Common tumor diseases in pets: causes, symptoms and treatment options

Introduction

Tumors in pets (dogs, cats, rabbits, guinea pigs, etc.) are a widespread problem that causes great concern for both pet owners and veterinarians. The Arndt Small Animal Center is therefore intensively dedicated to oncology in order to provide animals with cancer the best possible care and treatment. This article presents some of the most common tumors in pets, explains their causes and symptoms, and discusses the various treatment approaches.

(C) https://www.mdpi.com/2072-6694/10/11/404

Mast cell tumors

Mast cell tumors are a common cancer in dogs, particularly in older animals and certain breeds such as Boxers and Golden Retrievers. They originate from mast cells, which play a vital role in the immune system. Symptoms of these tumors can vary, but they often present as nodular skin lesions. Diagnosis is made through fine-needle aspiration and histopathological examination. Treatment typically involves surgical removal of the tumor, possibly in combination with chemotherapy and radiation therapy.

Lymphomas

Lymphomas are one of the most common types of cancer in dogs and cats. They affect the lymphatic system and can occur in various organs, such as the lymph nodes, spleen, or liver. Symptoms depend on the tumor's location and can be nonspecific, such as swollen lymph nodes, fever, loss of appetite, or weight loss. Diagnosis is made using fine-needle aspiration, blood tests, and imaging techniques. A combination of chemotherapy and immunotherapy is the standard treatment for lymphomas in pets.

Osteosarcomas

Osteosarcomas are aggressive bone cancers that occur primarily in large dog breeds such as Great Danes and Rottweilers. Symptoms are often painful and can include lameness, swelling, and fractures. Diagnosis is made through X-rays, computed tomography (CT) scans, and bone biopsies. A combination of surgery, chemotherapy, and radiation therapy is commonly used to treat osteosarcomas.

Breast cancer in female dogs

Breast cancer is a common tumor in female dogs, and its development may be hormone-dependent. Symptoms include lumps or swellings in the mammary gland, which are often painful. Diagnosis is made by fine-needle aspiration and histopathological examination. Treatment usually involves surgical removal of the tumor, possibly in combination with chemotherapy, radiation therapy, or hormone therapy, depending on the stage and aggressiveness of the tumor. Early spaying can significantly reduce the risk of breast cancer in female dogs.

Skin cancer in cats

Squamous cell carcinomas and basal cell carcinomas are common skin cancers in cats. They occur primarily in older animals and those with light-colored fur, especially those exposed to strong UV radiation. Symptoms can vary, but often present as scaly or ulcerated skin lesions. Diagnosis is made through skin biopsies and histopathological examination. Treatment may include surgical removal of the tumor, cryosurgery, radiation therapy, or topical medications.

Soft tissue sarcomas

Soft tissue sarcomas are a common tumor in dogs and cats, originating from connective tissue, fat, or muscle. Symptoms vary depending on the tumor's location and size, but may include swelling, pain, or impaired function. Diagnosis is made through fine-needle aspiration, computed tomography, and histopathological examination. Treatment typically involves surgical removal of the tumor, possibly in combination with chemotherapy or radiation therapy.

Treatment

Procedure of surgical therapy for tumor diseases in pets

Surgical treatment for tumors in pets is a common form of therapy and involves the removal of the tumor and sometimes surrounding tissue. The exact procedure can vary depending on the type and location of the tumor, but generally follows these steps:

1. Diagnosis and assessmentIf a tumor is suspected, a series of tests are initially performed to confirm the diagnosis and determine the exact location, size, and stage of the tumor. These tests may include imaging procedures such as X-rays, ultrasound, computed tomography (CT) scans, or magnetic resonance imaging (MRI), as well as biopsies to determine the type of tumor.
2. Planning the operationBased on the diagnostic results, a surgical plan is created. This plan includes details such as the type of surgery, the required equipment and personnel, and the expected duration of the operation. This planning also considers potential risks and complications, as well as the best method for postoperative pain management.
3. Performing the operationThe animal is usually placed under general anesthesia to avoid pain and stress during the operation. The veterinarian then removes the tumor and, if necessary, the surrounding tissue. In some cases, it may be necessary to remove an entire body part (e.g., a leg in the case of bone tumors). The exact technique and extent of the surgery depend on the type and stage of the tumor.
4. Post-treatment and monitoringAfter the operation, the animal will be closely monitored to ensure a good recovery and to prevent complications. Pain medication will be administered to alleviate discomfort. In some cases, physiotherapy may be necessary to support recovery and promote mobility.
5. Follow-up care and check-upsAfter discharge from the clinic, the animal will be examined regularly by the veterinarian to monitor the healing process and ensure that the tumor has not recurred. These examinations may include further imaging procedures and tests.

It is important to note that surgical removal of a tumor does not always result in a complete cure. In some cases, the tumor may recur or metastasize. The prognosis depends on many factors, including the type of tumor, its stage at the time of surgery, and the animal's overall health.

