Your Dog Got Cancer Because She Was “Predisposed?”


Last Updated on January 19, 2026 by Will Falconer, DVM

Your Dog Got Cancer Because She Was “Predisposed?”

Calling BS on Big Pharma

As if it weren’t enough that the commonest drug prescribed for the man-made itchy allergies your dog suffers from (Apoquel) appears to have cancer as its chief side effect, now Big Pharma wants you to believe its your dog’s fault she’s dying of malignancy.

This is both disturbing and an insult to your intelligence.

Jennifer brought this to my attention as she related an all too common heartbreak following Apoquel’s immune system suppression:

Our cocker years ago was put on Apoquel when it first came out. She got cutaneous lymphoma which is actually rare in the breed. Now it has come out that if dogs are “predisposed” to getting cancer (they) can get cancer from the drug.

Messing With Immunity

The backstory, of course, is that Apoquel works by partially suppressing your dog’s immune system. The fervent hope of every immune suppressant, antibiotic, pesticide, and chemotherapy drug is that “partial” translates to:

Don’t screw up the good guys!”

So it is with Apoquel. The itchy allergic dog is only that way because her immune system is in a state of high confusion. It’s viewing ordinary things like foods, grasses, pollen, and flea saliva as a signal to wildly ratchet up inflammation, as if these things were all significant threats to Sadie’s very existence.

By stepping in with a chemical that stops Sadie’s immune communication system, the hope was that this would merely turn off the itch, and let everyone resume a normal life and sleep at night in peace once more.

And, it brought at least initial relief to many itchy dogs. Quickly, in fact, often within hours of a pill being given.

But in small letters that could be easily overlooked was a veiled warning from Apoquel’s maker. It might also allow cancers to grow. Or infectious disease to get the upper hand.

 

IMPORTANT SAFETY INFORMATION Do not use APOQUEL® (oclacitinib tablet) in dogs less than 12 months of age or those with serious infections. APOQUEL may increase the chances of developing serious infections, and may cause existing parasitic skin infestations or pre-existing cancers to get worse.

 

source: https://www.zoetisus.com/products/dogs/apoquel/index.aspx

 

Therein lies the rub. Comments on my warning blog post about Apoquel are rife with stories of cancer coming to show itself after Apoquel was used for a period of time. If you tally them up, it would appear malignancy (and untimely death) is the chief side effect of Apoquel!

So much for partial suppression.

What’s a company to do? This is a big moneymaker for Zoetis! The drug is expensive, prescription only, and selling like hot cakes.

Misplaced Blame & Obfuscation

“Well, for starters, we could blame it on the dog!” (said some Zoetis marketer cum scientist one day)

“If your dog is ‘predisposed’ to cancer, well sure, it might get cancer after taking our drug. But that’s not our fault! We can’t fix a predisposition. That’s your dog’s problem.”

So, like Jennifer, you’re left with the heartbreak of losing your dog to cancer (when all you hoped for was itch relief from a drug promising that) and now you no longer have anywhere to place blame.

And how were you to know your dog was “predisposed” to cancer, anyway?

Here’s the scenario that plays out far too often:

  • Your dog received vaccines, likely multiple vaccines all at once.

  • That invasion overwhelmed her immune system: “Yikes, my defenses have been breached and I’ve got a bunch of foreign viruses running around my body! Red alert!

  • In that state of immune confusion and panic, normal things are mistaken for invaders, and inflammation becomes Sadie’s new normal. She can seldom rest now, as that inflammation is accompanied with skin and ears that torment her with The Itch.

  • “We can’t live like this! We’re up all hours of the night and day, trying to keep Sadie from turning herself into a raw bleeding mess! She’s miserable and so are we!”

  • Followed by the run to Dr. WhiteCoat’s clinic, seeking relief, anything! You’re offered a promising solution. Apoquel can stop this faster and more thoroughly than anything in the past arsenal of drugs ever could! Let’s send you home with some. Everybody’s using it, and it works!

  • Sure enough, seemingly within hours, Sadie’s itch drops from a 9 on the 10 scale to a 4! This does work, halleluja!

  • A month or a few later, Sadie is sick and it looks much different than just itchiness this time (although that appears to be increasing again, even though you continue to give the Apoquel…)

  • Back to Dr. WhiteCoat to see why. And that’s when the C Word bomb is dropped: Sadie now has cancer. Often, not just any cancer. No, this is cancer of her immune system! Lymphoma.

  • Options for treating this look horrible. Chemo will make Sadie sick and probably not extend her life significantly. And it’ll be a huge expense. Surgery or radiation is impossible, as her cancer is widespread throughout her lymph system.

  • Next up, you may hear this hopeless pronouncement: “Sadie must have been predisposed to cancer. That’s why she got this horrible disease.”

Why This is Such BS

Big Pharma dishes BS on cancer NOT being caused by Apoquel

There are several reasons this is completely bogus:

  • Predisposition can’t be measured (not unless you have high tech connections in laboratories).

  • According to scientists who study cancer and immunity, we ALL have cancer cells trying to grow in us at any given time. It’s our immune system that takes them out.

  • It conveniently misplaces blame, even though this clearly started after using Zoetis’ Apoquel, and the label warns you this could happen.

And most shameful, if it’s all your dog’s fault, Zoetis can keep right on profiting from this expensive drug while untold damage is done to your loved ones, all couched in supposedly “helping” your dog who’s suffering this 100% man-made disease.

The Way Out

You have options to prevent this common scenario, but they all work best the sooner you start. (Time is not on your side, here.)

  • Work on the initial cause: decrease or stop vaccinating, minimally those animals who’ve already had several. Annual vaccination being pushed at you? FIRE that vet!

  • If you MUST vaccinate, use immune support around that event to minimize chances of damage

  • If your animal is already damaged, focus again on strengthening the immune system. From allergies to cancer, it’s imperative that Sadie’s immune system gets back on track

  • Consider hiring a homeopathic vet (download my free Apoquel Alternatives Report for how to do this well)

You can say NO to vaccines and have some natural rearing strategies in place, like this or this.

Refuse to Take Blame. Take Responsibility Instead.

Being a victim in this Big Pharma led money grab is a horrible place to find yourself. It’s why I’m so focused in helping pet owners “call the shots” and protect their animals from the current “over-prevention” epidemic of immune dysfunction.

It all starts with knowledge. And applying that knowledge confidently, so your animal and you don’t become caught in the conventional medicine machine  that’s cranking out damage and early death while profiting ruthlessly.

You can do this. Tell us in the comments if you’ve already started and what you’ve seen (and how that feels). If this is new to you, keep tabs on what appears in the comments below. Learn from the experience of those who’ve successfully gone before you and have animals that are truly VITAL.

That’s why we’re here, after all.

I believe Vital Animals can change the world

One shiny, well-balanced individual at a time.


It all starts with you, the wise animal caregiver, and the health choices you make for the animals in your care.

And that's why this site is here. Care to join us? We're a Vital Animal Pack.

I'm in!