🧬 Vet Guide to Infiltrative Bowel Disease in Cats (2025) 🐱🔬

Chronic vomiting, diarrhea, or unexplained weight loss in cats can sometimes be traced back to something far more serious than hairballs or diet. Infiltrative bowel disease occurs when abnormal cells infiltrate the intestinal layers, disrupting absorption, motility, and immune balance. In this 2025 guide, Dr. Duncan Houston BVSc explains how to identify and manage these conditions—including inflammatory bowel disease (IBD) and intestinal lymphoma—in cats. 🩺🐾

🔍 What Is Infiltrative Bowel Disease?

The small intestine is responsible for digesting food, absorbing nutrients, and housing healthy bacteria. In infiltrative diseases, abnormal cells (often lymphocytes) invade the bowel layers, causing the tissue to thicken. This disrupts digestion, absorption, and immune defense. 🧪

When the intestinal wall thickens:

• 🚫 Food can't move efficiently—causing bloating, nausea, and discomfort
• 📉 Nutrients can't be absorbed properly—leading to weight loss and diarrhea
• 🩸 Ulcers and bleeding may occur

🔄 IBD vs. Intestinal Lymphoma

These two common infiltrative diseases look similar on the surface, but their causes and treatments differ:

1. 🧬 Inflammatory Bowel Disease (IBD)

• 🔬 Immune system overreaction to food or bacteria
• 📈 Causes inflammation, not cancer
• ✅ Treated with steroids, diet, and immune-suppressing meds

2. 🧫 Intestinal Lymphoma

• ⚠️ Cancerous infiltration of the bowel
• 🔍 Requires biopsy for diagnosis
• 💊 Small cell type responds well to treatment; large cell has a poor prognosis

🦠 Dysbiosis: Bad Bacteria Take Over

When the bowel lining is damaged, the balance of bacteria in the gut shifts. This can lead to:

• ☣️ Toxic bacterial byproducts
• 🚪 Bacteria invading normally sterile areas like the pancreas or liver

🩺 Diagnosis: How to Get Answers

The diagnostic path usually starts with bloodwork and moves to imaging and tissue sampling:

1. 🖥️ Abdominal Ultrasound

• 📏 Measures wall thickness and layering
• 🔬 May detect masses or enlarged lymph nodes
• 🧪 Can be used to guide needle aspirations

2. 📦 Biopsy: The Gold Standard

To distinguish IBD from lymphoma, tissue samples are needed. There are two main approaches:

• 🔬 Endoscopy: Minimally invasive; samples only inner bowel lining
• 🔪 Surgical biopsy: Invasive but provides full-thickness samples

PCR testing and Immunohistochemistry can confirm lymphoma if genetic markers show clonal (cancerous) lymphocytes. 🧬

💊 Treatment Options

For IBD (Immune-Mediated Inflammation)

• 💊 Prednisolone or budesonide (steroids)
• 🔄 Cyclosporine or chlorambucil (immune suppressants)
• 🍽️ Hydrolyzed protein or novel protein diet
• 🦠 Probiotics to balance gut bacteria

For Small Cell Lymphoma

• 💊 Prednisolone plus chlorambucil
• ⏱️ Remission often achieved within 3 weeks
• 📆 May require ongoing low-dose meds

For Large Cell Lymphoma

• 💉 Requires aggressive chemotherapy
• ⚠️ Prognosis is guarded; remissions are short

📋 Treating Without a Definitive Diagnosis

If biopsy isn’t feasible, a reasonable compromise treatment may include:

• 💊 Corticosteroids (prednisolone)
• 🍽️ Hypoallergenic diet
• 🧪 Probiotics or GI support supplements

Fortunately, treatments for IBD and small cell lymphoma often overlap. This approach can offer relief and remission even without a confirmed diagnosis. 🎯

📈 Monitoring Progress

• 📉 Improvement from IBD usually seen in 7–14 days
• 🧬 75% of lymphoma cases show remission in 21 days
• 📆 Ongoing medication and monitoring may be required

📲 Ask A Vet for Guidance

If your cat has chronic diarrhea, vomiting, or weight loss, don’t wait. Use the Ask A Vet app to connect with Dr. Duncan Houston or another licensed vet for help with diagnostics, diet plans, and advanced GI care. 📱

Visit AskAVet.com to start a conversation about feline bowel health today. 🐱

💬 Final Thoughts

Infiltrative bowel disease can be challenging to diagnose and treat, but with a proper plan and early intervention, most cats enjoy a vastly improved quality of life. Whether it's IBD, lymphoma, or something in between—Dr. Duncan Houston and Ask A Vet are here to help every step of the way. 🐾🧬