Skin depigmentation associated with toceranib phosphate in a dog

Area of Science:

• Veterinary Dermatology
• Oncology
• Pharmacology

Background:

• Drug-induced depigmentation is common in humans on tyrosine kinase inhibitors but not reported in dogs.
• Toceranib phosphate is a tyrosine kinase inhibitor used in cancer therapy.

Observation:

• An 11-year-old Bernese mountain dog developed skin erosions, alopecia, and depigmentation after starting toceranib phosphate for a mast cell tumor.
• Lesions included eyelid depigmentation, periorbital leukotrichia, and depigmentation of the nose and paw pads.

Findings:

• Histopathology suggested vitiligo, consistent with a cutaneous adverse drug reaction.
• Skin lesions resolved after discontinuing toceranib phosphate therapy.

Implications:

• This case highlights potential skin side effects of toceranib phosphate in dogs.
• It is the first report of presumed drug-induced skin depigmentation in a dog treated with toceranib phosphate, suggesting careful monitoring is needed.