Oncology is becoming more common every year. Despite the tremendous successes in the field of cancer treatment that have been achieved by modern scientists, pathologies of this type claim many lives every minute. Pets suffer from the same problems. So, a tumor of the mammary gland in a dog does not end well without qualified treatment, and therefore today we will discuss this disease in more detail.
As you know, mammary glands are necessary for feeding newborn puppies. They are arranged in two rows, extending from the chest to the back of the abdomen. Anatomically, the nipples are located on both sides of the linea alba. And now - the main thing. Have you ever looked at the belly of a male dog? Remember that they also have nipples, even if only in their infancy? So, males can also suffer from breast cancer, and not so rarely. Unfortunately, in this case the disease is much more severe and most often ends in death.
About measures to prevent cancer diseases
Benign and malignant mammary tumors can occur in all bitches with functioning ovaries. In fact, any female is at risk. Removing the ovaries can significantly reduce the risk of developing cancer, but only in cases where the operation is performed before six months of age.
Types of tumors
There are dozens of types of cancer and simple tumors, but they are all divided into only two types: benign and malignant. Of course, the most dangerous is the second variety, which annually causes the death of thousands of animals around the world.
Genetic predisposition
There is a genetic predisposition to breast cancer not only in humans (this is the scourge of some families), but also in dogs. For example, in toy and miniature poodles, English springer spaniels, English Cocker Spaniels, setters, German Shepherds, Maltese dogs And Yorkshire Terriers, as scientists and breeders have found, the risk of developing this disease is significantly higher than that of other breeds of these animals. Average age in this case - approximately 10.5 years (range from 1 to 15 years). It should be remembered that cancer practically does not occur in animals under the age of five. More precisely, I haven’t met. In the last decade this has become quite commonplace.
Read also: Weeping dermatitis in a dog: signs, symptoms, treatment, prevention
Important information
Single tumors are common in some teats, but in approximately 40% of dogs multiple tumors occur, involving both rows of mammary glands. This is often accompanied by strong inflammatory process or even necrosis, as a result of which in some dogs up to half of all the skin on the abdominal wall comes off. It must be remembered that a benign tumor can appear in the form of a small, moving ball, which is easy to notice when palpated. In the malignant course of the process, it often seems to be “attached” to the wall of the abdominal cavity, which is also easily detected by palpation.
In half of sick dogs, a benign process is diagnosed. These include: complex adenomas, simple adenomas, fibroadenomas and papillomas milk duct. Alas, the other half of the animals have a malignant form of the disease. In this case, much less pleasant types of neoplasms are diagnosed: osteogenic, cystic adenocarcinomas and others.
Symptoms
What are the symptoms? In general, they are quite simple: a small lump appears in the mammary gland. It grows over time. In case of severe malignant neoplasms, the tissues around this place can become inflamed and undergo necrosis. If you see that a cavity has opened up on your dog’s belly, and pus is flowing out of it, it’s time to sound the alarm: it is quite possible that this is not just a sore, but something more serious! In a word, if any doubts arise, it is better to take your pet to the veterinarian once again. It is possible that this will save her life!
Read also: Dermatomycosis in dogs and their manifestations
Why does it appear?
The exact reasons are still unknown. In some cases, the action of some carcinogenic substances is to blame, which often happens in cities with extremely poor ecology. As we have already said, some dog breeds are predisposed to cancer at the genetic level. Finally, constant feeding of moldy food clearly predisposes to such a sad outcome. It has also been noted that in animals with helminthic infestations the chances of cancer also increase. Don’t know how to treat your dog against “guests” in the intestines? Don’t be lazy and consult a veterinarian: it is quite possible that this way you will preserve the health and life of your pet.
Diagnostics
Since lumps in the mammary gland and its necrosis can occur in cases where oncology has nothing to do with it, it is very important to conduct a high-quality diagnosis. Full required chemical analysis blood, her microscopic examination and urine testing. Diagnosis will also include a chest x-ray and abdominal cavity, with the help of which possible metastases are identified. Finally, the most important thing is a biopsy of the tumor, which allows us to find out its nature. Microscopic examination is also very important lymph nodes.
Forecast
The prognosis and course of treatment that will be used for your dog will depend on many factors: the type of tumor, the condition of the animal, and the capabilities of the owner. Great value has the presence or absence of metastases. Malignant tumors less than five centimeters in diameter suggest a cautious prognosis; if the size is larger, it is unfavorable. All types benign neoplasms give a positive prognosis.
Therapeutic measures
Surgical removal of a dog's mammary tumor is the main treatment option. The tumor (or several) must be removed, as the dog’s life depends on it. Depending on the age of the animal, its physiological condition and general constitution, and also taking into account the general neglect of the process, the doctor can cut out both the tumor itself and the entire affected area, including muscles abdominal wall and mammary glands completely. As a rule, in most cases it is necessary to perform a difficult abdominal operation, since it is also necessary to remove the ovaries in order to avoid serious problems on hormonal grounds.
Ph.D. Yakunina M.N.- President of IRSO (Institute for the Development of Comparative Oncology), head of the chemotherapy department of the veterinary cancer center"Biocontrol" at the Russian Oncological Scientific center RAMS
Breast cancer in dogs
Dog mammary tumors account for 25% of all tumor diseases in dogs and are in second place in frequency of occurrence after skin tumors in females. The disease affects females aged 5 to 16 years, with the peak of the disease occurring in age group 7 - 10 years. In almost 50% of cases in dogs, the disease is malignant and in 25% of cases it has an unfavorable prognosis.
Breast cancer in dogs is hormone dependent. One of the main etiological factors the development of this pathology are hormonal disorders problems that arise during the patient’s life: absence of childbirth, frequent false pregnancies, drug suppression of lactation, cystic degeneration in the ovaries.
