Entries from September 2008 ↓

The question what causes cancer has been one of the most frustrating questions for scientists involved in cancer research. Despite huge amounts of funding and resource being spent on the subject, there is still an element of doubt behind what causes cancer. At the most we know what the risk factors are because most of the causes carry an element of doubt along with them.

Many factors that increase the risk of feline cancer and cancer in dogs can be classified under two categories:

* Carcinogens - viruses, chemicals and physical carcinogens that can be found in the environment
* There are certain DNA and RNA viruses, normally termed as tumor viruses that have the capacity to pass their own genetic information to the DNA of the cells they infect. It is a complex infection which may involve the virus turning into a cancer causing agent or merge partially with the infected cell.
* There are chemicals that may cause cancer directly or indirectly. Indirect carcinogens need enzymes present in the body to act as catalysts for them to turn carcinogenic. Direct carcinogens, however, are reactive compounds in their own right.
* Physical carcinogens include exposure to radiation: ionized or ultraviolet, fibers like asbestos, tobacco smoke and hyperthermia.

Genetic Disorders - inherited or acquired.

* A dog may inherit cells carrying genetic material from generation to generation. A gene that suppresses formation of a tumor may get inactivated. On the other hand a gene that causes normal cells to change into cancerous cells may get activated in the sperm or the ovum.
* In some cases cancerous cells develop during mitosis, the process of multiplication of cell by division and are not hereditary in nature. This is an instance of an acquired chromosomal defect where a parent cell passes on the genetic information to the daughter cells that it divides into.

Prediction of cancer is highly improbable. It is ultimately left to the correct reading of signs, such as symptoms of liver cancer in dogs, which can lead to an early detection of this fatal disease. Advancements in treatment therapies for cancer have resulted in many success stories of pet cancer treatment. If it is determined before metastasis affects vital organs, it is possible to extend the life of your dog as well as improve its quality for as long as he lives.

The success of any cancer treatment is directly related to the stage at which it is detected. There are strong possibilities of cancer in dogs spreading to vital organs making surgical removal an impossible task.

All cancers do not occur as tumors that can be seen on the surface of the body. And therefore these tumors are not too easy to notice and monitor. In many cases malignant cancer symptoms manifest themselves as symptoms that are related directly to the organ it affects. Symptoms like gastrointestinal bleeding or diarrhea are associated with a tumor in the stomach, small and large intestines or colon. Similarly, cancer in hormone producing organs surfaces in the shape of endocrinal disorders and brain or spinal cord tumors are associated with neurological symptoms.

However there are instances where cancer produces general symptoms that do not point to a specific organ. For example, the symptoms of liver cancer in dogs like loss of appetite, a distended stomach and weakness can be associated with cancer as well as other ailments. Some of the other non specific symptoms include weight loss, low grade fever, muscle weakness, skin rash, hair loss and lethargy.

As such, a wait and watch policy can prove to be extremely dangerous as there is always an accompanying risk of metastasis. Diagnostic procedures like laboratory screening, radiological testing are very helpful in determining existence of a cancer in the body in its early stages. Procedures employed in human oncology are similar to those used to determine prevalence of cancer in pets including feline cancer.

X-Rays are probably the most commonly used technique for radiographic imaging as advanced facilities like CT (Computed Tomography) and MRI (Magnetic Resonance Imaging) are not widely available in veterinary medicine. CT and MRI provide much better results with the ability to render section wise three dimensional images of areas hidden behind tissues.

Ultrasound imaging is commonly used by veterinarians for imaging solid organs and for guiding needles inside the body for drawing out liquid from a tumor for laboratory examination. PET (Positron Emission Tomography) is a recent addition in canine cancer diagnostic procedures.

Prevalence of cancer can also be determined by molecules termed as tumor markers. Cancer cells produce molecules that are different from the ones produced by normal cells. Different tumor markers associated with body organs also provide vital information on prognosis, staging and monitoring.

The next step after diagnosis is to determine the stage at which the disease is. Cancer staging is one of the most important aspects of cancer diagnosis that determines the treatment option that are best to take. Tumor size, invasion of regional lymph nodes and an understanding of the extent of spread of cancerous cell is necessary to evaluate prognosis and clinical management.

Although there are no known definite preventive measures to avoid pet cancer, timely intervention can prove to be of great help. It is highly recommended that you consult your veterinarian as soon as you see any signs of discomfort in your dog. It is the least that you owe to your ‘best friend’.

