Never IGNORE a Lump on Your Dog

(NOTE: If you found this post because you are searching for more information regarding Mast Cell Tumors, I also suggest that you check out my three part series:  Mysteries of the Mast Cell Tumor.)


I just learned a very important lesson, the hard way, that I feel should be shared with ALL dog owners. Any lump, bump, mass, or swelling on your dog should be looked at by a vet as soon as possible, even if you feel it is nothing to worry about….and even if they have had benign lumps in the past.

When we adopted Meadow, she came with a harmless looking lump on her belly, and a few months later, a small lump appeared on her hindquarters. We brought her in to the vet to get them looked at and he aspirated the one on her hindquarters and did a skin scraping on the one on her belly because she had some hair loss in the area. The aspiration came back that the lump was most likely an allergic reaction, probably from her vaccines. The skin scraping came back negative, and our vet felt that the small hard lump on her belly was a surface abrasion of some sort.

Then, in early August, Meadow developed a strange, strawberry looking growth on her ear. Back to the vet, and we were told it was a hystiocytoma, which would most likely dry up and fall off on its own – which it did, just a few weeks later. Interestingly, I went back through her records from when she was first rescued, and she also had a growth on her nose removed and biopsied back then, which had turned out to be another benign hystiocytoma.

Simultaneously, our vet was watching two lumps on Toby. My lumpy Lab had already had several aspirated in the past, some turned out to be cysts, some lipomas. When two more squishy lumps popped up on him, the vet said to just watch them, and aspirate them if they grow. Leah also sports a quarter sized lump on her torso, which my vet believes is a cyst. It has remained the same size and consistency for at least two years now…

So, when Meadow developed a new lump on her leg sometime in either August or September, (we can’t really remember when), we let it go for a while, deciding to just let the vet look at it during her next visit. After all, all three of our dogs had had lumps looked at, and each had consistently been benign. Additionally, the new lump was similar in appearance and feel to the one our vet had previously aspirated on Meadow’s hindquarter, so we weren’t all that concerned – especially when the lump went away.

But then it came back – same spot, same size, same shape. I told Nick, “We’ll have it looked at when Meadow goes in for her check up in March.” But then, when it went away again, we put it out of our minds.

When it came back yet again, we were even less concerned. After all, cancer doesn’t go away. Does it?

I briefly looked it up online, and the first article I came across said lumps sometimes hide behind muscles, sort of slipping in and out again. I discussed it with Nick and we wondered if that was what was happening with Meadow’s lump, rather than it actually going away like we initially thought. Thinking it was a little bizarre, but still unconcerned since it had remained roughly the same size, (when it was visible), I decided to bring Meadow in with Toby when he went for his annual exam in November, rather than waiting until March… 

Not long before their appointment, Nick found a new, tiny, very hard, odd shaped lump in Toby’s leg, and I added it to the ever growing list of things to have looked at. But then, just three days before the dogs’ joint appointment, I found another, HUGE lump in Toby’s chest. It cropped up out of nowhere and was the size of a golf ball! Worried about Toby, I started reading up on lumps on the internet while waiting for their appointment, and that is when I learned that mast cell tumors often shrink, grow, and shrink again. I also learned that the mast cell tumor is called “the great imitator” because it can look like any type of benign (and sometimes not so benign) lump a dog can get.

At that moment, I realized my mistake. I was worried about the wrong dog.

When we brought the dogs in and described the nature of Meadow’s lump to the vet, he too was suspicious. He was also suspicious of the little lump in Toby’s leg. He aspirated all three new lumps, but only obtained clear fluid from the golf ball sized one on Toby’s chest, which he felt meant it is most likely another lipoma.

But from each of the dog’s leg lumps, the needle pulled blood.