Breast cancer prevention
Due to the increase in last years recorded cases of mammary cancer, prevention of the development of tumor diseases of this localization is one of the most significant issues for dog owners. It is falsely believed that giving birth once can reduce the likelihood of developing cancer. It has been established that the absence of childbirth in animals can also be associated with the appearance of mammary gland cancer in them in the future. A well-known fact is high risk occurrence of mammary gland tumors in uncastrated females compared to spayed dogs. It has been established that castration of an animal before the first heat reduces the risk of developing the disease to 0.05%, while carrying out this manipulation after 1 heat increases this probability to 10%, and after 2 heat, to 25%.
The duration of development of mammary tumors in dogs can vary from 3 months to several years. This depends on factors such as the morphological type of the tumor, the rate of tumor growth and the hormonal status of the process, etc. The occurrence of a tumor process in the mammary gland in dogs is often preceded by dishormonal processes that develop against the background of increased estrogen production, such as hyperplasia, proliferative or fibrous - cystic mastopathy. These changes are usually a consequence of frequently occurring pseudolactation, which in animals can occur 2 to 3 months after ovulation. Currently, in veterinary oncology practice, mastopathy is considered precancerous condition mammary gland. Breast cancer in dogs can develop both against the background of dysplastic or benign changes in the organ, as well as “de novo”, without previous mastopathy.
Breast cancer in cats
Breast cancer in cats is the third most common cancer after lymphoma and skin tumors. It has an extremely aggressive course, a high degree of malignancy and a poor prognosis. Only in 10 - 14% of cases in the mammary gland of cats can you find benign processes, while malignant tumors are diagnosed in 86–90%. The disease mainly affects animals aged 10–12 years, but there are observations of the disease in cats at a young age.
In cats, mammary cancer is less hormonal in nature than in dogs. The timing of castration does not significantly affect the risk of breast cancer in cats. The use of hormonal castration drugs can also lead to the development of cancer in cats.
In cats, unlike dogs, the formation of mammary gland tumors is most often not associated with dishormonal tissue changes. Dishormonal disorders of the mammary gland in cats include the formation of fibroadenomatous hyperplasia, characteristic of cats young(1-2 years), which rarely degenerates into a malignant process.
The tumor develops “de novo”, rapidly progresses and metastasizes. Local spread of the process is usually associated with an increase in volume, germination of the underlying tissues and skin with the formation ulcerative defect above its surface. The latter is associated with a poor prognosis of the disease.
Main routes of metastasis for breast tumors is lymphogenous - according to lymphatic vessels to regional lymph nodes, and hematogenous - through blood vessels to internal organs. Cancer metastases are primarily detected in the lungs and liver, less often in the spleen, kidneys, adrenal glands, heart and bone. Possible damage to brain metastases from breast cancer. In addition, the tumor can spread through small lymphatic vessels and give rise to skin metastases.
Classification of breast tumor for dogs and cats, there are 4 stages of the disease, on which the prognosis of the disease directly depends. Currently widely used in veterinary practice TNM classification, developed in 1980 by Owen, which describes the state of the primary tumor focus, damage to regional lymph nodes and internal organs. At I-II stages The prognosis for the disease is favorable and the life expectancy of animals reaches 5 years; in addition, a complete cure is possible after one operation. At Stage III illness requires treatment complex treatment which includes both surgery and chemotherapy. Stage IV (presence of metastases in internal organs) cannot be treated surgically and can only be treated.
Based on the form of tumor growth, it is customary to distinguish two main clinical forms of breast cancer– nodular and diffuse. The diffuse form can be conditionally divided into infiltrative - edematous, diffuse - widespread and armored forms. The choice of tumor treatment method depends on the form of growth. With nodular growth, treatment most often begins with surgery, and with diffuse growth, surgery often leads to early relapse, so before surgery it is necessary to additional treatment: chemotherapy or radiation therapy.
To the main diagnostic methods, taking into account the possibilities of breast cancer metastasis, include initial examination tumors, as well as X-ray examination organs chest cavity and ultrasound examination of the abdominal organs. Morphological verification of the diagnosis is carried out by histological examination of the surgical material. In rare cases, for unresectable tumors, aspiration puncture biopsy is performed with cytological examination material.
Treatment of breast cancer in animals
Some time ago, in veterinary medicine it was believed that breast cancer was exclusively surgical problem. However, with the development of veterinary medicine, the identification of disease prognosis factors and the improvement of specific methods of antitumor therapy, the approach to the treatment of this pathology has become comprehensive.
The main treatment methods are surgery, antitumor chemotherapy and radiation therapy.
Surgical treatment breast cancer is a radical method and is aimed at complete removal primary tumor mass. Depending on the prevalence of the process, the following are used: radical methods Resections for breast cancer: regional mastectomy, unilateral mastectomy and, rarely, bilateral mastectomy.
Chemotherapy indicated for most patients after surgical treatment for the prevention of distant metastasis or in the preoperative period for primary inoperable, locally advanced or recurrent breast cancer.
In stage III breast cancer, the life expectancy of animals is not long and often does not exceed 7 months in dogs and 4 months in cats. Modern antitumor drugs make it possible to prolong the life of patients after mastectomy by almost 2 times.
Postoperative chemotherapy aimed at preventing metastasis in postoperative period and increasing the life expectancy of animals. The main drug in chemotherapy for breast cancer in animals is doxorubicin. The use of doxorubicin for stage III breast cancer in dogs leads to an increase in the life expectancy of animals by 2.5 times compared to the group of animals that received only surgical treatment and is 18.6 months. for 50% of patients (median life expectancy (MLS), compared with LFS of 7 months with one surgical treatment. In addition, 6 months. 82.4% of dogs survive, 1 year - 62.3%, and 20 months. - 41.7% of animals, and 23.8% of dogs live 3 years.
