Having a Heart to Heart Talk with Yourself About Your Pet’s Cancer Diagnosis

Cure Pet Cancer

November is National Pet Cancer Awareness Month. One in every four dogs and one in every five cats will develop cancer in their lifetime and @amcny is doing its part to raise pet cancer awareness by tweeting to #CurePetCancer to raise awareness.

Since cancer diagnoses are common in pets, many of my readers will face the difficult task of choosing cancer treatment decisions for their pet. Here is a list of questions you should ask yourself as you work through that decision-making process.

What kind of cancer specialist does my pet need?
Veterinary cancer specialists are not all the same. At AMC, we have three different types of cancer experts for pets: those that focus on administering chemotherapy, some who specialize in delivering radiation therapy, and the third type have special training in surgical oncology. We all know the basics of cancer treatment principals, but have different strengths within that core information. Your pet may need a consultation with one of us or all of us, depending on the type of cancer that has been diagnosed. The answer to this question lies in the biopsy because the type of tumor your pet has dictates the treatment options.

What kind of treatment is the oncologist recommending and is it right for my pet?
There are three main treatments for cancer: surgery, radiation and chemotherapy. Not every treatment is appropriate for every type of cancer and based on the biopsy, an oncologist will discuss what options are available to your pet and the expected outcome for each treatment option. Chemotherapy and radiation therapy require multiple treatments over several weeks to months. Surgery typically requires only a few visits to the hospital and has the highest chance of curing certain cancers. Cancer is most common in older pets and the grey muzzle set is also most likely to have other medical conditions which have to be taken into consideration in making the decision to pursue cancer treatment.

Do I have the resources to undertake the recommended treatment?
This question isn’t just about money, although cancer treatment can be costly. Another consideration when making the decision to treat your pet’s cancer is your time. Sometimes a trip to the surgical oncologist is all that is needed and other times 20+ trips are required for a course of chemotherapy. Be sure you understand what is required for the recommended treatment protocol. Your emotional resources count too. Maybe you are also caring for a seriously ill human family member and cancer treatment for the pet is more than you can handle. Or maybe it is the other way around and you can’t bear to lose two family members at once.

What is the prognosis for my pet with and without treatment?
This is a loaded question. The question is fair, but pet families who choose not to treat their pet’s cancer don’t often consult with an oncologist. That means oncologists, like me, don’t always have a good handle on the prognosis without treating many types of cancer.

If you have decided to make an appointment for a consultation with a veterinary cancer specialist, read about fancy cancer words that we try to keep out of our conversation with you, but sometimes accidentally slip into a conversation about treating your pet. Being prepared for a visit with a specialist will help to make sure all your questions are answered.

Strange Cancers from the Animal World

melinda at AMC

Being a veterinary oncologist by training, an article about cancer always catches my attention. I wanted to share some strange cancer news from the animal world for this week’s blog post.

Contagious Cancer in Dogs
I have a very special patient right now, Melinda, a recipient of a grant from AMC to the Rescue, the Animal Medical Center’s fund to support specialty care for animals in need of a forever home. Melinda has a strange cancer called transmissible venereal tumor. This tumor is contagious and typically spreads between dogs during mating. Even though this tumor can look ugly, it is usually curable with several rounds of chemotherapy, and Melinda is responding well to treatment. Analysis of the cells in transmissible venereal tumor finds fewer chromosomes than in normal dog cells. The chromosomes in the tumor are shaped differently than normal dog chromosomes. Transmissible venereal tumor was first reported in 1876, but genetic analysis tells us the tumor is thousands of years old.

Cancer Immunotherapy for Tasmanian Devils
Beginning in the 1990’s, wildlife biologists identified a new type of cancer in Tasmanian devils. Like the transmissible venereal tumor of the dog, the devil facial tumor has chromosomal abnormalities and is spread when a male devils fight over a potential mate. The tumors are fatal and in certain areas of Tasmania, nearly 90% of devils were lost to this disease. But in March 2018, an encouraging report was published in Nature. Scientists at the University of Tasmania created an antitumor vaccine from devil facial tumor cells which were modified to make them induce an immune response against a tumor already present on the face of a Tasmanian devil. In three of five devils treated with the vaccine, the tumors regressed. This is the first step to helping eradicate this tumor from wild devils and also saving this rare and endangered species.

