Canine Growths Suddenly Appearing Over Night

Do you know that in America, 1 out of every 25 large breed dogs will be diagnosed with cancer?

Below are screenshots taken from the r/DogAdvice subreddit over the last year. What's most interesting about most of these is that they're usually described as appearing very suddenly or growing to be large extremely fast. I've also noticed these posts tend to come in waves, I will see 10 posted within 2 days and then nothing for a week or month, then again another wave of posts will appear.

The majority of the images below will be described by a vet as a histiocytoma. Vets will dismiss them as 'benign' and just a random occurrence that happens after an injury or something. Totally normal, nothing to worry about.

But the truth is every tumor and growth is a sign of dysregulated cell behavior. Normal, healthy cells don’t spontaneously form lumps. Tumors and growths occur when the immune system fails to clear abnormal cells, or when epigenetic errors override healthy regulatory controls.

What vets call benign are actually early-stage failures of immune surveillance, DNA repair, and tissue signaling. Benign tumors should be seen not as harmless anomalies, but as early warning signs of systemic dysfunction—particularly immune misfiring, chronic inflammation, or exposure to biological stressors.

These growths are usually clonally derived (arising from one mutated cell) and exhibit uncontrolled proliferation (even if growth is localized). They are a result of abnormal gene expression, evasion of apoptosis, and sometimes angiogenesis (new blood vessel formation).

This means that every growth, no matter how 'benign', is showing some degree of oncogenic signaling, immune system failure and cellular imbalance. Basically it's evidence of a broken regulatory system.

Interestingly enough, these syndromes increased dramatically after the rise of multi-dose canine vaccination, especially in the 1980s–2000s. Vaccines stimulate antigen-presenting cells (APCs)—the same cell type involved in histiocytomas.

Many canine vaccines contain aluminum hydroxide or other pro-inflammatory adjuvants. These promote long-lasting inflammation and can remain in tissue for years. Puppies receive multiple vaccines at 6–12 weeks of age, while their immune system is still developing.

Prior to the mass vaccination of dogs, these tumors were virtually unreported in veterinary pathology. Their rise correlates with the introduction of combo vaccines (DAPP, rabies, Lepto, Bordetella) and the introduction of booster schedules.

What bothers me most is the absolute normalization of these growths as benign, random and 'normal'. In reality, these are not normal. They are not healthy. They are signs of malfunction and distress.

How often do you see wild animals with growths such as these? How "normal" would it be to see a dear or a raccoon or a bear with massive sores like this? We would immediately assume the animal to be diseased. But when it's our own pet, we listen to the vet when they dismiss it as nothing to worry about it.

Why? How are these somehow becoming normalized despite not existing 3 decades ago?

Another thing is, if we know some breeds have higher incidences of cancer than other, why don't we consider this in our vaccine protocol? If canine vaccines were truly about the health of our dogs, wouldn't we want to ensure the vaccines our breed is receiving doesn't put them at an even higher risk?

How can a one size fits all be beneficial to dogs with extremely different risk profiles?

"Boxers were the only large breed with more reactions than average. It also appears that smaller breed dogs and Boxers may be at higher risk for an allergic reaction to a vaccine." [Source]

See this issue really hits home with me as I have a boxer who had a horrible reaction to her rabies vaccine and now is losing the use of one of her hind legs. I can't tell you how much I had sobbed over this and sobbed over the fact I ever let them convince me to vaccinate her.