5 types of skin cancer in dogs

The skin is the largest organ of a dog, and tumors affecting this structure are common. Between 60 to 80 percent of skin tumors in dogs are benign, meaning if you notice a lump on your dog’s skin, there’s a good chance it won’t be anything to worry about. However, the visible appearance of a growth can’t be used to predict whether it’s cancerous. Therefore, any new lump or bump you detect on your dog’s skin should be evaluated by a veterinarian.


Many skin tumors can be cured with early surgical removal. If a growth is removed from your dog’s skin, it should be submitted for evaluation by a veterinary pathologist. This is the best way to determine if further treatment is necessary. The following is a list of the more common skin tumors seen in dogs, along with basic information about their behavior and recommended testing and treatment options.

Mast Cell Tumor


Mast cells are immune cells normally involved in allergic reactions. They contain packets of chemicals (called granules) that are released upon stimulation by an allergen. Mast cells are located throughout the body and dogs have a large proportion located within their skin. Mast cell tumors are found more frequently in Boxers, Boston Terriers, Labrador Retrievers, Golden Retrievers, Beagles, Pugs, Shar Peis, and Bulldogs.
A diagnosis of a mast cell tumor can usually be made via a fine needle aspirate. A small needle, the same size that’s used to draw a blood sample or give a vaccine, is introduced into the mass and a syringe is used to extract cells. These cells are distributed onto a slide and evaluated either by your veterinarian or submitted to a lab for analysis by a clinical pathologist.


Surgical removal is recommended for all confirmed mast cell tumors. A pathologist will review the sample and assign a “grade” to the tumor. The grade is the best predictor of whether follow-up testing and treatment is recommended. Low-grade tumors are usually cured with complete excision, whereas high-grade tumors are more likely to grow back and spread to distant sites in the body. In those cases, radiation therapy and chemotherapy are recommended to extend survival time.



Unlike people, most cutaneous (skin) melanoma tumors in dogs are benign. Melanoma occurs more frequently in dogs with dark pigmented skin. Cutaneous melanoma tumors are usually solitary and appear as small brown/black masses. They can also appear as large, flat, or wrinkled tumors. Fine needle aspirates can be done on such tumors; however, they are less likely to exfoliate (distribute into the syringe during aspiration), so the sample obtained in this manner might not be diagnostic. Most melanoma tumors are diagnosed after they are removed. Malignant (cancerous) melanoma occurs less frequently, but can be an aggressive disease. Distinguishing a benign melanoma from a malignant one is done via biopsy. Benign melanoma tumors are cured with surgery. Malignant melanoma tumors can spread to local lymph nodes and lungs and additional treatment with chemotherapy and/or immunotherapy for treating melanoma is recommended.

Squamous Cell Carcinoma


Squamous cell carcinoma is a rare form of skin cancer in dogs. Tumors are found more frequently in light-skinned, hairless, or sparsely haired portions of the skin. At-risk breeds include Dalmatians, Bull Terriers, and Beagles. Most squamous cell carcinomas of the skin appear as firm, raised, and often ulcerated plaques and nodules. Tumors can often grow outward into large masses and have a surface that resembles a wart. Squamous cell carcinoma occurs more frequently in Keeshonds, Standard Schnauzers, Basset Hounds, and Collies. Short-coated dogs who spend a long time outdoors also have a higher incidence of squamous cell carcinoma. Treatment includes surgery to remove the primary tumor. Incompletely excised tumors should be treated with radiation therapy to prevent regrowth. These tumors infrequently spread to local lymph nodes and the lungs. Some dogs develop multiple cutaneous squamous cell carcinoma tumors. These can be challenging cases to manage and may require medical treatment with either oral or topical drugs.

Tumors of the Skin Glands


Most glandular tissue tumors in dogs are benign (e.g. sebaceous hyperplasia or sebaceous adenoma). Malignant glandular tumors include sebaceous gland carcinomas, apocrine gland carcinomas, and eccrine carcinomas. Sometimes benign tumors can be recognized visually, but it is still best to remove any questionable mass and submit the tissue for biopsy. Most malignant glandular tumors can be treated with surgery alone. However, if the tumors are incompletely excised, radiation therapy is recommended to prevent recurrence. Dogs with malignant tumors should also be screened for any evidence of spread of disease via imaging tests (chest X-rays and regional lymph node aspirates).

Hair Follicle Tumors


Like glandular tumors, most hair follicle tumors are benign and cured with surgical removal, despite their intimidating assortment of names (e.g. keratinizing acanthoma, trichoblastoma, trichoepithelioma, pilomatricoma). Malignant hair follicle tumors include malignant trichoepithelioma and malignant pilomatricoma. Differentiating a benign tumor from a malignant tumor can only be done via biopsy.

