What is Canine Hemangiosarcoma?

Hemangiosarcoma (HSA) is an aggressive, malignant cancer that arises from the cells lining blood vessels (endothelial cells). Because it originates in vascular tissue, it tends to:

• Form blood-filled tumors

• Spread (metastasize) early and widely

Common primary sites include:

• Spleen (most common)

• Right atrium of the heart

• Liver

• Skin/subcutaneous tissues

Signs and Symptoms

Clinical signs are often subtle until a tumor ruptures and causes internal bleeding.

Early / vague signs

• Lethargy

• Decreased appetite

• Mild weight loss

• Intermittent weakness

Acute / advanced signs (often due to internal bleeding)

• Sudden collapse or fainting

• Pale gums (from anemia)

• Rapid heart rate

• Distended abdomen (especially with splenic tumors)

• Difficulty breathing (if heart involved)

A hallmark feature is episodic collapse followed by temporary recovery, caused by bleeding that temporarily stops.

Diagnosis

Diagnosis typically involves a combination of imaging and laboratory tests:

Initial tests

• Physical exam (may reveal abdominal mass or fluid)

• Bloodwork (often shows anemia)

Imaging

• Ultrasound: identifies masses (especially in spleen/liver)

• X-rays: evaluate metastasis (lungs)

• Echocardiogram: if heart involvement is suspected

Definitive diagnosis

• Histopathology (biopsy or after tumor removal) is required for confirmation

• Fine needle aspirates are often inconclusive due to blood contamination

Treatment

Treatment depends on tumor location and stage, but usually involves:

1. Surgery

• Splenectomy (removal of spleen) for splenic tumors

• Emergency surgery may be required if rupture occurs

2. Chemotherapy

• Commonly uses drugs like doxorubicin

• Aims to slow metastasis and extend survival

3. Supportive care

• Blood transfusions (if severe anemia)

• Pain management

• Management of complications (e.g., arrhythmias for cardiac tumors)

Prognosis

Unfortunately, hemangiosarcoma carries a poor prognosis.

• Without treatment:Survival is often days to weeks after diagnosis

• Surgery alone:Median survival ~1–3 months

• Surgery + chemotherapy:Median survival ~4–6 monthsSome dogs may reach 9–12 months, but this is uncommon

Metastasis is usually present at diagnosis, even if not detectable.

Occurrence in Bouviers (Bouvier des Flandres)

The Bouvier des Flandres is not among the highest-risk breeds, but there are some considerations:

What is known

• Bouviers are considered:

  • Moderate or uncertain risk

• Large and giant breeds (like Bouviers) tend to have a higher baseline risk than small breeds

• Cases have been reported in Bouviers, but:

  • There’s no strong breed-specific genetic link established

  • Data is limited compared to more common breeds

Practical takeaway

Owners of Bouviers should:

• Be alert for sudden collapse or weakness, especially in middle-aged to older dogs

• Consider periodic veterinary screening (e.g., abdominal ultrasound in senior dogs), though this is not universally recommended

Summary

Hemangiosarcoma is a fast-moving, often silent cancer that becomes apparent only when it causes life-threatening bleeding. While treatment can extend life modestly, early detection remains challenging. In Bouviers, risk exists but is not as clearly elevated as in some other large breeds,

HSA Articles/Helpful Links: 

https://www.akcchf.org/research-progress/canine-hemangiosarcoma/ 

What is Canine Lymphoma?

Canine lymphoma is a cancer of the lymphatic system, which includes lymph nodes, spleen, liver, bone marrow, and lymphocytes (a type of white blood cell).

It’s somewhat similar to non-Hodgkin lymphoma in humans and is one of the most common cancers in dogs.

Signs & Symptoms 

Symptoms depend on the form, but the most common type is multicentric lymphoma (affecting lymph nodes).

Most common signs:

• Enlarged lymph nodes (under jaw, in front of shoulders, behind knees)

• Lethargy

• Decreased appetite

• Weight loss

Other possible signs:

• Fever

• Increased thirst/urination

• Vomiting or diarrhea

• Difficulty breathing (if chest lymph nodes affected)

• Skin lesions (in cutaneous lymphoma)

Many dogs initially seem “normal” aside from painless swollen lymph nodes, which is a key early clue.

Diagnosis

Veterinarians usually diagnose lymphoma with minimally invasive tests:

Primary tests:

• Fine Needle Aspirate (FNA) of a lymph node→ quick, often done without sedation

• Cytology (examining cells under a microscope)

Additional diagnostics:

• Biopsy (for confirmation or subtype)

• Bloodwork (CBC, chemistry)

• Imaging (X-rays, ultrasound)

• Flow cytometry or PCR (to determine B-cell vs T-cell type)

Staging (How it’s “rated”)

Lymphoma is staged based on how far it has spread:

Stages I–V:

1. Single lymph node

2. Multiple lymph nodes (same region)

3. Generalized lymph node involvement (most common at diagnosis)

4. Liver and/or spleen involvement

5. Bone marrow or other organs (advanced)

Substage:

• A = no clinical signs

• B = systemic illness (fever, weight loss, etc.)

 Example: Stage IIIA (common and often still treatable)

Prognosis 

• Untreated: ~4–6 weeks survival

• With chemotherapy:

  • Remission rates: 80–90% (especially B-cell)

  • Median survival: ~10–14 months

  • Some dogs live 2+ years

How Common is it?

• Lymphoma accounts for about 7–24% of all canine cancers

• Occurs in roughly 1 in 15–20 dogs over their lifetime

Lymphoma in Bouvier des Flandres

The Bouvier des Flandres is considered a higher-risk breed.

What we know:

• Bouviers are genetically predisposed to lymphoma

• Risk is significantly higher than average, though exact percentages vary

• Typically diagnosed in middle-aged to older dogs (6–9 years)

Relative risk:

• Studies suggest Bouviers may have 2–5× higher risk compared to mixed breeds

• Lymphoma is one of the more common cancers seen in this breed

Key Takeaways

• Lymphoma is common, often treatable (but not usually curable)

• Early detection (especially enlarged lymph nodes) matters

• Bouviers have a notable genetic predisposition, so vigilance is important
  

Articles/Helpful Links:

https://www.akcchf.org/research/research-portfolio/program-area/lymphoma-research/

https://www.akcchf.org/grant-directory/03194-2/ 03194: A Blueprint to Develop Next-Generation CAR T Therapy for Canine Lymphoma