Start a Canine Cancer Treatment Program Now!
Interview with Dr. Tobin, DVM
Dr. Stephen Tobin is a holistic veterinarian who providestreatment using homeopathic herbs and nutrition. He speaks with us about hisphilosophy of animal care, pet nutrition, and his experience with the LonglifeProgram in the treatment of his patients.
How Does Longlife Treat Canine Cancer?
A cancerous tumor feeds off vital nutrients that flow through the bloodstream. Researchers have found that shark cartilage stops blood vessels from feeding and growing within the tumor. In clinical studies on the use of shark cartilage supplements, it was found that tumors did not grow larger than 2 millimeters in size, due to an antiangiogenesis effect, or a prohibiting of the growth of new blood vessels inside the tumor.
Longlife for Dogs is made from 100% pure shark cartilage and is formulated to promote maximum absorption. Longlife is a helpful tool in the prevention of metastasis during or after chemotherapy and can be combined with chemotherapy to increase appetite and help protect the immune system. Longlife for Dogs should be used as supportive supplements, not a substitute for quality care from a trusted veterinarian or oncologist.
Characteristics of Cancer in Dogs
Abnormality: Cells are the structural units of all livingthings. Each of us has trillions upon trillions of cells, as does a growing tree,a sponge in the ocean, or a dog asleep by the fire. Cells make it possible forus, and for dogs, to carry out all kinds of functions of life: breathing, walking,jumping, digesting food, and so on. However, all of these functions can onlybe carried out by normal healthy cells. Cancerous cells stop functioning as theyshould, become useless to the body, or become hostile to the body’s purpose.
Uncontrollability: The most fundamental characteristic ofcells is their ability to reproduce by dividing: one cell becomes two, two becomefour, and so on. In most parts of the body, cells continually divide and formnew cells to supply the material for growth or to replace worn-out or injuredcells. When a person cuts his or her skin, certain cells leap into action, dividingand dividing, producing news cells until the tissue is healed and the skin isrepaired. (Afterwards, they return to their normal rate of division.) In contrast,cancer cells divide in a haphazard manner that does nothing good, and often somethingbad, for the body. These typically pile up into a nonstructured mass. This massis known as a tumor.
Invasiveness: Sometimes tumors do not stay harmlessly inone place. Tumors often destroy the part of the body in which they originateand then spread to other parts, where they cause new harm. This is what differentiates malignantgrowths from benign growths, which remain in the partof the body in which they start. Although benign tumors may grow quite largeand press on neighboring structures, they do not spread to other parts of thebody. Frequently, they are completely enclosed in a protective capsule of tissue,and they typically do not pose danger to life. Malignant tumors do spread, andare life threatening.
Many diseases: Although cancer is often referred to as asingle condition, it is actually comprised of dozens of different diseases. Thesediseases are characterized by site of origin, method and speed of growth, andcharacter of the abnormal cells. Cancer can arise in many sites and behave differentlydepending on its point of origin. It is important to understand that cancer originatingin one body organ takes its characteristics with it even if it spreads to anotherpart of the body. For example, metastatic lung cancer starts in the lung; evenif it spreads to other parts of an organism’s body, it retains the characteristicsof its original organ.
In a dog, this abnormal cell phenomenon is called, simply, Canine Cancer.Canine cancer is a common disease which requires prompt and decisive veterinaryattention. Dogs with cancer elicit a strong emotional (and, it must be said,economic) toil on the animal’s caretakers. Huge strides are being taken to helpveterinarians recognize cancer in dogs and to assist in control and cure. Advancesin human cancer diagnosis and treatment often mirror the same protocols veterinariansutilize to diagnose, control, and treat cancer in animals.
Canine Cancer Definitions of Terminology
To best understand cancer, it is helpful to understand a few terms:
Cancer: Any malignant, cellular tumor; cancers are dividedinto two broad categories of Carcinoma and sarcomas: Acarcinoma is a malignant growth made up of epithelial cells (which form a membraneover an organ) tending to infiltrate surrounding tissues and give rise to metastases.A sarcoma is a malignant tumor originating from connective tissue or blood orlymphatic tissues.