Epitheliotropic Lymphoma


While technically not a skin tumor, another common cancer that occurs in the superficial layers of the skin is epitheliotropic lymphoma. Lymphoma is a blood-borne cancer of lymphocytes, a type of white blood cell. Lymphocytes are found throughout the body, including the skin, where they offer protection against various pathogens that this organ can come into contact with. There are several forms of lymphoma in dogs, and epitheliotropic lymphoma is a specific variant diagnosed via biopsy of an affected region of skin. Treatment of choice is chemotherapy. The prognosis is usually guarded; however, dogs who are diagnosed earlier in the course of their signs and have not received previous treatment with steroids can do well long-term. Epitheliotropic lymphoma should be considered as a diagnosis in dogs with persistent and progressive skin lesions that do not resolve with typical treatment for more common skin issues (e.g. food allergies or skin infection).



I’m part of the problem. Are you?

A recent suicide of another veterinarian once again sparked a burst of concern regarding the mental health of those of us entrenched in this profession. As an isolated event, this news is nothing short of tragic. What is equally as concerning is how this heartbreaking news is an alarmingly repetitive part of our community. In the past few years, we’ve lost far too many outstanding colleagues who felt the only way to relieve their pain was to take their own life.

Statistics describing the emotional status of the “average” veterinarian are shocking. Suicide rates for veterinarians are double that of dentists and physicians and six times higher than the general population. A recent survey indicates as many as one in six veterinarians had considered suicide. Nearly seven percent of male vets and 11% of female vets reported “serious psychological distress” in an online survey.

There’s a disturbing pattern where every few months another veterinarian ends their life – and the magnitude of response on part of those of us in the profession is astounding. We express anger and frustration at pet owners, practice owners, corporations, and the lenders of our student loans. We share information about the rigors we endure on a daily basis with the hope of emphasizing we are just as much a “real doctor” as a human MD.

We are quick to expose the darker side of veterinary medicine, partly in solidarity and partly to educate the public about our concerns. I’ve participated myself, having written several articles on the detrimental impact compassion fatigue has on our profession. There are only so many times we can tolerate being accused of being “in it for the money” or “heartless” before we shatter.

The saddest part to me is despite the commonality in our cause, thus far, we’ve been ineffective in our endeavors. The statistics remain as abysmal today as they were several years ago and fundamentally, veterinarians continue to kill themselves.

When I learned of this most recent suicide, like many of my peers, I felt compelled to express my outrage in written form. But I paused before typing any words. My silence stemmed partly because I knew I’d never be any more eloquent than those who already stated their piece about the tragedy. But a greater portion of my silence arose from a gnawing sensation that exclusively pointing my finger outward was inaccurate. I’d always avoided looking inward and never really asked myself, “To what end do I contribute to the problem?”

To best explain the impetus for my altered point of view, I need to provide a bit of background. After spending nearly eight years in private practice, I recently transitioned to working in academia. It’s been a remarkable change, as my focus has shifted from seeing cases as a primary veterinarian to training students how to become successful veterinarians and teaching house officers (residents) how to become remarkable veterinary oncologists.

While overall the pace is much slower than what I’ve grown accustomed to in private practice, our oncology service is capable of seeing a good number of new consults and rechecks each day and the cases we evaluate tend to be more complex in nature than what I’ve faced previously. I’m also no longer tasked with directly communicating with clients and referring veterinarians. This is the responsibility of the house officers completing their residency. While these individuals possess a solid core of knowledge in oncological principals, the fundamental thing they lack is experience. They are here to learn and grow as specialists, but they aren’t there yet. That’s a huge part of my job – shaping what type of oncologist they will become over time.

Despite all of their spectacular qualities, house officers lack the breadth of experience necessary to be as efficient as a board-certified specialist. They are exceptionally intelligent and motivated, but are fundamentally more methodical in their thought processes than I’d ever be. They are not yet proficient in understanding risk of treatment (or not to treat as it may be.) They will express anxiety about scenarios I’d never consider, simply because my experience over the years has afforded me a sense of self-trust and knowledge that their concerns are unfounded. They need more time to process data and discuss outcomes.

The same is true for our radiology department, where house officers perform all of the assessments of our x-rays, ultrasounds, and CT scans. We face the same struggle with the residents we ask for surgery consultations, who are also trainees lacking the same level of experience as the board-certified service chiefs who back up their plans. Every blood sample or cytology slide we submit will be first analyzed by someone learning to become a specialist. While all house officers at an academic institution are supported by someone like myself – an experienced board certified expert, the frontlines are managed by people who are only just learning how to become the authority.