Procedure of chemotherapy for tumor diseases in pets

Chemotherapy for tumors in pets is a commonly used treatment modality and can be used curatively or palliatively. The course of such therapy can vary depending on the type and stage of the tumor, the animal's overall health, and the individual treatment goals. The basic steps of chemotherapy are outlined below.

1. Diagnosis and staging: Before starting chemotherapy, an accurate diagnosis must be made. This is usually done through a combination of clinical examination, blood tests, imaging, and tissue biopsies. Staging, i.e., determining the extent of the disease, is equally important, as it influences the prognosis and the choice of therapy.
2. Therapy planning: Once a diagnosis and stage have been established, an individualized treatment plan is created. This plan is based on the available clinical data, including the type of tumor, its stage, the animal's overall health, and the treatment goals. Chemotherapy can be used alone or in combination with other therapies such as surgery or radiation therapy.
3. Administration of chemotherapy: Chemotherapy drugs are usually administered intravenously, but some can also be given orally or injected directly into the tumor. Treatment takes place in cycles, with rest periods in between to allow the body time to recover. The exact duration and number of cycles vary depending on the treatment plan.
4. Monitoring and adjustment of therapy: During chemotherapy, the animal is examined regularly to check the effectiveness of the treatment and manage any potential side effects. Blood tests and imaging may be used to monitor the course of therapy. The treatment can be adjusted depending on the animal's response.
5. Aftercare: After completion of chemotherapy, regular follow-up examinations are necessary to detect and treat any possible relapses early.

It is important to emphasize that chemotherapy in animals is generally less intensive than in humans and therefore has fewer side effects. The focus in veterinary medicine is on maintaining and improving quality of life. It is crucial that pet owners work closely with their veterinarian and communicate all concerns and questions openly.

Procedure of radiation therapy for tumor diseases in pets

Radiation therapy for tumors in pets is a significant treatment option for various cancers and aims to destroy cancer cells using high-energy radiation. The exact procedure for radiation therapy can vary depending on the type of tumor, its location, the animal's overall health, and individual treatment goals. The basic steps of radiation therapy are outlined below:

1. Diagnosis and staging: Before initiating radiation therapy, an accurate diagnosis of the tumor is essential. This diagnosis is usually based on a combination of clinical examination, blood tests, imaging, and histopathological examination of tissue samples. Staging, the determination of the extent of the tumor, is also crucial, as it influences the prognosis and the choice of treatment.
2. Radiotherapy planning: Once the diagnosis and stage of the tumor have been determined, radiation therapy can be planned. This usually involves a computed tomography (CT) scan of the affected area to determine the exact location and size of the tumor. This data is used to create an individualized treatment plan that specifies the direction and dose of radiation delivered to optimally treat the tumor while protecting surrounding healthy tissue.
3. Implementation of radiation therapy: The treatment itself is usually performed under anesthesia to ensure the animal remains still during therapy. The radiation is directed at the tumor using a special device called a linear accelerator. The treatment is typically administered in several sessions (fractions) spread over a few weeks. The exact number of treatments varies depending on the type and size of the tumor and the animal's overall health.
4. Monitoring and adjustment of therapy: During radiation therapy, the animal is closely monitored to assess its response to the treatment and manage any potential side effects. Regular clinical examinations and imaging can be used to evaluate the progress of the therapy. The treatment can be adjusted according to the animal's response.
5. Aftercare: After completion of radiation therapy, regular follow-up examinations are necessary to monitor long-term results and to detect and treat possible relapses early.

It is important to emphasize that radiation therapy is a specialized treatment available only at certain veterinary facilities. The decision to use radiation therapy should be made in close consultation between the pet owner and veterinarian, taking into account the individual needs and circumstances of the animal.

The course of immunotherapy for tumor diseases in pets

Immunotherapy for tumor diseases in pets is an emerging and promising treatment option for various cancers in animals. It aims to activate or modulate the animal's own immune system to recognize and destroy cancer cells. The course of immunotherapy can vary depending on the type of tumor, the stage of the disease, the animal's overall health, and the individual treatment goals. The basic steps of immunotherapy are explained below:

1. Diagnosis and staging: Before starting immunotherapy for tumors in pets, an accurate diagnosis of the tumor is essential. This is usually based on a combination of clinical examination, blood tests, imaging, and histopathological examination of tissue samples. Staging, i.e., determining the extent of the disease, is equally important, as it influences the prognosis and the choice of treatment.
2. Immunotherapy planning: Once the diagnosis and tumor stage are established, immunotherapy can be planned. This can take various forms, including the use of monoclonal antibodies, immune checkpoint inhibitors, cancer vaccines, or adoptive T-cell therapies. The choice of specific therapy depends on several factors, including the type of tumor, the stage of the disease, and the animal's overall health.
3. Administration of immunotherapy: Immunotherapy is usually administered intravenously or subcutaneously, but can also be injected directly into the tumor. The therapy is generally carried out in cycles, with rest periods between treatments to allow the immune system time to recover and respond.
4. Monitoring and adjustment of therapy: During immunotherapy, the animal is closely monitored to assess the effectiveness of the treatment and manage any potential side effects. Blood tests and imaging may be used to monitor the course of therapy. The treatment can be adjusted depending on the animal's response to the therapy.
5. Aftercare: After completion of immunotherapy, regular follow-up examinations are necessary to monitor long-term results and to detect and treat possible relapses early.

