Your Pet and Cancer

What is cancer?
Cancer is the common name given to all the various forms of malignant tumours. A tumour is a mass of cells that are growing out of control. There are two main types of tumours.

Malignant tumours or cancer are the most aggressive; they invade into the surrounding tissues and have the ability to spread to other parts of the body. It is this ability to produce secondary tumours that makes them so life threatening.

Benign tumours only grow locally and never spread. They can however cause serious problems just because of their physical size or position.

What should I do if I find a lump on my pet?
Not all lumps turn out to be tumours but it is important to ask your vet to have a look when you first notice one. A small tumour, even a cancer, is more likely to be cured if it is treated early. A biopsy may be necessary to determine the exact nature of the lump. “Let’s wait and see” is not a good option.

How can tumours affect the patient?
This depends upon where the tumour is and what type it is. When small, most tumours do not cause a problem; only when they are large do they affect the patient but by this stage they may be untreatable. As a general rule, malignant tumours (cancers) are more life threatening than benign tumours because of the risk of spread throughout the body.

There are many different types of cancer and each behaves in a slightly different way. It is therefore important to have a sample of the tumours sent for examination by a pathology laboratory.

The cause of Cancer in Cats and Dogs

The scientific basis of cancer
Every cell of the body is normally under very strict control imposed by the body as a whole. Very occasionally, a cell acquires the ability to divide and grow outside this normal control and a cancer develops. This happens when a number of genes within a cell change or mutate. Mutations occur in all of us all the time – in deed without mutations, evolution could not have occurred. Most of the time, these mutations come to nothing but occasionally they cause the cell to go wrong and develop into cancer.

Known causes of cancer (“risk factors”)
For an increasing number of human cancers the cause is known. Some of these risk factors are smoking (lung cancer), certain viruses (cervical cancer) and ultra-violet sunlight (skin melanoma). In addition, certain genes that are present in families have been identified.

In dogs and cats, there are only a few known risk factors for cancer. In cats, the virus known as Feline Leukaemia Virus (FeLV) is a definitive trigger for certain cancers (feline lymphoma and leukaemia). However, not all cats that are infected by FeLV will develop cancer and, conversely, not all lymphomas in cats are induced by FeLV infection.

Another example of a cancer, for which there is a known cause, occurs in white-faced cats that sit out in the full sun. The relatively hairless pink areas of the ear tips, eyelids and nose are prone to sunburn which can progress to skin cancer.

Breed related cancers
Certain breeds of dog appear to be susceptible to specific tumours. This may be related to the characteristics of the breed or due to a genetic predisposition. Bone cancer is more common in giant and large breeds such as Great Danes, Irish Wolfhounds, Rottweilers, and St Bernard’s. This is thought to be related to the rapid growth characteristics of the adolescent pup although there is also evidence for a genetic susceptibility in some of the giant breeds.

For example, Boxers have a relatively high incidence of tumours of the skin and the brain. Bernese mountain dogs appear to suffer from a variety of malignant cancers that tend to affect a younger age group than other dogs as a whole. Similarly Flat-coated Retrievers tend to have a relatively high incidence of cancer which behaves more aggressively than in other breeds of dog. These and other breed related tumours are highly suggestive of a widespread genetic susceptibility for the specific cancer associated with the breed. However, truly hereditary cancers (i.e. that are passed down in certain lines) are rare in dogs.

Further research will identify specific causes of cancers in dogs and cats and may lead to novel ways of treating them. More importantly, as the specific causes become known, specific ways of preventing that cancer may be possible.

 

Frequently Asked Questions

 

What is cancer?

Cancer is the common name used to refer to any malignant growth of cells. A tumour is a mass of cells that are growing out of control. Tumours can be benign or malignant.

Benign tumours only grow locally and are not cancer. They can usually be removed and usually do not grow back. Cells from benign tumours do not invade the tissues around them or spread to other parts of the body. Benign tumours are rarely a life threatening although they can cause serious problems due to their physical size or location.

Malignant tumours are cancer. Malignant tumours often can be removed although sometimes they grow back. They are the most aggressive tumours and invade into surrounding tissues.  Cells from malignant tumours can spread (metastasize) to other parts of the body. Cancer cells spread by breaking away from the original (primary) tumour and entering the bloodstream or lymphatic system. This ability to produce new secondary tumours (metastasis) makes them more serious and life threatening.