Concerned, our vet sent both samples out to the lab for a cytology report, and told us he’d call on Thursday with the results. When he called on Tuesday night instead, I knew something must be wrong. Toby’s lump turned out to be just another cyst in his ever growing collection, but Meadow’s ‘disappearing’ lump was indeed a mast cell tumor. Then the vet told me Meadow needs surgery to remove the lump – so it can be biopsied to see what stage cancer it is – and that he now wants to biopsy the benign looking one on her belly, just to be safe.

I was shocked. How can a four-and-a-half year old dog get cancer?

While waiting to take Meadow in for her pre-op blood-work and consult, I went over every inch of her, and discovered two more, smaller lumps.

I showed them to the vet during Meadow’s appointment yesterday morning, and while he feels that one of them is probably just a cyst, (it is hard and about the size of a deer tick), the other may be an issue. Although it is much smaller than the original mast cell tumor, it is similar in feel, and is located not too far away on the same leg. Rather than aspirate it, my vet is going to remove all four lumps and send at least three of them out to be biopsied when he performs her surgery, which is scheduled for December 1st.

Completely paranoid now, I checked her over again last night, and this time I discovered a little bump on her lip, smaller than an eraser head, and that is when  I also remembered the grain sized hard lump that Meadow has had inside her ear flap from when we adopted her. Nick and I have been watching it for the past year and a half, and it has never changed, but of course, I’m worried about it now too, and will be bringing both of these bumps to my vet’s attention.  

Please keep Miss Meadow in your thoughts. The best case scenario would be that she has a stage 1 mast cell tumor with clean margins (which generally don’t metastasize) and a bunch of benign lumps and bumps. And since Meadow does have a history of benign lumps, I am trying hard to remain hopeful that the cancer has not spread.

I am also trying very hard not to blame myself for not bringing her in to the vet sooner.

It appears I’m not the only one to have made this grave mistake. Now that I’ve been reading up on and talking to everyone I know about mast cell tumors, I’ve discovered other owners who have mistaken mast cell tumors for benign things, and still others whose dogs have had multiple lipomas (like Toby) but had a new lump turn out to be a tumor. So, please take this important message to heart, and check your dog regularly for new lumps and bumps. And if you find one, even if your dog has a history of benign growths, please get it  checked by a vet…

Even if you think it is nothing…

…Cancer can look like anything.

42 Responses so far.

  1. Kari says:

    Nope, never ever ever ever!

    Stop on by for a visit

    • Shana says:

      Please don’t ignore the bumps!! My baby Caramel had that exact bump on her stomach. She had it for years and we have always been in for shots and to the vets office, but nothing was every mentioned. I thought nothing of it, and I’m so upset it wasn’t mentioned or they didn’t notice it during her exams. She passed away yesterday morning 8-6-15 and I feel so empty inside and so hurt that I never thought it was anything. I wish I could of did something more. She was my love, my angel, my baby, and only 6-7 yrs old. Unsure of DOB as I adopted her in 2010.
      The vet said it was most likely a vein that burst in the stomach and she had stomach cancer. I want to know why I was never informed by any vet that you should maybe do tests to see things about cancer if you cant notice them? I wish i would of read up on bumps on dogs, maybe i wouldn’t be writing this today. I feel I did nothing. I was blinded, my dog was always happy hyper never sad. So lovable. I thought nothing of anything. Vet said that she went fast, and I just hope she wasn’t in pain during this time. Please send some prayers my way. Caramel had died in my brothers arms, and I wasn’t there. Very hard time right now. Please don’t ignore any bumps!! please!!!

