For years I've written about two things that, on the surface, look completely unrelated.
One is fatty lumps — lipomas — the soft, seemingly harmless-looking bumps that show up on so many dogs as they get older and why I don't rush to surgically remove them.
The other is something bigger and more serious: the connection I've watched for two decades between collar pressure on the neck and cancer.
I never planned to put these two topics side by side. But the more I sat with both, the more I realized they're not two stories. They're the same story, told at two different volumes.
Every Lump is a Message. Most People Just Hear Noise
When a dog develops a fatty lump, the instinct is to think of it as random. Bad luck. Something to remove and forget about.
But after thousands of dogs and thousands of lumps, I stopped believing in random.
I noticed something simple: lipomas don't scatter across the body evenly. They cluster. And more often than not, they cluster near a vertebra that is out of alignment and surrounding muscle that's tight, injured, inflamed.
I think of an injured part of the spine like a black hole of the body. It sucks up the body's energy and reduces blood circulation. Nerve signals get congested. Local cells and tissue are weakened.
And over time, that congestion shows up as a lump.
If you remove the lump but leave the congestion, you haven't solved anything. You've just turned off the warning light. And in my experience, that's exactly when dogs come back with two lumps where there used to be one because the body is trying even harder to get your attention.
That's why my approach has never been "cut first, ask questions later." It's: find out what the lump actually is with a simple fine needle aspirate, and then go looking for why it's there — usually starting with the spine.
Why I Kept Looking at Collars
Around the same time I was mapping lumps to vertebrae, I noticed a second pattern that disturbed me a lot more.
Dogs with tumors, not fatty lipomas, but real aggressive cancer, kept sharing the story, just more severe.
A neck injury. A pulling problem. Years on a collar, especially the strong pullers: Labs, Goldens, Shepherds, Rottweilers, the dogs that lean hard into every walk.
I started noticing toe tumors that lined up almost perfectly with nerve pathways running from the collar area, down the front leg, to the foot. Head, neck, and internal cancers that traced back to old cervical injuries. It wasn't one or two cases. It was a pattern I saw for twenty years.
I talked about this publicly more than once but there was no scientific proof of what I witnessed until 2025!
In 2025 and 2026, three separate pieces of research landed that made my twenty years of pattern-watching suddenly look a lot less like speculation:
- One study by Giampietri et al., published in the International Journal of Molecular Sciences, confirmed that tumors actively recruit nerve fibers, and that the most aggressive tumors have the heaviest nerve infiltration.
- Another study Fu et al., in MedComm, laid out how peripheral nerves actively regulate tumor growth, not just sit near it passively.
- Research at MD Anderson Cancer Center, published in Nature, showed that cancer-induced nerve injury actually helps tumors resist immune therapy.
Put plainly: the nervous system isn't a bystander in cancer. It's an active participant!
Here's the mechanism I believe connects a tight collar to that terrain.
Repeated pulling compresses the cervical vertebrae. Compressed vertebrae irritate nerve roots. Irritated nerves release inflammatory signals creating low-grade systemic inflammation. That inflammation, combined with reduced blood flow to the surrounding tissue, weakens local immune surveillance. Immune cells that should be patrolling and clearing abnormal cells simply don't reach the tissue the way they should.
Inflammation. Disrupted nerve signalling. Weakened local immunity. That combination is exactly what modern cancer research identifies as fertile ground for a tumor to take hold.
Interestingly, this correlates almost perfectly to something Traditional Chinese Medicine described thousands of years ago: Qi and Blood stagnation in the body.
Different language, same observation.
Connecting the Two Carefully
I want to be precise here, because this matters: a fatty lipoma is not cancer, and I am not telling you that one turns into the other. That is rare.
What I am telling you is that both conditions can grow out of the same soil. A lipoma is often the body's early, benign way of signalling that a section of the spine and its nerve supply are under chronic stress.
A tumor, in a small number of cases with a much longer runway of nerve compression and inflammation, may be what happens when that same terrain is left undisturbed for years.
One is a whisper. The other is a shout. But they can start in the same place - low-grade chronic inflammation, undetected injuries.
That's why I no longer look at a new lump on a dog and think only, "what is it?" I also think, "what is it near, and what spinal segment needs attention?"
What I'd Actually do About it
If your dog has a lump, or pulls hard on leash, or has a history of neck and back pain and inflammation, here's the order I'd work through it in:
1. Get any new lump properly assessed. A fine needle aspirate is quick, low-stress, and tells you whether you're dealing with a benign fatty lipoma or something that needs closer attention — without the risk of surgically disturbing something that shouldn't be disturbed.
2. Switch to a well-fitted front-clip harness. This is the single most actionable change in this whole story. A good harness removes compressive pressure from the neck entirely. I recommend the Perfect Fit Harness specifically because of how it distributes pressure across the chest instead of the throat. Based on the new research, a good harness is truly a cancer-prevention device.
As a result, I always use a harness for Pax, and never attach the leash to the collar.
3. Get your dog's spine properly assessed. A veterinary chiropractor, physical therapist, or osteopath can find cervical misalignment that won't correct itself. In my experience, combining chiropractic care or IMS with physiotherapy gets better and longer-lasting results than any one approach alone. For dogs prone to lumps, monthly maintenance sessions matter more than people expect.
4. Support the nervous system and immune system nutritionally. A fresh, species-appropriate diet is the foundation.
I lean on GreenMin for whole-food mineral support of immune function, FeelGood Omega for its anti-inflammatory effect on nervous tissue, and MitoBoost to support cellular energy in tissue that's been under chronic stress. JointPowder and a good probiotic round out the picture for dogs already carrying lumps or spinal tightness.
5. Reduce the toxic load around your dog. Pesticide-treated lawns, chemical flea and tick products, and heavily processed food all add to the inflammatory burden your dog's nervous system is already managing. Cleaning that up isn't dramatic, but it adds up.
The Part I Keep Coming Back to
The body rarely does anything without a reason. A lump isn't bad luck. A pattern of tumors along the same nerve pathways isn't coincidence.
I myself experienced an example of what I am writing about today. After three severe neck injuries, a lump showed up on my salivary gland - adjacent to the cervical spine. I was lucky, it was benign but who knows what it would be if I didn't pay attention to eating healthy, nourishing and detoxing my body… I was lucky.
It took the scientific world a long time to catch up to what dogs were showing me in the exam room but in 2025, it finally did.
Now you have the info, now you can act. Don't ignore the pain and inflammation, get your dog treated, get a harness and FAB4.
Your dog will thank you for it with what I hope will be many happy moments together.
Take care, and give your dog a hug for me.
PS: As you may have already figured, the same principles apply to people too.
References:
Giampietri, C. et al. "Roles of Peripheral Nerves in Tumor Initiation and Progression." International Journal of Molecular Sciences, 2025.
Fu, X. et al. "Peripheral Nerves in Cancer: Regulatory Roles and Therapeutic Strategies." MedComm, 2026.
MD Anderson Cancer Center. "Cancer-Induced Nerve Injury Promotes Resistance to Anti-PD-1 Therapy." Nature, 2025.