How does cancer happen?

Cancer begins in the basic unit of life for the body, cells. A group of cells forms a tissue and a group of tissues forms an organ in the body. Cells normally divide and grow to form new cells as the body needs them. When cells grow old and die, new cells take their place. This process may go wrong when the genetic material (DNA) of a cell becomes damaged or changed, producing mutations that affect normal cell growth and division. When this happens, new cells are formed that the body does not need; alternatively, old cells do not die as they normally should through programmed cell death (apoptosis). These extra cells can form a mass of tissue called a growth or tumour.

Cancer results when changes occur in genes that control normal cell division and death. Substances that cause DNA mutations are known as mutagens, and mutagens that cause cancers are known as carcinogens. These genetic changes may result from environmental or lifestyle factors, such as exposure to sunlight (ultraviolet radiation) or carcinogens (cancer-causing substances) or they may be inherited (from one or both parents). However, having an inherited gene alteration does not always mean that cancer will develop, just that the risk of developing cancer is increased. Most forms of cancer are sporadic, meaning that there is no inherited cause of the cancer.

 

Defining cancer

Most cancers are named for the cell type, tissue or body organ from where they start. For example, bone cancer starts in a bone, lymphoma starts in the lymphatic system and cancer that begins in basal cells of the skin is called basal cell carcinoma.

The main categories of cancer include the following types:

Carcinoma is cancer that begins in the epithelium of the skin or in tissues that line internal organs.

Sarcoma is cancer that begins in the connective or supportive tissues of bone, cartilage, fat, muscle and blood vessels.

Leukaemia is cancer that starts in the blood-forming tissues of the lymphatic system or bone marrow and causes large numbers of abnormal blood cells to be produced and enter the bloodstream.

Lymphoma and myeloma are cancers that begin in the cells of the immune system.

Central nervous system cancers begin in the tissues of the brain and spinal cord.

Cancer cells can invade and damage nearby tissues and organs. Cancer cells can also break away from the original (primary) tumour, enter the bloodstream or the lymphatic system and form new tumours in other organs. This type of spread of cancer is called metastasis.

When cancer spreads and forms a new tumour in another part of the body, the new tumour has the same kind of abnormal cells and the same name as the primary tumour. For example, if bone cancer spreads to the lungs, the cancer cells in the lungs are actually bone cancer cells. The disease is called metastatic bone cancer and not lung cancer. The new or secondary tumour is called ‘distant’ or metastatic disease.

 

Why has my pet developed cancer?

As in human medicine, we often cannot explain why one pet develops cancer and another does not. Research has shown that certain risk factors increase the chance that a person will develop cancer. It is likely that many of the most common risk factors for cancer in people also affect our pets, including age, sunlight (ultraviolet radiation), certain chemicals, some viruses, certain hormones, poor diet, lack of physical activity, being overweight or a family history of cancer.

Many of these risk factors can be avoided. Others, such as family history, cannot be avoided. Several factors may act together over time to cause normal cells to become cancerous. When thinking about the risk of cancer remember that not everything causes cancer. Having one or more risk factors does not mean that an individual will get cancer. Some individuals are more sensitive than others to the known risk factors.

One of the most important risk factors for cancer is growing older. Most cancers occur in older pets although pets of all ages can get cancer. This means that as our pets are living longer, the incidence of cancer is rising. It has been reported that about 1 in 4 dogs are affected by cancer and about 1 in 6 cats are affected by cancer in their lifetime. In the 2004 purebred dog health survey, 1 in 4 dogs died due to cancer from 1994 to 2004 (http://www.thekennelclub.org.uk/). The median age of diagnosis of cancer was 8 years in a survey of 36,006 live dogs with 22,504 conditions in total. The median age at death due to cancer was 10½ years in a survey of cause of death for 15,881 dogs from 1994 to 2004. In a survey of cause of death in UK cats, cancer was the second most common cause of death after trauma overall and most common reason for euthanasia (http://www.vickijadams.co.uk/). 

 

What is a risk factor?

A risk factor is something that is associated with an increased risk of disease. Risk factors are not necessarily causal, because association does not imply causation. For example, being old cannot be said to cause cancer, but older pets are more at risk of developing cancer because they have experienced more cell damage and exposure to potential carcinogens during their lifetime. Having a risk factor does not mean that your pet will get cancer just as not having a risk factor does not mean that your pet will not get a cancer.