Neoplasm: an abnormal new growth of tissue in animals orplants; a tumor.
Benign tumor: One lacking the properties of invasion andmetastasis and showing a lesser degree of abnormal cellularity than malignanttumors. These are usually surrounded by a fibrous capsule.
Malignant tumor: Has the properties of invasion and metastasisand displays cells with widely varying characteristics.
Metastasize: to spread throughout the body, of cancer cells.
Growth: any kind of an abnormal increase in size of tissue.
Lump: A growth or fluid-filled cyst or any structure risingabove the normal surface of a tissue plane.
Hemangiosarcoma in Dogs
Hemangiosarcoma is an aggressive cancer that arises from the blood vessels.The cancer can occur anywhere in the body, but there are several locations thatare more common. Early and aggressive treatment can lengthen the dog's life,but this cancer is often metastatic and complete remission is rare.
Dogs At Risk for Hemangiosarcoma
Hemangiosarcomas can occur in any dog. It does not discriminate on the basisof breed, age, or sex. However, several breeds of dogs seem to be at greaterrisk for hemangiosarcoma, including German Shepherds, Golden Retrievers, Boxers,and English Setters.
Researchers do not currently understand why dogs develop hemangiosarcoma.Because of the increased incidence in several breeds, a genetic link appearsto be one of several likely causes. Because hemangiosarcoma is rarely found inhumans, less research has been done and the amount of information about the causeof this tumor is somewhat limited.
Symptoms of Hemangiosarcoma
Hemangiosarcomas can occur anywhere on or in a dog's body, but primarily arepresent in the spleen, liver, heart, and skin. The skin form of hemangiosarcomahas a better prognosis and recovery rate than the internal forms. The skin formis more present in cats, and is sometimes associated with sun damage on light-skinned/hairedanimals. The internal form is usually diagnosed by the palpitation of a largemass in the abdomen or with symptoms of sudden blood loss, which results fromthe rupture of the fragile tumor and a subsequent loss of blood into the abdomen.Symptoms include weakness or collapse and pale mucous membranes. Occasionally,dogs will have symptoms of chronic blood loss, which include pale gums, slowcapillary refill time (CRT), irregular heart rate, and generalized weakness.
Once a tumor is suspected, abdominal and chest X-rays are often performedto determine the extent of organ involvement and to find out whether or not metastasisis present. Hemangiosarcoma is an aggressive tumor, and metastases are oftenpresent at the time of initial diagnosis. A biopsy or positive identificationof a removed tumor by a veterinary pathologist is usually recommended.
Lymphoma in Dogs
Lymphoma, otherwise known as Lymphosarcoma, is a common cancer and can occurin the lymph nodes, spleen, liver, and other organs. The cancer can be aggressiveand if left untreated can be fatal.
Dogs at Risk of Lymphoma
Lymphomas primarily affect middle-aged to older dogs. There does not appearto be a differentiation as to breed or sex. Only a small portion of dogs areclinically ill at presentation; the majority are brought in because of recentlyidentified swellings or lumps.
Causes of Lymphoma
While we understand how lymphomas form, we still do not understand why. Incats, there appears to be a strong link between some forms of lymphoma and infectionwith feline leukemia virus, but in dogs such a link is not apparent. Some authorshave speculated that environmental factors (exposure to pesticides or strongmagnetic fields) might play a factor, but there is currently no strong proofof this. At the same time, some studies have also hinted at a possible geneticcorrelation.
Symptoms of Canine Lymphoma
The symptoms of lymphoma are related to the location of the tumor(s). Tumorsthat develop in the lymph nodes often present as swellings with no other symptoms.The gastrointestinal form often is accompanied by vomiting, diarrhea, weightloss, and lack of appetite. The chest form often presents with shortness of breathand muffled heart sounds. The cutaneous (skin) form can present in several differentways, including single or multiple lumps in the skin or mouth. These bumps canitch or be red and ulcerated.
