Tumors are an unfortunate reality for our canine companions. Over the course of their lives, one in four dogs develops neoplasia (i.e., the abnormal growth of cells in the body), and a serious percentage of dogs over the age of 10 are at risk of developing cancer. If you've noticed an unknown lump growing on your dog's skin, you're probably wondering if your dog's health and life are in jeopardy. There's no need to panic; anywhere between 60%-80% of tumors are benign, meaning that they lack the ability to become cancerous and threaten your dog's health. However, benign is not synonymous with inoffensive, which is why your canine friend will require medical attention and a healthy diet in order to keep the benign tumor in check.

Today's article will cover the various aspects of benign tumors in dogs, from diagnosis and typology to treatment and the proper diet to starve off the tumor.

What is a Tumor?

Tumors are accumulations of cells that continuously multiply instead of completing their natural cycle. Based on their severity, canine tumors are organized in five categories numbered with Roman numerals (0 - IV); the more cancerous cells spread, the higher the number. But a more straightforward division separates tumors into two categories:

• Benign tumors: The cells contained in benign tumors cannot metastasize and spread to other tissue. Although not cancerous, benign tumors require attentive medical care towards removal.
• Malignant tumors: The cells contained in malignant tumors possess the ability to metastasize and invade neighboring tissue. Such tumors require immediate medical attention towards containing and inhibiting cancerous cells from spreading.

14 Benign Dog Tumor Types

Canines can develop any of the following main types of benign tumors:

#1: Cysts

These tumors are sac-like, non-cancerous structures that have a lining of epithelial cells. There are numerous types of cysts depending on the kind of cells that are lining the structure. The location will help to identify the exact type of cyst as well. Generally, the treatment will be observation without therapy, though surgical removal is sometimes necessary.

Some common types of cysts are as follows:

• Infundibular Cyst (aka Sebaceous Cyst)
• Follicular Cyst
• Hybrid Cyst
• Isthmus-Catagen Cyst
• Apocrine Sweat Gland Cyst
• Matrical Cyst
• Fibroma

These benign tumors come from the skin and subcutaneous connective tissue cells known as fibroblasts. They are typically located on older female Boston terriers, boxers, Golden retrievers, Doberman pinschers, and fox terriers. As a general rule, the tumors are solitary and are commonly found on the flanks, limbs, and groin. Fibromas can be stalked or dome-shaped, soft or firm, containing the skin pigment melanin. A microscope exam is necessary to make a proper diagnosis. Treatment requires close observation, surgical removal, or cryosurgery.

#2: Basal Cell Tumor

Basal cell tumors come from the basal cells found within the skin. These are most commonly found in older canines. These tumors often occur as solitary nodules that can be stalked or broad-based. More often than not, these tumors are located on the neck, shoulder, or head of the canine and are often pigmented. As a result, they are often mistaken for melanoma. Tissues of the tumor must be biopsied and examined under a microscope to receive an accurate diagnosis. The recommended treatment is known as wide surgical removal. In some cases, it may be needed for the dog to undergo chemotherapy and/or radiation. The breeds at greatest risk of basal cell tumors are Poodles and Cocker Spaniels.

#3: Ceruminous Gland Adenoma

This particular type of tumor comes from the ceruminous (earwax) cell glands in the ear canal anal. Typically, these tumors are small stalked masses. They are generally located near the eardrum. The symptoms are very similar to that of chronic ear infections. The tumor cells must be examined under a microscope to diagnose ceruminous gland adenomas. Treatment will involve resectioning the complete ear canal, and chemotherapy and radiation are often necessary.

#4: Cutaneous Histiocytoma

This is also a benign tumor of the skin, and it affects very young dogs—usually those of one to three years of age. They come from monocytes and macrophages, the white blood cells in the canine's skin. They are generally located on the head and neck, and they're hairless, round, pink-red lesions that can often ulcerate. Due to their outward appearance, they can sometimes be known as "button tumors." After onset, these tumors will generally regress within four to eight weeks. If they do not, however, surgical removal is typically necessary.

#5: Intracutaneous Cornifying Epithelioma

These tumors come from the skin cells found between the canine's hair follicles. They are generally located on the neck, upper chest, lower abdomen, and legs. They may secrete a substance that is similar to toothpaste. A microscope examination is necessary to diagnose the tumor accurately. Surgical removal will be necessary, though chemotherapy can be effective in some cases to treat the tumor.

#6: Lipoma

This tumor is a growth that consists of mature fat cells or lipocytes. It is generally a soft, well-circumscribed, subcutaneous, fluctuant mass over the sternum, chest, abdomen, and upper part of the limbs. Generally, these tumors are found in older females who have been spayed. They can occur as a single mass or as multiple masses. Some of them are infiltrative, which means that they can penetrate the deeper body tissues; however, most tumors are located just beneath the skin. A sample of the tumor needs to be examined under the microscope to diagnose these tumors, which determines whether mature lipocytes are present. Surgical removal is generally necessary to treat lipomas. However, depending on the size and location of the tumor, it may be recommended by the dog's veterinarian to simply leave the lipoma alone. If it is recommended to go the surgical route, it is ideal for removing the lipoma while it is still small.