The effect of a risk factor is often expressed as a relative risk (RR). In epidemiology, relative risk is the risk of developing a disease relative to exposure to a risk factor. Relative risk is a ratio of the probability of disease occurring in a group exposed to the risk factor compared to the probability of disease occurring in a non-exposed group. Another term for the relative risk is the risk ratio because it is the ratio of the risk in the exposed divided by the risk in the unexposed. For example, a RR of 3.0 means that the relative risk of cancer associated with smoking was 3 and that smokers were 3 times as likely as non-smokers to develop lung cancer. While a RR of 3 sounds high, the absolute risk is 1 case of lung cancer for every 10,000 smokers and this is very small.

In survival analysis, the hazard ratio (HR) is used instead of RR and median survival times can be compared between those individuals exposed to one treatment compared to another treatment. One study that used survival analysis for cats with oral squamous cell carcinoma (OSCC) showed that whether the cat received non-steroidal anti-inflammatory (NSAID) therapy after surgery was associated with survival. The hazard ratio was 2.2 (95% confidence interval:  4.8 – 10.2), meaning that a cat that did not receive post-operative NSAID therapy was more than twice as likely to die due to its tumour than cats that did receive NSAIDs. This HR is an important estimate of the prognosis for a cat with an OSCC. Also, the median survival time for cats that did not receive post-operative NSAID therapy was 38 days from the date of diagnosis, which was significantly less than the median survival time of 84 days for cats that did receive NSAIDs, controlling for breed and COX-1 staining (link to REF Hayes et al.). The median survival time (MST) is the time, often expressed as the number of days, months or years, when 50% of the patients are still alive.

 

Cancer statistics

Incidence is the number of newly diagnosed cases during a specific time period.

Mortality is the number of deaths during a specific time period.

Survival is the proportion of patients alive at some point after the diagnosis of their cancer.

Prevalence is the number of cases alive on a certain date.

Lifetime risk is the probability of developing or dying from cancer, in the course of one’s lifespan.

Median survival time (MST) is the period of time that has passed by which 50% of the patients have died due to their disease.  

 

How most people think about risk

Researchers describe risk as the estimated chance of developing a disease during a certain time period, such as within the next 5 years or during a lifetime. People perceive risk as the probability of something happening, such as their pet developing cancer.

Most people are concerned about the chances of their pet developing cancer as an individual or personal risk. What you consider your pet’s personal risk may be influenced by what you have heard from your veterinary surgeon, the media and from your family and friends. Many people view their pet’s risk of developing cancer as higher or lower than it actually is due to the influence of all these sources of information.

 

How veterinary surgeons, researchers and doctors think about risk 

When veterinary surgeons talk about risk they are thinking about numbers. Cancer risk in people is based on numbers of reports of cancer from medical facilities into a central registry. These reports count the total number of people who are diagnosed with a cancer in the United Kingdom. They also provide information about how many men or women are diagnosed, and their age and race. The risk numbers that come from these types of information may be presented as relative risk (RR) or absolute risk (AR). In human medicine, clinical trials are used to test the effectiveness of treatments and there is much more information available than in veterinary medicine.

Other information about risk comes from medical studies. In veterinary medicine, there are very few sources of information about cancer in pets. Using observational studies, veterinary surgeons can look at exposure factors that may affect cancer risk. They draw conclusions about how these and other specific factors affect cancer risk by looking at groups of animals who have a certain risk factor and those who do not. Veterinary surgeons then look at how many individuals in the two groups are diagnosed with cancer. By comparing how many animals in each of these groups actually develop cancer, veterinary surgeons are able to estimate relative risk – that is the risk that one group will get cancer compared to another group.
 

What is prognosis?

Prognosis means to make a prediction of the probable course and outcome of a disease. The likelihood (chance) of recovery from a disease, based on the available evidence.

Certain factors can affect the prognosis and treatment options, including age, general health, presence of concurrent conditions, whether this is the first diagnosis or recurrence, etc.

Prognosis is usually expressed as a probability of survival some time after diagnosis, such as the one-year survival rate being the probability of surviving for 1year from the time of diagnosis. Alternatively, it can be expressed as the period of time that has passed until 50% of the patients are still alive, and this is the median survival time (MST). 

 

What is the link between genes and cancer?