In cats, the use of doxorubicin after surgery increases the life expectancy of animals by 2 times and is 8.7 months. versus 4 months with one surgical treatment. In addition, 90.1% of cats live 3 months, 33.1% live 1 year, and 14.3% live more than 3 years. Postoperative chemotherapy should begin within the first 5 days after surgery but no later than 14 days.
The role of preoperative chemotherapy consists of influencing primarily the primary tumor focus, and secondly micrometastases, which always exist against the background of the tumor. The use of preoperative chemotherapy is indicated for locally advanced tumor process or with diffuse clinical form breast cancer, when surgical treatment is not possible. Preoperative chemotherapy usually involves 2 to 3 courses of treatment, depending on the effectiveness of the procedure. Treatment usually uses doxorubicin or taxotere.
The use of doxorubicin in dogs with primary inoperable breast cancer will allow surgery in 45% of dogs after chemotherapy, but it is not possible to significantly prolong the life of animals. Life expectancy is only 5 months, and only 22.2% of dogs live more than 1 year.
The most appropriate use of chemotherapy using Taxotere. Surgery is possible in 80% of animals after chemotherapy, with LFS = 9.8 months, 38.9% of patients survive 1 year and 1.5 years - 19.8% of patients.
In cats, the use of preoperative chemotherapy with doxorubicin allows achieving resectability in 81% of cats, but LOS is only 5 months, with 47.5% of cats surviving 6 months and 38% of patients surviving 10 months.
The use of Taxotere allows 86% of cats to undergo further surgery. LFS is 6.9 months, with 50% of cats living for 6 months, 37.5% for 1 year, and 18.7% for 18 months.
For disseminated stage IV breast cancer (with metastases) Chemotherapy is the main method of treatment and is aimed at prolonging the lives of patients with improving their quality of life. It is known that at this stage the life expectancy of animals is 1-2 months, and with the development of tumor pleurisy - no more than 1 month without treatment. The main drug used for chemotherapy at this stage is Taxotere.
In dogs, the use of taxotere (usually in combination with doxorubicin) can increase the life expectancy of animals by 2 times. The life expectancy is 4 months, with 31% of dogs living for 6 months and 15.6% of dogs for 1 year.
In cats with stage IV breast cancer, the use of Taxotere increases the life expectancy of animals by 3 times. MTP in the group was 5.8 months, with 41.2% of cats showing no signs of progression within the first 6 months, and 27.7% within 1 year.
Treatment of cats with tumor pleurisy that developed against the background of breast cancer with taxotere leads to a 3-fold increase in the life expectancy of animals. At the same time, the accumulation of liquid in the pleural cavity. MFL=3.2 months, with 3 months. 54% live, 6 months. - 31%, and 1 year month. - 9% of cats.
Radiation therapy
Radiation therapy is a local treatment method that can significantly reduce the risk of relapse during complex treatment of breast cancer. The use of the method is most common in humane medicine, where organ-saving operations are important. In veterinary medicine, where the scope of surgical treatment is always radical, the method is used as an additional treatment in the preoperative and less often in the postoperative period.
The role of hormone therapy in the treatment of mammary cancer in small pets has not been clearly established. The use of immunomodulators is largely associated with palliative measures aimed at supporting the patient in the disseminated stage of cancer, however, the effectiveness of the method has not been statistically confirmed.
When I was 12 years old, our dog died - Caucasian Shepherd Dog Aza. She was a year older than me. She was euthanized because she was suffering from severe pain. I remember as if it were recently - I do my homework, lying on the floor next to her, sometimes I stroke and talk to her, when she starts whining again, I give her pills, again and again, but they don’t help... We noticed a tumor, when Aza was about 9 years old. We immediately took Aza to the veterinary hospital, but they didn’t help us there. The tumor grew and metastasized.
Now there is an opportunity to help such animals. Dog owners need to know this. The problem is poor awareness of both owners and veterinarians O modern views for diagnosis and treatment oncological diseases. Therefore, there are a large number of neglected cases when it is actually difficult to do anything. It’s hard for both the doctor and the animal, because the higher the stage of the disease, the more aggressive treatment and worse prognosis.
Any veterinarian at the institute has studied how a malignant tumor differs from a benign one, and this is what bothers him when he is faced with a mammary tumor. I take the first textbook I come across and read: “Benign tumors have a capsule, do not infiltrate tissue when growing, do not metastasize, do not recur, do not ulcerate, do not cause general reaction body and exhaustion" (Workshop on general and private veterinary surgery, 1988). And so, a dog with a single tumor node with a diameter of, for example, 3 cm in one mammary gland, has existed for a long time, grows slowly, does not seem to be fused with the surrounding tissues, the dog feels great. What diagnosis will the doctor make? Benign breast tumor. He remembers well what is written in the textbook. No need to worry. And after the next heat, the tumor increases several times, becomes inflamed, ulcerates, regional lymph nodes enlarge, the dog drinks a lot, loses weight. In a couple of months, a harmless tumor turned into a malignant one? What's the matter? So what should I do? The doctor says that it is dangerous to operate on a malignant tumor, because it may “metastasize.”
Or this option: a dog with a single tumor node with a diameter of 5 cm in one mammary gland, has existed for a long time, grows slowly, does not seem to be fused with the surrounding tissues, the dog feels great. The doctor diagnoses a benign breast tumor and removes the tumor. Sometimes the uterus and ovaries are also removed at the same time, but more on that separately. After a couple of months, something incomprehensible happens to the dog - she loses weight, she feels bad, then an incomprehensible cough, pain, lameness or even paralysis, and even in the area surgical suture something grows again and nothing helps, the dog dies.. What is this – a relapse? Metastasis? But was the tumor benign? A similar case can be studied in detail using the example of Elena Dubrovina’s article “ Clinical case: Pancreatic adenoma in a dog." There at the very beginning detailed history The disease said that the dog had recently had a tumor removed from the “extreme” (??) mammary gland, and that’s where it all started. Read it, it describes a typical clinical picture generalization of the tumor process after non-radical tumor removal.
