Beads face

There aren’t 50 options to fight cancer. The main options are surgery, chemo, and radiation therapy.

Unfortunately, chemo and radiation therapy can be expensive and can have side effects.

Around 15 years ago, I was lucky to hear about a revolutionary option that is easy, cheap, and has few side effects.

Was it too good to be true?

Well, we’ve used this treatment in multiple patients ever since, including at LRVSS, with impressive results.

What is our secret weapon?
Chemo beads.

What are chemo beads?
Chemo beads are tiny spheres that measure 3 mm in diameter, or about 1 tenth of an inch.

They contain a tiny dose of a common chemo drug called cisplatin, which is used IV in some cancer patients.

One of the most common side effects of cisplatin is kidney damage. By including a minuscule dose in the beads, we are able to eliminate this risk.

Cisplatin is then slowly released from the beads and kills remaining cancer cells that may have been left behind during surgery.

As cisplatin is released, the beads are absorbed by the body over 4-6 weeks.

Beads foot

Chemo beads were placed after removal of a cancerous tumor (fibrosarcoma) in Max’ foot, an 8 year old Weimie.

What do chemo beads do?
Cisplatin beads are good at preventing some cancers from coming back.
However, they do not prevent spreading (metastasis), e.g. to the lungs or in the case of anal sac cancer, to a lymph node under the lower spine (sub-lumbar lymph node).

What happens in surgery?
After the tumor is removed, we place tiny cisplatin-impregnated beads around the area.

The number of beads varies with the size of the tumor. They come in packages of 3 beads. They are typically placed every 1-2 cm.

To decrease complications, we limit ourselves to a maximum of 6 beads in cats.

In dogs, the maximum number of beads so far has been 15.

This means that the tumor can’t be too big for the patient to be an ideal candidate.

What is the best time to place chemo beads?
In my mind, the best time is at the time of surgery, when we know exactly where the tumor was and where cancer-free edges (margins) are questionable.

Implanting beads after the surgery (eg after the biopsy reveals unclean edges) has 4 drawbacks:

  • It is difficult to know where margins were.
  • It requires another anesthesia
  • It requires another surgery
  • Therefore, it means there are additional costs.

So placing beads at the time of surgery is ideal.

Beads tongue

Chemo beads were placed after removal of a cancerous tumor (fibrosarcoma) in Nittany’s tongue, a 7 year old Golden.

What are additional benefits of chemo beads?

  • The cost of cisplatin beads is a fraction of current “follow-up” options (chemo and radiation).
  • There are no known generalized (systemic) side effects.
  • It’s a one-time treatment.
  • There is no need to take your dog to an oncologist multiple times over weeks or months.

What are complications of chemo beads?
Complications are rare and typically local.

They occasionally include swelling, irritation, redness, and skin drainage.

Although IV cisplatin is toxic to the kidneys in dogs (and deadly in cats), side effects have not been observed after bead placement in either species.

Ironically, chemo drugs can cause cancer. Therefore, the pet owner should not touch any drainage with their bare hands. Should the incision drain, it is important to wear disposable, single-use gloves to clean the area (if at all needed).

We also recommend avoiding touching any “bodily fluid” with your bare skin. This includes saliva, tears, vomit, pee, and poop.

One surgeon had a situation where the owner decided to remove the plastic cone (E collar) from his dog. The dog chewed his wound open, and a chemo bead fell on the floor. The same could happen if you allow another pet to lick the incision.

Should this happen with your pet, never touch the bead with your bare skin. Again, use gloves. Please keep your pets separated, and leave your pet’s E collar on 24/7 if it was recommended by your surgeon.

Cisplatin beads have not been approved by the Food and Drug Administration (FDA) for use in cats and dogs. However, there are very few FDA chemotherapy drugs approved for pets! Most of what we use are actually human drugs. Cisplatin is a human drug, which has been approved by the FDA and is commonly used IV.

In which cancers are chemo beads used for?
We have used those beads in a variety of other cancerous tumors.

Indications for cisplatin beads include tumors removed with “thin margins” such as:

  • Soft tissue sarcomas (nerve sheath tumor, fibrosarcoma, hemangiopericytoma)
  • Skin melanoma
  • Some carcinomas (squamous cell carcinoma, salivary gland carcinoma, thyroid carcinoma, anal sac carcinoma).

The tumor we’ve used chemo beads the most commonly (I would guess in 90% of patients) is anal sac carcinoma, an aggressive cancer of an anal sac.

Beads anal sac

Beamer, an 11 year old shepherd, had a large cancerous tumor of the anal sac (adenocarcinoma). The needle measures 2 inches (5 cm)

What’s my take on chemo beads?
In our patients, the beads have been remarkably well tolerated, and we have not seen any toxicity at all, in the kidney or anywhere else.

Overall, I would say chemo beads have kept their promise.
Amazingly, we can use beads in cats despite the fact that IV cisplatin is deadly.
They are overall effective and much cheaper than all other options, with minimal side effects.

That said, I don’t want to overpromise. They are not a miracle option.

In some patients, they have made a remarkable difference (compared to average survival times for a given cancer).

I would say that the disadvantages greatly outweigh the benefits, and they should be strongly considered in the right patient, with the right tumor, and with the right owner.

If you would like to learn how we can help your pet with safe surgery and anesthesia, please contact us through

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Phil Zeltzman, DVM, DACVS, CVJ, Fear Free Certified