Diagnosis of Canine Lymphoma
Lymphoma is diagnosed with a combination of tests, including blood tests,fine needle of the tumor, biopsies, X-rays, and ultrasound. The exact tests performeddepend on the location of the tumor.
Histiocytomas in Dogs
Histiocytomas can affect dogs of any age or breed. Though they can appearon any location on the body, the vast majority of histiocytomas appear on thehead. Histiocytomas usually occur on dogs under three years of age; they areone of the most common tumors in this age group.
These tumors appear rapidly and are small, round, and hairless. They willoften ulcerate and then become smaller and go away. They usually appear as asolitary mass, but more than one may be present at a time. These tumors are benignand are not considered to be a health risk.
Treatment for Histiocytomas
Treatment often involves simply letting the tumor run its course. Histiocytomascan be surgically removed, if they are bothering the dog and are in a locationwhere removal will allow for closure of the skin. They can also be treated withtopical steroids and antibiotics if they ulcerate or become inflamed or infected.However, most dogs never receive nor require any treatment intervention. If adog owner sees a small tumor that develops on his or her dog, he or she shouldmake sure to have it examined by a veterinarian.
Mammary Tumors in Dogs
Mammary tumors are the most common tumors in female dogs that have not beenspayed. Mammary tumors can vary from small, simple nodules to large, aggressive,metastatic growths. With early detection and prompt treatment, even some of themore serious tumors can be successfully treated. Cats also suffer from mammarytumors, and they have their own unique set of problems that will be discussedin a separate article.
Dogs At Risk of Developing Mammary Tumors
Mammary tumors are more common in unspayed, middle-aged female dogs (thosebetween 5 and 10 years of age), although they can, on rare occasions, be foundin dogs as young as 2 years. (They are rare in dogs that were spayed at lessthan 2 years of age.) Occasionally, mammary tumors will develop in male dogs(in the same way that men can sometimes develop breast cancer), and these areusually very aggressive and have a poor prognosis.
Spaying greatly reduces the chances of a female dog developing this condition.In those females spayed prior to their first heat cycle, mammary tumors are extremelyrare. The risk of malignant mammary tumors in dogs spayed prior to their firstheat is 0.05%. It is 8% for dogs spayed after one heat, and 26% in dogs spayedafter their second heat. The elimination or reduction of certain hormones causesthe lowering of incidence of the disease in dogs that have been spayed—this isthe scientific consensus. These hormones are probably estrogen, progesterone,a similar hormone, or possibly a combination of two or more of these.
Types of Canine Mammary Tumors
There are multiple types of mammary tumors in dogs. Approximately one-halfof all mammary tumors in dogs are benign, and half are malignant. All mammarytumors should be identified through a biopsy and histopathology (microscopicexamination of the tissue) to help in the treatment of that particular type oftumor. This is, of course, a role for the veterinarian.
The most common benign form of canine mammary tumors is actually a mixtureof several different types of cells. Single tumors rarely possess more than onetype of cancerous cells. This combination cancer in the dog is called a “benignmixed mammary tumor” and contains glandular and connective tissue. Other benigntumors include complex adenomas, fibroadenomas, duct papillomas, and simple adenomas.
The malignant mammary tumors include the following: tubular adenocarcinomas,papillary adenocarcinomas, papillary cystic adenocarcinomas, solid carcinomas,anaplastic carcinomas, osteosarcomas, fibrosarcomas, and malignant mixed tumors.
Canine Mammary Tumor Symptoms
Mammary tumors present as a solid mass or as multiple swellings. When tumorsdo arise in the mammary tissue, they are usually easy to detect by gently touchingand retouching the mammary glands. When tumors first appear they will feel likesmall pieces of pea gravel just under the skin. They are very hard and are difficultto move around under the skin. They can grow rapidly in a short period of time,doubling their size every month or so.