Some types of cancer can be found before they cause symptoms. Checking for cancer (or for conditions that may lead to cancer) in individuals who do not have signs is called screening. Screening can help your vet find and treat some types of cancer early. Generally, cancer treatment is more effective when the disease is found early. There is currently no effective genetic or blood test that is a reliable screening tool for the diagnosis of cancer in dogs. Regular physical examinations, laboratory testing and imaging studies are the best tools that vets have for the early diagnosis of cancer.

There are a number of recognised syndromes in people where there is an inherited predisposition to cancer, often due to a defect in a gene that protects against tumour formation. Examples include certain inherited mutations in the genes BRCA1 and BRCA2 that are associated with an elevated risk of breast cancer and ovarian cancer, and individuals with Down syndrome have an extra chromosome 21 and are known to develop malignancies such as leukaemia and testicular cancer.

 

Why does cancer affect certain breeds more than others?

Most cancers develop as a result of changes in genes (mutations). A normal cell may become a cancer cell after a series of gene changes occur. Some gene changes that increase the risk of cancer are passed from parent to offspring. These changes are present at birth in all cells of the body. While it is uncommon for cancer to run in a family, certain types of cancer do occur more often in some families than in the rest of the population. For example, cancers of the breast, ovary, prostate, and colon in people. Several cases of the same cancer type in a family or line of pedigree dogs may be linked to inherited gene changes, which may increase the chance of developing cancers. However, environmental factors may also be involved.

If you think your pet may have a pattern of a certain type of cancer in the line, you may want to talk to your veterinary surgeon about ways to detect cancer early should it develop in your pet. You may also want to ask about genetic testing. These tests can check for certain inherited gene changes that increase the chance of developing cancer. But inheriting a gene change does not mean that your pet will definitely develop cancer. It means that your pet has an increased chance of developing the disease.

Some breeds of dogs are more likely to be affected by certain types of cancer than other breeds of dogs. The 2004 purebred dog health survey showed that several breeds were more likely to be affected by certain cancers, including malignant histiocytosis in Bernese Mountain Dogs and mast cell tumours in Golden retrievers (http://www.thekennelclub.org.uk/).

What are the clinical signs of cancer in pets?

The clinical signs of cancer in pets are often vague and non-specific. It is often just a concern of the owner that their pet is just not doing well. The most common signs of cancer in small animals include the following:

When these or other signs occur, they are not always caused by cancer. They can be caused by inflammation, infections, benign tumours or other problems. It is important to take your pet to see a veterinary surgeon in order to obtain a diagnosis. Your veterinary surgeon will perform a physical examination and may order blood tests and/or recommend a biopsy. In most cases, a biopsy is the only way to know for certain whether cancer is present. During a biopsy, the veterinary surgeon removes a sample of tissue from the abnormal area. A pathologist then studies the tissue under a microscope to identify cancer cells.

 

How is cancer diagnosed?

If your pet shows one or more clinical signs that may suggest cancer, your veterinary surgeon will need to find out whether it is due to cancer or to some other cause. Your vet will perform a physical examination and may order laboratory tests, imaging studies and/or recommend a biopsy. In most cases, a biopsy is the only way to know for certain whether cancer is present.

 

Laboratory Tests

Tests of the blood, urine, or other fluids can help veterinary surgeons make a diagnosis. These tests can also give an indication of how healthy your pet is by demonstrating how well the body organs (such as the kidneys or the liver) are doing their jobs. Also, high amounts of some substances may be a sign of cancer. These substances are often called tumour markers. However, abnormal lab results are not a sure sign of cancer. Veterinary surgeons cannot solely on laboratory tests to diagnose cancer.

 Imaging studies

Imaging procedures create pictures of areas inside your body that help the veterinary surgeon see whether a tumour is present. These pictures can be made in several ways:

Radiographs:  Radiographs (x-rays) are the most common way to view organs and bones inside the body.

Ultrasound:  An ultrasound device sends out sound waves that people cannot hear. The waves bounce off tissues inside your body like an echo. A computer uses these echoes to create a picture called a sonogram.

MRI:  A strong magnet linked to a computer is used to make detailed pictures of areas in your body. Your veterinary surgeon can view these pictures on a monitor and can print them on film.

CT scan:  An x-ray machine linked to a computer takes a series of detailed pictures of your organs. Your pet may receive a contrast material (usually by injection) to make these pictures easier to read.