No Cancer in Elephants
Studying cancer in animals helps researchers understand cancer in humans. For example, bone cancer or osteosarcoma occurs more commonly in dogs than in children and for years, the dog has served as a model for developing new osteosarcoma treatments. Elephants are a species less likely to get cancer than other animals, like humans and dogs. By studying the DNA of elephants, scientists have found clues to why these majestic creatures are resistant to cancer. One reason is elephants have multiple copies of a gene TF53. The gene codes for a protein p53 which helps to remove mutant cells before they become cancerous.

In a second study, scientists found elephant’s cells repair damage quickly and that keep cells from going rogue and becoming malignant. Understanding the unique resistance of elephants to cancer may lead to methods of cancer prevention in creatures more susceptible to cancer.

Cancer is a frightening and devastating disease in everyone, including pets, wildlife and humans. But by studying the biology of cancer in multiple species, we can make progress in understanding and treating this dreaded disease.

Should You Be Concerned About Fatty Tumors in Your Dog?

lipoma

The Animal Medical Center’s Usdan Institute for Animal Health Education provides our clients and the broader community with important, relevant, and timely animal health information. A dog owner reached out to the Institute for information on lipoma, a fatty tumor found most commonly in dogs. I will recap my answer to their question here.

What is a lipoma?
A lipoma is the most common skin tumor found in dogs and is a benign accumulation of fat cells. Some dogs never have one, and others can be very lumpy because of multiple lipomas. Because medical terms can be confusing, be sure you don’t confuse lipoma with lymphoma. Lymphoma is a malignant tumor of lymph nodes and is the most common malignant canine tumor treated by AMC oncologists.

What does a lipoma look and feel like?
A lipoma is a mass under the skin, which you may notice because the lipoma causes the fur to stick up funny, or you run into the lump when you are petting your dog. Lipomas are usually soft and easily movable; they are not attached to the underlying body wall. Some lipomas can attain giant proportions and cover the entire side of your dog, without causing any medical issues. Veterinarians cannot rely on how the skin mass looks or feels to determine if the mass is a lipoma. Mast cell tumors and soft tissue sarcomas, two potentially malignant tumors, also develop under the skin and can feel soft and squishy just like a lipoma. I have seen dogs with ten lumps, nine are lipomas and the tenth is a nasty mast cell tumor.

Should I have my dog’s lipomas removed?
The presence of a lump on your fur baby is worrisome to many dog families, but the vast majority of lipomas never cause a problem in a dog. Occasionally, a lipoma becomes very large and interferes with ambulation. These are often found in the armpit, and removal improves the dog’s quality of life immeasurably.

Are lipomas ever malignant?
The word, lipoma, implies a benign tumor, but there is a malignant version of lipoma, a liposarcoma. A liposarcoma is not a lipoma gone bad, but a tumor arising from juvenile fat cells. Dogs affected by a liposarcoma can have a good prognosis, but usually need a major surgical procedure to completely remove the tumor.

My dog is really lumpy, now what?
Lipomas are easily diagnosed via cytology. Cytology can sort out the difference between mast cell tumors and soft tissue sarcoma as well. Talk to your veterinarian about any lumps you find on your dog. If the lumps are sometimes hard to find, use a permanent marker or white-out painted on the fur to make finding them easier during your pet’s examination.

Are Purebred Dogs Sicker than Mutts?

westminster dog show

This week was the week New York City went to the dogs; the annual Westminster Kennel Club Dog Show was in Madison Square Garden on Monday and Tuesday and there were activities all over the city related to man’s best friend. The Animal Medical Center veterinarians were at the Show triaging dogs unlucky enough to get sick during the second longest running sporting event in the United States.

I always love to visit the rows and rows of cossetted purebred dogs in the benching area of the show. But all those purebred dogs made my veterinary mind drift to lists of diseases prevalent in certain breeds: Addison’s disease in Nova Scotia duck tolling retrievers, renal dysplasia in Shih Tzu dogs, or cardiomyopathy in the Doberman pinscher, to name a few. I can also assure you all three of these diseases are not exclusive to purebred dogs and can be diagnosed in any dog.

