What are Skin Masses in Dogs?

Introduction

For years, Rachel and her fluffy Samoyed, Snowball, had been the best of friends, sharing countless memories together. One day, as Rachel was giving Snowball a much-needed brushing, she felt an unusual lump beneath the dog’s thick fur. Startled, she examined the area more closely, revealing a concerning skin mass. Knowing that her beloved pet’s health could be at stake, Rachel immediately sought the advice of her trusted veterinarian.

Skin masses are small bumps that are raised above the skin. They’re usually harmless, but sometimes they cause discomfort and itching. Your dog’s skin can be scary, but the good news is that 60-80% of canine skin masses are benign.

Tumors most commonly appear on the ears, paws, face, neck, and tail. Skin masses may be red, white, yellow, brown, black, or any combination. The color depends on the dog’s diet and breed.

Some breeds, such as poodles, are prone to developing skin masses. Other breeds, such as huskies, are not. They are most common between two and five years of age, but some dogs develop them at any age.

Most skin tumors may be benign, meaning they won’t grow or spread. However, some may be cancerous. To determine whether a skin mass is malignant, veterinarians perform biopsies. This involves removing tissue samples for microscopic examination.

Common Skin Masses in Dogs

Sebaceous Cysts

The most common skin tumor in dogs is called a sebaceous cyst. Sebaceous cysts develop when oil glands become blocked, causing them to swell and form a lump. Sebaceous cysts are typically on the face, ears, paws, tail, and neck. They may also develop in the armpits, penis, or perineum. Sebaceous cysts are benign and do not require treatment. However, a doctor may recommend surgically removing them if they become large or bothersome. They can be benign (noncancerous) or cancerous.

Apocrine Gland Cysts

Apocrine glands are small hair follicles located throughout the body. They secrete sebum (a waxy substance) and produce sweat. The apocrine glands in dogs’ skin include the anal sacs, axillae, eyelids, external ear canal, genitalia, perineum, tail base, thyroid, and umbilicus.

Cysts form when these glands become blocked due to excessive oil production. This blockage prevents normal drainage of the gland contents. Over time, this fluid buildup creates pressure within the gland, causing it to rupture.

This condition is called an apocrine gland cyst. It usually occurs in older dogs, especially those who spend much time outdoors. However, some breeds are prone to developing them, including Boxers, Golden Retrievers, German Shepherds, Labrador Retrievers, Poodles, Rottweilers, Shih Tzu, and Yorkshire Terriers.

There are two types of apocrine gland cysts: primary and secondary. Primary cysts occur spontaneously, whereas secondary ones develop after trauma. Secondary cysts may be caused by surgery, infection, or inflammation.

Primary cysts appear on the face, neck, chest, abdomen, back, and legs. Secondary cysts often appear on the head, ears, paws, and genitals.

Symptoms vary depending on where the cysts are located. Some dogs show no signs at all. Others experience itching, swelling, redness, pain, discharge, bleeding, or crusting.

Follicular Cysts

Follicular cysts are benign skin tumors that develop in hair follicles. They’re usually found in older dogs and may be associated with hormonal imbalances. The most common symptom is the innocent neck, back, or chest growth.

If your dog develops a large mass, it should be examined by a veterinarian. Follicular cysts can cause pain and discomfort and sometimes lead to infection.

Granulomas

Granulomas are dermal tumors that commonly occur in puppies and young adult dogs. They’re usually benign (noncancerous) and slow-growing. However, some types of granulomas can be cancerous.

There are two main types of granuloma: dermal and epidermal. Dermal granulomas grow beneath the skin’s surface, while epidermal granulomas grow above the surface. Granuloma is typically found on the face, neck, legs, paws, tail, and chest.

Dermal granulomas tend to appear as small bumps or lumps on the skin. Epidermal granulomas often appear as red or pink patches on the skin.

Both types of granuloma may cause pain and discomfort when scratching them. In addition, the condition can lead to hair loss and infection.

Lipomas

Lipomas are benign tumors made up of fat cells. They’re usually found in the neck, shoulders, back, hips, thighs, and abdomen. Lipomas are often mistaken for fatty lumps, but they’re soft and rubbery.

They grow slowly over the years, and most people never notice them. However, some owners report that their dog develops a lumpy growth on their skin.

Squamous Cell Carcinoma (Malignant Tumors)

Squamous cell carcinomas are tumors affecting the skin and are made up of squamous cells, which line the body’s surface. SCCs usually appear as red bumps, lumps, or sores on the dog’s skin. They may be painful and cause bleeding or crusting over the area.

They’re not contagious, but they can be painful and disfiguring. The treatments vary depending on the location and severity of cancer. Some cases may require surgery, radiation therapy, chemotherapy, or combinations.

Mast Cell Tumors

Mast cells are immune system cells found throughout our bodies. They’re responsible for producing histamine when we come into contact with allergens. Histamine causes swelling and itching.

When mast cells become cancerous, they produce too many histamines, causing skin inflammation. The condition is called a mast cell tumor. They usually occur in older dogs and cats but can also affect younger animals.

