TL;DR: Black crusty warts on older dogs are usually benign sebaceous adenomas, but you should consult a veterinarian if the growth bleeds, changes rapidly, or appears infected.
What are these black, crusty growths appearing on my dog?
Finding a new lump or bump on your pet can be alarming. When owners describe "black crusty warts," they are often seeing sebaceous adenomas or old-age warts. These are typically benign growths originating from the oil glands in the skin. Over time, the surface can become pigmented (turning black) and develop a dry, crusty texture due to exposure to the air or minor irritation. While they may look unsightly, they are common in aging dogs and are often harmless skin changes.
When is a black crusty growth considered a veterinary emergency?
The urgency level for black crusty warts is generally Low and typically does not require immediate after-hours care. However, you should schedule a routine appointment if you observe the following:
- The growth begins to bleed frequently.
- There are signs of infection, such as pus or a foul odor.
- Your dog is constantly licking or chewing at the site.
- The growth is rapidly changing in size or shape, which may indicate more serious conditions like melanoma.
How does sending a photo help the veterinarian triage my pet?
Providing your veterinarian with a clear, high-resolution photo can significantly speed up the triage process by offering several benefits:
- The medical team can evaluate the exact location, texture, and color of the growth before you step into the office.
- A photo taken at home provides a stable reference point for the vet to monitor growth over time.
- It captures the growth's appearance clearly in case the pet is too stressed or restless to be examined easily during a live exam.
Clinical Context (Merck Veterinary Manual)
Black, crusty, wart-like lesions on a dog's skin may be associated with a papillomavirus infection, appearing as multiple discrete, erythematous, black or brown hyperkeratotic plaques and papules. These lesions are typically nonpruritic and uncommonly ulcerated. Acrochordons (cutaneous tags, soft fibromas, fibrovascular papillomas) are also a possibility, appearing as pedunculated exophytic growths, often covered by a verrucous epidermal surface. For older dogs presenting with a festering toe, particularly accompanied by swelling of the digit, loss of the nail, and destruction of underlying bone, radiographs and a deep punch biopsy that includes bone are indicated to rule out malignant melanoma.
Chapter: Dermatology, Oncology
Source: The Merck Veterinary Manual, 11th Edition (Page 947)