Is Hybrid Vigor a Myth or “Dog”-Ma?
The list of diseases associated with purebred dogs is long, but does that mean purebred dogs are less healthy than the basic Heinz 57 model? Probably not. One way to assess health is to look at cause of death. In a study of over 70,000 dogs from North America where the cause of death was known, the number one cause in most breeds was cancer, but the number one cause in mixed breed dogs was also cancer! The fact that cancer is so common in our canine companions reflects the high-quality medical care available to dogs in the United States and Canada. Well cared for dogs don’t die of distemper or parvovirus, they get vaccinated. Dog owners use heartworm preventative and flea/tick medications to prevent parasitic and tick-borne illnesses. Few people let their dogs off leash unattended, protecting them against trauma from automobile accidents. Good health care allows dogs to live to a ripe old age where they are at risk for developing cancer.

Common Diseases Occur Commonly
A recent study of Border Terrier health from England looked at common disorders in this healthy, hearty breed. When seen by a primary care veterinarian, dental disease, ear infections and obesity topped the list of diagnoses in this group of British Border Terriers. Compare that to a widely published list of pet insurance claims and you see the same disease in a large population of insured American dogs, where ear infections and tooth abscess are included in the top ten list. Seems that no matter where you look, dogs all seem to have similar problems.

Lifestyle and Disease
Lifestyle may play as much a role, if not more, than breed does when it comes to health. The study of 70,000 dogs reported infectious disease as the most common cause of death in Treeing Walker Coonhounds. These dogs are commonly used as hunting dogs and their outdoorsy lifestyle may predispose them to infections. The bold Jack Russell Terrier most commonly fell victim to trauma, perhaps due to daredevil personality. Age plays a role in cause of death as well. Young dogs were more likely to die from traumatic causes, but rarely cancer.

The best way to have a healthy dog, purebred or mutt, is to keep him at an ideal body weight, feed a good quality food, make sure he has plenty of exercise and at a minimum, an annual veterinary visit. Hats off to all the Westminster competitors, all of us at AMC think you are all top dogs.

The Difference Between Diagnostic Radiology, Radiation Therapy and Interventional Radiology

radiation therapy

At first glance, these three disciplines within veterinary medicine seem pretty much the same, but at the Animal Medical Center, diagnostic radiology, radiation therapy, and interventional radiology represent three different groups of veterinarians with three very different sets of background and training. What ties these three disparate groups together is their use of radiation to diagnose and treat disease.

Diagnostic Radiology
These days you are more likely to find a Department of Diagnostic Imaging in a hospital than a Radiology Department. Radiology is an older term, used when x-rays were the only testing modality using radiation available in medicine. Today, AMC’s Diagnostic Imaging Service uses not only traditional x-rays but also ultrasound, computed tomography (CT) scans, and magnetic resonance imaging (MRI) in the diagnostic evaluation of patients. AMC’s Diagnostic Imaging Service also has a fluoroscopy unit, which is like a video x-ray. This machine allows us to watch bodily functions like blood flow or swallowing in real time. To see an example of fluoroscopy, read about Molly the Ganaraskan. Every veterinarian at AMC depends on our diagnostic imaging team for their expertise in imaging sick pets and helping us to make an accurate diagnosis.

Radiation Therapy
A very accurate description, AMC’s Radiation Oncology Service uses radiation to treat tumors. Specifically, we have a linear accelerator (linac), a giant machine that creates various types of radiation depending on patient needs. Our state-of-the-art linac can make electrons for superficial treatments, produce high energy pinpoint beams for stereotactic radiosurgery, and stereotactic body radiation therapy. Diagnostic Imaging’s CT scanner interfaces with Radiation Oncology’s 3-D computer planning system. The interface allows the linac’s multileaf collimator to sculpt the radiation beam to precisely target the tumor being treated. The veterinarians working in radiation therapy have training in both the physics of radiation as well as the management of cancer.