What is a biopsy?

In most cases, your veterinary surgeon will need to perform a biopsy to make a diagnosis of cancer. During a biopsy, a sample of tissue is removed and sent to a diagnostic laboratory where a pathologist will look at the tissue under a microscope to identify cancer cells.

The sample of tissue may be obtained in several ways:

With a needle: The veterinary surgeon uses a needle to withdraw tissue or fluid. This is often referred to as a fine needle aspirate.

With an endoscope: The veterinary surgeon uses a thin, lighted tube (an endoscope) to look at areas inside the body. The veterinary surgeon can remove tissue or cells through the tube.

With surgery: Surgery may be excisional or incisional. In an excisional biopsy, the veterinary surgeon removes the entire tumour. Often some of the normal tissue around the tumour also is removed. In an incisional biopsy, the veterinary surgeon removes just part of the tumour.

 

Is cancer treatable?

Yes, cancer is treatable. Cancer treatment may include surgery, radiation therapy, chemotherapy, hormone therapy, and/or biological therapy.  The 3 main types of therapy used in veterinary oncology are surgery, radiation therapy, chemotherapy or a combination of these methods.

The veterinary surgeon may use one method or a combination of methods, depending on the type and location of the cancer, whether the disease has spread, the patient's age and general health, and other factors. Because treatment for cancer can also damage healthy cells and tissues, it often causes side effects. Some people may worry that the side effects of treatment are worse than the disease. However, owners and veterinary surgeons generally discuss the treatment options, weighing the likely benefits of killing cancer cells and the risks of possible side effects. Veterinary surgeons can suggest ways to reduce or eliminate problems that may occur during and after treatment.

Many owners will want to take an active part in making decisions about their pet’s medical care and it is natural to want to learn all you can about your pet’s disease and treatment choices. However, it is often difficult to take in every that your veterinary surgeon says after the diagnosis is made. It often helps to make a follow-up appointment and to prepare a list of questions before the appointment.

Click here to link to a list of questions to ask your veterinary surgeon before treatment begins.

To help remember what you are told, you may wish to take notes or ask whether you may use a tape recorder. Some people also want to have another family member or friend with them when they talk to the veterinary surgeon - to take part in the discussion, to take notes, or just to listen.

You do not need to ask all your questions at once. You will have other chances to ask the veterinary surgeon or nurse to explain things that are not clear and to ask for more information.

Your veterinary surgeon may refer you to a specialist, or you may ask for a referral. Specialists who treat cancer include surgeons, medical oncologists and radiation oncologists.

The treatment plan depends mainly on the type of cancer and the stage of the disease.

Veterinary surgeons also consider the patient's age and general health. Often, the goal of treatment is not to cure the cancer but to maintain as normal a quality of life as possible in your pet for as long as possible. In this case, the goal is to control the disease or to reduce clinical signs associated with the cancer for as long as possible. The treatment plan may change over time.

 

What is remission?

Complete remission (CR) is defined as when the tumour can longer be detected. This can be based on physical size or by imaging with radiography or ultrasound. Unfortunately complete remission is not the same as a cure. Generally the smallest mass that can be detected by radiographs is about 0.5 cm, more sophisticated imaging can detect down to 0.25cm but this still represents approximately a million cells.

Partial remission is defined as a reduction in size by more than 50%. Static or stable disease is defined as change in size (smaller or larger) of less than 25% and progressive disease is defined as increase in size of more than 25%. Using these definitions helps your vet to define the next course of action.

How is cancer treated?

Most treatment plans include surgery, radiation therapy, chemotherapy or a combination of these methods. Some cancer treatments involve hormone therapy or biological therapy. Some cancers respond best to a single type of treatment. Others may respond best to a combination of treatments. Treatments may work in a specific area (local therapy) or throughout the body (systemic therapy).

 

What is local cancer therapy?

Local therapy removes or destroys cancer in just one part of the body. Surgery to remove a tumour is local therapy. Radiation therapy to shrink or destroy a tumour also is usually local therapy.

Systemic therapy sends drugs or substances through the bloodstream to destroy cancer cells all over the body. It kills or slows the growth of cancer cells that may have spread beyond the original tumour. Chemotherapy, hormone therapy, and biological therapy are usually systemic therapy.

Your veterinary surgeon can discuss the treatment choices and the expected results. You and your veterinary surgeon can work together to decide on a treatment plan that is best for your pet.

