Home » Diseases » In dogs » Leiomyosarcoma of the Stomach or Intestine (Stomach and Intestinal Cancer)

Leiomyosarcoma of the Stomach or Intestine (Stomach and Intestinal Cancer) in Dogs

Occurrence: very rare
Location of illness: Abdomen/pelvis

Author: Dr. med. vet. Gisa Löwe | Last modified: 06.11.2025

Leiomyosarcoma of the stomach or intestineThe intestine is the medical term for the gut, including the small intestine (intestinum tenue) and the large intestine (intestinum crassum). It plays a central role in the digestion and absorption of nutrients. is a rare, malignantMalignant means "cancerous" and is used to describe tumors or neoplasms that grow invasively and have the ability to metastasize. Malignant tumors can cause serious health problems in dogs and cats. tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. that originates from smooth muscle cells in the stomach and intestinalIntestinal refers to the intestine, the part of the digestive tract that extends from the stomach to the anus. Intestinal diseases affect the small and/or large intestine. wall of dogs.

The most important facts at a glance

Leiomyosarcomas are malignantMalignant means "cancerous" and is used to describe tumors or neoplasms that grow invasively and have the ability to metastasize. Malignant tumors can cause serious health problems in dogs and cats. Tumors that arise from the smooth muscle cells of the stomach and intestines in dogs. The exact cause is unclear, but genetic factors and environmental factors such as chemicals or radiation may play a role. Symptoms include Vomiting, bloody stool, Flatulence, and Weight loss. Physical examinations, imaging procedures such as X-rays or ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow., and biopsies are often used for diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. to determine the type of TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions..

The main treatment is surgical removal of the TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions.. In some cases, chemotherapyChemotherapy refers to the treatment of diseases, especially cancer, with chemical substances or drugs. It aims to kill cancer cells or prevent their growth, but can also affect healthy cells. or radiation therapyRadiation therapy is the use of radiation, most often to treat cancer. It can be used to kill cancer cells or slow their growth without significantly damaging surrounding healthy tissue. is used to combat remaining cancerCancer refers to the uncontrolled proliferation of cells that can lead to tumors or spread throughout the body. Various types of cancer occur in dogs and cats, ranging from skin cancer to lymphomas. cells. The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. depends on various factors such as TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. size, location, and the dog’s health. Early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. improves the chances of recovery. Regular follow-up examinations are important to prevent recurrence.

Since the causes are not fully known, there are no specific preventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. measures. However, a healthy lifestyle and regular veterinary examinations can help reduce the risk. Current research focuses on genetic analyses, new diagnostic procedures and innovative treatment methods such as immunotherapies. The goal is to improve diagnostic accuracy and develop personalized therapies to increase the quality of life of affected dogs. Collaboration between veterinarians, researchers and pet owners is crucial for progress in the treatment of this disease.

Causes

Leiomyosarcomas belong to the soft tissue sarcomas and arise from smooth muscle cells, which are typically found in the walls of hollow organs such as the stomach and intestines. These cells can proliferate uncontrollably and form malignantMalignant means "cancerous" and is used to describe tumors or neoplasms that grow invasively and have the ability to metastasize. Malignant tumors can cause serious health problems in dogs and cats. Tumors that grow into the surrounding tissue and may metastasize.

The exact cause of leiomyosarcomas in dogs is not fully understood. As with many cancers, genetic factors are believed to play a role. Mutations in the genes that regulate cell growth and division can lead to uncontrolled cell proliferation.

There is also evidence that environmental factors, such as exposureExposure refers to the Contact with or subjection to certain substances, environmental factors, or pathogens. In veterinary medicine, this can include Contact with toxins, allergens, or infectious agents that can cause health problems in dogs and cats. to certain chemicals or radiation, as well as chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. Inflammatory conditions, can increase the risk of developing leiomyosarcomas. Further research is needed to better understand these relationships.

Symptoms

Very common symptoms:

Common symptoms:

The symptoms of leiomyosarcomas in the stomach and intestinalIntestinal refers to the intestine, the part of the digestive tract that extends from the stomach to the anus. Intestinal diseases affect the small and/or large intestine. area can vary depending on the location and size of the TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions.. Common signs include Weight loss, Vomiting, and DiarrheaDiarrhea refers to the condition of frequent, watery bowel movements, which can be a sign of infections, digestive disorders, or other health problems., which are often non-specific and can also occur with many other diseases.