The dog normally has five mammary glands, each with its own nipple, on boththe right and left side of its lower abdomen. In half of the cases, more thanone growth is observed. Benign growths are often smooth, small, and slow growing.Signs of malignant tumors include rapid growth, irregular shape, firm attachmentto the skin or underlying tissue, bleeding, and ulceration. Occasionally tumorsthat have been small for a long period of time may suddenly grow quickly andaggressively, but this is the exception and not the rule.
It is very difficult to determine the type of tumor based on physical inspection.A biopsy or tumor removal and analysis are almost always needed to determinewhether the tumor is benign or malignant, and to identify what type it is. Tumors,which are more aggressive, may metastasize and spread to the surrounding lymphnodes or to the lungs. A chest X-ray and physical inspection of the lymph nodesoften help in confirming this.
Mammary cancer spreads to the rest of the body through the release of individualcancer cells from the various tumors into the lymphatics. The lymphatic systemincludes special vessels and lymph nodes. There are regional lymph nodes on boththe right and left sides of the body under the front and rear legs. They arecalled the "axillary" and "inguinal" lymph nodes, respectively.
Prevention of Mammary Tumors in Dogs
Few cancers are as easily prevented as mammary cancer in dogs. There is adirect and well-documented link between the early spaying of female dogs andthe reduction in risk of mammary cancer. Dogs spayed before their first heathave an extremely small chance of ever developing mammary cancer. Dogs spayedafter their first heat but before 2.5 years are at greater risk, but face lessrisk than dogs that were never spayed or spayed later in life. Early spayingis still one of the best things pet owners can do to improve the health of theirdogs.
Testicular Tumors in Dogs
Testicular tumors are considered one of the most common tumors in older intact(unneutered) male dogs. The overall incidence in dogs is not very high becauseof the large number of dogs that are castrated. However, in intact male dogs,these tumors are considered fairly common. The tumors are usually fairly easyto recognize and diagnose. Treatment is castration; this is usually sufficientto eliminate the disease.
Dogs At Risk of Testicular Tumors
Testicular tumors are most common in intact (unneutered) older male dogs.However, they can occur in intact males of any age. There does not appear tobe any breed predilection for this tumor, and the cause of testicular tumorsis unknown. Dogs that have one or both testicles that are not descended (cryptorchid)are 13 times more likely to develop a tumor in the undescended testicle thandogs with normal testicles. Except for the increased risk of these tumors incryptorchid dogs, no other risk factors are readily apparent.
Types of Canine Testicular Tumors
There are three common types of testicular tumors: Sertoli cell tumors, seminomas,and interstitial cell tumors. While there are differences in the types of tumors,they are often treated similarly and are therefore commonly lumped together astesticular tumors.
Symptoms of Testicular Tumors in Dogs
Sertoli cell tumors show symptoms of swelling of the testicular and scrotalarea. Approximately half of Sertoli cell tumors produce estrogen. In that case,the dog suffers symptoms of hyperestrogenism. The symptoms include an enlargedprostate gland, enlarged mammary glands and nipples, symmetrical hair loss, anemia,and the tendency to attract other male dogs. Sertoli cell tumors may metastasizeto the abdomen, lung, thymus, and brain; however, this occurs in less than aquarter of cases.
Diagnosis of Canine Testicular Tumors
Based on history, presentation, and most of all pathological identificationthrough a biopsy or microscopic examination of the removed tumor. Dogs suspectedof a testicular tumor should also have abdominal and chest X-rays to check formetastasis as well as a chemistry panel and a blood count.
Prognosis for Dogs with Testicular Tumors
For dogs with treated testicular cancer, the prognosis is usually very good.The low rate of metastasis makes surgical castration very successful and curativein most dogs. Dogs that develop hyperestrogenism from Sertoli cell tumors oftenhave a regression of symptoms once the tumor has been removed. In severe hyperestrogenismthat results in anemia, some animals may need transfusions and more aggressivetreatment. The prognosis for testicular tumors that have metastasized is moreguarded and the outcome varies widely depending on location, type, and treatment.