Because cancer treatments often damage healthy cells and tissues, side effects are common. Side effects depend mainly on the type and extent of the treatment. Side effects may not be the same for each person, and they may change from one treatment session to the next. At any stage of cancer, supportive care is available to relieve the side effects of therapy, to control pain and other symptoms, and to ease emotional and practical problems.

How is surgery used to treat cancer?

Surgery is an operation to remove cancer. In most cases, the veterinary surgeon removes the tumour and some tissue around it. Removing nearby tissue may help prevent the tumour from growing back. The veterinary surgeon may also remove some nearby lymph nodes.

The side effects of surgery depend on many factors, including the size and location of the tumour, the type of operation, and the patient's general health. It takes time to heal after surgery. The time needed to recover is different for each type of surgery. It is also different for each patient. It is common to feel tired or weak for a while.

Most patients are uncomfortable or have some pain after surgery, although this pain can be controlled with medicine. Before surgery, you should discuss the plan for pain relief with the veterinary surgeon or nurse. The veterinary surgeon can adjust the plan if your pet needs more pain relief.

Some owners may worry that having surgery (or even a biopsy) for cancer will spread the disease. This seldom happens. Surgeons use special methods and take many steps to prevent cancer cells from spreading. For example, if they must remove tissue from more than one area, they use different instruments for each one. This approach helps reduce the chance that cancer cells will spread to healthy tissue.

Similarly, some people worry that exposing cancer to air during surgery will cause the disease to spread. This is not true. Air does not make cancer spread.

 

Radiation Therapy

Radiation therapy (also called radiotherapy) uses high-energy rays to kill cancer cells in a targeted area. Radiation can be given externally by a machine that aims radiation at the tumour area. Radiation treatments are painless. The side effects are usually temporary, and most can be treated or controlled. Patients are likely to feel very tired, especially in the later weeks of treatment. Radiation therapy may also cause a decrease in the number of white blood cells, which help protect the body against infection. With external radiation, it is also common to have temporary hair loss in the treated area and for the skin to become red, dry, tender, and itchy.

There is no risk of radiation exposure from coming in contact with a patient undergoing external radiation therapy. External radiation does not cause the body to become radioactive. With internal radiation, a patient may need to stay in the hospital, away from other people, while the radiation level is highest.

The side effects of radiation therapy depend mainly on the dose and type of radiation your pet receives and the part of the body that is treated. For example, radiation to the abdomen can cause nausea, vomiting, and diarrhoea although these side effects are generally rare. The skin in the treated area may become red, dry, and tender. Your pet also may lose your hair in the treated area.

Your pet may become tired during radiation therapy, especially in the later weeks of treatment. Resting is important, but veterinary surgeons usually advise owners to try to maintain as much activity as they can.

Fortunately, most side effects go away in time. In the meantime, there are ways to reduce discomfort. If your pet has a side effect that is especially severe, your veterinary surgeon may suggest a break in the treatment.

 What is chemotherapy?

In cancer treatment, chemotherapy is the use of drugs that kill cancer cells throughout the body. Healthy cells can also be harmed, especially those that divide quickly. The veterinary surgeon may use one drug or a combination of drugs. Most patients receive chemotherapy by mouth or through a vein. Either way, the drugs enter the bloodstream and can affect cancer cells all over the body. Chemotherapy is usually given in cycles. Then they have a recovery period of several days or weeks before the next treatment session. Most patients have their treatment at the veterinary practice or at home. Some patients may need to stay in the hospital during chemotherapy.

What are the side effects of chemotherapy?

Anticancer drugs have potential side effects some of which can be serious and potentially life-threatening, however with the doses used in veterinary oncology these are uncommon or mild. The side effects of chemotherapy depend mainly on the drug(s) and the dose(s) the patient receives. Although hair loss is a common side effect of chemotherapy in people it does not occur in most breeds of dogs and cats. Breeds such as poodles, old English sheepdogs, bearded collies and others with continuously growing hair do tend to go bald. Anticancer drugs may also cause temporary fatigue, poor appetite, nausea and vomiting, diarrhoea, and mouth sores. Drugs that prevent or reduce nausea and vomiting can help with some of these side effects.

When drugs damage healthy blood cells, your pet may be prone to infections, to bruise or bleed easily. Normal cells usually recover when chemotherapy is over, so most side effects gradually go away after treatment ends.

