Keeping PETS out of vets since 2011

AC4 | Naturally assists in the fight with cancer in your pet.


AC4 contains a proprietary blend of sustainably harvested seaweeds and one red moss. Each has been proven effective in the fight against cancer (in humans and rats). We do not make any claims beyond this. As a potent antioxidative and anti-inflammatory and considering the sheer nutritional kick in seaweed, we do believe AC4 would make an excellent accompaniment to most conventional treatments but please ask your vet if on conventional medicines.

What is AC4 and how does it work?

You have to be very careful with claims concerning cancer. The organic, sustainably harvested seaweeds and mosses used in this product have been selected based on the results of the numerous clinical studies which we go through here.

The seaweeds used in Ac4 have been shown to be anti-tumour / anti-cancer in a range of clinical animal studies, largely rats (see table below). We absolutely cannot make any claims after this. We let the science speak for itself and sincerely hope it will help.

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There is LOTS you can do for cancer in dogs, most importantly diet but also some additions that you likely have around the house. Please check out our article on the cause and dietary solution to cancer in dogs.

When you should NOT use AC4…

There are no known drug clashes so far for AC4 and, in our opinion, it can be used alongside any recommended conventional treatments (but please consult with a good vet first). However, AC4 IS a potent anti-inflammatory so if your vets is using further anti-inflammatories please ensure to remind them they are using Ac4.

Further, we do not recommend to use Ac4 in pets with HYPERthyroid issues.

Does not ship to…


Please note…



Weight400 g

Customer Reviews

Based on 3 reviews
Michael Ussher
AC4 review

I bought this along with Irish Kelp last year & never got to use it since I gave it as gift to a friend for an older dog. I then bought the Canident version to prevent tartare build up & now I have finally used AC4. After feeding it for the last 2 weeks I have been gradual in increasing the small scoop & have had no issues. I have every faith in this product that our pouch will be more resistant to an early onset of cancer. My understanding is that seaweed slows down digestion to allow better absorption of the nutrients from the food. I use pumpkin (butternut scotch) as part of his balanced diet which helps to keep him regular.

John Brookes
Certainly worth a try

My 6 yr-old Dachshund/Chihuahua mix, Zoë, appeared to be gaining weight. When there was no mistake about that, and she began to avoid me when I went to touch her, I knew something was terribly wrong; and, on 11/17/20, took her to the vet, who diagnosed her with "an aggressive, fast-growing tumor" that was pressing on her intestines & spine, and, was deemed inoperable. In the x-rays, it was huge!!! We put her on Dexamethasone, a steroid, which had reported having some rare incidences of complete remission. Notwithstanding, she began to bloat as the tumor kept growing. She loved to chase her squeaky tennis ball; but, she was slowing down noticeably, and her bowel movements were often strained and looked like pudding. In desperation, I began researching to see what I might do for her. On 6/9/21, I happened on to Dogs First site, saw the AC-4, and ordered the small size. After a period of time on AC-4, her bloat began to go down, which was noticeable to people who we often met on our daily walk. Her energy returned, and her bowels began to have some form and quite often began to look normal. Most incredibly, she would get some hematomas which would disappear - so her body was absorbing the tumor's leakage. I showed pics to the vet who was amazed. I am absolutely certain that the AC-4 was working, and that she may well have been on the road to a remission. So, when I began to get low, I ordered the large bag on Oct 6th, 2021; but, unfortunately, it got lost somewhere in transit. The result was that, after being off AC-4 for several weeks, she went downhill rapidly; and, I began to give her Gabapentin to ease her discomfort. Finally, when the shipment failed to arrive, on 11/9/21, 8 days short of one year from diagnosis, I made the painful decision to let her go. The vet said that she lived 10x longer than he had expected. I have no doubt whatsoever that AC-4 was instrumental in her improvement, and, had we been able to continue with it, she may have survived.

Just bought a 2nd pack...

My younger Staffie is nearly 13 and has a cancer of the bladder. I put a scoop in with both her daily meals and she either doesn't notice it or genuinely loves it!
There's loads of great advice on Dogs First for which I'm very grateful - thank you Dr Brady.