  2. I’m going to be thinking only the happiest thoughts for Meadow that all turns out with the best possible outcome. It is so easy to second guess yourself. Our beloved white Pittie girl Paige had a slight disappearing limp in her front right leg over the course of 3 months. She loved to jump on and off the high bed in the bedroom as she protected the house from the passerbys. We thought each time she had just come down too hard on the leg. Finally after Christmas 2008 I thought it best we check it out. She had an agressive bone cancer. We took her front leg in hopes that we could get it all. She was with us another year and 9 months, a time we are SO thankful for. So you are right don’t ignore even if you feel you are being over zealous. We can’t be all knowing, we can only do the best we can. Thinking and praying for you and waiting with bated breath for the results. Please kiss your babies for me and tell them it’s from a fellow puppy lover. :-)

  3. Donna says:

    Hi Diane – Thank you so much for commenting and sharing your experience. I am very sorry for you loss, but also glad to hear that you were able to have nearly 2 more years with your precious Paige. :-)

  4. lexy says:

    thinking positive thoughts for you all and meadow

  5. Poor Meadow! We hope it all turns out okay for her. She deserves a break!

  6. Teri says:

    Thinking good thoughts for Meadow!

  7. oh no! I’m sorry to hear that. Zoe had a few MCT’s removed several years ago and had severe skin/allergy issues afterwards. We finally got her on some *real* dog food and most of the problems have gone away. I hope that surgery goes well- I’ll be thinking about you and your pups!

  8. Donna says:

    Thanks Terri and Dennis!

    Amanda…sorry you went through this with Zoe, but good to know she is okay. We’ve never had any allergy issues with Meadow, and she’s actually on a pretty good food because Toby’s got severe allergies and I feed them all the same diet (much easier), so hopefully we won’t end up with those types of problems too.

  9. ForPetsSake says:

    You’ve done the right thing by having it checked out – please don’t beat yourself up. You would never intentionally hurt your babies. Many hugs to you.

  10. First of all hoping everything works out for you and meadow. Secondly, thank you for sharing this.

  11. [...] Meadow’s confirmed mast cell tumor was around the size of a half-dollar – this one is about the size of a raisin, when it is even visible. In fact, if thicker coated Toby or Leah had a lump that small, I never would have even seen it in the first place…which is good news for Meadow, because even if it is another tumor, our vet said we caught it WAY early. (Another reason why you should NEVER ignore a lump on your dog.) [...]

  12. [...] second tumor, which we noticed even faster than the first (once we learned the hard way what to look for), was removed in July of 2012, with wide margins all around, including underneath – meaning [...]

  13. [...] Most people would sprint to their vet if their dog developed something like that – while the nearly invisible ones often go unnoticed – which is exactly what happened with Meadow’s first tumor. [...]

  14. Gilly says:

    Hey there,
    Last night when I was massaging my four legged best friend, I felt a lump on her left inner thigh under some sparse fur. It didn’t feel like her usual ‘allergic reaction’ bumps besides which she hasn’t had any of those for over a year. I came on line and found this article. It is only small, like half a hair clip but when I try and feel around it I cant get hold of it like its part of her muschle instead of under skin :-( There is no colour to it and she doesn’t seem bothered when I press it and she is eating and playing ok – but tomorrow (its sunday today so cant) I will be taking her to the vets but my vets tends to be dismissive of things. Should I demand a skin scrape / blood test / needle to be put into lump to check for blood on that first visit because I don’t want to be told to ‘go away and check for changes’ …. can someone let me know EXACTLY what I should demand at this stage rather than be fobbed off. The truth of the matter is, my pooch (Rea) saved my life a number of years ago and we have been extraordinarily close and inseperable since – like romeo and Juliet !!lol …. if she goes I go…. so to say … so if anyone can advise on what I should be asking for on this first visit id be very greatful – I will also keep everyone posted in case someone else in this situation reads this page (which is great by the way – please keep us updated on meadown!) ..

    • Donna says:

      Hi Gilly…sorry to hear that you found a lump on Rea..and I hope it turns out to be nothing. I always start out with “I’m not a vet,” but if it were me, I would demand that a fine needle aspirate be done. I feel that is the best first defense to get a better idea of what is going on. Again, it may be nothing, but then it will set your mind at ease. And if it isn’t “nothing” you can have it diagnosed and treated as soon as possible. Please come back and let me know how you make out.

