Histiocytic Sarcoma in Dogs: Understanding This Cancer

Histiocytic sarcoma (HS) is a serious cancer that affects dogs. It is more common in middle-aged to older dogs, but can happen at any age. Some dog breeds like Bernese Mountain dogs, Flat-Coated Retrievers, and Rottweilers have a higher risk of getting HS.¹ This cancer comes in several types, affecting different parts of the body. For example, one type affects bones, joints, and skin while another can spread to multiple organs quickly.²

Key Takeaways

• Histiocytic sarcoma is a severe cancer found most often in older dogs, but it can affect any dog.
• Some breeds, such as Bernese Mountain dogs, Flat-Coated Retrievers, and Rottweilers, are more likely to get this type of cancer.
• The cancer can appear in different ways, leading to various symptoms and outcomes.
• Diagnosis requires various tests like biopsies and imaging.
• There are treatments such as surgery, chemotherapy, and radiation, with survival depending on the cancer’s extent.

What is Histiocytic Sarcoma in Dogs?

Histiocytic sarcoma (HS) is a rare but aggressive cancer in dogs. It starts with too many histiocytes, a kind of immune cell. This cancer can quickly spread all over the body.²

An Aggressive Form of Cancer

HS happens in various places like the skin, bones, and other organs. It can show up as a single growth or many growths at once. There’s also a fast-moving type that starts in the spleen.²

Affecting Various Locations in the Body

Some HS stay in one spot, like the bones or skin. Others, scattered HS, hit many organs at the same time. The spleen is linked to a kind that moves quickly.²

Predisposed Breeds

HS affects some breeds more, like Bernese Mountain dogs and Rottweilers.² Yet, it can show up in any dog, these breeds are just more likely to get it.

Clinical Signs and Symptoms

Localized Histiocytic Sarcoma

Localized histiocytic sarcoma mainly impacts bones, joints, skin, and lungs. Signs might include limping, a swollen limb, coughing, or hard breathing. Your dog may also develop a new lump while being petted.¹²

Disseminated Histiocytic Sarcoma

Disseminated histiocytic sarcoma spreads to different organs. Dogs with this condition might seem tired, eat less, lose weight, vomit, or have diarrhea. These issues depend on which organs are affected.¹²

Hemophagocytic Histiocytic Sarcoma

This type is rare but very serious. It causes problems like severe anemia and low platelets. Symptoms include weakness, pale gums, bruises, and bleeding.¹²

Diagnosis and Staging

To find out if someone has histiocytic sarcoma, a biopsy or fine needle aspirate is done on the tumor. Doctors look at these samples under a microscope to spot HS cells’ unique features.³

Biopsy or Aspirate

Doctors also run tests like checking your blood, urine, and chemicals in your blood. This shows how the cancer affects your body. They use imaging tests, like x-rays and ultrasounds, to see if the cancer has spread.¹

Blood Tests and Imaging

If the lymph nodes near the tumor seem wrong, they check them too. This tells them if the cancer has spread. Knowing this helps choose the best treatment.¹

Lymph Node Evaluation

Treatment Options

When dealing with histiocytic sarcomas on the skin, bone, or joints, surgery is the main way to treat them. Doctors might recommend removing the cancer through surgery, which could mean taking out a small area or, in more severe cases, amputating the limb.¹

Surgical Resection

Chemotherapy is a key treatment if the cancer has spread or after surgery for localized cases. Medicines like lomustine (CCNU) and doxorubicin, or a mix of these, have the best outcomes.¹

Chemotherapy Protocols

For tumors that weren’t fully removed or not suitable for surgery, radiation might be helpful. It’s also used to ease symptoms in advanced cases. Early signs show radiation could be beneficial in these situations.¹

Radiation Therapy

histiocytic sarcoma dog

Histiocytic sarcoma is a severe cancer seen in many dog breeds, like Bernese Mountain dogs²¹, Flat-Coated Retrievers²¹, and Rottweilers²¹. Some dogs get a single tumor, while others can have it spread to many organs. There’s also a rare, fast-spreading type called hemophagocytic variant.²

In dogs, histiocytic neoplasms can be found in the skin or as tumors that may spread.³ They usually have a bad outcome. To know for sure it’s histiocytic, doctors need to use special tests called immunohistochemistry.³

Histiocytic sarcoma mostly hits older dogs, but younger ones can get it too. Sadly, the outcome isn’t good for most, with many living just 3-4 months if not treated. But, some dogs with the localized form can live longer, up to a few years, with aggressive treatment.¹

Prognosis and Survival Times

Dogs with localized histiocytic sarcoma that get both surgery and chemotherapy do better. They can live for about 1-1.5 years after treatment.¹ But for those with a more spread-out version, life expectancy is lower. They might only live a few months.¹

