Behind this complicated name lies an aggressive form of cancer in dogs, also known as malignant histiocytosis. This hereditary condition occurs primarily in Bernese Mountain Dogs, Retrievers, and Rottweilers. In Bernese Mountain Dogs, it is the leading cause of death. It primarily affects male dogs between the ages of two and eight. The disease is relatively rare in other dog breeds.
Histiocytes are cells of the immune system that are found primarily in connective tissue, but also in all other organs; as phagocytes, they engulf and break down microorganisms, cellular debris, and dead cells. A mutation leads to a pathological proliferation of the degenerated cells in one or more organs. There is a marked tendency toward metastasis (=formation of secondary tumors). The secondary tumors spread rapidly and, due to their invasive growth, cause severe organ damage and ultimately lead to the dog’s death.
The cause of the degeneration is currently unknown. However, a genetic predisposition has been identified in the Bernese Mountain Dog.
In terms of presentation, a distinction is made between whether the disease is localized as a cutaneous form or spreads throughout the entire organism as a disseminated form. Another particularly aggressive form is hemophagocytic (i.e., blood-eating) histiocytoma, which frequently affects the bone marrow. The tumor cells "eat" the red blood cells of the affected dog, causing the dog to develop anemia.
Since histiocytoma is a tumor of the hematopoietic system, virtually any organ in the body can be affected. In the disseminated form, the skin is usually not involved. In most cases, the lungs, liver, spleen, lymph nodes, and bone marrow are affected. Depending on the tumor’s location, the clinical presentation of the disease can therefore vary widely and be non-specific. Affected dogs typically exhibit nonspecific symptoms such as weakness, lethargy, loss of appetite, fever, and weight loss. If the lungs are involved, breathing difficulties and coughing may occur. In rare cases, ataxia (impaired coordination), paralysis, or epileptic seizures may also occur. The disseminated form progresses rapidly and, in most cases, leads to death within less than six months.
The cutaneous form manifests as nodules and plaques on the skin, with the nasal mucosa, conjunctiva of the eyes, and, in male dogs, the scrotum being particularly affected. The skin lesions often occur in episodes, are difficult to define, and tend to become ulcerated. The disease worsens with each episode and metastasizes particularly to the lymph nodes, spleen, and bone marrow.
In the case of hemophagocytic histiocytoma, the uptake of red blood cells by the tumor cells leads to anemia, resulting in pale mucous membranes and weakness. If you notice any such changes in your dog, please take him to your veterinarian immediately.
Based on your preliminary report and a thorough clinical examination, your veterinarian will already have indications of a tumorous condition. Enlarged lymph nodes and swelling of the liver or spleen are usually present. Unfortunately, by the time symptoms appear, the disease is already quite advanced.
This initial suspicion can be further confirmed with an X-ray or ultrasound examination. However, X-rays or ultrasound images can only show enlargements. The exact type of tumor can only be determined by taking a tissue sample. In a procedure known as fine-needle aspiration, the tumor is punctured with a thin, long needle, and a cell sample is extracted. This sample is then examined in the laboratory. Based on the cell type and its changes, the nature of the tumor can be more precisely determined. However, depending on the tumor’s location—such as in the lungs—the procedure can only be performed at high risk to the patient and must therefore be carefully weighed. Diagnosis becomes more difficult for your veterinarian in the case of a hemophagocytic histiocytoma, as while enlarged livers and spleens can be detected on X-rays or ultrasound, no actual tumors are visible.
There is no cure for this type of cancer. Treatment involves the use of chemotherapy drugs (agents designed to kill tumor cells) or radiation therapy. However, these treatments merely improve the dog’s quality of life and delay the progression of the disease. Surgical intervention is also rarely feasible or likely to be successful due to the location of the tumors. In cases of severe, treatment-resistant symptoms, such as severe shortness of breath caused by tumor masses in the lungs, the dog should be euthanized given the hopeless prospects for a cure (see article on Euthanasia).
The prognosis for this aggressive form of cancer is generally poor. Despite a wide range of treatment options, a cure is not possible. Depending on the type of tumor, the type of treatment, and the dog’s response to treatment, life expectancy after diagnosis ranges from a few weeks to a few months.
Since the cause of the cellular degeneration remains unknown, true prevention is not possible.
Due to the genetic predisposition of the Bernese Mountain Dog, a genetic test has been developed. This test provides breeders with information on the risk that their breeding dog will develop histiocytoma. This enables responsible breeders to avoid risky matings and thus reduce the incidence of the disease.
The prostate gland is the most important sex gland in male dogs. It is located behind the bladder and surrounds the beginning of the urethra. The secretion produced by the prostate gland is a component of semen and is ejaculated together with the sperm produced in the testicles. Prostate disorders are usually diagnosed in older, unneutered male dogs. These disorders can cause various changes in the gland.
Claw disorders are relatively rare in dogs. However, injuries, excessive licking or poor grooming can cause the claw bed to become inflamed due to the penetration of bacteria or fungi. Symmetrical lupoid onychodystrophy (SLO) is the most common form of claw bed inflammation in dogs. This rare but extremely painful disease of the claw bed mainly affects large dogs (Great Danes, Rhodesian Ridgebacks, German Shepherds) and can be triggered by various factors.
This brain disorder, which has not yet been fully researched in dogs, causes seizures that can be very frightening for dog owners. Epilepsy can be treated very effectively with medication, but its cause is still not fully understood.
A hernia is a bulge in the abdominal wall through which the peritoneum and intestines can protrude. Perianal hernia, also known as perineal hernia, is a condition that occurs in 90% of older, unneutered male dogs, in which fat and abdominal organs protrude under the skin in the perineal area (the area between the anus and the external genitalia).
This eye disease, also known as Collie Eye Anomaly (CEA), is a hereditary condition affecting Collies, Shelties, and some related breeds. It is a congenital developmental disorder of the back of both eyes that can lead to visual impairment or even blindness.
When the body produces antibodies against its own structures, this is referred to as an autoimmune disease. The immune system mistakenly attacks parts of the body, thereby damaging certain functions and organs—in some cases leading to their complete destruction. Autoimmune diseases in dogs include various forms of the pemphigus and lupus complexes. The individual diseases are distinguished based on the different target structures in the body.
The soft palate is a muscle extension approximately 10 cm long that separates the nasal cavity from the throat. As the name suggests, dorsal displacement of the soft palate (DDSP) describes a change in position in which the soft palate temporarily or permanently covers the epiglottis, leading to coughing, difficulty swallowing, and breathing problems.
There are all kinds of dangers lurking for cats, not only outside but also in the home. Young, playful, and curious kittens are particularly at risk. Therefore, take the necessary safety precautions before a cat moves in with you. With the right knowledge, you will be on the safe side.
Entropion is also colloquially referred to as a rolled eyelid and describes the inward rolling of the upper or lower eyelid. It can affect the entire eyelid or just part of it.
Cats communicate through various channels. Their behavior, body language, vocalizations, and scent markings, which are largely invisible to humans, speak volumes. But how can "cat language" be translated into "human language"?
Have you ever wondered whether your dog can see the magnificent colors that nature sometimes presents us with? Have you ever thought about how your dog sees you and how it perceives its environment with its eyes?
Fungal diseases are among the most common skin diseases in horses. They occur regardless of the season, are easily transmissible, and cause circular, scaly, non-itchy skin lesions. Young horses whose immune systems are not yet fully developed are particularly affected. Humans can also become infected with a skin fungus from horses, meaning that it is a zoonosis.
