Has anyone had a horse which had a melanoma or sarcoma have it remain unchanged visually, but eventually metastize to lymphoma of the spleen, liver or intestine? Or if not, is that possible?
Not speaking from personal experience with a horse, but tumors certainly can metastasize without obvious visible change. Some cancers are widely metastatic already when they’re first discovered. However, a sarcoma or melanoma cannot turn into a lymphoma. Totally different origins.
reliable website for equine cancer and my mare’s story
Here’s some general information that is reliable and might be beneficial to you:
http://www.vetmed.ucdavis.edu/ceh/docs/horsereport/pubs-HR26-2-bkm-sec.pdf
My mare’s melanomas did not metastasize to organs that we’re aware of, but here’s her story if you would like to read further:
When we were in Washington and my mare was almost a year old she was diagnosed with a melanoma on the pastern/heel bulb area of a front leg. Following protocol it was frozen by our vet but it never really responded completely the way it was supposed to, though it did slough some and stopped growing. Because of its location it would be hard to remove with clean edges and still pull tissue back together to heal, especially with a youngster that liked to play a lot, and so surgery was put on the back burner and we adopted a “wait and see” approach.
When she was about three years old I noticed another “bump” that was a bit different growing on the same leg just below her “armpit.” At this time we were in northern California and my mare was checked by the local vet and previous history discussed. Within a very short time the bump grew dramatically outward and she became quieter and quieter (so not her), and so I opted to take her to UC Davis. It was there we met the head of equine oncology, Dr. Alain Theon, who was working on equine melanoma. He brought in the head of equine dermatology to figure out the perplexing case of my mare. They brought in the chief resident of surgery to consult as well. They finally opted to surgically remove the bump on her pastern, the one on the upper leg, and another little lump by her eye (same side). During the three weeks of stall rest following the surgery she healed well and was quiet. They taught me to be an expert on correctly pressure wrapping her pastern so it could heal correctly. I believe it was the pastern melanoma that they did not get clean edges on the biopsy. The one tiny bump by the eye was benign. The upper leg biopsy had clean edges.
Once she started having turnout she was still very quiet, just not herself, and then more bumps began appearing directly above that leg and even along her spine. My “air fern” was losing weight. Back to UC Davis for more consultation. At that time Dr. Theon was working on a theory/study that melanoma in horses can be related to the immune system. Oh, they bounced around ideas as they tried to figure this out. Is the melanoma working up along the nervous system? How does immunity play into this? Why doesn’t she have melanomas where horses typically do? Could her early road run incident (a few months before the first melanoma appeared on pastern) have damaged cells in her foot/leg and opened it up to melanoma and immunity compromise? Could it have spread internally? Etc. What I learned was that no matter how fabulous these vets were and they really were, we still are learning about melanomas.
still following? Congrats if you are.:winkgrin:
Rather than biopsy areas on her back and perhaps create an overly sensitive back in the future, it became another wait and observe time. Over the next few weeks she finally started gaining back some weight, she began to play again, and just overall lost that lethargic demeanor that worried me. Last checkup at UC Davis showed no lumps or bumps anywhere and surgical sites were well healed.
Fast forward another year to the discovery of another lump on the opposite shoulder. sigh Our local vet removed it and sent it off to UC Davis for biopsy. Results were another melanoma and clean edges. Yay for clean edges! No particular lethargy or weight loss this time.
Really fast forward to age nine years. We have not had another suspicious bump and none of the weight loss or lethargy that was evident during those couple of months at age three.
Not sure if any of this will be helpful to you, but I remember hunting constantly for any information related to equine melanoma when I was so worried about my mare so thought it was best to share. Let me know if I can answer any questions for you and I’ll be curious to see what you find out.
SID - Yes and no. We recently lost my husband’s QH mare to cancer. It was rather odd as she was a regular chestnut with chrome (and developed a large odd greying patch on her left flank in her teens). She was 22 and looked great last spring, but by summer was noticeably losing weight. After doing all the usual things and getting no real improvement we started walking down the long diagnostic trail.
Long story short, we found “melanomic” cells and evidence that her bone marrow was involved. We never found any evidence of any tumors, either on the outside or on as much of the inside as we could see with ultrasounds and scopes (or palpatations). Unfortunately there were no treatment options and she had very, very few redblood cells left by the time we were no longer able to manage her and keep her comfortable. She made it to December before we sent her on to be with her “friends who had gone on before” her.
From what I learned of melanoma during this process is that it is quite deadly in non greys and unpredictable in greys. Greys can tolerate melanoma for many, many years and there is no good predictor of whether or not tumors will turn malignent.
I know this isn’t what you asked, but I hope it is helpful on some level. Big jingles in any case.
SCFarm
Actually, I’ve done a lot of research today and “yes/no” seems to be what I’m reading (the Horse, UCDavis, UK vet sites as well).