Interventional Radiology
Specialists in interventional radiology use minimally invasive techniques to make image-guided diagnoses and also deploy high tech treatments for a variety of diseases. Using a range of techniques which rely on the use of images generated by diagnostic radiology equipment such as fluoroscopy, ultrasound, CT scan, or MRI imaging, the interventional radiologist precisely targets various organs with treatments such as stents, occluders and medications. Watch a video where AMC’s interventional radiology team uses fluoroscopy to close off abnormal blood vessels in the liver. The veterinarians in our Interventional Radiology Service have diverse backgrounds in surgery, internal medicine plus specialized training to use minimally invasive equipment.

Linked together by their use of radiation as a diagnostic and therapeutic tool, diagnostic radiology, radiation therapy and interventional radiology are just a few of the highly trained specialists at AMC working to make sick pets healthy again.

Feline Lymphoma

feline lymphomaNovember is National Pet Cancer Awareness Month. Last spring I wrote about canine lymphoma, so in honor of Cancer Awareness Month, I thought I would do the same for feline lymphoma.

What is Lymphoma?
Lymphoma is cancer of the immune system. The immune system is distributed throughout the body to protect against infections. Lymphoma in cats most commonly affects the gastrointestinal tract, although since the immune system is distributed throughout the body, lymphoma can be seen in any organ in the body including the eyes, in front of the heart, and in the kidneys, liver or spleen. Unlike canine lymphoma, feline lymphoma rarely occurs in the lymph nodes.

In cats (and also humans) it is not a single disease, but is probably more than 20 different diseases; each of the 20 or so forms of lymphoma behaves somewhat differently and the prognosis varies between types. The most common form of lymphoma we see in cat intestines is called small cell lymphoma. We also see an intestinal variant called large cell lymphoma. The photomicrograph on the right shows a rare form of feline lymphoma called large granular lymphoma. The name comes from the granules seen in some of the cancerous lymphocytes.

How is Lymphoma Treated?
Three major types of treatments underlie all cancer therapy: surgery, radiation therapy and chemotherapy. Since lymphoma is widespread throughout the body at the time of diagnosis, surgery is not generally used for treatment as removal of all the lymph tissue in the body is impossible, but sometimes a solitary mass of lymphoma may be removed from the intestine if the mass is causing problems for the cat. Surgery may also be recommended to obtain a biopsy for diagnosis. Radiation therapy can be used in select cases of feline lymphoma, especially if chemotherapy stops working. However, chemotherapy remains the mainstay of feline lymphoma treatment.

Multiple Lymphoma Protocols
In my office file drawers, I have a big fat folder of articles describing various chemotherapy protocols for the treatment of lymphoma. Many of them are simply a riff on a theme. In my opinion, there are three basic options for chemotherapy of feline lymphoma:

  1. Steroids, glucocorticoids, cortisone, and prednisone are all names for the same type of drug. In lymphoma, steroids kill the cancer cells but are not “traditional” chemotherapy agents.
  2. Treatment with a single chemotherapy drug. This is most commonly used in intestinal small cell lymphoma. Steroids and chlorambucil can keep a cat with small cell lymphoma in remission for months.
  3. Using multiple chemotherapy drugs known to be effective against lymphoma and combining them into a rotational schedule which minimizes toxicity and maximizes efficacy.

How Long Will My Cat with Lymphoma Live?
Like with dogs, the answer is: it depends. Cats treated for small cell intestinal lymphoma often live 2-3 years and some can even discontinue chemotherapy. More aggressive forms of lymphoma like large cell lymphoma may only survive months despite multi-agent chemotherapy. A board certified veterinary oncologist can give you the most accurate prognosis for your cat.

Helpful Hints About Lymphoma

  • Feline lymphoma is an internal disease. Cat owners will notice weight loss, poor appetite and possibly vomiting/diarrhea which are common clinical signs of multiple cat illnesses like inflammatory bowel disease, pancreatitis and diabetes. A full medical evaluation is required to make a lymphoma diagnosis.
  • Because cat lymphoma typically occurs in the intestines, biopsies are frequently used to diagnose lymphoma in cats. Often high tech testing like flow cytometry or DNA analysis are required to confirm a lymphoma diagnosis in a cat.
  • In a survey of cat owners who chose to treat their cat’s lymphoma, 85% were completely satisfied with their decision.

