What Do Enlarged Lymph Nodes Mean for Your Dog or Cat?

Discovering a swollen lymph node on your pet during a cuddle or grooming session can be surprising and worrying. At Memorial Villages Animal Hospital, we understand that moment and use thorough exams and individualized diagnostics to find answers. Enlarged lymph nodes can reflect anything from a minor infection to a more serious condition, and early evaluation helps us see what your pet’s body is responding to. Our team uses advanced imaging and in-house testing within our comprehensive services to guide you with clear, calm support.

Because some changes need timely attention, we offer emergency and urgent care during regular hours so pets can be evaluated quickly. If you’ve noticed a new lump or your pet just seems off, contact us so we can take a closer look and provide the thoughtful, gold-standard care your pet deserves.

When You Notice a Lump: What Enlarged Lymph Nodes Tell Us

Feeling an unexpected bump under your dog’s neck or behind your cat’s leg raises instant questions: What is it? Was it always there? Should I worry?

Enlarged lymph nodes are a sign that your pet’s immune system is responding to something, not a diagnosis on their own. They can point to infection, inflammation, or, less commonly, cancer. Getting your pet checked early helps us identify the cause and make a clear plan.

Here you’ll learn what lymph nodes do, common reasons they swell, how we check them, and what treatment might look like. Most importantly, our team is here to answer your questions and guide next steps.

What Lymph Nodes Do and Where to Feel Them

Lymph nodes are small, bean-shaped filters that help fight infection and keep fluids in balance. When they detect a problem, they can swell as they ramp up immune cells. Lymph nodes are located in key areas, and knowing where they are can help you notice changes sooner. You can sometimes feel them at home, especially in dogs:

  • Mandibular: under the jaw on both sides
  • Prescapular: in front of the shoulder blades
  • Axillary: in the armpits
  • Inguinal: in the groin
  • Popliteal: behind the knees

Cats have the same spots for lymph nodes, but are smaller and harder to feel. This is one reason our wellness exams include careful palpation and, when needed, digital imaging.

Why Do Lymph Nodes Become Enlarged?

The medical term for enlarged nodes is lymphadenopathy. Think of it as an alarm that points to an underlying cause. The pattern of swelling, your pet’s age and breed, and any other symptoms help us narrow it down.

Common categories include:

  • Infections and inflammation
  • Immune reactions
  • Cancer

Infections and Inflammation

Many swollen nodes are linked to treatable infections. Examples include:

  • Dental disease or abscesses that swell nodes under the jaw
  • Skin or ear infections affecting nearby nodes
  • Upper respiratory infections
  • Tick-borne illnesses like Lyme disease
  • Contagious diseases like leptospirosis
  • Environmental fungal disease

These often improve with targeted treatment once we confirm the cause.

Cancer as a Possible Cause

Lymphoma is the most common cancer that affects lymph nodes in dogs and cats. In dogs, canine lymphoma often shows up as painless, firm swelling in multiple nodes, especially under the jaw, in front of the shoulders, behind the knees, and in the groin. While serious, there are treatment options that focus on comfort and time together.

In cats, feline lymphoma often affects the intestines, and symptoms can include weight loss, vomiting, and decreased appetite along with enlarged nodes. Other types of cancer in pets can also spread to nearby lymph nodes.

Other Less Common Reasons

Some pets develop temporary node swelling after vaccines or as part of an allergic or immune response. Rarely, issues with lymph flow, such as lymphedema, can cause swelling. When needed, our digital imaging and lab testing help rule these in or out.

How We Find the Cause: Simple, Stepwise Diagnostics

We start with a thorough physical exam and history, then choose tests based on what we see. Our goal is to keep things as simple and efficient as possible while still getting clear answers.

What We Learn from the Exam

During an exam, we gently feel all accessible nodes, note their size and texture, and check if they’re tender. We also look for clues like fever, dental disease, skin or ear infections, weight loss, cough, or abdominal changes. This helps us decide the next best step.

Getting Cellular Answers

A fine-needle aspiration (FNA) is often the first test. It uses a small needle to collect cells from a lymph node for review under a microscope. It’s quick, often doesn’t need sedation, and gives fast, helpful information. Our complete on-site laboratory allows us to perform cytology analysis immediately, so we can provide answers during your visit.

