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Palladia Experiences (Mast Cell Tumor Diagnosis in Dog)

It kills me to be writing this post. Sorry for the novel.

My 13 year old dog, who is the light of our lives, was diagnosed with an incredibly aggressive and fast moving subcutaneous mast cell tumor, that is located in a very difficult area.

On Wed, 1/18 I found a walnut sized tumor on my dog’s throat, right below his jaw. I know that it was not there the day before. I took my dog to our primary vet clinic, thinking it could be a blocked salivary gland or an abscessed tooth (although unlikely because he was not in any pain).

The vet did a fine needle aspiration on the tumor. A quick look at the slides was inconclusive, so she sent the slides out to a specialist. The next day we got the results - a mast cell tumor. I immediately started trying to find an appointment for a surgical consult with a board certified surgeon.

Within 48 hours of the aspiration, the tumor had tripled in size and had spread to underneath his muzzle. We took him to the ER, who prescribed prednisone and advised an oncology consult, saying that with the size and the location of the tumor, it was unlikely that a surgeon would be able to remove it.

Over the weekend, as we processed all this information, my husband and I had been considering my dog’s quality of life versus treatment. Our dog is incredibly anxious and hates going to the vet. Our thought coming out of the weekend was that we would keep him home, keep him comfortable and happy as long as we could.

Today, our primary vet, that has treated our dog for 10+ years, called and strongly recommended that we consider treating with Palladia. She strongly felt that it was minimally invasive and disruptive, and would provide our dog with longer/better quality of life.

Does anyone have any first hand experience with Palladia? I did read that some dogs tolerate it really well, others do not.

My dog is currently pain free, eating and drinking normally. I want what is best for him. :heart:

I’ve had a dog and cat both with mast cell, although before this drug came on the market. The dog was treated with surgery, and eventually died of something else. The cat was not diagnosed initially (she lived with a friend, her vet didn’t see the need to send those “lipomas” to pathology, sigh) and died of mast cell, it spread everywhere.

It seems reasonable to try palladia. Have a plan on how to treat any potential side effects before starting, along with those drugs on hand. Don’t play telephone tag and have to wait to treat if side effects develop. And be ready to make the call if it’s not working. Discuss with the vet what that (“not working”) will look like. Perhaps loop in a vet that does euthanasia at home now, just in case. (I’m sorry to suggest, but having a plan could be helpful.)

Have you confirmed the dx? It sounds like it’s progressive very, very rapidly.

I’m so sorry you’re facing this :frowning:

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@Simkie , the specialist confirmed the mast cell tumor diagnosis from the needle aspiration. My rudimentary understanding is that typically they would remove the tumor and send it off for histology to determine what grade the tumor is. Unfortunately due to the location and the size, we are not able to remove it. My vet feels it’s most likely at least a Grade III, due to the nature of how progressive it has been.

I could share photos, if it would help.

I have quite a bit of experience with mast cell cancer, unfortunately. One of my dogs was diagnosed with an incredibly aggressive MCT. We were able to surgically excise it, but it took two surgeries to get good margins. His was Grade III with a mitotic index of 48, basically off the charts. Our oncologist recommended a multi-agent chemo protocol, Vinblastine and Palladia, because it was so aggressive. Our boy tolerated everything incredibly well. Chemo in dogs is way different than chemo in humans - quality of life is paramount, and physiologically they tolerate it way better than we do. Long story short, he kicked cancer’s ass and was officially in remission one year after starting treatment. His initial prognosis was 2-6 months without chemo. Tragically, we lost him to a cardiac event about 4 months ago. It was a kick in the teeth for him to come through cancer treatment so successfully and then just die in bed one morning. Anyway…

Other advice for MCT, which I’m sure your oncologist will confirm: start Benadryl ASAP! He will be on it for life. When your vet did the FNA, no doubt it aggravated the tumor and triggered a histamine release, which is why the tumor has grown so quickly. They can grow and shrink overnight. I would also ask for staging diagnostics. Since surgery isn’t an option, you can do chest X-rays, spleen u/s and cytology, and check the local lymph nodes for spread.

I know you asked about Palladia specifically - I would not hesitate putting another one of my dogs on it. There is also a compounded generic form that much cheaper.

Good luck! It’s a crappy diagnosis for sure. But it is possible to manage and even beat it.

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@Inimitable this is really helpful information.
I am going to include some photos, if that is ok. It’s a lot to unpack in such a short time. Less than a week ago I had a healthy dog. Yes, he is 13 years old, but he had no significant health issues. One thing to note, this dog HATES going to the vet. He’s a fairly anxious and neurotic dog in general. He has a very small, routine world that he is comfortable with and anything outside that is pretty traumatic to him. We sedate him for his routine yearly vaccination and wellness appointments.

Here is the tumor when I discovered it Wed 1/18:

Here is the reaction to the FNA on Fri 1/20:

We have had him on Benedryl and Tagamet since the initial finding of mast cells on the FNA slide 1/19. We added Prednisone on 1/20.