Preventing Cancer in Your Pet

#curepetcancerNovember is National Pet Cancer Awareness Month. Pet cancer can be just darn bad luck, but some cancers have a known cause. While you can’t change your large breed dog’s risk for developing osteosarcoma or your pug’s predisposition to mast cell tumors, I want to make my readers aware of some practical tips to prevent cancer in their pet.

Consider Spaying or Neutering Your Pet
Spaying your female dog before her first heat significantly decreases her risk of breast cancer. Spaying removes the ovaries and uterus, and the infrequent diagnosis of ovarian and uterine cancer in dogs is a direct result of this frequently performed surgery.

Neutering a male dog similarly decreases the risk of testicular cancer, although this is not a highly malignant form of cancer in dogs. The role of neutering in preventing prostate cancer is less clear and some research suggests it may not prevent prostate cancer in dogs. Clearly, this is an area where more research is needed.

Minimize Sun Exposure
Exposure to the sun’s ultraviolet rays is a known cause of skin cancer in humans. Because pets wear a furry coat every day, their sun exposure is minimal, but cats with light colored fur around their eyes, nose and ears where the fur is thin can develop squamous cell carcinoma from prolonged sun exposure. Light coated dogs that like to sun bathe on their backs can develop skin cancer in the sparsely haired area on their tummies. If your pet spends a lot of time outdoors and has a light coat color, investigate options for sun protection.

Get Your Portly Pet Thinner
Obesity is the number one nutritional disease of pets in America. Obese pets suffer from several illnesses including diabetes, hypertension and arthritis. Cancer may not be the most common disease associated with obesity, but it can lead to cancers affecting the breast and bladder, which have been associated with obesity in pets.

Avoid Toxins
Lymphoma is the most common tumor treated by veterinary oncologists. While genetics play a role in the development of this disease in golden retrievers, boxers, bull mastiffs and Scottish terriers, veterinary oncologists know little about the cause of this disease in most dogs. One study from a group of Italian veterinarians suggested dogs living in industrial areas and also dogs exposed to paints and solvents developed lymphoma at a younger age than dogs not exposed to those chemicals, so keep your dog away from any painting projects or your art studio.

Limit Injections
In the early 1990s, an astute pathologist recognized a new tumor in cats. The tumors, belonging to the sarcoma family of tumors, were found at the sites of vaccination. The tumors occur in only a small number of vaccinated cats, but when they occur, oncologists must use all available treatment options to control the tumor. The occurrence of these tumors, resulted in changes to vaccination protocols. Today, veterinarians use fewer vaccines, manufactured to maximize feline safety. Administration of vaccines at non-traditional sites is also under investigation.

Prevent Feline Leukemia Virus Infection
The feline leukemia virus is a cancer causing virus of cats. Before control measures like vaccination against the virus were instituted in the 1980s, veterinary oncologists treated hundreds of young cats suffering from lymphoma near their hearts. Today, we see very few cases of feline leukemia virus-induced lymphoma because this disease is preventable if you keep your cat indoors and away from cats infected with the virus.

Quit Smoking 
In people, 9 out of 10 lung cancers are caused by smoking. Your doctor would want you to quit smoking to decrease your risk of lung, throat and bladder cancer among others. But did you know your smoking can cause cancer in your pet? Dogs living with a smoker have a greater risk of developing nasal cancer, and cats exposed to secondhand smoke have a greater risk of developing lymphoma and oral squamous cell carcinoma.

Following these tips will help to decrease the number of pet cancer cases requiring veterinary oncologists to #CurePetCancer less often and that should make us all happy.

Spicing Up Cancer Treatment

animal medical center blogIn its new report on pet supplements, the market research group Packaged Facts forecasts a domestic market for pet supplements of $697 million in 2019. This trend is certainly true in the cancer therapy world. As a veterinary oncologist, I know that if your pet receives a diagnosis of cancer, you will be desperate to find treatments with the ability to eradicate the cancer without side effects. In this situation, I know that most owners will most certainly investigate herbal and natural supplements to treat their pet’s tumor, with or without my knowledge. I am here to urge caution: a couple hours spent on the internet can easily convince you that feeding your pet a turmeric spiced salad of mushrooms and broccoli can rid your pet of any ailment, including cancer. With all the available (mis)information out there, here are my thoughts on some herbal and natural remedies which have been scientifically validated as a treatment for cancer – as well as some that look interesting but still need more study.