But the fact is that the behavior of a tumor does not depend on its external signs, but on what cells it consists of. How can you see the cells? Under a microscope. Moreover, a specialist who has seen hundreds, or better yet thousands, of preparations should look through the microscope.
About mastopathy and mastitis in dogs
Particularly advanced cases occur in animals that for a long time treated for “mastopathy” and “mastitis”. Why they are not diagnosed on time is not clear. After all, such animals should be especially wary of cancer. Just like in animals, for which false pregnancy and pseudolactation are commonplace. Mastopathy to the touch resembles a “bag of shot”; Mastitis is an inflammation of the mammary glands. If you detect enlarging nodules, “bumps,” compactions, or ulcerations in the area of the mammary glands, first of all you need to think about a neoplasm.
Small nodules are rarely detected by owners, especially in big dogs with thick fur, only the most attentive find them. And the tumor nodes are not necessarily located in the immediate vicinity of the nipple or under it, they can be between them. The mammary glands in dogs are not several separate glands with nipples, but like two wide continuous ribbons. In woolly dogs, the tumor is often noticed only when it ulcerates. It looks like purulent wound. And the dog is diagnosed with purulent mastitis.
If your dog is female, if she is 7-8 (or older) years old and you notice a growing round or lumpy induration in the area of the mammary glands, or as some describe it, “on the abdomen”, it is almost certainly a breast tumor. Most mammary tumors in dogs are cancer. It’s a real cancer, the kind that happens to people too, but there are significant differences. And the treatment is basically the same as for people - surgical removal, chemotherapy, radiation. Sometimes owners, having learned the diagnosis of their dog, refuse treatment because they compare the severity of this disease with that of women. It is not right. In humans, breast cancer is much more malignant, “eviler”. According to B. Kitchel, three quarters of cases of mammary gland tumors in dogs are not dangerous and can be cured surgically. But this is where B. Kitchel lives, and here the situation is probably worse due to the ignorance of owners and veterinarians.
So, if your dog has been diagnosed with a mammary tumor, here's what you need to know. First of all, the doctor must determine the stage of the process.
The stage depends on:
1. The size of the largest tumor node, the number of nodes does not matter. A dog can have one tumor with a diameter of 1 cm, or ten tumors with a diameter of 1 cm, this does not affect the stage and prognosis. 2. Condition of regional lymph nodes. Regional for the mammary gland are the axillary and inguinal lymph nodes. They can be examined by palpation (feeling). If something is palpable in them, it is considered that metastasis to the lymph nodes has occurred, and the stage increases. Sometimes metastasis to the lymph nodes has occurred, but it is impossible to palpate. How to be in this case? Read on. 3. Presence of distant metastases. In breast tumors, distant metastases in the vast majority of cases occur in the lungs. How can this be determined? Take a photo of the lungs. And not the kind where you can’t even see the heart, but a good one. Not only large tumors metastasize, small ones too. Again, it all depends on what cells the tumor consists of. Much less often there may be metastases in the liver - this is determined by ultrasound. It must be said that any palpation of the liver is complete nonsense, it exists only to impress the owners. It is very rare for dogs to develop mammary tumor metastases to the bones, and there is usually lameness or neurological impairment. If there are no such symptoms, then bone metastases are usually not looked for. Metastases in other organs are casuistry, that is, they are very rare.
Thus, if you called a doctor home, he looked only at the tumor and immediately made some kind of diagnosis and talks about prognosis, some treatment methods, you don’t have to listen to him. He has no idea about the stage of the tumor process, and therefore cannot know how to treat your dog. I’m not saying in the sense that he didn’t study well at the institute and doesn’t know anything and wants to ruin your favorite, but in the fact that he doesn’t have enough data to put accurate diagnosis, and therefore talk about probable methods of treatment. He must order additional tests to determine the stage.
Why is it important to know the stage? Because treatment and prognosis depend on this. Stages I and II are treated surgically and are not required additional methods(chemotherapy, radiation). At these stages, the lymph nodes are not affected by the tumor process. That is, if during examination the dog’s lymph nodes are unchanged and there are no metastases to the lungs, stage I or II (depending on the size of the largest tumor node) is assigned and the dog can be operated on. But I already wrote above that it is not always possible to determine by touch whether there are tumor cells in the lymph nodes or not. This is why there are certain rules for operations for breast tumors. One of these rules is that regional lymph nodes must also be removed. After surgery, the removed tumor and lymph nodes are sent for histological examination. Histological examination implies that the removed material will be processed in a special way, sections will be made and it will be examined under a microscope to see what cells the tumor consists of and whether there are tumor cells in the lymph nodes. Again, you need an experienced specialist. And if there are these cells in the lymph nodes, then things are bad. This will be the third stage, and in this case chemotherapy is needed after surgery, since they believe that since the tumor cells have spread to the lymph nodes, there is no guarantee that they have not spread further. And in this case, to prolong the life of the animal, chemotherapy is needed. That is, the stage necessarily requires clarification after surgery.