Dogs with a large TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. may also show signs of AbdominalThe term “abdominal” refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. pain, loss of appetite, and lethargy. In some cases, gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. Bleeding may occur, which is recognizable as bloody stool or Vomiting of blood.

Since the symptoms are often non-specific, it is important to consult a veterinarian for persistentPersistent means lasting or continuing for an extended period. In veterinary medicine, it can refer to chronic diseases or symptoms that do not subside. or unusual signs in order to make an accurate diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients..

Diagnosis

The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. of a leiomyosarcoma usually begins with a thorough clinical examination and a detailed medical historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits.. The veterinarian will ask about specific symptoms and perform a physical examination to determine signs of Pain or abnormal massesIn pathology, the term "mass" is used to describe an abnormal lump or growth in the body. A mass can form in the skin or subcutaneous tissue, or even inside the body. The causes can be benign (not cancer) or malignant (cancer). in the abdomenThe abdomen, also known as the abdominal cavity, is the part of the body located between the rib cage and the pelvis. It houses several important organs, including the stomach, liver, kidneys, intestines, and spleen..

Imaging procedures such as X-rays or ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. examinations of the abdomenThe abdomen, also known as the abdominal cavity, is the part of the body located between the rib cage and the pelvis. It houses several important organs, including the stomach, liver, kidneys, intestines, and spleen. can help determine the size and location of the TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions.. In some cases, an endoscopyEndoscopy is a diagnostic procedure that uses an endoscope (a thin, flexible tube with a light source and a camera at the end) to examine and visualize the inside of the body, often for diagnostic or therapeutic purposes. may be required to allow direct visual inspection of the inner stomach or intestinalIntestinal refers to the intestine, the part of the digestive tract that extends from the stomach to the anus. Intestinal diseases affect the small and/or large intestine. walls.

The definitive diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is often made by a biopsyA biopsy is a medical procedure in which a small amount of tissue is removed from the body to be examined under a microscope for signs of disease. Biopsies can help diagnose cancer and other conditions., in which a tissue sample of the Tumor is taken and examined histopathologically. This analysis makes it possible to confirm the type of TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. and assess its malignancyMalignancy refers to the aggressiveness of a tumor, that is, its ability to grow invasively and metastasize. Malignant tumors can be life-threatening in dogs and cats and require specific treatment..

Therapy

The main treatment for leiomyosarcomas in the stomach and intestinalIntestinal refers to the intestine, the part of the digestive tract that extends from the stomach to the anus. Intestinal diseases affect the small and/or large intestine. area is usually surgical. Complete removal of the TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. is the primary goal to provide the best chance of cure. In some cases, partial resection of the affected intestinalIntestinal refers to the intestine, the part of the digestive tract that extends from the stomach to the anus. Intestinal diseases affect the small and/or large intestine. segment may be necessary.

Depending on the location and stage of the TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions., adjuvant therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. such as chemotherapyChemotherapy refers to the treatment of diseases, especially cancer, with chemical substances or drugs. It aims to kill cancer cells or prevent their growth, but can also affect healthy cells. or radiation therapyRadiation therapy is the use of radiation, most often to treat cancer. It can be used to kill cancer cells or slow their growth without significantly damaging surrounding healthy tissue. may be recommended to attack remaining cancer cells and reduce the risk of metastasisA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body.. The decision on the best treatment strategy should be made individually and can be supported by an oncologist.

SupportiveSupportive refers to supportive treatments that aim to alleviate symptoms and improve quality of life without directly treating the underlying cause of the disease. therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions., such as the administration of Pain relievers or medications to support digestion, may also be necessary to improve the dog’s quality of life during treatment.

Prognosis and follow-up care

The prognosis for dogs with leiomyosarcoma depends on various factors, including the size and location of the Tumor, the presence of metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body., and the dog’s general health. With early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and complete removal of the Tumor, the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. can be relatively favorable.

However, leiomyosarcomas tend to grow aggressively and, if left untreated, can lead to serious complications. Dogs with advanced TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. stages or metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. generally have a poorer prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop..

Regular follow-up examinations are important to detect and treat the recurrence of the Tumor or the occurrence of metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. early.

Prevention

Since the exact causes of leiomyosarcomas are not fully known, there are no specific measures to prevent these Tumors. However, general health guidelines, such as a balanced diet, regular exercise, and minimizing exposureExposure refers to the Contact with or subjection to certain substances, environmental factors, or pathogens. In veterinary medicine, this can include Contact with toxins, allergens, or infectious agents that can cause health problems in dogs and cats. to potentially carcinogenic substances, can help reduce the overall risk of cancerCancer refers to the uncontrolled proliferation of cells that can lead to tumors or spread throughout the body. Various types of cancer occur in dogs and cats, ranging from skin cancer to lymphomas..