We all know that temporary treatment and relief from cancer in dogs is possible but a permanent cure is not, especially when metastasis has occurred and affected vital organs. Small localized cancers are curable and a dog can live a normal life. Benign tumors do not technically fall under cancer and can be removed surgically without fear unless of course a vital organ is involved.

Treating cancer, including canine and feline cancers with chemotherapeutic drugs is beset with dangers. Most veterinarians are against the use of these drugs since the affects are sometimes worse than the ailment. Mostly veterinarians suggest chemotherapy if the dog owner insists and is adamant to prolong the life of his dog, irrespective of its quality.

If you are looking for a better quality of life rather than just adding the number of years, you should look towards a holistic treatment for cancer. A natural approach is devoid of toxicity, has no side effects and attempts to fight cancer cells in a natural way. Success, of course, is not in your hands but you can provide a comfortable life to an already beleaguered animal.

The first step should be to clear the pet’s environment of all potentially carcinogenic materials and chemicals. Change his environment so that there is no contact with harmful pesticides, chemicals and toxic materials. Clean the household where remnants of these tend to accumulate. Throw out the plastic feeding bowl and use ceramic or metal. Start giving filtered water to the dog.

Homoeopathy can do wonders if a remedy is found that meets all the symptoms present in your dog. Such a remedy can prove to be one of the best tools to manage cancer.

There is a strong correlation between nutrition and cancer. Commercial pet foods available in the market carry preservative and synthetic substances that may be carcinogenic and may cause harm to the process of healthy cell multiplication. Home cooked and organic food is best for your dog’s health. If home food is not an option, opt for health foods for dogs that are available in health stores. Before buying make sure that they do not contain hormones, pesticides or antibiotics.

You may also choose to give therapeutic level supplements of antioxidants, Vitamin C and Vitamin A. Many herbs also help in fighting cancer and can be given directly or along with a meal. Discuss with your veterinarian and select a few herbs and natural foods that are rich in zinc, selenium and omega 3 fatty acids. Fish oil or flaxseed oil have anti cancer properties and increase oxygen uptake to cells.

Caring for a dog with cancer requires dog owners to be well-conversed with the minute details of how symptoms of cancer manifest in pets. Cancer tends to remain concealed till a long time. For example, the symptoms of liver cancer in dogs are vague and are normally ignored or associated with milder conditions. Creating a program for home cancer care will go a long way in curbing the growth of cancer cells. If you can start such a program right from the time you bring your dog home, it may even prevent the dreaded disease.

In recent times there has been a significant rise in the incidence of cancer in dogs, as well as feline cancer. The main culprit seems to be the manner in which we have treated our environment and the lifestyle of convenience that we have adopted. We look for ready made quick solutions for everything - for ourselves and for the pets we bring home. Home cooked food seems to have become a thing of the past. Commercial pet food containing harmful preservatives and coloring agents are becoming the order of the day with scant regard being paid to the long term effects of chemicals and toxins that go in to produce them.

We all know that cancer takes time to be detected. We also know that it usually manifests itself when it is almost impossible to cure it completely. What most of us would like to know is why it is so. The term neoplasia is used interchangeably with cancer. Neoplasia is the pathological process that results in the formation and growth of a tumor. It requires a billion cells or thirty times of dividing and multiplying before a tumor can be seen. And malignancy occurs only when these rapidly dividing cancer cells invade normal tissue.

Malignant cancers can spread through the blood stream or lymphatic vessels. There are many types of cancers that spread to specific neighboring or distant organs but the most common sites are lymph nodes, lungs and liver. To add to the problem, symptoms of most types of cancer, like the symptoms of liver cancer in dogs, tend to surface prominently only when the disease has reached an advanced stage.

It is imperative that due attention be paid to even subtle behavioral and physical changes in dogs for ruling out or confirming the prevalence of cancer. Many types of cancer can be effectively treated, even cured, if they are attended to in the early stages. Some of the signs that may indicate cancer as an underlying cause are easily short listed into ten symptoms. It will not be out of place to mention here that these signs apply to humans also.

* An abnormal swelling that refuses to go away even after treatment.
* A sore, lesion or a wound that does not heal within a reasonable time period.
* Weight loss despite sufficient diet.
* Incessant bleeding or discharge from any opening in the body.
* Difficulty in urinating or passing stools.
* Chronic diarrhea or vomiting.
* Loss of stamina and difficulty in breathing.
* Subtle changes like increased sleep, lack of interest and refusal to play.
* Bad smell.
* Refusal to eat for more than two days.

Most of the symptoms can be noticed easily if you are observant and indulgent while grooming. Any abnormal sign that was not there when you last groomed the dog should be brought to the notice of the veterinarian. Nine time out of ten it may turn out to be a minor ailment but that should not reason to be negligent. Remember that early detection can save the life of your pet.