Although the side effects of chemotherapy can be distressing, most of them are temporary. Your veterinary surgeon can usually treat or control them.

Does cancer always cause pain?

Having cancer does not always mean having pain. Whether a patient has pain may depend on the type of cancer, the extent of the disease, and the patient's tolerance for pain. Most pain occurs when the cancer grows and presses against bones, organs, or nerves. Pain may also be a side effect of treatment. However, pain can generally be relieved or reduced with prescription medicines recommended by your veterinary surgeon.

 What about complementary and alternative therapy?

Some people with cancer use complementary and alternative medicine (CAM); an approach is generally called complementary medicine when it is used along with a standard treatment (s). An approach is called alternative medicine when it is used instead of standard treatment. However there are no controlled trials in pets that show any benefit from ‘alternative medicine’.

Acupuncture, massage therapy, herbal products, vitamins or special diets, visualization, meditation, and spiritual healing are types of CAM. Many people say that CAM helps them feel better. However, some types of CAM may change the way standard treatment works. These changes could be harmful. Other types of CAM could be harmful even if used alone. Before starting these types of treatment for your pet, you should discuss this with your veterinary surgeon.

 What is a second opinion and what is a referral?

Before starting treatment, you may want another opinion about your pet’s diagnosis and treatment plan. A second opinion is usually sought when there is doubt about the diagnosis or treatment whereas a referral is usually to seek specialist management of the case. 

The Royal College of Veterinary Surgeons' guidelines to referrals are:

"Part 2D Referrals and second opinions

34. All veterinary surgeons should recognise when a case is outside their area of competence and be prepared to refer it to a colleague whom they are satisfied is competent to carry out the investigations or treatment involved. They should also be aware that the client has a right to request a referral or second opinion. Care must be taken not to give the impression to the client that the referral is to an 'RCVS recognised specialist' if this is not so. The initial contact should be made by the primary veterinary surgeon, and the client then asked to arrange the appointment .

35. The distinction between a second opinion and a referral should be clearly understood by both veterinary surgeon and client. A second opinion is for confirmation of diagnosis, whereas a referral to a referral practice will be for diagnosis and possible treatment, after which the case will be referred back to the original practice. Neither a second opinion veterinary surgeon nor a referral practice should ever seek to take over the case.

36. The referring veterinary surgeon has a responsibility to ensure that the client is fully aware of the level of expertise of the referral veterinary surgeon, for example as a 'specialist' by experience, a certificate holder, or an 'RCVS recognised specialist'. The referral veterinary surgeon should discuss the case with the client and report back to the primary veterinary surgeon.

37. A full case history and instructions as to the particular reason for referral should be supplied, together with an indication of the client's wishes and responsibility for the fees incurred. Any further information which may be requested should be supplied promptly.

38. Veterinary surgeons should not use a referral as an opportunity to pass on difficult clients, or known bad debtors."

 What about nutrition?

Your pet needs enough calories to maintain a good weight. Your pet also needs enough protein to remain strong. Eating well may help your pet feel better and have more energy. Sometimes your pet may not feel like eating. Your pet may be uncomfortable or tired. Your pet may find that foods do not taste as good as they used to. In addition, the side effects of treatment (such as poor appetite, nausea, vomiting, or mouth sores) can be a problem. If your pet is having trouble chewing and swallowing, your pet may need to add sauces and gravies. Your veterinary surgeon can suggest ways to help your pet to eat well.

Many owners want to know how they can help their pet fight cancer by eating certain foods or taking vitamins or supplements. But, there are no studies that prove that any special diet, food, vitamin, mineral, dietary supplement, herb, or combination of these can slow cancer, cure it, or keep it from coming back. In fact, some of these products can cause other problems by changing how your cancer treatment works. It is best to talk to your veterinary surgeon before putting your pet on a special diet or giving any supplements.

 


You can contact us at
Animal Cancer Trust
5 Flag Business Exchange, Vicarage Farm Road, Peterborough, Cambs PE1 5TX
08701 644225
www.animalcancertrust.org.uk
info@animalcancertrust.org.uk

Registered charity no. 1094779 Animal Cancer Trust is a Registered company limited by guarantee in England & Wales no. 04434009. The registered address of the company is Lacon House, 84 Theobald’s Road, London WC1X 9AA. Please use address above for correspondence.