Regular veterinary examinations can help detect and treat health problems early before they develop into larger problems. Good cooperation with a veterinarian is crucial to ensure the health and well-being of the dog.

Outlook on current research

Research on leiomyosarcomas of the stomach or intestineThe intestine is the medical term for the gut, including the small intestine (intestinum tenue) and the large intestine (intestinum crassum). It plays a central role in the digestion and absorption of nutrients. in dogs is an active and ongoing area that focuses on various aspects of this rare form of cancerCancer refers to the uncontrolled proliferation of cells that can lead to tumors or spread throughout the body. Various types of cancer occur in dogs and cats, ranging from skin cancer to lymphomas.. A core area of research is the genetic analysis and identification of biomarkers that can help in the diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. of this disease. Researchers are working to identify the genetic mutations that contribute to the development of leiomyosarcomas. These genetic studies are crucial to developing targeted therapies that target the specific genetic changes present in a dog’s Tumors.

Another focus is on the development of new diagnostic procedures. Traditionally, the diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. of leiomyosarcomas is made by tissue samples and histopathologicalHistopathological refers to the microscopic examination of tissue samples for the diagnosis of diseases. This technique is used to identify the specific characteristics of diseases at the cellular level in dogs and cats. examinations. However, current studies are investigating the use of imaging techniques such as magnetic resonance imaging (MRI)Magnetic resonance imaging is an imaging technique that uses strong magnetic fields and radio waves to create detailed images of the inside of the body. It is used in veterinary medicine to diagnose diseases of the brain, spine, and other organs. and positron emission tomography (PET) to better detect Tumors and assess their spread in the dog’s body. These techniques could improve the accuracy of the diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and facilitate the planning of surgical procedures.

Therapeutic research focuses on developing new treatment methods that are not only more effective but also less invasiveInvasive describes medical procedures or pathogens that enter the body or penetrate tissue. In medicine, invasive procedures can range from minimally invasive techniques to open surgery.. Chemotherapeutic approaches are being further optimized to minimize side effects and improve the quality of life of affected dogs. There are also ongoing clinical trials investigating the effectiveness of immunotherapies, in which the dog’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. is stimulated to fight the TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions.. This type of therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. could be a promising addition or alternative to conventional treatments.

Another promising direction of research is the development of personalized medicine approaches. By analyzing the genetic and molecular profiles of the Tumors, tailored treatment plans can be created that are tailored to the specific needs of each individual dog. This could significantly improve the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. for dogs with leiomyosarcomas and lead to better treatment outcomes.

The research is also accompanied by the development of new drugs that target molecular targets that play a role in TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. development. These targeted therapies could be used in combination with existing treatments to increase effectiveness and slow the progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms. of the disease. In addition, the role of nutrition and lifestyle in the preventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. and management of leiomyosarcomas is being investigated, as these factors may have an impact on the health and well-being of dogs.

In summary, research on leiomyosarcomas of the stomach or intestineThe intestine is the medical term for the gut, including the small intestine (intestinum tenue) and the large intestine (intestinum crassum). It plays a central role in the digestion and absorption of nutrients. in dogs has made significant progress in recent years. The combination of genetic studies, advanced diagnostic techniques and innovative therapeutic approaches offers hope for better treatment options and an improved prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. for affected dogs. The continued collaboration between veterinary physicians, researchers and pet owners is crucial to translate these advances into clinical practice and improve the lives of dogs with this challenging disease.

Frequently asked questions (FAQs)