Here is today, 1/23:

Aww buddy. He is precious. That is quite a reaction. :cry: Hopefully the Benadryl and Tagamet help bring it down.

It sounds like you are doing all of the right things and moving very quickly. Honestly, I think that’s what saved our boy - we caught it early and, once diagnosed, started treatment as quickly as space and time would allow.

If you haven’t already found them, I highly recommend joining these two FB groups: Pet Parents of Mast Cell Tumor Dogs and Holistic Help for Dogs with Mast Cell Cancer. It’s a wealth of info and people are super helpful.

Diet changes, supplements, herbs, etc. are all things to consider - especially since he’s an anxious dude about the vet. We took a hybrid holistic/conventional medicine approach with our boy and were happy we did. It’s also nice that the Palladia is an oral chemo so it’s given at home, easy peasy.

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You dog looks a ton better. Hoping this keeps up and shrinks that sucker. I had a dog with a mast cell tumor. The stupid vet I went to first dismissed it as a fatty tumor and nothing to worry about. When it kept growing in size, I took her to another vet, he took one look and said it was a MCT and needed to be removed ASAP. He did a biopsy to make sure and it was as suspected. Luckily it was near her arm pit so was pretty easy to get to and were able to remove it fairly simply.

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Thank you @Spudsmyguy :heart:

His tumor continues to shrink on the Prednisone and Benedryl. Now it’s about the size of an egg. We went back to our primary vet today to do blood work to make sure his liver and kidney function will tolerate the Palladia. If we get the all clear, we will start Palladia and see how it goes.

Today 1/26:



I hope the tumor is continuing to shrink and he’s doing well.

Thank you so much :heart:. He’s doing great so far. We started the Palladia and he’s doing great, with no side effects. The tumor continues to shrink. I know there is no cure, but I am grateful that he is comfortable and that the time I have left with him is of the best quality that I can provide.


Wonderful news! The first cat I ever had had multiple mast cell tumors but luckily removal was curative. I never knew until this thread how bad it could be.

Jingles for continuing success in treatment. Give him a hug for me.

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Hey @ floppyammy
Hope your doggy is still doing ok with Palladia and his life is comfortable and pain free.

My Furbaby just got diagnosed with Grade III MCT, it’s in her lymph nodes, spleen and getting hold of the liver. We will be starting Palladia tomorrow and I’m reading so many positive stories that i have hope for her too.
I’m familiar with safe practice, the possible side effects, basically all the good and the bad but thought of not being able to comfort them (and myself) is getting to me now.
Can you tell me how you managed not being able to hug and kiss your dog, and not letting him lick you? Does he even notice that your behaviour towards him has changed?


Hi @Gosh, I’m sorry to say that we lost my boy one month from the day of his diagnosis. We never knew the extent of his cancer; he was so anxious about vet visits that he had to be sedated. We chose not to put him through extensive staging and testing, as we felt that was not in his best interest for his quality of life.

His case was also complicated by plummeting kidney values. We don’t know if that was caused by the steroids we used to try to control the tumor, age or other factors.

I can say that he tolerated the Palladia really well and I’m not sorry we tried it. I can’t say if it made a difference or not. It was a long shot at best any way.

As for handling the Palladia and contact with my dog, other than using gloves to give him the Palladia and picking up waste, I didn’t change how I interacted with my dog. He was never a licker, but if he had been, I might have discouraged the licking and maybe washed the areas that got licked, but that’s about it.

I continued to lay on the floor with him and hold him every day. We both needed that. I didn’t hesitate to put my face near his or kiss his fur, as I had always done.



Also to add, further reading I did on Palladia indicated that it is far less effective on subcutaneous Mast Cell Tumors than cutaneous. I believe less than 40% of subcutaneous mast cell tumors respond to Palladia. If I had known that, I may not have opted to try it at all. But everything happened so quickly, I didn’t have a lot of time to make decisions. At the very least, I don’t regret it.

I’m so sorry to hear this… but I can tell you’ve done what’s best for him. The photo you posted breaks my heart.
Thanks for your reply, my dog is a licker and i kiss her a million times a day so it will be hard to keep that distance but i suppose it’s a small price to pay for trying to make her better,

I’m so sorry for your loss, @floppyammy.

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I just remembered, towards the end of his life, when his appetite was waning, I fed him by hand, whatever he would eat. So I guess I wasn’t very diligent with the no contact stuff. :woman_shrugging:

I have no regrets


@ floppyammy
it doesn’t seem you have been negatively affected by the saliva so i will not panic too much myself.

Take care.

Thank you Gosh. I wish you love and light on your journey. Please stop back in and let me know how it goes. :pray: :heart:


@floppyammy I’m so sorry for your lost, was he a sighthounds? I have a 13yo retired greyhound and he’s such a precious soul. You did your very best for your friend. We had a dog in treatment with something similar to palladia (She had an aggressive chest cancer) and we did the same as you, the vet told us to be careful but not paranoid, it would have been really dangerous for a kid but we didn’t have any issue.