Understanding the Link Between Cancer and Low Albumin in Dogs
Albumin is a vital protein produced by the liver that plays several roles in maintaining a dog's health. It regulates
fluid balance within blood vessels, transports crucial molecules (like hormones and medications), and acts as an
antioxidant against oxidative stress. When albumin levels fall below normal, the condition is known as
hypoalbuminemia, which can signal severe underlying health issues, including certain forms of cancer.
What Is Hypoalbuminemia?
Hypoalbuminemia refers to abnormally low levels of albumin in the bloodstream. In dogs, this typically means values under 2.5 g/dL, with values below 2.0 g/dL considered severe. While hypoalbuminemia is not a disease in itself, it is a critical clinical sign that needs thorough diagnostic investigation.
How Cancers Cause Low Albumin
Certain cancers disrupt the body’s ability to maintain adequate albumin levels through various mechanisms, including inflammation, nutritional compromise, and direct loss through bodily systems such as the gastrointestinal tract. The most notable cancer types that may cause hypoalbuminemia include:
- Lymphoma: Especially those affecting the gastrointestinal tract (GI lymphoma or alimentary lymphoma), where protein-losing enteropathy (PLE) leads to the loss of albumin through intestinal damage.
- Neoplasia-associated inflammation: Cancers provoke an immune response, leading to inflammation that reduces albumin synthesis during the acute phase reaction.
- Metastatic liver cancers: These can impair liver function, reducing albumin production directly.
Protein-Losing Enteropathy and Cancer
Protein-losing enteropathy (PLE) is a common mechanism by which cancers such as GI lymphoma cause hypoalbuminemia. PLE leads to the loss of proteins through the damaged intestinal lining. Common PLE-associated cancers include:
- Intestinal lymphangiectasia
- Inflammatory bowel disease (sometimes linked to lymphoma)
- Alimentary lymphoma
In these cases, the damaged intestinal barrier cannot retain albumin, allowing it to leak into the gastrointestinal tract and be excreted.
Other Contributing Conditions
While cancer is a significant cause, other illnesses can also contribute to low albumin levels. These include:
- Liver failure: Where albumin synthesis is reduced.
- Protein-losing nephropathy: Kidney diseases that allow albumin to pass into the urine.
- Severe infections or inflammations: Can suppress albumin production during systemic responses.
- Malnutrition or starvation: Leads to inadequate building blocks for albumin synthesis.
Clinical Signs of Hypoalbuminemia
Signs may include:
- Edema (swelling)
- Ascites (fluid in the abdomen)
- Pleural effusion (fluid in the lungs)
- Weakness and lethargy
- Gastrointestinal signs like vomiting or diarrhea
Diagnosis
A veterinarian begins diagnostics with a physical exam and blood chemistry panel to assess serum albumin levels. Once hypoalbuminemia is confirmed, further diagnostics are pursued to determine the root cause:
- Urinalysis and UPC ratio: To assess kidney protein loss.
- Abdominal ultrasound or imaging: Helpful in visualizing intestinal lesions, tumors, or liver changes.
- Intestinal biopsies: Often needed to diagnose PLE and identify cancers like lymphoma.
- Complete blood count (CBC): To check for systemic inflammation or signs of neoplasia.
Treatment and Management
Treatment targets the underlying cause. Cancer-related hypoalbuminemia may require:
- Chemotherapy: For lymphomas and other treatable cancers.
- Immune-suppressants: For associated inflammatory conditions.
- Nutritional support: Including ultra-low-fat or highly digestible diets.
- Supportive therapies: Including IV fluids, plasma infusions, or colloid solutions for acute stabilization.
Prognosis
The prognosis depends on the underlying cancer and how early intervention occurs. For cancers like alimentary lymphoma, earlier diagnosis followed by targeted chemotherapy can result in better outcomes. For untreatable cancers or those presenting with multiple systemic failures, the outlook is more guarded.
Monitoring and Long-Term Care
Ongoing care involves:
- Regular blood tests to monitor albumin and overall health
- Dietary adjustments tailored to the dog’s condition
- Monitoring for swelling, ascites, and appetite changes
- Strict medication adherence and follow-up consultations
Conclusion
Cancer-related hypoalbuminemia is a serious condition that requires a thorough diagnostic and therapeutic approach. While challenging, early intervention and targeted treatment offer hope. Dogs diagnosed with lymphoma or gastrointestinal cancers must be closely monitored and supported with consistent veterinary care to improve their quality of life.