Beyond my responsibilities to the house officers, I’m also tasked with teaching veterinary students how to be good doctors. I must take the time to belabor pathophysiology and anatomy to ensure they have a strong foundation for clinical work. I have to constantly monitor their progress and remember the fundamental aspect that they lack pattern recognition not because they are not good at what they do, but because they haven’t seen that pattern just yet.

This all equates to an inherent slowness of the process and I must set boundaries as to what our service can reasonably accomplish each day. I have to restrict our schedule to include a specific number of rechecks and new appointments. I need to be cognizant of what I’m asking our staff to accomplish, because even a slight overload could very well surmount available resources. But the caseload far exceeds those restrictive numbers and the waitlist for an appointment with our service is a month long, which is tantamount to eternity for a worried owner with a pet newly diagnosed with cancer.

Here is where I’ve recognized I’m failing to support our profession, and worse, potentially contributing to its failure.

I’m the first to sort out how to squeeze in one more consult. Or to add on a few rechecks. I never want to disappoint pet owners. I’m compelled to help all the newly diagnosed patients. My wants frequently come at the expense of the very people I’m tasked with training. The model I’m setting forth to my trainees is to put owners and their pets first, even to the point of driving yourself down.

I’ve taken my own obligations and passed them along to my apprentices. I expect house officers to see another new consult, even when they’ve been assigned their “maximum” daily load. I ask them to stay late to talk to owners of cases presented on the emergency service whose pets are diagnosed with cancer because I think it’s the right thing to do. I expect students to be one time for 8am rounds, even when they have complicated treatments to accomplish on their hospitalized patients and lack the experience and confidence to ask for help.

While I’m assured my intentions are pure, I’m not accomplishing anything more than setting these fresh-faced doctors, and doctors-to-be, up to fail. I’m telling them this is the “normal” way to approach their profession, yet these are the very attributes I’ve condemned as being the cause of compassion fatigue. Is it fair for me to expect them to share my obligation to fit in the case, talk to the owner, and appease the referring veterinarian? Why am I ok with adding strain to people who already feel stretched thin, years before they’ve even achieved their board certification and have the ability to make such choices for themselves? If I can’t teach them to set boundaries now, when will they learn how to do so in their professional life?

How can I be angered at the status of our profession yet so obviously contribute to the issue at hand? How many others are behaving the same way as I am? How can I rectify sending the mixed message of “take care of yourself and your mental health, but please stay late and see one more case?”

Veterinarians know there’s a problem. We will never control what pet owners say or do and there’s little we can do to control for the debt required to graduate vet school. We will never shut down Dr. Google or eradicate the piles of misinformation surrounding animal health and wellness.

But we can control what we ask of ourselves and our colleagues. And while we may never control the expectations of others, we can teach each other to recognize our limits and be okay with saying no. This is especially those of us tasked with instructing those coming up through the ranks on how to be successful doctors.

It just might be the only way we protect ourselves and the future of our profession.

I’m here to make cancer less scary…

A few weeks ago I was asked to be formally interviewed as a means to introduce me to the surrounding community. NC State takes an active role in promoting recently hired faculty and as the new kid on the block, it made sense it would be my turn to spend some time describing myself and my goals to the community.

As much as I enjoy writing and and publishing posts online for the virtual world to read and examine, if I’m being honest I’d tell you, I detest having my picture taken and I really dislike talking about myself. There’s a huge disparity between publishing written information and posting pictures of my cats and really delving into the more sensitive issues on a “face to face” basis. But I recognized the goal of the assignment was far more important than my personal hang ups and agreed to sit down and talk about veterinary oncology and my choice to leave private practice and work in academia.

The goal here isn’t self-promotion – it’s to promote awareness of veterinary oncology. To let pet owners know there are specialists available who are experts in the diagnosis and treatment of cancer in companion animals. To assure them that the diagnosis of cancer doesn’t equal “there’s nothing we can do.” Pet owners should know the goals of veterinary oncology are not the same as human oncology. While the two disciplines are certainly intertwined, the approach to each case is vastly different. We promote quality of life, not life at all costs.

My wish is everyone facing a diagnosis of cancer in their pets would at least be offered the opportunity to talk to a veterinary oncologist. While a consultation doesn’t equal committing to a treatment plan, you will never be able to make the most informed decision unless you are presented with all the facts.

And the best person to help you make that decision is a veterinary oncologist.

Read all about my new job at NC State College of Veterinary Medicine and veterinary oncology by clicking here