#7: Cutaneous Hemangioma

This type of tumor is a benign growth that comes from cells found in blood vessels (also known as endothelial cells) within the skin or subcutaneous tissues. Skin hemangiomas are typically smaller than subcutaneous hemangiomas, and they also appear with a reddish-black tint and as a dome. These tumors can be caused by several things, including the sun, some chemicals, or have an unknown cause. They tend to affect middle-aged to older canines, and numerous breeds are affected. A skin biopsy must be taken, followed by electron microscopy and immunohistochemistry, the process of detecting specific antigens with a tissue sample, to diagnose these tumors. A few different options are available, such as surgical removal, electrosurgery, and cryosurgery (which is freezing), to treat cutaneous hemangiomas.

#8: Mast Cell Tumor

Mast cells are part of a canine's immune system, and they are a crucial part of a canine's inflammatory response to tissue trauma. When it comes to mast cell tumors (MCT), they can be located on various parts of the body, though they are typically located in the skin. The actual cause of mast cell tumors is unknown. There is a breed predisposition toward these tumors, with Boston terriers, boxers, English bull terriers, and English bulldogs being at the most risk. The tumors are generally solitary masses located in the skin of the extremities, head and neck, and trunk. There have been reported stomach and intestinal ulcers in as many as 80% of canines with MCT. Research has shown that this may result from many histamines that the MCT releases. It is important to understand that all canine mast cell tumors are not benign; in fact, up to half of them may become malignant. As a result, all mass cell tumors need to be biopsied and microscopically identified. Treatment will typically involve a wide surgical excision (which consists of removing the tumor surgically along with a wide area of skin around it), chemotherapy, and/or radiation.

#9: Nevus

Nevus (more commonly referred to as a mole) is a well-defined skin defect that can come from any skin component or combination of skin components. Nervus is often used with a qualified like a sebaceous gland or epidermal. A biopsied tissue sample must be examined under the microscope to properly diagnose a nevus tumor. Treatment typically consists of observation without therapy or surgical removal.

There are a few different types of nevi, including the following:

• Sebaceous Gland Nevus
• Epidermal Nevus
• Organoid Nevus
• Collagenous Nevus
• Vascular Nevus
• Comedo Nevus
• Hair Follicle Nevus
• Apocrine Sweat Gland Nevus
• Papilloma

Canine papillomas can result from a virus, or they can occur spontaneously. There are two different types of papillomas: oral and cutaneous.

The oral papilloma in dogs is highly contagious and can be spread from one dog to another via direct or indirect contact. It generally affects canines younger than two years of age and is the most common type of papilloma tumor. Numerous lesions are generally seen in and around the canine's mouth. The tumor will often undergo spontaneous regression within a few months of onset, and then the canine is immune to infection afterward. If a regression doesn't occur, chemotherapeutic agents can minimize and eliminate the tumors.

The cutaneous papilloma in dogs is benign and of non-viral origin. However, this tumor is more common in older canines. This tumor is a whitish-gray color and is shaped similar to a cauliflower. They are generally located on the head, feet, and eyelids. As a general rule, a single cutaneous papilloma can be surgically removed and curative.

#10: Perianal Adenoma (Hepatoid Gland Tumors)

This is a specific type of tumor that comes from the perianal glands located around the anus. They can also be located around the skin of the canine's tail, thigh, prepuce, and the top of the canine's back. These tumors are commonly found in older intact male canines, and as a general, they are benign. They are also referred to as hepatoid gland tumors because, at a cellular level, the tumors are similar to that of liver cells or hepatocytes. They can be either solitary or multiple, dependent on whether testosterone is present. They generally regress when the dog is castrated. Surgical removal is the next step if castration doesn't result in full regression.

#11: Sebaceous Gland Tumors

These tumors come from the cells of the sebaceous glands. This gland produces a waxy/oily substance that lubricates the hair and skin of canines. They are similar to warts or cauliflowers and common in canines, especially spaniels. They can appear anywhere on the canine's body, and they are generally solitary, though they can appear in multiple lesions. The recommended treatment is surgery. It is rare for them to recur locally; however, as many as 10 percent of canines could develop a sebaceous gland tumor in a different location.

#12: Skin Melanoma

These tumors come from the cells that produce melanin, known as melanocytes. The various pigments in a canine's skin result from the melanin produced by these melanocytes. The tumors found in the skin are typically benign, but tumors in other body areas like the nail bed or oral cavity may be malignant and metastatic. Melanoma tumors are often found on the trunk and face. An examination under the microscope will reveal brown cells to block granules. The ideal treatment is surgical removal.

#13: Trichoepithelioma

These tumors come from hair follicle sheath cells and are generally solitary lesions. They can be found on the head, tail, and limbs in canines older than five years. They are cystic or solid, elevated, round, and well-defined. They can ulcerate and sometimes lose their hair. A biopsy is necessary, as well as a microscopic exam. Veterinarians prefer to surgically remove the tumor.