What is a leiomyosarcoma of the stomach or intestineThe intestine is the medical term for the gut, including the small intestine (intestinum tenue) and the large intestine (intestinum crassum). It plays a central role in the digestion and absorption of nutrients. in dogs? A leiomyosarcoma is a malignantMalignant means "cancerous" and is used to describe tumors or neoplasms that grow invasively and have the ability to metastasize. Malignant tumors can cause serious health problems in dogs and cats. type of TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. that arises from smooth muscle cells. These Tumors can affect the stomach or intestines of dogs and are often difficult to diagnose because they lie deep in the tissue and symptoms may not appear until advanced stages.
What symptoms can occur in a dog with leiomyosarcoma? The most common symptoms include Vomiting, Diarrhea, Weight loss, loss of appetite, and AbdominalThe term "abdominal" refers to anything that concerns the belly or the abdomen. It is an adjectival expression used to describe the location, symptoms, or conditions that occur in the abdominal area. pain. Since these symptoms can also occur with many other diseases, an accurate diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is important.
How is the diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. of a leiomyosarcoma made? The diagnosis usually requires a combination of imaging procedures, such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. or X-rayX-ray is an imaging technique that uses X-rays to create images of the inside of the body. It is often used to diagnose bone fractures, lung diseases, and other conditions., and a biopsyA biopsy is a medical procedure in which a small amount of tissue is removed from the body to be examined under a microscope for signs of disease. Biopsies can help diagnose cancer and other conditions. of the suspicious tissue. A histopathologicalHistopathological refers to the microscopic examination of tissue samples for the diagnosis of diseases. This technique is used to identify the specific characteristics of diseases at the cellular level in dogs and cats. examination of the biopsyA biopsy is a medical procedure in which a small amount of tissue is removed from the body to be examined under a microscope for signs of disease. Biopsies can help diagnose cancer and other conditions. is crucial to confirm the type of TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions..
What treatment options are available for dogs with leiomyosarcoma? The primaryPrimary refers to the first or original cause of a disease or condition, as opposed to secondary causes or symptoms that develop from it. treatment often consists of surgical removal of the TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions.. Depending on the stage and spread of the disease, chemotherapyChemotherapy refers to the treatment of diseases, especially cancer, with chemical substances or drugs. It aims to kill cancer cells or prevent their growth, but can also affect healthy cells. and radiation may also be considered to combat remaining cancerCancer refers to the uncontrolled proliferation of cells that can lead to tumors or spread throughout the body. Various types of cancer occur in dogs and cats, ranging from skin cancer to lymphomas. cells.
What is the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. for dogs with this type of cancerCancer refers to the uncontrolled proliferation of cells that can lead to tumors or spread throughout the body. Various types of cancer occur in dogs and cats, ranging from skin cancer to lymphomas.? The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. depends on various factors, including the size and location of the TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions., whether it can be completely removed, and whether the cancerCancer refers to the uncontrolled proliferation of cells that can lead to tumors or spread throughout the body. Various types of cancer occur in dogs and cats, ranging from skin cancer to lymphomas. has spread to other parts of the body. In general, the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. is better if the TumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. is detected and treated early.
Are there risk factors that promote the development of leiomyosarcomas in dogs? The exact reason for the development of leiomyosarcomas is not fully understood, but genetic factors, environmental factors, and pre-existing conditions may play a role. Certain breeds may also be at higher risk.
Can leiomyosarcomas be inherited in dogs? While there is no specific evidence for the inheritance of leiomyosarcomas, genetic predispositions may occur in certain breeds. Further research is needed to better understand these relationships.
How can I reduce the risk of stomach or intestinalIntestinal refers to the intestine, the part of the digestive tract that extends from the stomach to the anus. Intestinal diseases affect the small and/or large intestine. cancerCancer refers to the uncontrolled proliferation of cells that can lead to tumors or spread throughout the body. Various types of cancer occur in dogs and cats, ranging from skin cancer to lymphomas. in my dog? A balanced diet, regular veterinary examinations, and avoiding known carcinogenic substances can help reduce the risk. It is also important to recognize and investigate symptoms early.
How can pet owners help their dogs after diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients.? In addition to medical treatment, it is important to support the dog emotionally. A comfortable environment, stress-free walks and appropriate nutrition can contribute to the quality of life. Regular veterinary check-ups are also crucial to monitor the progress of the treatment.
Is there support for pet owners of dogs with leiomyosarcomas? Yes, there are many resources and support systems, including online forums, self-help groups, and specialized veterinarians who focus on the care of animals with cancerCancer refers to the uncontrolled proliferation of cells that can lead to tumors or spread throughout the body. Various types of cancer occur in dogs and cats, ranging from skin cancer to lymphomas.. Sharing with other pet owners can also be helpful.

You can find an interesting overview of gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. problems in dogs, supplemented with information on the intestinalIntestinal refers to the intestine, the part of the digestive tract that extends from the stomach to the anus. Intestinal diseases affect the small and/or large intestine. microbiome and the importance of probiotics, here: https://petsvetcheck.de/fachbeitrag/magen-darm-probleme-beim-hund/