Turkey Tail Mushrooms and Hemangiosarcoma
Coriolus versicolor, also known as the turkey tail mushroom, has been brewed into tea for centuries in Asian countries, and more recently used to treat cancer. Currently, it is being investigated as an immune system supplement in human cancer patients in a Food and Drug Administration (FDA) sanctioned clinical trial. This mushroom is also undergoing investigation in veterinary patients, specifically dogs with hemangiosarcoma, because it contains a protein-bound complex sugar which appears to have anti-cancer properties.

Researchers at the University of Pennsylvania School of Veterinary Medicine treated dogs with a commercially available Coriolus versicolor product and found the longest reported survival time for dogs with hemangiosarcoma. More trials are underway to confirm this exciting result and many of the dog patients I see with hemangiosarcoma are already receiving mushroom therapy.

Veggies, Bladder Tumors and Scotties
Scottish terrier dogs have the highest risk of developing bladder tumors of any breed of dog. In a study designed to identify dietary components protective against the development of bladder cancer in Scotties, vegetables proved helpful. In the study, a human member of the Scottie dog’s family completed a dietary survey about their dog including questions about weekly consumption of yellow-orange, green leafy, cruciferous, or other types of vegetables. Scotties without bladder cancer consumed more servings of green leafy and yellow-orange vegetables per week than those with bladder cancer. So, maybe mom was right – eating vegetables is good for you!

Too Soon for Turmeric
A spice of great interest these days is turmeric, Curcuma longa, the yellow spice in Indian curry powder. The subject of intense investigation, one of turmeric’s active ingredients, curcumin, has anti-cancer, anti-inflammatory and antidepressant effects and may prove useful in disparate conditions such as arthritis, cancer and post-traumatic stress disorder. But as of this writing, studies of curcumin are predominantly laboratory studies or studies of research dogs, not pet dogs with disease. In the lone clinical trial of a curcumin extract in dogs with arthritis, a benefit of therapy was not seen. All this indicates that curcumin has medicinal properties but that more research into clinical use of turmeric is needed to identify whether pets with cancer will benefit from this spice.

Melanoma Medicine
Oral melanoma is one of the most deadly tumors in dogs, because these tumors are often advanced by the time of diagnosis and currently available treatments do not cure all dogs. Japanese researchers are investigating an organic compound, lupeol, as a treatment for oral melanoma in dogs. Extracted from olives, mangoes, strawberries, grapes, figs, vegetables, and other medicinal plants, lupeol has shown promise as an anticancer agent in cell culture, rodent models and most recently in a small canine clinical trial in Japan. I find the source of this compound intriguing since we all know grapes and raisins can be deadly for dogs. After reading this, please don’t feed your dog fresh grapes hoping they will help your pet’s cancer. In the meantime, we’ll have to keep our fingers crossed regarding whether we will continue to see promising data on this potential new treatment for canine melanoma.

Too Spicy?
Since most of us have herbs and spices in our kitchen, we assume they are safe, but when it comes to pets, that assumption may not be correct. Don’t crank up the stove and decide home cooking would be healthier for your pet with cancer until you check with your veterinarian about creating a safe and healthy diet for your pet.

Radiation Therapy Machines: Machines and Methods

radiation therapyMay is Pet Cancer Awareness Month. Since the goal of Pet Cancer Awareness Month is to educate pet owners about cancer, I am going to devote this week’s blog to clearing up some of the confusion over the various forms of radiation therapy. Radiation therapy machines treat cancer by delivering high energy radiation to a tumor, killing the tumor cells. There are several types of prescriptions for the dose of radiation delivered to a tumor.