#14: Transmissible Venereal Tumor

These tumors come from the macrophage/monocyte system and can be spread during mating or any other type of close contact. They are generally located on the external genitalia as well as the face. The masses are similar in appearance to cauliflower, and they are solitary or multiple, ulcerated, and friable. The identity of the tumor can be identified under the microscope, and the treatment consists of surgical removal, radiation and/or chemotherapy.

Benign Tumor Symptoms

Benign tumors manifest themselves in different shapes and sizes. For example, lumps and bumps typify senior dogs. Others, such as lipomas, appear as skin tags or fatty tumors. As for the body areas, benign tumors can appear, both on and under the skin, throughout the body. This, however, does not necessitate immediate medical care. It's only the benign tumors located in discomforting areas, such as the paw or the legs, that could impair your dog's proper walking motion and call for surgical intervention. Larger and, therefore, aesthetically unsightly tumors might call for surgical removal as well.

How are Benign Tumors in Dogs Treated?

The treatment options for benign tumors vary from surgical removal to radiation and immunotherapy. The treatment option of your choice mainly depends on the body area and the size of the tumor. However, if the benign tumor does not impair your dog's movement, nor is it aesthetically displeasing, switching to a healthier diet, rich in fresh, whole foods, with meat and vegetables, is sure to assist your dog's immune system in keeping the tumor in check. A fresh, natural diet has the additional advantage of being low in carbohydrates (tumors rely on carbohydrates for energy).

Here are the three ways how a natural diet can help your dog's immune system keep benign tumors in check:

#1: Ensuring Toxic Waste Removal From the Canine Body

A dog with a benign tumor needs a strong system to remove unnecessary waste and prevent fat cells from accumulating and interfering with other healthy cells. The nutrients and microorganisms that support this process are:

• S-Adenosyl-Methionine (SAMe): this essential amino acid, found in abundance in meat and sunflower seeds, fortifies your dog's heart and liver health and assists in several metabolic functions.
  
• Digestive enzymes: out of the three main digestive enzymes, lipase is the more appropriate option for dogs with benign tumors through the process of turning fat into fatty acids and glycerol. You can increase your dog's digestive enzyme intake by adding the Volhard Digestive Enzymes supplement to his diet!

• Red yeast rice: a helpful ingredient that prevents lipid accumulation in the canine body, thus hindering the growth of benign tumors.

#2: A Healthy Blood Flow

Blood flow is a paramount factor in encouraging or inhibiting benign tumor growth. A healthy blood flow will help remove fat cells from the body and prevent the danger of fat cell accumulation. The two nutrients that support a healthy blood flow are:

• Omega-3 fatty acids: abundantly found in krill oil and fish, omega-3 fatty acids are sure to improve blood circulation and give your dog's cardiovascular system a well-deserved boost!
• Antioxidants: antioxidants help cleanse the blood of harmful agents, reduce oxidation, and promote healthier blood circulation and nutrient absorption levels.
• CoQ10: this chemical compound, found in most animals and bacteria, decreases vascular resistance, thus allowing the blood to circulate more efficiently throughout the body. The healthiest sources of CoQ10 for your dog are: organ meat (liver and heart), fatty fish (salmon and sardines), vegetables (cauliflower, broccoli, and spinach), fruit (strawberries), and legumes (lentils and soybeans).

#3: Supporting a Healthy Gut Microbiome

The Volhard approach to canine nutrition pays considerable attention to the gut microbiome, and for undeniable reasons. The gut microbiome is the immune system's health barometer; a balanced gut microbiome promotes a healthy immune system, whereas dogs with " Leaky Gut Syndrome" are prone to excessive histamine levels and severe allergic reactions. Furthermore, dogs with malign tumors, such as mast cell tumors, are at risk of excessive histamine levels being released into their bodies. An unhealthy diet, medication, stress, vaccines, and age can throw your dog's gut flora out of balance.

What your dog needs is a diet that will help him get rid of excess histamines and bring balance to the gut microbiome. A low-histamine diet must include:

• Coconut milk
• Fresh wild-caught fish
• Fresh pasture raised meats
• Fresh organic vegetables (except eggplants, tomatoes, and spinach)
• Gluten-free organic grains
• Non-citrus fresh fruits

The nutrients that make the list of any low-histamine diet are:

• Vitamin B6: chicken, turkey
• Copper: asparagus and liver
• Vitamin C: fruits and vegetables (except for those high in histamine)
• Black cumin (6) and quercetin are also two natural medicines that have antihistamine properties

A Parting Reminder

As you can see, numerous tumors and growths can appear in a canine's skin. Your veterinarian must examine any new growth as soon as it is noticed on your canine. Some of the aforementioned lesions may look similar, which is why a biopsy and microscopic examination by a qualified and trained pathologist in veterinary medicine is necessary. Early identification and treatment are a must to help ensure a positive outcome. For more advice on dog nutrition, health, and training, make sure that you contact us or check out our blog! 

Volhard Dog Nutrition and its expert nutritionists are now offering online consultations to help more dog parents discover why, what, and how to feed their dogs the healthiest of foods! Speaking to a Volhard nutritionist will help you understand the inseparable relationship between healthy food, a healthy body, and a healthy mind. If you're interested in contacting one of our Volhard nutritionists, don't hesitate to access our consultation page!

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