• Prevalence: The most common form (50-70% of cases).
• Affected Area: Stomach and intestines.
• Subtypes: Small cell (indolent, better prognosis) and large cell (aggressive).
• Typical Patient: Often affects older cats.

Mediastinal Lymphoma:

• Affected Area: Chest cavity and thymus.
• Key Association: Strongly linked to Feline Leukemia Virus (FeLV).
• Typical Patient: More common in younger cats.
• Primary Symptom: Can cause severe breathing difficulties.

Multicentric Lymphoma:

• Affected Area: Multiple lymph nodes throughout the body.
• Nature: A generalized, systemic disease.
• Progression: Tends to be rapid.
• Prognosis: Generally poorer.

Renal Lymphoma:

• Affected Area: Kidneys.
• Complication: Often leads to kidney failure.
• Nature: An aggressive form.
• Spread: Frequently metastasizes to the central nervous system (CNS).

Nasal Lymphoma:

• Affected Area: Localized to the nasal cavity and sinuses.
• Symptoms: Causes breathing issues, nasal discharge, and sneezing.
• Prognosis: Often better with localized treatment.
• Spread: Rarely metastasizes.

CNS (Central Nervous System) Lymphoma:

• Affected Area: Brain or spinal cord.
• Origin: Often secondary to other forms (e.g., renal).
• Symptoms: Neurological signs like seizures or paralysis.
• Prognosis: Typically poor.

Risk Factors

Feline Leukemia Virus (FeLV)

• Strong Association: FeLV-positive cats have up to 60 times greater risk.
• Linked Form: Most strongly associated with the mediastinal form.
• Prevention: Vaccination significantly reduces risk.
• Action: Testing for FeLV is essential in any cancer workup.

Feline Immunodeficiency Virus (FIV)

• Moderate Association: FIV-positive cats have a 5-6x increased risk.
• Linked Form: Most commonly associated with alimentary lymphoma.
• Mechanism: Chronic immune dysfunction may allow for cancer development.

Other Risk Factors

Recognizing the Symptoms

Alimentary (GI) Lymphoma Symptoms

Primary Digestive Signs:

• Progressive weight loss (most common sign)
• Frequent or chronic vomiting
• Persistent diarrhea
• Poor appetite or anorexia
• Lethargy and weakness
• A palpable mass in the abdomen

Mediastinal Lymphoma Symptoms

Primary Respiratory Signs:

• Difficulty breathing (dyspnea)
• Open-mouth breathing
• Coughing
• Changes in meow or voice
• Exercise intolerance
• Swelling in the neck or chest area

General Symptoms (All Types)

Systemic Signs:

• Unexplained weight loss
• Lethargy and decreased activity
• Reduced appetite
• Intermittent fever
• Enlarged, firm lymph nodes
• Pale gums (indicating anemia)

Location-Specific Symptoms

Diagnosis: A Step-by-Step Process

1. Veterinary Examination

Physical Assessment Includes:

• Palpation of all peripheral lymph nodes.
• Thorough abdominal examination.
• Auscultation (listening) of the chest.
• Body condition and muscle mass scoring.
• Careful weight assessment and history.

2. Diagnostic Testing

Essential Blood Work:

• Complete Blood Count (CBC): Checks for anemia and abnormal cells.
• Serum Chemistry Panel: Evaluates organ function (kidneys, liver).
• FeLV/FIV Testing: Crucial for prognosis and treatment planning.

Imaging Studies:

• X-rays (Radiographs): Of chest and abdomen to look for masses.
• Ultrasound: Provides detailed evaluation of abdominal organs, lymph nodes, and intestinal walls; often guides biopsy.
• CT Scan or MRI: For precise tumor mapping, especially for nasal or CNS lymphoma.

Definitive Diagnosis: Biopsy

• Fine Needle Aspirate (FNA): Minimally invasive; samples cells from lymph nodes or masses.
• Surgical Biopsy: Provides a larger tissue sample for histopathology, the gold standard.
• Endoscopic Biopsy: For GI lymphoma, obtained via scope.

Staging: Determining the stage (I-V) of the disease—how far it has spread—is critical for predicting prognosis and selecting the most appropriate treatment protocol.

Treatment Options in 2026

Chemotherapy: The Cornerstone of Treatment

Key Principles:

• It is the most effective treatment for achieving remission.
• Cats generally tolerate chemotherapy much better than humans, with fewer severe side effects.
• The primary goal is long-term remission and quality of life, not necessarily cure.
• Protocols are tailored to the type and stage of lymphoma.

Common Chemotherapy Protocols:

What to Expect:

• Treatments are typically outpatient.
• Visits occur every 1-3 weeks.
• Blood work is required before each treatment to ensure safety.
• Most cats experience minimal side effects like mild, transient nausea or lethargy.
• Significant hair loss is rare (whiskers are not lost).

