Hi stranger! Signing up for MypetMD is easy, free and puts the most relevant content at your fingertips.

Get Instant Access To

  • 24/7 alerts for pet-related recalls

  • Your own library of articles, blogs, and favorite pet names

  • Tools designed to keep your pets happy and healthy

or Connect with Facebook

By joining petMD, you agree to the Privacy Policy.

PetMD Seal

Hair Follicle Tumors in Dogs


Trichoepitheliomas and Pilomatricomas in Dogs


Hair follicle tumors are generally benign tumors that originate in the hair follicles in the skin. There are two types of hair follicle tumors, trichoepitheliomas, which arise from cystic hair follicles (follicles that have closed over, like a sac), and pilomatricomas, which arise from the cells that produce the hair follicles.


Trichoepitheliomas are small benign tumors, often found along a cat's back, shoulders, flank, tail or limbs. Pilomatricomas are rare skin tumors that develop from the hair matrix, where the cells which grow the hair follicles develop and are contained. Pilomatricomas are small and are often found on the trunk of middle-aged dogs.


Hair follicle tumors should be immediately evaluated by a veterinarian. The prognosis for these hair follicle tumors is generally positive, as the majority of the tumors are found to be benign.


Breeds that have been shown to be predisposed to hair follicle tumors are Golden Retrievers, Basset Hounds, German Shepherds, Cocker Spaniels, Irish Setters, English Springer Spaniels, Miniature Schnauzers and Standard Poodles. The prognosis for these hair follicle tumors is generally positive, as the majority of the tumors are found to be benign.


Symptoms and Types



  • Back
  • Shoulders
  • Flank
  • Tail
  • Limbs



  • Trunk/torso of the body




  • Unknown
  • Suspected genetic link




Your veterinarian will perform a thorough physical exam on your dog, taking into account the background history of symptoms and medical health history that you provide.


Your veterinarian will conduct a complete physical exam on your dog, including a blood chemical profile, a complete blood count, an electrolyte panel and a urinalysis.


Samples of the tumor will need to be taken for a close examination of the structure of the tumor. Samples will be taken for histopathologic laboratory analysis, both by fine needle aspirate (fluid sample) and by tissue biopsy. Such an analysis will determine exactly which type of hair follicle tumor is present and whether it is benign or malignant. Although this type of tumor is often found to be benign, it is possible that histopathological results will show it to be a different kind of tumor, in which case the treatment may need to be more aggressive.




Related Articles

Wart Virus in Dogs

The term papillomatosis is used to describe a benign tumor on the surface of the skin. A virus, known as the papillomavirus, causes the growth....

Fatty Layer or Nodule Under the Skin in Dogs

The term “panniculitis” refers to an inflammation of the subcutaneous fat tissue. That is, the layer of fat just under the dog's skin becomes...

Skin Bumps (Papulonodular Dermatoses) in Dogs

Papulonodular dermatoses are skin diseases that are characterized by papules and nodules on the skin.

Inflammation of the Skin Blood Vessels in Dogs

Cutaneous vasculitis is inflammation of the blood vessels due to a proliferation of neutrophils, lymphocytes, or, rarely, with eosinophil deposition....