Mast cell tumors may appear as red bumps or lumps on the skin. Some dogs develop multiple tumors at different locations. The most common area is between the shoulder blades. Other common sites include the neck, back, chest, abdomen, paws, tail, ears, muzzle, face, lips, gums, tongue, genitals, feet, and joints.

Sebaceous Adenomas

Sebaceous gland tumor (sebaceous adenomas) is a rare dermal cancer that affects dogs. The cause is unknown, but it may be linked to exposure to environmental toxins, including pesticides and herbicides.

While SA is not typical among humans, it does occur occasionally. Most cases involve older dogs, especially those who live outdoors.

Malignant Melanoma (Cancerous Tumors)

Malignant melanoma (MM) is a form of cancer that starts in the cells that produce pigments called melanocytes. These cells live in the outermost layer of the skin, known as the epidermis. The most common type of malignant melanoma occurs when these cells become damaged or mutated, causing them to grow out of control and multiply rapidly. This uncontrolled growth forms a tumor.

Causes of Benign Skin Tumors in Dogs

If you notice unusual growths on your dog, immediately take him to the vet. The sooner you catch them, the better! Skin masses are often found on the head, neck, shoulders, legs, paws, tail, chest, abdomen, genitals, and back.

Causes include allergies, parasites, hormonal imbalances, and nutritional deficiencies. However, fleas, ticks, and food sensitivities are the most common reasons.

• Flea allergy dermatitis (FAD) occurs when dogs lick themselves excessively after being bitten by fleas. Fleas bite dogs to feed on their blood and saliva. This triggers allergic reactions in the dog’s body.
• Ticks transmit Lyme disease; Rocky Mountain spotted fever, ehrlichiosis, anaplasmosis, babesiosis, and tularemia. Ticks also carry tapeworms, which can infect humans.
• Food sensitivity is another common cause of skin masses. Dogs who eat certain foods develop skin rashes. Some dogs react only to specific ingredients in these foods, such as wheat, corn, soybeans, dairy products, eggs, beef, chicken, fish, shellfish, peanuts, tree nuts, and chocolate.
• Hormonal imbalances occur when adrenal glands produce too abundant or deficient hormones. Hormonal imbalances can lead to skin problems, including acne, hair loss, excessive shedding, oily skin, dry skin, and dandruff.
• Dietary factors, such as poor nutrition or lack of vitamins and minerals, can cause nutritional deficiencies. Nutrient deficiencies can result in skin conditions, including alopecia, eczema, and dermatitis.

Common Symptoms of Canine Skin Masses

Some common symptoms include:

• Redness
• Swelling
• Pain
• Bleeding
• Changes in eating habits
• Loss of appetite
• Weight loss
• Difficulty breathing
• Fever
• itching/ scratching
• Diarrhea
• Lumps on the body

Diagnosis of Skin Masses in Dogs

A definitive diagnosis is necessary to determine how your vet might treat common dog tumors. The doctor may recommend blood tests, x-rays, ultrasound scans, biopsies, or other diagnostic procedures during this visit. In addition, your veterinarian should examine his skin closely and perform a biopsy to determine whether he has a skin mass.

Your veterinarian will use a needle to remove the tissue sample from the lump. Then, he’ll send the sample to a lab where a pathologist will examine it under a microscope.

The pathologist will tell your veterinarian whether the sample contains cancer cells. If there are no signs of cancer, your veterinarian will recommend surgery to remove the tumor. Surgery is not recommended for every case of tumors because some cases resolve themselves without treatment. However, surgical removal is necessary if the tumor grows too large or causes problems.

Treatment Options for Dermal Masses in Dogs

Your vet may suggest additional treatments, such as surgery, chemotherapy, radiation therapy, or immunotherapy. These treatments are often effective against certain cancers but come with risks. Your vet will help you weigh these risks and benefits when deciding on your dog’s care.

While most skin masses are benign, some can indicate serious health problems. So keep an eye out for any abnormal growths on your dog. If you notice anything suspicious, contact your vet right away.

Prevention for Skin Tumors in Dogs

Canine skin tumors are unsightly but also painful and expensive to treat. Fortunately, there are ways to prevent them from occurring in the first place.

1. Be aware of the risk factors associated with canine skin tumors. These include breed, age, diet, exercise, and exposure to sunlight.
2. Keep your dog safe from sunburns. Ensure he wears sunscreen daily, especially during peak hours when the sun is strongest.
3. Avoid giving your dog too many treats. This includes table scraps, leftovers, and food containing caffeine, chocolate, onions, garlic, or alcohol.
4. Limit your dog’s access to swimming pools, hot tubs, ponds, lakes, rivers, and streams.
5. Ensure your dog doesn’t spend excessive time outdoors during midday hours.
6. Watch out for signs of heatstroke. Dogs who become overheated often develop skin problems, including dermal cancer.
7. Consider having your veterinarian perform regular exams to detect skin abnormalities early.

Frequently Asked Questions