Prevention of Canine Testicular Tumors
Testicular tumors are easily prevented through routine castration of maledogs. Castration in young dogs prevents aggression, roaming, urine marking, anda variety of other unsavory male behaviors. Castration is safe and relativelyinexpensive, and in the long run saves the owner money.
Mast Cell Tumors in Dogs
Canine mast cell tumors account for up to 20% of all skin tumors in dogs.While they often appear small and somewhat insignificant, they can be a veryserious form of cancer. Some mast cell tumors are easily removed without thedevelopment of any further problems, while others can lead to a life-threateningdisease. Proper identification and treatment are very important in controllingthese tumors.
Canine Mast Cell Tumors Defined
Mast cells are cells that normally occur in the skin and other tissues, suchas the intestines and respiratory tract. They are part of the immune system ofthe body. They contain large amounts of histamine, heparin, and proteolytic enzymes(enzymes which break down protein). These can be toxic to foreign invaders, suchas parasites, and are released when the mast cell is triggered by the immunesystem.
A mast cell tumor is formed from many of these mast cells. Because of thehistamine, heparin, and enzymes present in mast cell tumors, they can createproblems when damaged or removed. Large amounts of these substances can be releasedinto the body and have significant effects on heart rate, blood pressure, andother body functions. Sites where the tumors are removed can sometimes refuseto heal and can become difficult to manage.
Dogs At Risk of Developing Mast Cell Tumors
Mast cell tumors can develop in all ages and breeds of dogs. There appearsto be a hereditary factor to these tumors most common in Boxers, Boston Terriers,Pugs, English Bulldogs, and other brachiocephalic breeds (those having a short,wide head). Golden Retrievers may also be at increased risk. Most mast cell tumorsdevelop in older dogs, usually those 8.5–9.5 years of age.
The exact cause of mast cell tumors is still unknown. A viral source has beensuggested, as well as hereditary and environmental factors. It is quite possiblethat there are a variety of causes for the development of this tumor. Becausethis tumor is not found in humans, less research and information has been availablefor the veterinarian than for tumors that are found in both humans and animals.
Symptoms of Mast Cell Tumors in Dogs
The appearance of mast cell tumors can be widely variable. They can be eitherbenign or malignant and can be found on any part of the body. They are foundmost commonly on the trunk, limbs, and perineal (genital) area, and can be foundon the skin or in the underlying tissue. They can be single or multiple and canbe smooth, bumpy, or even ulcerated.
Systemic signs, such as vomiting, duodenal ulcers, blood in the stool, andabnormalities in blood clotting, occur in some dogs with mast cell tumors. Thesesigns result from the release of histamines from the active mast cell tumors.
Diagnosis of Mast Cell Tumors in Canines
Since they occur in a variety of shapes and locations, a biopsy is necessaryto properly identify a mast cell tumor.
Mast cell tumors are commonly graded and staged (classified) as to how theyare expected to behave. This is performed by examining the tumor after it hasbeen removed. The grading and staging helps determine what type of further treatmentmay be necessary and the prognosis.
Mast cell tumors are "graded" as to how likely they are to be malignant.The higher the grade, the more serious the tumor.
- Grade I: Occur in the skin and are considered benign. Although they may belarge and difficult to remove, they tend not to spread to other areas of thebody. Most mast cell tumors are Grade I.
- Grade II: Extend below the skin into the subcutaneous tissues. Their cellsshow some characteristics of malignancy and their response to treatment can beunpredictable.
- Grade III: Invade areas deep below the skin, are very aggressive, and requiremore involved treatment.
In addition to grading mast cell tumors, they are also staged, which is ameasurement of how they have spread in the body. A tumor is staged after it isremoved and examined, along with the neighboring lymph nodes. Staging is basedon how many tumors were present, how involved the lymph node is, and whetherthe entire tumor was removed.
- Stage 0: One tumor in the skin incompletely removed, with no lymph node involvement.
- Stage I: One tumor in the skin, with no lymph node involvement.
- Stage II: One tumor in the skin, with lymph node involvement.