The tumor may be small, but it has already metastasized to the lymph nodes, and then it will also be stage III and chemotherapy will be needed. Stage IV includes tumors of any size that have metastasized to the lungs. At these stages, surgical treatment alone will not help, and may even harm. This is why there is such conflicting data on the success of treating mammary tumors in dogs. Nothing is known about the prevalence of the process, but it is treated surgically. If 2 months after the operation the dog dies from metastases, this means that they were simply not detected during the preoperative examination, and such a dog should not have been operated on at all, or the operation was not done radically. This is where the myth comes from that treating breast cancer is useless and better than a dog put to sleep “when she starts to suffer.”
About the radical nature of the operation
More about the rules that must be followed during operations for breast tumors. Metastasis occurs through the lymphatic vessels, so it is necessary to take into account the characteristics of lymphatic drainage from the mammary glands. From the first three glands (counted from the head), lymph drainage (and therefore metastasis) occurs in the axillary lymph nodes, and from the last three - in the inguinal lymph nodes. The division first, second, third, etc. is conditional, the mammary glands are two continuous ribbons. Thus, the lymphatic drainage from the third mammary gland is mixed, tumor cells have the ability to spread “both forward and backward.”
For example, the tumor is located in the fourth and fifth (in most dogs this is the penultimate and last, respectively) mammary gland. It is necessary to remove the last three mammary glands along with the inguinal lymph nodes. If only the tumor is removed, where is the guarantee that the tumor cells have not spread to adjacent breast tissue and lymph nodes? Such an operation cannot be considered radical. If the tumor is in the first or second mammary gland, the first three glands are removed along with axillary lymph nodes. And if the tumor is in the third gland, it is necessary to remove the entire ridge of the mammary glands with the inguinal and axillary glands.
Can you give me an example neighbor's dog Dina, who did not undergo any examinations or pictures, but simply had the tumor removed, and she is still alive. Well, it happens. I'm happy for Dina. It's like a lottery, you can win. But those who didn’t win are no longer there.
Mastectomy is not a nonsense operation and requires, in addition to certain knowledge and skills of the surgeon, also adequate anesthesia and postoperative rehabilitation. Since the disease affects older animals, which may have chronic diseases of cardio-vascular system, liver, kidneys and other organs, in order to avoid their exacerbation, a preoperative examination is necessary and, if necessary, special training to the operation. None of this is easy. And it’s not enough to know about it theoretically. Need experience. And it is not surprising that your beloved veterinarian Ivan Ivanovich Ivanov, who so masterfully crops ears, performs caesarean sections and expertly treats anything, will throw up his hands when he discovers a mammary gland tumor. It’s better for him to squander them than to do something at random. “Do no harm” - this also applies to veterinarians. It is painful to watch animals with relapses being treated after non-radical tumor removal. And this is in Moscow, where there are plenty of clinics capable of providing qualified assistance.
Regarding removal of the uterus and ovaries
We often hear that it is useless to remove a mammary tumor without immediately sterilizing the animal. How can we explain the fact that tumors also appear in sterilized animals? Only sterilization before the first heat reduces the risk of mammary tumors. Significantly reduces the risk, but does not eliminate the possibility of disease. Only a small proportion of tumors are hormone dependent. Such studies have been carried out and they have shown that only a small part of tumors contain hormone receptors. That is, they removed the tumor and sterilized it, but tumors still appear in the remaining mammary glands. Why was it sterilized then? It also happens that they sterilize, but the tumor is left behind. So, it won’t go anywhere, and it won’t even stop growing. Sterilization – abdominal surgery, together with the removal of a mammary tumor, is a difficult intervention, especially for an elderly animal. And if the tumor was not radically removed and no metastases were found, no amount of sterilization will save you from the generalization of the process. By the way, mammary tumors also occur in males.
Oddly enough, sometimes there are people who do not even know what cancer is. I don’t mean any specific knowledge, but simply concepts - oncology, cancer, chemotherapy are unfamiliar to them. They don’t know that a cure for cancer has not yet been invented. Adults, educated people, living not in a remote village, but in a civilized society, demand one hundred percent guarantee in the treatment of cancer. Why can't it be guaranteed? full recovery with even a small breast tumor? Judge for yourself. Let the dog have a tiny tumor of the mammary gland without metastases to the lymph nodes and lungs, an operation was performed according to all the rules, a histological examination of the removed tumor and lymph nodes was carried out, the diagnosis was tubular mammary cancer, stage I. With approximately 95% probability we can say that such a dog will live calmly and happily until old age and will not remember that she once had cancer. But 5% remain adverse outcomes, and there is no guarantee that your dog will be unlucky. That is, out of 100 dogs, 95 will fully recover, and 5 dogs will still have problems. (95 and 5% are not statistical data, but very approximate figures) And this is for stages I and II, let alone the subsequent ones, where we are not talking about a cure, but about prolonging life. I think that even when they come up with a cure for cancer, there will not be a 100% cure rate. It's cancer! Remember that people still sometimes die from appendicitis and even the flu. You need to have an idea about such things. I recently read the completely fair words of one doctor that at school for some reason all sorts of sine-cosine integrals, French revolutions and botany are intensely drilled into children, but for some reason they are not taught the basics of medicine. But everyone will definitely have to deal with diseases and medicine.
I hope that if you ever get into trouble and your dog gets sick from this unpleasant illness, my article will help you avoid the fate of those who fell into the hands of veterinarians ignorant in oncology issues and wasted time. Of course, if possible, it is necessary to treat the animal in a specialized institution, where there are all diagnostic tools, necessary equipment and specialists.
Anna Dubova, veterinarian
Breast cancer in dogs
Tumors of the mammary gland of dogs account for 25% of all tumor diseases in dogs and are in second place in frequency of occurrence after skin tumors in females. The disease affects females aged 5 to 16 years, with the peak of the disease occurring in the age group of 7 - 10 years. In almost 50% of cases in dogs, the disease is malignant and in 25% of cases it has an unfavorable prognosis.