Radiation Oncologists and Their Machines
A number of different machines are available to administer radiation:

  • The Animal Medical Center uses a Varian Clinac® linear accelerator (linac) to deliver radiation therapy to tumors. Our linac has a multi-leaf collimator (MLC) which moves while the radiation beam is on, sculpting the beam around the tumor, protecting normal structures from radiation. Here is a MLC in action. Radiation using a MLC is called image modulated radiation therapy (IMRT). We also can utilize a 3-dimensional computerized treatment planner. The AMC’s linac can also be used to deliver stereotactic treatments. I will expand on stereotactic treatment below.
  • The Cyberknife® is a linac merged with a robotic arm, which allows the machine to dance around the patient. The radiation beam turns on and off, zapping the tumor from multiple angles. Treatment from multiple angles creates a treatment field conforming to the shape of the tumor.
  • A Tomotherapy machine is a cross between a linac and a CT scan. Tomotherapy creates an image of the tumor immediately prior to treatment and uses the image to direct treatment. Both imaging and treatment occur using the same machine.
  • The Gamma Knife® treats brain tumors. And although the word knife suggests this machine does surgery, it does not. It precisely delivers a high dose of radiation to a very focal area in the brain while avoiding normal brain tissue.

Radiation Therapy Prescriptions
Radiation can be prescribed in a number of different fashions. The standard for many years has been administration of multiple small doses of radiation with the goal of eradicating the tumor. This course of treatment is often referred to as “definitive” or “hyperfractionated” therapy. Oncologists commonly recommend this type of treatment to follow when a surgical procedure has not removed every last tumor cell. The opposite of hyper is hypo and oncologists often use a few large doses of radiation to treat tumors that cannot be removed by surgery. Oral melanoma is a good example of a tumor treated this way.

The most advanced dosing schemes for radiation therapy are Stereotactic Radiation Therapy (SRT), which includes both Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT). Stereotactic treatments use high doses of radiation given over one to three treatments. On-board imaging equipment allows precise delivery of the radiation dose in stereotactic treatments. Stereotactic radiosurgery, like the Gamma Knife, is not a form of surgery. It is typically administered in a single dose and is reserved for treatment of brain tumors. Stereotactic radiosurgery was the first type of stereotactic radiation therapy. Stereotactic Body Radiation Therapy, as the name implies, is administered outside the brain. The AMC’s Clinac is able to deliver both SRS and SBRT.

The “Best” Type of Radiation Therapy
No one radiation therapy machine or prescription is “best.” The type appropriate to treat your pet’s tumor will be determined by the biopsy results, surgical resectability of the tumor, and size and location of the tumor. The AMC has a board certified radiation oncologist who can help you make the best decision possible to manage your pet’s cancer with radiation.

Toe Tumors in a Dog: A Cancer Survivor’s Story

Dog toe tumorsThis photo shows something unique. Look carefully and you will see a dog with three toes on each foot. No, he wasn’t born this way, Pogo is a cancer survivor. The missing toes were amputated because of a cancer diagnosis in a toe on each of his front feet.

How common are toe tumors?
Research has shown just over half of toe masses are malignant tumors. The most common malignancy of canine toes is squamous cell carcinoma, and the dog pictured here lost his first toe when surgeons cured him of this tumor. Three years after the diagnosis of squamous cell carcinoma, Pogo’s family, ever vigilant since the first cancer diagnosis, noticed a mass on one of his paw pads. Given his prior cancer diagnosis and knowing some dogs have multiple toes affected with squamous cell carcinoma, Pogo returned to AMC to have the second toe removed. Surprisingly, the diagnosis was melanoma, which is the second most common toe tumor.

What dogs get toe tumors?
Any dog can develop a tumor of the toe, but large breed, black coated dogs such as standard poodles, Rottweilers, Labrador retrievers and giant schnauzers have an increased risk of developing squamous cell carcinoma of the toe. Melanoma too, has been reported more often in black coated dogs, and in one study, the Scottish terrier was predisposed to melanoma.

How would I recognize a toe tumor?
An observant dog owner may notice their dog licking one particular toe, suggesting the toe hurts and cluing them in to a potential problem requiring medical attention. The presence of a mass on the toe suggests a toe tumor, but other possibilities include an infection, inflammation from a foreign object lodged in the toe, or a benign tumor. A broken or bleeding toenail may be another sign indicating the presence of a toe tumor. Should you see any of these abnormalities on your dog’s toes, head to your veterinarian’s office immediately.

If your dog develops a toe tumor, don’t despair; early detection and prompt surgical intervention can make your dog a cancer survivor too.