Other Treatment Modalities

Surgery:

• Used for solitary, accessible tumors (e.g., some nasal or intestinal masses).
• Often performed to obtain a diagnostic biopsy.
• Can provide palliative relief from obstructions.

Radiation Therapy:

• Highly effective for localized forms like nasal lymphoma.
• Used as a primary treatment or after chemotherapy.
• Valuable for palliative pain relief in bone involvement.

Steroid-Only Treatment (Prednisone):

• An inexpensive option that can induce temporary improvement.
• Median survival is typically 2-4 months.
• Often used as part of palliative care or combined with other chemotherapies.

Supportive & Complementary Care

Essential Support:

• Appetite Stimulants: Mirtazapine or capromorelin.
• Anti-nausea Medications: Maropitant (Cerenia®).
• Pain Management: As needed.
• Nutritional Support: High-calorie, easily digestible diets; feeding tubes if necessary.
• Probiotics: To support GI health.

Holistic Adjuncts (Discuss with Your Vet):

• Veterinary acupuncture for pain and nausea.
• Omega-3 fatty acids (fish oil) for anti-inflammatory effects.
• Antioxidant supplements.

Understanding the Costs (2026 Estimates)

Diagnostic Costs

Treatment Costs

Chemotherapy (First Year):

Additional Ongoing Costs:

• Recheck exams and blood work: $150 - $300 per visit.
• Supportive medications: $50 - $150 per month.
• Follow-up imaging: $500 - $1,000.

Palliative Care (Monthly Estimate):

• Prednisone and basic supportive care: $50 - $200/month.

Prognosis and Survival Rates

Factors Influencing Prognosis

Positive Prognostic Indicators:

• Small cell (indolent) lymphoma, especially alimentary.
• Early disease stage (I or II).
• Rapid, complete response to initial chemotherapy.
• FeLV/FIV negative status.
• Good overall health and appetite at diagnosis.

Negative Prognostic Indicators:

• Large cell (aggressive) lymphoma.
• Advanced disease stage (IV or V).
• FeLV-positive status.
• Poor response to initial treatment.
• Presence of CNS involvement.

Survival Statistics (With Chemotherapy)

Without Chemotherapy (Prednisone Only): Median survival is typically 1-3 months, with variable quality of life.

Prioritizing Quality of Life

Monitoring Your Cat During Treatment

Signs of a "Good Day":

• Eating and drinking normally.
• Engaging in play or showing interest in surroundings.
• Appearing comfortable and resting peacefully.
• Maintaining normal grooming habits.
• Seeking out affection and interaction.

Red Flags ("Poor Days"):

• Refusing food for more than 48 hours.
• Hiding persistently and avoiding contact.
• Showing obvious signs of pain (vocalizing, tense posture).
• Difficulty breathing.
• Profound lethargy or weakness.

Making the Difficult Decision

Quality of Life Scales: Tools like the "HHHHHMM" Scale (Hurt, Hunger, Hydration, Hygiene, Happiness, Mobility, More good days than bad) can provide objective guidance.

When to Consider Euthanasia:

• When medical management can no longer control pain or discomfort.
• When there are consistently more bad days than good days.
• When your cat has lost interest in all things they once loved.
• This should be an ongoing, compassionate discussion with your veterinarian.

Making Informed Decisions: Questions for Your Vet

1. What specific type and stage of lymphoma does my cat have?
2. What are all the treatment options, including pros, cons, and costs?
3. What is the realistic prognosis with the recommended treatment? What is it without treatment?
4. What are the potential side effects of treatment, and how are they managed?
5. How will we measure success (e.g., remission, quality of life)?
6. What is the long-term monitoring plan?
7. What palliative care options are available if we choose not to pursue aggressive treatment?

Conclusion

A lymphoma diagnosis is daunting, but it is not a hopeless situation. Modern veterinary medicine offers effective treatments that can provide many cats with extended periods of good-quality life. The path forward depends on early detection, an accurate diagnosis, and a treatment plan tailored to your cat's specific condition, your family's circumstances, and—above all—your cat's well-being.

Collaborate closely with your veterinarian or a board-certified veterinary oncologist. Remember, the ultimate goal is not just to extend life, but to ensure the life your cat lives is comfortable, happy, and full of love. Whether you choose aggressive chemotherapy or compassionate palliative care, let your cat's quality of life be your guiding principle.

Last Updated: March 2026
Early detection through regular veterinary care offers the best chance for a positive outcome. If you notice any persistent changes in your cat's health or behavior, schedule a veterinary consultation promptly.