Breast cancer in dogs is hormone dependent. One of the main etiological factors in the development of this pathology are hormonal disorders that occur during the patient’s life: lack of childbirth, frequent false pregnancies, drug suppression of lactation, cystic degeneration in the ovaries.
Breast cancer prevention
Due to the increase in recorded cases of mammary cancer in recent years, prevention of the development of tumor diseases of this localization is one of the most significant issues for dog owners. It is falsely believed that giving birth once can reduce the likelihood of developing cancer. It has been established that the absence of childbirth in animals can also be associated with the appearance of mammary gland cancer in them in the future. It is a known fact that the risk of mammary tumors in unspayed females is higher than in spayed dogs. It has been established that castration of an animal before the first heat reduces the risk of developing the disease to 0.05%, while carrying out this manipulation after 1 heat increases this probability to 10%, and after 2 heat, to 25%.
The duration of development of mammary tumors in dogs can vary from 3 months to several years. This depends on factors such as the morphological type of the tumor, the rate of tumor growth and the hormonal status of the process, etc. The occurrence of a tumor process in the mammary gland in dogs is often preceded by dishormonal processes that develop against the background of increased estrogen production, such as hyperplasia, proliferative or fibrocystic mastopathy. These changes are usually a consequence of frequently occurring pseudolactation, which in animals can occur 2 to 3 months after ovulation. Currently, in veterinary oncology practice, mastopathy is considered to be a precancerous condition of the mammary gland. Breast cancer in dogs can develop both against the background of dysplastic or benign changes in the organ, as well as “de novo”, without previous mastopathy.
Breast cancer in cats
Breast cancer in cats is the third most common cancer after lymphoma and skin tumors. It has an extremely aggressive course, a high degree of malignancy and a poor prognosis. Only in 10–14% of cases benign processes can be found in the mammary gland of cats, while malignant tumors are diagnosed in 86–90%. The disease mainly affects animals aged 10–12 years, but there are observations of the disease in cats at a young age.
In cats, mammary cancer is less hormonal in nature than in dogs. The timing of castration does not significantly affect the risk of breast cancer in cats. The use of hormonal castration drugs can also lead to the development of cancer in cats.
In cats, unlike dogs, the formation of mammary gland tumors is most often not associated with dishormonal tissue changes. Dishormonal disorders of the mammary gland in cats include the formation of fibroadenomatous hyperplasia, characteristic of young cats (1-2 years), which rarely degenerates into a malignant process.
The tumor develops “de novo”, rapidly progresses and metastasizes. Local spread of the process, as a rule, is associated with an increase in volume, germination of the underlying tissues and skin with the formation of an ulcerative defect above its surface. The latter is associated with a poor prognosis of the disease.
Main routes of metastasis for breast tumors it is lymphogenous - through the lymphatic vessels to the regional lymph nodes, and hematogenous - through the blood vessels to the internal organs. Cancer metastases are primarily detected in the lungs and liver, less often in the spleen, kidneys, adrenal glands, heart and bone. Possible damage to brain metastases from breast cancer. In addition, the tumor can spread through small lymphatic vessels and give rise to skin metastases.
Classification of breast tumor for dogs and cats, there are 4 stages of the disease, on which the prognosis of the disease directly depends. Currently, the TNM classification, developed in 1980 by Owen, is widely used in veterinary practice, which describes the state of the primary tumor focus, damage to regional lymph nodes and internal organs. In stages I-II of the disease, the prognosis is favorable and the life expectancy of animals reaches 5 years; in addition, a complete cure is possible after one operation. In stage III of the disease, complex treatment is necessary, including both surgery and chemotherapy. Stage IV (presence of metastases in internal organs) cannot be treated surgically and can only be treated with chemotherapy.
Based on the form of tumor growth, it is customary to distinguish between two main clinical forms of breast cancer – nodular and diffuse. The diffuse form can be conditionally divided into infiltrative - edematous, diffuse - widespread and armored forms. The choice of tumor treatment method depends on the form of growth. With nodular growth, treatment most often begins with surgery, and with diffuse growth, surgery often leads to early relapse, so additional treatment is necessary before surgery: chemotherapy or radiation therapy.
Russian spaniel, female, 13 years old, diffuse breast cancer, stage four
To the main diagnostic methods. Taking into account the possibility of breast cancer metastasis, include a primary examination of the tumor, as well as an X-ray examination of the chest organs and an ultrasound examination of the abdominal organs. Morphological verification of the diagnosis is carried out by histological examination of the surgical material. In rare cases, for unresectable tumors, an aspiration puncture biopsy with cytological examination of the material is performed.
X-ray of a 13-year-old cat showing multiple metastatic lesions of mammary cancer in the lungs
Treatment of breast cancer in animals
Some time ago, in veterinary medicine it was believed that mammary cancer was exclusively a surgical problem. However, with the development of veterinary medicine, the identification of disease prognosis factors and the improvement of specific methods of antitumor therapy, the approach to the treatment of this pathology has become comprehensive.
The main treatment methods are surgery, antitumor chemotherapy and radiation therapy.
Surgical treatment Breast cancer treatment is a radical method and is aimed at complete removal of the primary tumor mass. Depending on the extent of the process, the following radical resection methods for breast cancer are used: regional mastectomy, unilateral mastectomy and, rarely, bilateral mastectomy.
Chemotherapy is indicated for most patients after surgical treatment to prevent distant metastasis or in the preoperative period for primary inoperable, locally advanced or recurrent breast cancer.
In stage III breast cancer, the life expectancy of animals is not long and often does not exceed 7 months in dogs and 4 months in cats. Modern antitumor drugs make it possible to prolong the life of patients after mastectomy by almost 2 times.
