Enlarged Lymph Nodes in a Dog: Holly’s Story
Lymph nodes are part of the lymphatic system. So, by definition, they already are little nodules. Normally, however, you wouldn’t be able to feel them—only when they swell up.
The job of lymph nodes is to work with the immune system. They form and store immune cells and filter harmful substances.
The potential causes of lymph node enlargement include:
- infections
- inflammation
- auto-immune reactions
- cancer
Dental issues are one of the common causes of swollen lymph nodes.

Holly’s Story
Holly is a senior Maltipoo. In the past years, she had a few urinary tract infections, but overall she’s been in good health.
A couple of months back, when her mom found enlarged lymph nodes on Holly’s neck, she saw a veterinarian. Because Holly also ran a mild fever, the veterinarian suspected an infection and put Holly on antibiotics.
The routine blood work they ran didn’t show anything suspicious.
First signs of trouble
A few days into the treatment, Holly lost interest in her food. She was also panting and looking uncomfortable. The antibiotics Holly was getting were suspect, so the veterinarian changed her medication.
That, however, didn’t seem to make Holly feel any better. She was still panting and fussing about food. Her fever improved, but nothing else did.
Two days later, Holly’s fever returned, along with an increased heart and respiratory rate. Something was still wrong, and the antibiotics weren’t fixing it.
Holly’s decline
Holly kept growing weak. Was it from her not eating, the fever, or whatever was causing both? At this point, Holly was still drinking normally but refused to eat altogether and had her mom force-feeding her.
Nothing her mom tried was making Holly any better.
Could it be the teeth?
Like many senior small-breed dogs, Holly’s teeth were in bad shape. Is it possible that dental disease was indeed behind Holly feeling so poorly and running a fever?
With the antibiotic treatment, Holly’s lymph node swelling did go down. But Holly was not well. It was time to aspirate the nodes and look at what was inside them.
Holly’s lymph node cytology
The veterinarian retrieved samples of the cells in Holly’s lymph nodes and sent them to a lab. And then the bad news arrived—Holly had lymphoma. Time is of the essence to get an appointment with a veterinary oncologist. There are treatment options for canine lymphoma.
Lymphoma is a cancer of white blood cells. What happens is that the blood cells multiply out of control.
Two basic types are classified based on which cells are affected — B cells or T cells. B-cell lymphoma is the most common type in dogs. Treatment can extend life expectancy substantially.
Besides lymph node enlargement, common symptoms of lymphoma include:
- loss of appetite
- weakness
- lethargy
- weight loss
As you can see, all are ambiguous and can be signs of any significant illness. That’s why it is always important to investigate and get to the bottom of these symptoms.
To learn more about canine lymphoma, check out Dr. Sue Cancer Vet’s YouTube Lymphoma in Dogs playlist.
Related articles:
Facial Swelling in Dogs: Why Is My Dog’s Face Swollen?
Further reading:
Lymph Node Inflammation (Lymphadenopathy) in Dogs