Localized Histiocytic Sarcoma

Most, around 70-91%, who have this type will see it spread far away.⁴ Yet, with the right treatment, some can beat the odds. They could live for as long as 1.5 to 3 years after treatment.¹ After the initial treatment, they usually have about 243 days before the disease returns. The time between the second time of relapse is about 201 days.⁴

Disseminated Histiocytic Sarcoma

Those with spread-out histiocytic sarcoma don’t have surgery as a good option.¹ Their chances are not as good, with most only living a few months more.¹

Hemophagocytic Histiocytic Sarcoma

The hemophagocytic form is very rare and very aggressive. The chance of survival is thin, less than two months.¹

Side Effects of Treatment

Getting treatment for histiocytic sarcoma in dogs can have risks. Surgery, the main treatment for the early stage, can be risky. It includes problems from surgery and recovering, and the chance of infection.

Chemotherapy, used for more advanced stages or after surgery, can bring on stomach problems. Dogs might eat less, feel tired, and have fewer white blood cells.¹

Radiation therapy, for tumors not fully removed or to relieve pain, might upset the stomach. It can also irritate the skin and slow down healing if used with other methods.

The oncology team will help pet owners handle these side effects. Their aim is to keep the dog happy and feeling well during treatment.

Genetic Factors and Breed Predispositions

Some dogs are more likely to have a certain kind of cancer called histiocytic sarcoma. This is due to their genes. Scientists know which genes these are for those breeds.

Bernese Mountain Dogs

Bernese Mountain dogs often get histiocytic sarcoma. Studies show they have unique genes that raise their risk.⁵ About a quarter of their cancer cases are this type. And, 80% of the spread of this disease is in them too.⁵ Sadly, they live only 49 days after finding out they have it.⁵

Flat-Coated Retrievers

Flat-Coated Retrievers are also prone to histiocytic sarcoma. It’s a big reason for their death.⁵ More than 40% of their cancer cases are this type. Their life expectancy after diagnosis is just four months.⁵

Rottweilers

Rottweilers also face an increased risk of histiocytic sarcoma. Scientists are still learning about the genetics behind this risk. They’ve found certain parts of the genes that might be why they’re more likely to get these cancers.⁶

Supportive Care and Management

Supportive care and management are key for dogs dealing with histiocytic sarcoma. This includes pain management, making sure they get the right nutrition, and keeping an eye out for side effects from treatments. The oncology team will join forces with the pet’s owner to craft a care plan just for that dog. This plan will aim to maintain a good quality of life, even while fighting the disease.

Keeping the dog from feeling too much pain is very important, especially with tumors near bones, joints, or other tender spots. Giving them nutritious food and adding supplements if necessary is crucial. This helps keep their body strong and fights off any health damage from treatments. The oncology team will watch closely for any bad reactions to chemo or radiation, making sure to address them fast. This way, they try to make the dog’s life as good as it can be.

The oncology team and the dog’s owner working in sync is a powerful duo. Their teamwork ensures the dog feels as good as possible, deals with treatments well, and enjoys the best quality of life despite the disease. Together, they help the dog through this tough fight.¹

Cost of Treatment

Treating histiocytic sarcoma in dogs can be expensive. The oncology team helps pet owners with a detailed treatment plan. They also give cost estimates specific to the patient’s needs.

Surgery to remove tumors can cost between $3,000 and $5,000. The actual cost might change depending on the tumor’s location.¹

Drugs like Lomustine and Doxorubicin for chemotherapy cost $400 and $350 each. Pets need several treatments which keep happening for several weeks.¹

Zoledronate, another chemo option, costs about $200 per treatment.¹

Definitive radiation for tumors not fully removed may cost $4,500 to $6,000. Palliative radiation is between $1,000 to $3,000.¹

These estimates don’t cover extra care, being at the hospital, or dealing with side effects. The oncology team ensures pet owners understand the costs. They also help make a treatment plan that’s good for the dog and the budget.⁷

Source Links

1. https://hospital.cvm.ncsu.edu/services/small-animals/cancer-oncology/oncology/canine-histiocytic-sarcoma/
2. https://www.vet.upenn.edu/docs/default-source/ryan/oncology-handouts/histiocytic_sarcoma_in_dogs_ek-ksdoc.pdf
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1978291/
4. https://pubmed.ncbi.nlm.nih.gov/19453368/
5. https://bmccancer.biomedcentral.com/articles/10.1186/1471-2407-11-201
6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10385400/
7. https://apositiveconnection.com/2015/12/18/the-big-c-weighing-the-costs-of-medical-treatment/