- Stage III: Multiple large, deep skin tumors, with or without lymph node involvement.
- Stage IV: One or more tumors with metastasis in the skin, with lymph nodeinvolvement. This stage is subdivided into those that have no other signs (substagea) and those that do have some other clinical signs (substage b).
Prognosis of Mast Cell Tumors in Dogs
The prognosis depends primarily upon the grade and stage of the tumor. Thelower the grade, the better the prognosis. In addition, dogs with Stage I tumorshave the best prognosis, compared to those staged higher. Dogs with tumors onthe limbs appear to have the best prognosis, much better than those with tumorsin the nail bed, genital areas, muzzle, and mouth. Finally, those dogs with mastcell tumors in the internal organs have the least favorable prognosis.
Bone Cancer in Dogs
Bone cancer in dogs can be a challenging disorder to overcome. Bone cancercan occur in any canine. The hallmark of bone cancer (as with all cancers) isuncontrolled cell growth, invasion of cells into nearby structures, and sometimesa dispersal to distant organs, which is termed metastatic cancer. Since any cellin the dog's body has the potential to develop into a cancerous cell, bone cancerdramatically illustrates what can happen when illness occurs.
When a cell turns cancerous by a disruption of its own physiology, normalneighboring cells usually consume the rogue cell. On other occasions, the defectivecell simply self-destructs and is swept away. But in certain circumstances, amodified cell (mutant) makes more cells just like itself. More and more cellsarising from that single mutated cell eventually change the environment and carveout their own territory, spreading themselves into more and more neighborhoods.Metastatic bone cancer cells break away and flow to entirely new environmentswithin the dog's body and begin the malignant process all over again.
Cancer is also termed neoplasia, which means new growth. A cancerous cellgrows faster than normal and divides and multiplies at an abnormal rate; itsoffspring do likewise. From that one abnormal neoplastic cell, more of its kindinvade and crowd out surrounding tissues. With bone cancer, there are four typesof cell lines capable of evolving into a neoplastic condition:
Osteosarcoma: causing nearly 80% of all bone cancers, thismost common form of bone cancer arises from cells that deposit bony minerals.Aggressive invasion and rapid growth make this form of cancer a dreaded threat.
Chondrosarcomas: these tumors arise from the cartilage jointsurfaces at the ends of bone and generally have a less aggressive tendency toinvade and spread than osteosarcomas.
Fibrosarcomas: originate from fibrous connective tissue adjacentto bone, are locally invasive into the bone, and have a low tendency to spread.
Synovial cell carcinomas: originate from joint tissues andinvade the associated bone. These tumors are less aggressive than osteosarcomas.
A definitive diagnosis of bone cancer can only be made via microscopic evaluationof a bone biopsy. Veterinary pathologists classify the degree of malignancy ofthe cells and likeliness of metastasis to other tissues. Neoplastic cells canbe carried by the blood and lymph from the original site of the cancer to distanttissues, at which time a new cancerous growth arises. Called metastatic cancer,whenever distant growths are present in a dog's body, the magnitude of the illeffects on the patient are remarkably increased, and the chances of a cure drasticallyreduced.
At-Risk Breeds for Canine Bone Cancer
Most commonly seen in long bones such as the femur, bone cancer has a predilectionfor larger breeds, including the Greyhound, Saint Bernard, and Mastiff.
Diagnosis of Canine Bone Cancer
Chronic, low-grade lameness with gradually increasing swelling near a jointalerts the veterinarian to the potential of a tumor. Radiographs of the affectedarea will display changes in a bone that are totally unlike the defects usuallyassociated with arthritis. On occasion, an apparently normal dog will be presentedwith a spontaneous lameness. A physical examination, followed by a radiographicevaluation, will reveal the cause of the break to be due to bone cancer. Thisbreak is termed a pathological fracture.
Osteosarcoma continues to be one of the most challenging types of cancer totreat. Part of the therapeutic challenge arises from the fact that at the timeof diagnosis there often has already been metastasis to other areas of the body.