canine skin cancer

SIGNS AND SYMPTOMS

According to the Texas A&M University College of Veterinary Medicine, dogs are 35 times more predisposed to skin cancer as compared to humans and and 6 times more predisposed than cats.

Typical signs of canine skin cancer include:

• A lump or bump that may or may not be ulcerated. 
• The skin may be red or has a flaky appearance

The cancer can result in: itching, causing the dog to chew and scratch the affected area incessantly.

Systemic symptoms depend on the location of the tumor, the seriousness of the cancer and whether it has metastasized.
Some systemic signs may include:

• Appetite loss
• Vomiting (maybe bloody)
• Diarrhea
• Lethargy
• Coughing
• Wounds that cannot heal
• Enlarged lymph nodes

A typical dog tumor shown breaking through the skin:



Common malignant dog skin tumors are as follows:
1. Squamous Cell Carcinoma (SCC)

The tumors can appear many places but are seen most commonly on and around the eyes, ears, nose, mouth, and areas with little hair.

At first, SCC tumors look much like other common skin irritations such as a raw ulcer or non-healing sore, making them difficult to identify.

Typical Cause: Sun damage

Signs of SCC:

• Scabs
• Hair loss
• Irritated skin
• Loss of teeth with limited healing
• Raised red bumps on the skin

Breeds commonly affected by this type of canine skin cancer include:

• Shih tzus
• Standard poodles
• Mastiffs
• Basset hounds
• Blood hounds

2. Mast cell tumors



Typical Cause: Hereditary & environmental factors

Most common fatal skin cancer in dogs.

Mast cell tumors that appear in:

• the armpit area
• mammary tissue
• groin, anus or genital areas
• in the lips, eyelids, or body openings are likely to be malignant.

The appearance of canine mast cell tumors are unsual and can mimic other benign skin lesions such as lipomas (fatty tumors).

Because of their ability to mimic benign skin tumors, these dangerous mast cell tumors often are not diagnosed until later in the disease, resulting in a worse prognosis for the dog patient.

Usually found in the skin, but they can also be commonly found on the:

• Trunk
• Limbs
• Genital Area

The tumor can be single or multiple, and it can be smooth, bumpy, or ulcerated.

Signs of Mast Cell Tumors:Itching and inflammation of the skin
Occasional local bleeding while tumor is scratched
Ulcers in the gastrointestinal tract causing mild to severe bleeding
Vomiting
Blood in the stool

3. Hemangiosarcoma

Typical cause: Important genetic factors

There are 2 types of skin associated hemangiosarcoma in dogs:

I. Dermal (skin)Signs include:

• Dark appearance of skin
• Raised skin lesion (usually on hairless areas eg. Abdomen)

II. Hypodermal (under the skin)Signs include: Soft mass of tumor Or Firm mass of tumor with ulceration
Breeds most commonly affected by this type of canine skin cancer include:

• German Shepherds
• Golden Retrievers
• Labrador Retrievers
• Boxers
• Schnauzers
• Pointers
• Doberman Pinchers

4. Perianal Tumors
Tend to occur on hairless skin around the anus
Appear raised
Can occur as multiple masses that may become ulcerated and secondarily infected

5. Limpoma

• Tend to appear as fatty tumors
• They are benign
• Can be confused with mass cell tumor

6. Sebaceous Hyperplasia
Can be solitary or multiple
Typically:

• Raised
• Firm
• Wart-like/Cauliflower-like
• Range from a few millimeters to several centimeters in diameter
• Usually pink but can be yellow or darkly pigmented
• Oily, ulcerated or alopecic (hair loss on and around the lesion)
• Common on the belly (ventral abdomen) but can occur anywhere

7.. Histiocytoma



Most common sites:

• Head 
• Pinna 
• Neck 

Common Signs

• Nodules are typically:
• Solitary 
• Red 
• Dome-shaped 
• Sparsely haired 
• Appear rapidly 
• Ulcerated but not painful

8. Melanoma
Signs and Symptoms:

• Bad breath.
• Drooling.
• Bleeding from mouth
• Facial swelling 
• Decreased appetite
• Chewing on one side of mouth

Typically occur as :

Single growths
May or may not be pigmented or dark in colour
Generally, benign melanomas are deeply pigmented, smaller and well defined

9. Fibrosarcoma

Typical Signs and Symptoms:

• Swelling of the bones
• Difficulty eating
• Difficulty swallowing
• Signs of pain
• Signs of lameness
• Poor mouth odor
• Bleeding from the mouth

10. Basal Cell Tumor
Typical Signs and Symptoms: Solitary, firm, well circumscribed, hairless growth

Areas usually affected:

• Head 
• Neck 
• Shoulders