eosinophils and enzymes to break down wounds after surgery
95% on skin or just under the skin
50% on trunk, 40 % on leg < 1 % in spleen liver and kidneys
Supportive therapy when treating Mastocytomas in dogs
- H2 antagosits like Ranitidine or Famotidine
- H1 Diphenhydramine
Diagnosis of Mast Cell tumour in dogs
Very easy on Cytology of a fine needle aspirate of the mass . This is examined under the microscope while the owners waits during the consultation and a diagnosis confirmed.
We recommend aspirating the regional lymph node prior to surgery to determine if the mastocytoma has spread. It is also a good prognostic indicator.
One in four dogs gets a second MCT in their life.
Therapeutics – treating a mast cell tumour in a dog
Wide surgical excision with clean margins easiest!
Radiation therapy – Definitive radiation therapy daily for 3 weeks!! – Usually curative
Chemotherapy = radiation if dirty margins or spread – Vinblastine and Prednisilone therapy with or without radiation is an option.
Systemic therapy – Thyrosine Kinase Inhibitor – Palladia
Masivet – for non surgical MCT – active is masitinib. also a TYROSINE KINASE INHIBITOR Due to its spectrum of inhibition, Masivet® has demonstrated efficacy in the treatment of mast cell dysfunctions and its related complications. This range leads to masitinib having further potential indications like atopic disease.
Palladia – Tocerab 2.5 – 2.75mg /kg at a three times a week dose on Mon/Wed/Fri dose rate
Can not stop Palladia once its working –ever – yes its lifelong! Like marriage ! but Expensive – $450 per month great for hard to reach places or owners to say good bye.
Dr Phil is a Senior Fellow of the University of Melbourne faculty of Veterinary Science and is accredited by AQIS (Australian Quarantine and Inspection Service