  15. MAGGIE says:

    Oh my goodness thank god for this site. I found a quarter size lump (?? cyst) on my Marty’s stomach 3 days ago..I just made an appointment for him to see his vet tomorrow…This boy is 12 yrs old (Bichon)my pride and joy. 2 months ago he had over 8 skin tags removed one was full of blood behind his ear and was dismissed as a wart (REALLY?. Thanks again for this site.

  16. Julie says:

    Thank you for your story, and for the updates, I’ll pray for you and your Meadow. Today was the first time our vet seemed worried about our Landon’s mass under his skin. He is a 5 year boxer and my whole world :( Im hoping & praying for a simple explanation that doesn’t involve malignant cancer.

    • Donna says:

      Hi Julie…I hope it turns out to be something benign for Landon. Are you waiting on lab results, or are they planning surgery? Please check back and let me know how your baby is.

  17. Sherrie says:

    Hi Donna. How is Meadow? My husband found a lump on our schnauzer, Gabbi, the other day while bathing her. We have an appointment with our vet Monday afternoon. We’re very nervous, please say a prayer for Gabbi.

    • Donna says:

      Hi Sherrie…Meadow is doing well. In addition to her tumors, both she and my Lab, Toby, have multiple benign lumps and bumps….let’s hope that Gabbi’s lump turns out to be benign too! It’s always best to get them checked…and most times…it is nothing to worry about and you can put your fears to rest. Good luck at the vet, and please come back and let me know how you make out. :-)

  18. Kara says:

    Hi Donna, I know this thread is a few months old, but I figured I would try and chat with you and see if you are still checking it. How are your babies doing, for starters? What happened with the lump on your dog that went several months without diagnosis? was this the one that was stage 2? My story is: we noticed a couple of lumps on our almost 6 year old yellow lab and brought her in. SO nervous of what they were going to say, she aspirated one near her arm pit and the one on her belly and they were both just lipomas. The one on her leg she dismissed as just a superficial skin thing or a cyst of some kind. This was not our normal vet as he was not in the office that day. About a month later we discovered another lump about 6 inches above the armpit one. Went back to this same vet at my office since she was familiar with the situation and we felt comfortable with her, and aspirated that as well and determined another lipoma, sigh of relief, right?! While we were there I had her look at the others again including the leg which she dismissed, but I explained it sometimes looks a little more red than other times. Still said it was on the surface of the skin and she was not concerned. Fast forward to 5 days ago (6 months after all of the above happened)Nala is now 6 years and 2 months old. I came home from work and noticed her leg was bleeding, the bump that was “nothing”. Thinking still it was nothing and maybe just whatever that skin thing was maybe got infected or she was biting at it or whatever, we brought her to our usual vet on Saturday morning (the next day). He immediately wanted to aspirate it, which I wish the other one just did from the beginning no matter WHAT she thought…we just trusted she knew what it was….and to my complete shock and immediate stomach sickness, Mast Cell Tumor. I cried uncontrollably basically all weekend. She went for Surgery 2 days later, first thing Monday morning. He took it out and the surrounding tissue and off to the pathologist it goes. The wait for these results is a KILLER. I am so so so concerned that because it was misdiagnosed and it waited SO long before being taken out, are we doomed? Is it automatically in stage 3 or 4? Worried sick is an understatement. I have never been so nervous in my life. And could this have just been a cyst, or something that turned INTO mast cell? Or was it always mast cell from the minute it appeared on her leg. Just wondering how long your baby had this from the time you noticed till the time it came out and what was the final diagnosis? I am sick over this. We take SUCH good care of her and bring her in immediately when something is wrong, regardless of cost, etc. So the thought that she may have cancer that went too far over something we could have fixed THEN and it’s not even our fault is KILLING me. Any help or advice on what others have gone though will be so helpful to me. As I wait for these results, the blogs and websites are my only hope for some kind of answers. Now of course I am thinking back on any little thing she has done, even the smallest things and feeling like “what if that was cause she is loaded with cancer now?” Ugh. I don’t know how I will survive until next week, waiting. Thanks so much in advance for any help.