With the amount of funds, time and effort that has gone into cancer research, one would think that it is high time that there was a permanent cure or vaccine to prevent the disease. Despite the enormous progress that has been made in this field, science is still far from a permanent solution for human as well as canine cancer.

Every now and then we keep on hearing about vaccines for different types of cancers. For example a study revealed that the human papilloma virus was significantly effective in preventing vulval and vaginal cancer lesions in women. Another significant development reported in recent times is that of a conditional approval of a vaccine for canine melanoma.

It is difficult to treat advanced melanoma regardless of whether it occurs in humans or dogs or as a form of feline cancer. In later stages the melanoma is extremely resistant to chemotherapeutic drugs and radiation. This resistance led to a need to look for new modes of treating the deadly cancer. The emphasis was on developing a vaccine that would rein in the immune system.

Melanoma in dogs is similar to a form of skin cancer in humans. In dogs, it usually occurs around the mouth, nail beds and foot pads. It is a highly aggressive form of cancer in dogs that leads to death within a year. A DNA based vaccine, created from actual melanoma tumor cells has shown remarkable results. The cells are first treated so that they stop multiplying by division. DNA is the then introduced in the cells to release an immune stimulant. The combination of these cells and the immune stimulant is injected into the skin of the patient.

Clinical trials have been encouraging with the average survival time of dogs with melanoma increasing from 90 days to 389 days. In 12.5% of dogs out of the 40% who responded positively to the vaccine, the cancer disappeared totally.

Normally cancer does not show early signs. In other cases like the symptoms of liver cancer in dogs, the symptoms are so similar to various other mild disorders that detection is almost impossible based on only symptoms. This particular aspect of cancer often delays treatment, often leading to death as prognosis is directly related to the stage to which the disease has reached.

The recent approval, although conditional, for a vaccine for treating canine melanomas bodes good news for humans as well. Humans develop this type of cancer in the same way as dogs do. The treatments meted out are similar too. Trials being conducted on animals that live in the same environment as humans in conjunction with human trials may help in providing a safer treatment of cancer for all. Let us hope that we hear of a major breakthrough in this research and that it is not hampered by lack of funds, a hurdle that most serious researches face.

Despite a good prognosis for some types of cancer, due to the fatality and toxicity of the medication associated with it, pet owners are often confronted with a dilemma whether to go for a treatment or not. Most of the times, cancer in dogs occurs in old age making dogs more vulnerable to the side effects of conventional treatment. Surgery has a limited scope in as far as it can only excise parts of the tumor.

There is a dire need for exploring new areas of cancer treatment. Despite significant developments in this field, a lot more needs to be done to develop new strategies and drugs that target only cancerous cells and spare the normal cells.

The development of any new treatment needs to be done keeping in mind that any medication should cure the disease with a minimum of side effects. To achieve this goal the therapy has to target and destroy only the cancer cells while it allows the normal healthy cells to live.

Let us try to understand how radiation and chemotherapy work to kill malignant cells. These therapies make use of the fact that malignant tumors have cells that grow rapidly by division whereas the normal cells are mostly in a resting stage. Chemotherapy attempts to intervene at the DNA function of cells to divide and multiply thus leaving the normal cells alone.

There is an exception to this rule because even some normal cells like those in bone marrow and the GI lining naturally continue to divide and replace dead cells all the time. Moreover, sometimes normal cells start dividing and replacing after the treatment is given. This leaves a very small margin of error.

Another limitation of conventional drugs is the field of recurrence. There is a great amount of heterogeneity within the cells of a single tumor. As the tumor increases in size, some of the cells get lesser blood supply causing them to divide at a reduced pace compared to others in the same tumor. This results in making some cells resistant to drugs and they can survive even after the patient is cured of the disease. These cancerous cells remain dormant for a time and lead to recurrence of cancer at a later stage.

On the other hand, surgery has a different set of limitations. Pet cancer, including canine and feline cancer has the uncanny property of surfacing when it has already metastasized to neighboring, distant and even vital organs. This either rules out surgery or at best results in partial excision of a tumor. And therefore, chemotherapy and radiation become necessary. It is only in rare cases like liver cancer where pet owners can notice the condition early enough for treatment since the symptoms of liver cancer in dogs are quite apparent at an early stage.

