Hair Loss Related to Skin Cancer in Dogs

There are many forms of skin cancer a dog can be diagnosed with.  In some cases, hair loss can be associated with the affected area which is what owners notice in the first place.  It causes them to bring their dog in for a veterinary visit only to discover it is a result of skin cancer.  If your veterinarian suspects skin cancer, there are a series of tests she will recommend in order to come to a complete diagnosis.  There are treatments available for skin cancer in dogs.  Your dog’s prognosis will depend on the stage of his cancer, how large the affected area is, and similar considerations.

If you notice hair loss in your dog, you should take him to his veterinarian for an examination.  While it may be something non-life threatening like an allergy, there is a chance it could be related to a form of skin cancer.

Symptoms of this condition may include

• Varying sized lumps
• Ulcerated lumps
• Similar in appearance to a wart 
• Hair loss in the related area

Types

There are a variety of skin cancers your dog can be diagnosed with.  There are skin squamous cell carcinomas which typically appear on the head, lower legs, abdomen, and rear.  He can also be diagnosed with sweat gland tumors, papillomas, lipomas, histiocytomas, and perianal growths which can develop in different locations of the body respectively.

If your dog is currently being treated for cancer, certain chemotherapy agents, for example doxorubicin, can cause hair loss in your pet.  Luckily this type of hair loss is reversible.  It can also cause scaling of the skin and hyperpigmentation.  The hair loss is first seen at injection sites and head but then can extend to the ventral neck, thorax, abdomen, and inner surfaces of the limbs. 

If your dog is not being treated but has hair loss in the area where cancer has been diagnosed, it may be due to the skin being sick.  The skin is unable to produce hairs as it normally would since the tumor is interfering with normal bodily functions.

When you arrive at the veterinary clinic, your veterinarian will begin by performing a full physical exam on your dog.  She will want to check him over entirely to note any other symptoms he is displaying in addition to his presenting concern of the specific skin area.  She will also collect a verbal history from you about your dog’s condition.  She will want to know what symptoms he has been experiencing, when they started, if the if the area in question has been getting bigger or changing in texture, if any other pets in the home are experiencing symptoms, and similar questions.  

The only way to truly diagnose any type of mass or skin condition is through diagnostic testing.  If his skin cancer is in the form of a mass or lump, she may suggest a fine needle aspirate (FNA).  She will stick a needle in the sample in an attempt to collect cells from the mass.  She will then evaluate the cells to check if any are cancerous.  However, this test can be inconclusive.  The sample taken is so small, it is possible there are cancer cells within the mass but she just did not collect any with her needle.  This brings us to surgical removal of the suspected area and then performing a biopsy on it.  This is the only way to get a 100% diagnosis of the mass.  

If the skin cancer is more of a superficial skin type of irritation, she may try other diagnostic testing to rule out other possible symptoms.  Hair loss associated with an odd change in the skin can be from parasites or allergies so she will need to rule out these as possible causes.  She may also take a superficial sample of the skin to evaluate the hair loss to rule out possible causes of the hair loss alone.

Blood work, urinalysis, and other diagnostic lab work may be suggested as a part of the diagnostic procedure.  This will indicate if there are other issues going on internally in regards to organ function and blood production.

If your dog is indeed experiencing hair loss from skin cancer, you will have to treat the underlying cause first.  If you do not treat the skin cancer, the hair loss will only continue and return as his condition progresses.  Chemotherapy, radiation, cryosurgery, hyperthermia, and surgery are all treatments you can utilize to treat your dog’s condition.  

You can also choose to use more holistic therapies such as vitamin B, C, A, and E in addition to other cancer therapies.  These therapies can be used as a nutrition booster to help your dog’s nutrition system.  This may give him the vitamins he needs to begin producing hair in the related area.

If you treat just the hair loss, all you are doing is masking the symptoms of cancer.  Even if you do try to just treat the issues of hair loss, there is no guarantee it will work.  As the cancer progresses it will only make your dog’s immune system more concerned with other things within the body, not the production of hair. Additional therapies and medications will be administered in accordance with your dog’s needs.

If your dog is able to overcome his cancer, his hair should return in full.  The hair loss itself is more of a secondary concern than a primary one. Treat the cancer, and in turn, you will also be treating the hair loss.  With or without treatment for his cancer your dog’s prognosis of recovery can range from fair to poor.  The prognosis depends on the stage of cancer, how aggressive it is, and how early it is caught and treatment started.  If a small area is concerned and the cancer caught early, his prognosis of recovery is fair to good.  If caught later or if it involves a larger area, his prognosis only declines.