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Masitinib

Prescription

Tyrosine Kinase Inhibitor (Chemotherapy)

Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team

Species

Dog, Cat

Brands

2 available

Interactions

1 documented

Formulations

Mechanism of action

Selectively inhibits c-Kit (CD117) tyrosine kinase, blocking stem cell factor (SCF)-dependent signaling involved in mast cell tumor growth, survival, and differentiation. Also inhibits PDGFR and FAK.

At a glance

Class

Tyrosine Kinase Inhibitor (Chemotherapy)

Schedule

Prescription (Chemotherapy)

Storage

Store at room temperature below 30°C

Dosing

🐕

Dog

FDA-approved for Grade 2–3 recurrent/non-resectable canine mast cell tumors with

Dose

12.5 mg/kg

Route

Frequency

q24h

🐈

Cat

Not approved in cats; limited veterinary oncology data

Dose

—

Route

Frequency

N/A

Educational reference only

This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

💊

Other — 1

Strength

—

Storage

Store at room temperature below 30°C

Safety

Monitoring parameters

CBC q2 weeks for first 3 months, then monthlyBiochemistry panel (hepatic, renal)Body weightAlbumin levels

Educational reference only

Interactions

Moderate — 1

Meloxicam

moderate

Both can cause GI ulceration independently (masitinib: GI toxicity from c-Kit inhibition; meloxicam: prostaglandin inhibition). Combined GI toxicity risk.

Management: Monitor GI signs closely. Use gastroprotectant (omeprazole). Some oncologists avoid concurrent NSAIDs with TKIs.

Educational reference only

Brands

Other markets

Masivet

Kinavet

FAQs

Frequently asked questions

›What is Masitinib?

Masitinib is a tyrosine kinase inhibitor (chemotherapy) used in pets. Selectively inhibits c-Kit (CD117) tyrosine kinase, blocking stem cell factor (SCF)-dependent signaling involved in mast cell tumor growth, survival, and differentiation. Also inhibits PDGFR and FAK.

›What is Masitinib used for in pets?

Masitinib is used in veterinary medicine for: FDA-approved for Grade 2–3 recurrent/non-resectable canine mast cell tumors with; Not approved in cats; limited veterinary oncology data.

›What is the Masitinib dose for dogs?

For dogs, Masitinib is typically dosed as follows — FDA-approved for Grade 2–3 recurrent/non-resectable canine mast cell tumors with: 12.5 mg/kg PO q24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What is the Masitinib dose for cats?

For cats, Masitinib is typically dosed as follows — Not approved in cats; limited veterinary oncology data: undefined undefined PO N/A. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›Does Masitinib need a prescription?

Yes. Masitinib is a prescription medication and should only be administered under veterinary supervision.

Educational reference only

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

Plumb's Veterinary Drug Handbook
Withrow & MacEwen's Small Animal Clinical Oncology
Merck Veterinary Manual
NRC Nutrient Requirements of Dogs and Cats
Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

ASPCA Animal Poison Control Center Guidelines
AAHA Diabetes Management Guidelines
ASPCA Poison Control Guidelines
RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

EPIC Study (J Vet Intern Med 2016)
JVIM FAT CAT Study

Regulatory & approvals — 1

CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

Washington State University VCPL MDR1 Database

Related medicines

Other medicines in the same class (Tyrosine Kinase Inhibitor).

Toceranib Phosphate

Inhibits multiple receptor tyrosine kinases including KIT, VEGFR, and PDGFR, blocking tumor cell proliferation and angiogenesis

dog