    • Donna says:

      Hi Kara…I’m so sorry to hear that you Lab has a mast cell tumor, and I’m hoping for good news for the biopsy results. Waiting is awful, that’s for sure! Since the tumor was removed on Monday, I’m hoping you may already have your biopsy results as I type this.

      All three of Meadow’s were tricky to diagnose, and all three took several months to diagnose. We thought the first one was a bug bite! We live in a very buggy area, on Long Island, next to the woods, so whenever the lump appeared, it just looked like a mosquito bite. Until one day I realized the bite kept returning in the same spot! On that one, we did not get clean margins, but we did not seek further treatment, because even though it turned out to be a grade 2 tumor, it was very low on the mitotic scale, which means it was not likely to spread, luckily.

      The next two tumors took a while to diagnose, simply because they would disappear within hours, and they never seemed to appear when our vet was available to aspirate them. But those two we ended up catching early enough to get clean margins on. Both of them were also Grade 2s, but low on the mitotic scale. It is that scale that is most important in your biopsy results. Make sure to ask the vet what it was.

      As for thinking this is your fault, you need to just stop that now. At least you didn’t think it was a bug bite! You asked the vet to look at it…twice! Let’s just hope for good results. I’m glad the surgery part is behind you…I’m sure you worried about that too.

      Also, I recommend reading my three part mast cell series of posts, which you can find here:

      Please let me know how your baby makes out. I’ll be thinking of you both.

      • Kara says:

        Hi Donna, Thank you so much for responding! After I sent you the message I did end up reading all of your blogs and see that you were ending the blogging, so I appreciate you responding still. I have not got the report yet back. The vet says it takes about 8 or so days once they send them to the pathologist and they do what they do then send the results. Painful, huh? I don’t get why so long, especially in this situation where the doggy parents are on edge! I am truly in a panic thinking about it every day. I know it is not my fault, but I am just sick over the thought that she now had this lump for about 6 months and how could it not spread in SO long of a time. I have been preparing for the worst, because there is no way it is going to be good that long later. I have been reading countless hours and hours of material online. And early detection and removal seems key. The one thing I did find is that usually a higher grade tumor tends to really get larger in size as time goes on, and also that some mast cell tumors are not even necessarily cancer and can be totally benign. Hers was pretty small and also did not get too much bigger at all in all of those months. The only time it changed was just on Friday when I noticed it was suddenly bleeding. Which I also am concerned might be a horrible sign. But I am holding on to all the hope in the whole wide world. She just turned 6 and has a lot of fun to be had still! She has other lumps that seemed even more concerning to me and we have had every one aspirated as they showed up. Luckily all were lipomas. I am also hoping that since no other mast cell tumors popped up in all of that time that it has not spread. Ugh. How stressful! Also all of her regular blood work and organ function and all of that were fine, and she has not acted any different of showed signs of sickness in those months. Have you read anywhere or have any knowledge in your findings if something can actually start off as a cyst or benign and THEN turn into cancer? I have been trying to look and see if that was the case. I am just thinking maybe when the other vet looked at them they really WERE nothing? That’s my only hope. I will keep you posted. Let me know if you have any insight on that. Thank you so much for sharing your stories and helping so many people who are going through this for the first time understand it all a little better!!

        • Donna says:

          No problem at all about responding. Like I said in my final post, the tumors are one of the reasons I am keeping this site active and not just closing it down. A few things to be aware…First, even if she does develop other mast cell tumors, it does not mean it has spread internally. Some dogs are just prone to them, like our Meadow. Each was an individual tumor though, not a sign of metastatic cancer. And yes, some mast cell tumors can be very benign, which would be wonderful news! Maybe it started bleeding because she scraped it on something? Could that be possible?

          I don’t know if the bleeding relates to severity of the disease, so try not to jump the gun, as hard as it is. Sorry you have to wait so long for your results. I can’t remember how long it took for us to get the results, but each lab is different anyway, so that would be no help to you.