FNA can point to:

  • Reactive changes from infection or inflammation
  • Lymphoma or other cancers
  • Sometimes bacteria or yeast

If FNA isn’t clear or we need more detail, a biopsy may be recommended. Cytology vs biopsy represents different levels of detail: FNA is less invasive and quick, while biopsy gives a more complete picture when needed.

When We Need More Information

Depending on results, we may suggest:

  • Bloodwork and urinalysis to check overall health using our complete on-site laboratory
  • Chest and abdominal radiographs or ultrasound with our digital imaging capabilities
  • Additional testing in suspected lymphoma cases to guide treatment choices

We work with a board-certified radiologist twice weekly to ensure accurate interpretations, and we tailor the plan to your pet and your goals. For cases requiring ultrasound evaluation, our board-certified radiologist performs ultrasounds every two weeks and can perform ultrasound-guided fine needle aspirates when needed for deeper or harder-to-reach lymph nodes.

Treatment: What Happens Next

Treatment depends on the cause. Our focus is relief, recovery, and quality of life.

Managing Infections and Inflammation

Many pets improve quickly with targeted care:

  • Antibiotics for bacterial infections
  • Antifungals for fungal disease
  • Specific antibiotics for tick-borne illnesses
  • Dental care for tooth and gum infections
  • Wound care for skin infections

Most lymph nodes shrink as the underlying issue clears. We’ll schedule rechecks to confirm progress and adjust as needed.

Addressing Lymphoma and Other Cancers

For lymphoma, the goal is remission, which means reducing cancer cells to undetectable levels and restoring comfort. While lymphoma is rarely cured, many pets enjoy excellent quality of life during remission.

  • Multi-agent chemotherapy protocols often offer the best chance for longer remission
  • Single-drug options or palliative medications may be chosen for a gentler approach
  • For cats, protocols are adjusted to their needs, and outcomes vary by type and location

For cancers that have spread to lymph nodes, treatment targets the primary tumor with surgery, radiation, chemotherapy, or a combination. Throughout, we center decisions on your pet’s comfort and your family’s preferences.

Home Checks and Follow-Up: What to Watch

Whether your pet has an infection or a more complex condition, regular monitoring matters. We’ll guide you on simple at-home checks and when to reach out.

Try this quick lymph node check:

  1. Choose a calm time when your pet is relaxed.
  2. Feel under the jaw on both sides for the mandibular nodes.
  3. Check in front of the shoulders for prescapular nodes.
  4. Feel behind the knees for popliteal nodes.
  5. Compare both sides and note any changes in size or firmness.

Call us if you notice nodes getting larger, new lumps, or changes in appetite, energy, breathing, or comfort. We’ll help you decide the next step.

FAQs: Quick Answers for Pet Owners

Are swollen lymph nodes always cancer?

No. Infections and inflammation are common causes. That’s why a timely exam and simple tests like FNA are so helpful.

How urgent is it to see a vet?

If a node is new, growing, or your pet seems unwell, schedule soon. We offer emergency and urgent care during regular hours for prompt evaluation.

Will my pet need surgery?

Often, no. Many cases are diagnosed with FNA. If results are unclear or cancer is suspected, a surgical biopsy might be recommended.

Can lymph nodes go back to normal?

Yes. When the underlying cause is treated, nodes often return to normal size over days to weeks.

What if I’m not sure what I’m feeling?

That’s okay. Bring your pet in for an exam, and we’ll check together.

Moving Forward with Expert Support and Clear Answers

Finding a swollen lymph node can raise concerns, but quick evaluation provides clarity and a plan. Many causes are treatable, and even serious conditions like lymphoma can be managed with compassionate, individualized care.

At Memorial Villages Animal Hospital, we take a thorough approach, using advanced diagnostics to reach answers and treatment plans that fit your pet and your family. Whether your pet needs antibiotics or comprehensive cancer care, we’re here with steady guidance at every step.

If you’ve noticed changes in your pet’s lymph nodes or found a new lump, book online or call us at (346) 263-0917. Contact us today so we can help, guide, and be a partner in your pet’s care, easing your worries with clear next steps and gold-standard support.