Postoperative chemotherapy is aimed at preventing metastasis in the postoperative period and increasing the life expectancy of animals. The main drug in chemotherapy for breast cancer in animals is doxorubicin. The use of doxorubicin for stage III breast cancer in dogs leads to an increase in the life expectancy of animals by 2.5 times compared to the group of animals that received only surgical treatment and is 18.6 months. for 50% of patients (median life expectancy (MLS), compared with MLS of 7 months with one surgical treatment. In addition, 82.4% of dogs survive 6 months, 1 year - 62.3%, and 20 months - 41 .7% of animals, and 23.8% of dogs live 3 years.
In cats, the use of doxorubicin after surgery increases the life expectancy of animals by 2 times and is 8.7 months. versus 4 months with one surgical treatment. In addition, 90.1% of cats live 3 months, 33.1% live 1 year, and 14.3% live more than 3 years. Postoperative chemotherapy should begin within the first 5 days after surgery but no later than 14 days.
The role of preoperative chemotherapy consists of influencing primarily the primary tumor focus, and secondly micrometastases, which always exist against the background of the tumor. The use of preoperative chemotherapy is indicated for locally advanced tumor processes or for diffuse clinical forms of breast cancer, when surgical treatment is not possible. Preoperative chemotherapy usually involves 2 to 3 courses of treatment, depending on the effectiveness of the procedure. Treatment usually uses doxorubicin or taxotere.
The use of doxorubicin in dogs with primary inoperable breast cancer will allow surgery in 45% of dogs after chemotherapy, but it is not possible to significantly prolong the life of animals. Life expectancy is only 5 months, and only 22.2% of dogs live more than 1 year.
The most appropriate use of chemotherapy using Taxotere. Surgery is possible in 80% of animals after chemotherapy, with LFS = 9.8 months, 38.9% of patients survive 1 year and 1.5 years - 19.8% of patients.
In cats, the use of preoperative chemotherapy with doxorubicin allows achieving resectability in 81% of cats, but LOS is only 5 months, with 47.5% of cats surviving 6 months and 38% of patients surviving 10 months.
The use of Taxotere allows 86% of cats to undergo further surgery. LFS is 6.9 months, with 50% of cats living for 6 months, 37.5% for 1 year, and 18.7% for 18 months.
For disseminated stage IV breast cancer (with metastases) Chemotherapy is the main method of treatment and is aimed at prolonging the lives of patients with improving their quality of life. It is known that at this stage the life expectancy of animals is 1-2 months, and with the development of tumor pleurisy - no more than 1 month without treatment. The main drug used for chemotherapy at this stage is Taxotere.
In dogs, the use of taxotere (usually in combination with doxorubicin) can increase the life expectancy of animals by 2 times. The life expectancy is 4 months, with 31% of dogs living for 6 months and 15.6% of dogs for 1 year.
In cats with stage IV breast cancer, the use of Taxotere increases the life expectancy of animals by 3 times. The MTP in the group was 5.8 months, with 41.2% of cats showing no signs of progression within the first 6 months, and 27.7% within 1 year.
Treatment of cats with tumor pleurisy that developed against the background of breast cancer with taxotere leads to a 3-fold increase in the life expectancy of animals. At the same time, the accumulation of fluid in the pleural cavity slows down and in 80% completely stops. MFL=3.2 months, with 3 months. 54% live, 6 months. - 31%, and 1 year month. - 9% of cats.
Radiation therapy
Radiation therapy is a local treatment method that can significantly reduce the risk of relapse during complex treatment of breast cancer. The use of the method is most common in humane medicine, where organ-saving operations are important. In veterinary medicine, where the scope of surgical treatment is always radical, the method is used as an additional treatment in the preoperative and less often in the postoperative period.
The role of hormone therapy in the treatment of mammary cancer in small pets has not been clearly established. The use of immunomodulators is largely associated with palliative measures aimed at supporting the patient in the disseminated stage of cancer, however, the effectiveness of the method has not been statistically confirmed.
Oncological disease - terrible diagnosis not only for people, but also for our pets. And, unfortunately, cancer in dogs is not something exceptional or rare. According to veterinarians, about 30% of males and about 50% of females over the age of 10 suffer from this fatal disease. Is it possible to defeat oncology? What should an owner do to help a four-legged family member?
Human cancer is practically no different from animal cancer - it is a non-contagious cellular mutation that occurs at the DNA level. In recent years, many researchers have confirmed the “single cell theory.” According to this theory, terrible changes suddenly occur in a single cell and it “forgets” its functions. Over time, by dividing the mutated cells become more and more numerous, they form into groups - tumors, and into daughter formations - metastases. For example, breast cancer in dogs often leads to the formation of metastases in the bone or lung tissue, in the liver or kidneys.
Gradually, the tumor grows, replacing and displacing healthy cells of the organ. Because cancer cells“do not remember” their functions, the organ stops working properly. In addition, the tumor physically compresses adjacent tissues, which leads to even greater inhibition of performance. When the neoplasm begins to decompose, bleeding, ulceration and other signs of tissue breakdown are detected.
Owners often wonder whether dogs have cancer of one or another organ. Unfortunately, animals suffer from all types of cancer to which humans are predisposed. Mostly old animals suffer from cancer, but sometimes young animals aged 1-3 years, most often females, suffer. Does not exist universal medicine, because cancer - common name various types mutations, i.e. several different diseases. Folk remedies You can support a dog, but only a veterinarian should treat it!
Contrary to popular belief, most types of cancer can be defeated once and for all. But provided that the disease is detected at an early stage, and the veterinarian is an oncologist, and not a regular therapist.
It is impossible to say for sure how long dogs with cancer live - it depends on many individual factors. If the cancer cells are not too active and the disease is detected at an early stage, a complete cure or full life long years. Much depends on the location of the tumor - the diseased kidney can be removed, but surgery on the story’s brain is not always possible. Therefore, the veterinarian will answer this question only after thorough examination and monitoring the dynamics of the disease.