          I can’t recall coming across any incidences of a cyst or benign lump changing to mast cell cancer, but it also wasn’t the focus of my searches. I do know that mast cell tumors are called “the great imitators” because they can resemble other things, which is why I now get all lumps and bumps aspirated too. It is hard not to worry about every new lump that crops up, but you should know that Meadow has about thirteen or so benign lumps too, many of which occurred after the tumors, so try not to panic when you see new ones. Just be aware, check her regularly, and get them checked (like you’ve been doing).

          My yellow Lab is covered in both cysts and lipomas too, and I know those types of lumps are pretty common in Labs. And, many dogs only get one mast cell tumor and never get another. In fact, I think our Meadow is in the minority with her multiple tumors, but I learned later that Vizslas (and many red dogs) are prone to them…

          If you have any other questions, ask away. I’ll be sending you positive vibes for good lab results!

          • Kara N. says:

            Donna, you have no idea how helpful your words have been. Thank you so much again and I will definitely keep you posted. I appreciate your positive vibes I feel them. Talk with you soon and thank you

          • Kara N. says:

            Hi Donna. Update: Nalas pathology report came back as a high stage one low stage 2 with completely clean margins and low index, no spreading and no further treatment required. I am sure you know the relief and pure happiness I feel. She will go for her follow up to get the stitches out and I will as further questions, but it’s a miracle given how long that was there after the other vet misdiagnosed it. I’m thrilled beyond words! Now we just have to watch her and hope she doesn’t ever have another one! Thank you so much for your page and insight!

          • Donna says:

            You don’t know how happy I am to see this update! I’m so glad for you and Nala! Thanks for stopping back to let me know. :-)

  19. PointerMom says:

    Greetings, I just felt the need to write and thank Donna for the information she has shared. I discovered a bump on my German Shorthaired Pointer’s hind quarters and immediately went to the internet and discovered this thread. The picture shown in this article is identical to the bump I discovered on my dog. Because of this, I made a vet appointment immediately which we just returned from. The vet wants to get a second opinion (she seems really young…) as it appears that there are some MCT-type cells. Thanks again for sharing your story, especially the picture, as that was the driving factor for me to get to the vet. Many thanks.

  20. Mom2GSDs says:

    Wow. So many years, and you’re still helping people and their dogs. I Googled “lumps on dog’s leg” after I found a small mass on my 7-year-old German shepherd’s knee. She’s got a thick coat, so it was dumb luck I felt it. I was planning to wait until her check up in October to have it looked at, but thought I’d better learn more. NO MORE!!!! Between now and Monday, when the vet’s office opens, I will check every inch of her and her sister. Thanks to you, I will sleep better.

    • Donna says:

      Hi…I’m glad you found my post useful, and I do hope it turns out to be nothing, but better to get it checked. I’m partial to shepherds, my mom has two now and she always had one (or more) when we were kids. Great dogs!! Please check back and let me know how you make out.

  21. Sandi says:

    Doing my research–discovered a lump on my Sammi’s leg yesterday. Taking her to vet this morning–very frightened.

    • Donna says:

      Hi Sandi…I’m so sorry you found a lump on Sammi’s leg. I hope it was nothing. If you do stop back here, please let me know how you made out at the vet.

      • Sandi says:

        Thanks, Donna. Vet x-rayed her and said no evidence of cancer and she feels it is a synovial cyst. Still I am waiting and watching the lump.

        • Donna says:

          Oh good. Glad your vet feels it is nothing to worry about. Is the cyst on a joint?

          • Sandi says:

            Yes, very close. She didn’t want to aspirate for that reason

          • Donna says:

            Yeah, I understand how that goes….my Lab has a cyst inside the joint on his front leg. You know, vets are usually pretty good at telling cysts apart from growths…my vet generally calls it before he even aspirates. I hope it stays small and never gives Sammi an ounce of trouble!

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