It should be emphasized that immunotherapy in animals is still a relatively new field, and many of the currently available therapies are still in the research and development phase. Therefore, it is particularly important that pet owners carefully discuss the potential risks and benefits of such therapy with their veterinarian or oncologist.

The course of hormone therapy for tumor diseases in pets

Hormone therapy for tumors in pets is a medical treatment that aims to control or inhibit tumor growth by modulating the body's natural hormonal systems. In pets, it is often used for certain types of tumors, such as mammary tumors, prostate tumors, or pituitary tumors. The exact procedure for hormone therapy can vary depending on the type of tumor, the animal's overall health, and individual circumstances, but it generally follows these steps:

1. DiagnosisFirst, the veterinarian must ensure that the tumor in the pet is hormone-dependent, meaning that its growth and spread are influenced by specific hormones in the animal's body. This is usually done through a biopsy of the tumor and possibly additional tests to check for the presence of specific hormone receptors.
2. Decision for therapyIf the tumor has been confirmed as hormone-dependent and other treatment options, such as surgery or chemotherapy, are considered less suitable or insufficient, hormone therapy may be considered. Several factors must be taken into account when deciding on hormone therapy, such as the animal's age and general health, potential side effects of the therapy, and the pet owner's preferences.
3. Treatment planningThe exact type of hormone therapy depends on the specific tumor and its response to certain hormones. Various types of medication can be used, including hormone blockers, which inhibit the production or action of certain hormones, and hormone replacement therapies, which provide hormones that slow or stop tumor growth. The veterinarian will create an individualized treatment plan that specifies the type of medication, the dosage, and the schedule for administration.
4. Implementation of the therapyHormone therapy is usually administered in the form of tablets or injections, which the animal receives regularly. The exact duration of treatment can vary, but in many cases, long-term therapy is necessary to effectively control tumor growth.
5. Monitoring and adjustment of therapyDuring hormone therapy, regular monitoring of the animal is necessary to assess the effectiveness of the treatment and to monitor for possible side effects. Based on these observations, the veterinarian can adjust the therapy if necessary, for example, by changing the dosage or trying a different medication.
6. AftercareAfter completion of hormone therapy, the animal will continue to be examined regularly to ensure that the tumor remains under control and no new health problems arise.

It is important to note that hormone therapy cannot treat all types of tumors in pets and does not always lead to a complete cure. However, in many cases, it can help slow or stop tumor growth and improve the animal's quality of life.

Frequently asked questions about tumor diseases in pets:

Summary

A cancer diagnosis in pets can be emotionally distressing for pet owners. However, many cancers can be successfully treated with early detection and appropriate therapy. The Arndt Small Animal Clinic places great emphasis on comprehensive diagnostics and individualized treatment approaches to ensure the best possible well-being and quality of life for affected animals. Pet owners should not hesitate to consult their veterinarian or the Arndt Small Animal Clinic if they suspect their pet has cancer, in order to ensure professional and timely treatment.

For further questions or advice, please contact Veterinarian Sheila Martins, TÄ Anna Daum or GPCert Oncol. Catherine Grötz-Stergiou.

Literature on tumor diseases in pets

1. „"Withrow and MacEwen's Small Animal Clinical Oncology" by Stephen J. Withrow, David M. Vail, and Rodney Page. This book is considered a standard work in veterinary oncology and covers a wide range of tumor diseases in domestic animals.
2. „"Veterinary Cancer Medicine" by Mark H. Thrall. This book offers comprehensive information on the diagnosis and treatment of tumor diseases in pets.
3. „"Small Animal Oncology: An Introduction" by Susan M. North and Tilly Watson. This introductory book provides an overview of the different types of cancer that can affect pets.
4. „"Canine and Feline Cytology: A Color Atlas and Interpretation Guide" by Rose E. Raskin and Denny Meyer. Although not specifically focused on cancer, this book offers valuable information on the interpretation of cytological samples, an important part of cancer diagnosis.
5. „"Cancer in Dogs and Cats: Medical and Surgical Management" by Wallace B. Morrison. This book offers detailed guidance on the medical and surgical treatment of cancer in dogs and cats.

Please note that you can purchase these books on tumor diseases in pets from your local bookstore or online. Some may also be available in public or university libraries. Furthermore, it is important to note that this literature is written in English.