Total excision is only possible in cases of a benign tumor, which is, in most cases, harmless. On the other hand, any increase in dosage of chemotherapeutic drugs or time of radiation exposure has an accompanied and corresponding risk of increase in toxicity. Pet owners need to take an educated decision based on the general health of the dog and risks involved. In fact owners have to strike a balance between compassion, quality of life after treatment and benefits likely to be derived from treatment.

While a serous nasal discharge may only be a sign of infection caused by bacteria or viruses, a mucoid, purulent or bloody nasal discharge can be indicative of nasal cancer in dogs . Young puppies and kittens must be checked for a cleft palette if they are discharging milk from their nasal passages.

The nasal cavity in dogs is a complex structure consisting of nostrils that open up in two air passages that are lined with scrolled spongy bones called turbinates. A clear serous discharge coming out from both the nostrils may also be caused by the presence of small mites but mucoid and purulent discharges need to be investigated since they can be signs of any of the following:

* Foreign matters such as grasses or weeds that may have enter the nose while sniffing.
* Dental infections, especially in the roots of upper teeth.
* Fungal infection.
* Nasal cancer.

If blood is present in the discharge, it is almost certain that the cause is either a fungal infection or nasal cancer that is taking root in the passage. Cats with fungal infection in the nose must be checked for prevalence of feline cancer or the leukemia virus. Final diagnosis is done only after ruling out that the bleeding is not caused by violent sneezing since that can also result in temporary bleeding.

Nasal cancer usually occurs as paranasal sinus fibrosarcomas (a sarcoma derived from fibroblast cells, often able to generate collagen) or paranasal sinus chondrosarcomas (a malignant neoplasm of cartilage cells). Both types of sarcomas grow slowly but are progressive and invasive in nature.

Diagnosis of nasal cancer involves routine blood and urine tests, biochemical profiling, biopsy and CT scans. Apart from the nasal discharge and bleeding, other symptoms that dog owners should keep a watch out for include:

* Excessive sneezing.
* Tears.
* Bad breath.
* Loss of appetite for a long period.
* Facial deformity.
* Bulging eyes.
* Seizures that indicate metastasis to the brain.

Nasal tumors usually do not respond to chemotherapy and other anti-cancer drugs. Surgery is also a difficult procedure since the structure of the nose is extremely complex. And therefore it is difficult to remove the tumor from the nose. Radiation therapy is available in select cities and veterinary schools but this method usually reduces the size of the tumor only. It is dangerous to ignore treatment as nasal tumors can spread to the brain and cause seizures and the condition may also breakout through facial bones and distort the dog’s appearance permanently.

Cancer is actually an uncontrolled growth of cells resulting from an accumulation of changes in the structure of the genes that control cell division and multiplication. Melanoma is one of the several malignant neoplasms, usually of the skin. The affected cell is mostly melanocytes, a cell in the basal layer of the epidermis that produces melanin under the control of the melanocyte-stimulating hormone. Benign and malignant skin tumors are a common form of canine and feline cancer.

Melanoma cancer in dogs occurs commonly in dark skinned animals, usually in areas under haired skin, as small, dark brown to black lumps. In certain cases they may appear as large flat wrinkled masses. Other areas where melanomas can also appear include mouth, digits and behind the eye. A swelling or increase in size of lymph nodes is the first clinical sign of a malignant melanoma. Although the pigment called melanin is the distinctive characteristic of such tumors, some melanomas may not display a darkly colored pigment.

Malignancy is established with the aid of a microscopic examination. For this purpose a small piece of the tumor is cut off and evaluated. The pathologist then grades the melanoma according to how rapidly the cells are proliferating. This gives an estimate of the likelihood of metastasis.

The best treatment of melanoma is a total excision through surgery. To be on the safer side, the surgeon may remove some of the neighboring tissue as well. If the tumor is confined to a particular area this amounts to a full cure. The excised sample is again sent for histological examination to ascertain whether the entire tumor has been removed or not.

Melanomas can also spread to distant organs in the body. Complete remission in such cases is rare and it affects the long term survival of the dog to a great extent. Once the tumor has metastasized, cancer can start presenting itself as varied symptoms like the symptoms of liver cancer in dogs.

To the relief of dog owners, all moles in the skin are not malignant. It is normal for a dog or a cat to have dark pigmented areas of skin, particularly in the tongue, gum and eyelid tissue. As a general rule small skin tumors tend to be benign and the ones in the mouth toes, fingers or eyes are mostly malignant. Benign melanomas are seen as dark masses up to two inches in diameter. Unless the mole or a lump starts increasing in size, or elevates above the surface of the skin or bleeds, there is no need to worry. Such a condition necessitates an examination of the lump that you may see on the surface of your dog’s skin.