Types and symptoms of cancer
Oncological diseases are very insidious and develop unnoticed, without any signs of illness. early stages. Moreover, in 90% of cases, cancer can be cured at stage I or 0, and if a dog has stage II or III cancer, the chances of recovery drop to 50%. Therefore, prevention and regular annual visits to the clinic - examination, and urine biochemistry tests are extremely important.
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The lion's share malignant tumors occurs in non-sterile bitches due to constant hormonal changes during periods of estrus, childbirth, feeding and pregnancy. Many owners of bitches ask veterinarians whether dogs get cancer if the girl has never given birth or, on the contrary, gives birth from heat to heat. Unfortunately, this is not of particular importance - nulliparous people, those who have given birth once, and those who give birth through estrus or every estrus get sick. Therefore, veterinarians recommend sterilizing all bitches that are not of breeding value: removal of the uterus and ovaries is 100% protection against cancer of these organs and 90% protection against breast cancer. In addition, all females are sterilized at the age of 7-8 years (at the end of breeding work).
1. Breast cancer in dogs can be detected at an early stage by palpation (unexplained lumps, lumps, lumps in the nipples). The owner should regularly feel the bitch's nipples, gently and without pressure, or visit the clinic regularly for examination by a doctor. In the later stages, the tumors are clearly noticeable - the nipples enlarge, change shape and color, protruding bumps appear (if the tumor opens, a bleeding ulcer will remain in its place).
2. Uterine cancer is more difficult to detect in dogs. As a rule, the only external manifestations– constant spotting, characteristic of many other diseases (pyometra, endometritis, genital infections). Indirect sign– miscarriages, non-viable offspring, empty matings. Contribute to the disease hormonal drugs(anything that shifts in time or stops estrus, any contraception like a sex barrier, etc.). Many of these drugs lead to tumor formation after a single use!
Obvious signs of cancer in dogs appear only in the later stages. In addition to direct symptoms, which depend on the location of the tumor, it is noticeable general deterioration condition - sudden whining (pain), gastrointestinal disorders, weakness and apathy, reluctance to make contact or obsession, drowsiness, loss of interest in what previously caused delight (treats, games).
3. Large and giant dogs are often diagnosed with cancer bone tissue. Symptoms also appear in later stages, so breed owners are at risk (all severe large dogs) should immediately contact a veterinarian if they notice slight lameness, changes in gait, cautious movements, some fatigue and/or reluctance to follow commands associated with running and jumping.
4. Skin cancer in dogs accounts for about 15% of all cancer diagnoses. Unfortunately, the fur makes it difficult to notice the tumor, so you need to carefully examine your pet while bathing and brushing. The neoplasm resembles a mole, age spot or a crusty lump that does not go through. The color varies, from pink to almost black. In any case, if something strange appears on your pet’s skin, contact your veterinarian.
Owners often think that squamous cell carcinoma in dogs it only happens on the skin. This type of cancer actually affects cells squamous epithelium and mucous membranes, and they are on the internal organs and in the mouth.
5. Cancer of the stomach and intestines is manifested by symptoms from the gastrointestinal tract: alternating constipation and diarrhea, changes in appetite, vomiting, blood in the stool (black - stomach, scarlet - intestines). There is noticeable weight loss, some weakness and drowsiness, and anemia develops. Often dogs, even with well-groomed teeth, develop an unpleasant, intrusive odor from their mouths.
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6. Liver cancer in dogs often leads to jaundice (yellowish mucous membranes) due to bile entering the blood. In the early stages, appetite deteriorates somewhat and activity decreases; stool changes (color, smell, consistency) are possible. The dog gradually loses weight, becomes weaker, and loses interest in life. Without treatment, cachexia quickly sets in - almost complete failure from food, rapid exhaustion, complete apathy, constant diarrhea and vomiting.
7. Lung cancer begins with a dry, hysterical, debilitating cough. The dog suddenly coughs and breathes heavily without experiencing physical activity. Over time, the cough becomes wet, and the sputum may contain patches of pus and/or blood.
8. Spleen cancer in dogs, like in people, is diagnosed relatively rarely. Some specific symptoms not observed, general signs of malaise - weakness, poor appetite, exhaustion, cachexia, apathy. Possible ascites - accumulation of fluid in the peritoneum.
9. Kidney cancer also does not manifest itself in any way until late stages. Noticeable signs include blood in the urine, colic (strange gait, whining, constrained movements). The dog gradually weakens, moves less, eats poorly, and swelling of the limbs may appear.
Diagnostic methods
There is an opinion that dogs sense cancer by a specific smell - many cancer institutes have conducted successful studies confirming this theory. Unfortunately, even if dog nose is able to smell cancer in a person, a pet is unlikely to detect the disease in himself, and it is even more doubtful that he will be able to somehow inform the owner about it. Therefore, it is important to undergo a preventive examination once a year and take urine and blood tests for biochemistry - a certain shift in the indicators will allow the veterinarian to suspect something is wrong at the very beginning of the development of the disease. To confirm or refute the diagnosis, you will need to donate blood and urine again to detect “tumor markers”, the presence of which is highly likely to suspect cancer.
Since it is possible to diagnose cancer in a dog only by conducting a targeted study, it is used to confirm the diagnosis. various methods"search". The choice of method depends on what type of cancer and location the veterinarian suspects. In particular, these are x-rays, ultrasound, fluorography, mammography, gastroscopy, MRI or CT; consultation with a highly specialized specialist is required. If a tumor is detected, the doctor will take a puncture - a piece of tissue for cell analysis(to determine whether it is cancer or benign).
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