Understanding Histiocytic Sarcoma in Bernese Mountain Dogs

Bernese Mountain Dogs are a beloved breed known for their gentle nature and stunning coats, but unfortunately, they're also prone to a rare and aggressive form of cancer called histiocytic sarcoma. This cancer affects the immune system and can be particularly challenging to diagnose and treat.

Histiocytic sarcoma is a type of cancer that originates from a specific type of immune cell called histiocytes. These cells play a crucial role in the body's defense against infection and disease, but in the case of histiocytic sarcoma, they become malignant and start to grow uncontrollably.

The symptoms of histiocytic sarcoma in Bernese Mountain Dogs can be quite subtle at first, making it difficult to diagnose. Common signs include weight loss, lethargy, and swelling in the lymph nodes or spleen.

The cancer can also cause anemia, which is a condition where the body doesn't have enough red blood cells to carry oxygen to the tissues. This can lead to a range of symptoms, including pale gums, rapid heartbeat, and shortness of breath.

Discover more: Bernese Mountain Dog Mass

Histiocytic sarcoma is a group of malignant cancers that arise from histiocytes.

It's a relatively uncommon cancer, but some breeds are overrepresented, suggesting a heritable element.

Histiocytic sarcoma typically occurs in middle-aged and older dogs.

It's worth noting that some breeds are more prone to this cancer than others, which can help with early detection and prevention.

Bernese Mountain Dogs are at a higher risk of developing histiocytic sarcoma, a genetic disease that affects the breed more than any other. This is particularly concerning, as up to 25% of Bernese Mountain Dogs may develop histiocytic sarcoma.

The average age of onset for histiocytic sarcoma in Bernese Mountain Dogs is around 7 years old, which is considered middle-aged for the breed. Typically, this disease originates in the spleen but can metastasize to other areas such as the lungs, liver, bone marrow, and lymph nodes.

A genetic predisposition within the breed is strongly suspected, although the precise cause remains elusive. Prior joint disease or preexisting orthopedic disease has also been identified as a risk factor, with a correlation between prior joint disease and the risk of histiocytic sarcoma around a joint, known as periarticular histiocytic sarcoma (PAHS).

Here are the breeds that are more susceptible to localized histiocytic sarcoma:

These breeds, including Golden Retrievers, are more prone to disseminated histiocytic sarcoma as well.

Symptoms of histiocytic sarcoma in Bernese Mountain Dogs can be quite varied and may depend on the organ or organs affected.

Dogs with localized histiocytic sarcoma typically notice palpable masses on or under the skin, and they're not systemically ill.

With disseminated histiocytic sarcoma, signs can be nonspecific and harder to pinpoint, and may include decreased appetite, lethargy, weight loss, fever, and lesions on the skin.

Here are some common symptoms of disseminated histiocytic sarcoma in Bernese Mountain Dogs:

Diagnosing histiocytic sarcoma can be challenging, but it's essential to identify histiocytes through biopsy of affected tissues.

Reactive histiocytosis is a condition that affects dogs, and it's characterized by the proliferation of histiocytes in the skin and subcutis. Cutaneous histiocytosis is a form of reactive histiocytosis that's confined to the skin and subcutis, with rare involvement of regional lymph nodes.

The clinical presentation of cutaneous histiocytosis is commonly described as multiple cutaneous nodules, crusts, or areas of depigmentation that appear to wax and wane on the face, ears, nose, neck, trunk, extremities, perineum, and scrotum.

Middle-aged to older dogs are commonly affected by cutaneous histiocytosis, with no reported breed or sex predilection.

Systemic histiocytosis is a more severe form of reactive histiocytosis that involves the skin, ocular and nasal mucosa, and peripheral lymph nodes.

Symptoms of Histiocytic Sarcoma can be quite varied and depend on the organ(s) involved and the subtype of the disease. For localized histiocytic sarcoma, most owners notice palpable masses on or under the skin.

The clinical signs for disseminated histiocytic sarcoma can be nonspecific and harder to pinpoint. Symptoms may include decreased appetite, lethargy, weight loss, fever, lesions on the skin, coughing or difficulty breathing, limping, neurologic signs, swollen lymph nodes, bulging eyes, and a distended abdomen.

Dogs usually show a combination of symptoms because the disease is at an advanced stage and has already affected multiple sites in the body by diagnosis. This is why a definitive diagnosis can only be achieved by biopsy of affected tissues.

Common presenting clinical signs for histiocytic sarcoma include the presence of a mass, lethargy, and lameness. Your veterinarian will start with a full physical exam to identify these signs.

Here are some common symptoms associated with histiocytic sarcoma:

Treatment and management of histiocytic sarcoma in Bernese Mountain Dogs often requires a combination of therapies. Effective treatment can improve survival outcomes, even for dogs with metastatic disease.

Surgery is most useful for localized histiocytic sarcoma, where aggressive surgical resection can provide the best chance of cure. For dogs with disseminated histiocytic sarcoma, surgery provides only palliative relief and is seldom curative.

Chemotherapy may prolong survival time, although the prognosis is still poor. CCNU (lomustine) is considered the most effective chemotherapy for histiocytic sarcoma, with a 46% response rate.

A study showed that lomustine after surgery improved median survival times to 19 months for localized histiocytic sarcoma, and to 5.5 months for disseminated histiocytic sarcoma. Other chemotherapy protocols have been tried, but have not shown to be more beneficial.

Here are some chemotherapy protocols that have been studied:

Histiocytic sarcoma is a highly aggressive disease that requires a comprehensive treatment approach. Effective treatment often involves a combination of local and systemic therapy, even for localized forms.

Surgery is most useful for localized histiocytic sarcoma, and aggressive surgical resection is recommended for optimal outcomes. For dogs with disseminated histiocytic sarcoma, surgery provides only palliative relief and is seldom curative.

Chemotherapy may prolong survival time, but the prognosis is still poor. CCNU (lomustine) is currently considered the most effective chemotherapy for histiocytic sarcoma, with a 46% response rate.

Here are some key statistics about CCNU:

Immunotherapy has shown promise in treating disseminated histiocytic sarcoma, with initial studies demonstrating durable clinical remissions and prolonged survival in some dogs.

Integrative Therapies can be a helpful complement to traditional treatments for some people.

Physical therapy and rehabilitation, including hydrotherapy, treadmill, and passive range of motion exercises, may be beneficial if movement is compromised.

Acupuncture can help with comfort levels, although it hasn't been specifically studied for histiocytic sarcoma.

There's anecdotal support for using acupuncture, acupressure, and traditional Chinese medicine to target the tumor and alleviate symptoms of cancer treatment.