Calli is my mare who about 6 months ago came up RH lame (but holding the leg way up in the air, intermittently, would walk sound, then up in the air).
Almost simultaneously we discovered a pea-sized melanoma on her throatlatch. She’s a dark bay, btw.
Diagnostics at Va Tech EMC, showed what was “believed” to be a stress fracture of the femur, but they could not actually lay her down under for complete films because if were a fracture, she could have a catastrophic break upon coming out from under. They also made a point to say that they could not rule out osteosarcoma.
I was told to just keep any eye on that melanoma (or sarcoma, whatever) for any changes. No changes.
Stall rest for 4 months…sound horse. BUT, the glitch is this…massive weight loss starting about 3 mos. into stall rest. I mean massive. Changed her feed, free choice hay (that would have made her explode in the past) yet she still kept dropping weight. Not anxious in her stall, best buddy with her…and she had a 4 month layup when she was 7 mos. Very laid back, lovely gal.
Started turning her out (still sound) 24/7 with some limited grass, free choice hay, huge increases in concentrates (plus oil…I feed all my Shire x’s oil)…and she is simply wasting away. Her attitude is great, but is a bit anorexic with the hay…not the grain. And the hay is superlative and this years, already cured.
In the last week her muscle is literally falling off her bones. She’s now on 10 lbs. of Senior feed, 3 cups oil, free choice timothy and she is simply wasting away. Attitude is great…but then this is a very, very stoic gal.
I lost an 8 yr. old several years ago to lympocarcoma with NO warning except a week before we had to put her down. The kind that invaded her chest cavity and the symptoms were not apparent until she went off feed, high heart and respiration rate (tumors pressing on lungs and heart), blood from nose. She was “happy” too and was not lethargic or depressed. Very shocking. She was a black mare and I did see on melonoma around her anus a few months before.
So you can see my reason for asking. The only outward sign (in hindsight) with my other mare was a small, unchanging tumor. With Calli, I can only conclude that that outward sign is indicative of internal cancer which is wasting her. BTW, when she first started losing weight so rapidly, CBC and Blood Chem showed nothing…but that’s not unusual for cancers.
If she really had bone cancer, I would think that she would have not gone sound…we’re very puzzled. I hesitate to take her to the EMC for diagnostics because if it is, for instance, intestinal cancer – which her clinical symptoms seem to indicate (progressive weight loss despite massive increases in food/calories) it is seldom actually diagnosable until necropsy. And there is no treatment.
Perhaps the two issues (femur problem) and melanoma are unrelated. I suspect that they are. Just trying to get some info here.
I bred her and raised her and this is a Shire/TB mare who has been an airfern all her life…even when in very intense dressage work. I mean I have had to dry lot her in the summer most of her life. She’s 17 years old and was/is my top dressage teacher that I finally hoped to start to ride now, until that femur “fracture”. A love a gal and a real superstar.
Insights?
Many, many years ago we had a 17 year old gray broodmare, daughter of Bill Cody, with two egg sized bumps on her throat, that were there for a few years and no others.
One afternoon she came up to water with an obviously broken front leg, at the shoulder level.:eek:
I will never forget the shock of seeing her there, in the pasture below the barn, the pond behind her, on three legs, but unconcerned, seeing us and wanting to come to us for a treat but not being able to walk very good.
The vet was coming anyway and when he got there he called the break a result of osteosarcoma, not related to the gray horse melanomas and euthanized her.
I don’t know how he came with that diagnosis, because he examined her, but didn’t necropsy her.
It may have been an educated guess.
I hope your mare will rally and all will be fine after all.
How long ago did you run the bloodwork? Maybe ask your vet if it would be worth repeating to check and see if her calcium levels have become elevated? I know in small animal medicine that can be indicative of cancer brewing somewhere in there.
Good luck. The unexplained weight loss is definitely concerning. 
I’m so sorry.
Yep on the bloodwork. My vet and his back up are both out of town until Monday. I may call upon another. Her “eye” is getting dim this evening, and I know that look all too well, though she is acting strong.
What besides a CBC and Blood Chemistry, might be more telling? Though my last horse with lymphosarcoma showed nothing.
Also considered a belly tap and run it up to the hospital along with a fecal occult blood test to see if there is blood in the GI tract.
I can DO all this stuff for my own curiousity and knowledge, but if it’s what I think it is it will do nothing to save her. That’s the hard part. Wanting to know, then realizing there is no remedy.
I just want to say I am sorry. It must be very hard, waiting to see what will happen, feeling there is nothing to be done. You are so pro-active w/your horses…
I hope you have some sort of resolution soon.
I had a mare with lymphosarcoma a few years ago and she went as follows:
She was a perfectly healthy 8 y/o TB mare carrying her first foal. Six weeks before the eleven month mark she developed a snotty nose and I mean bad snotty. When she dipped her head to eat or drink huge gobs of stuff fell out of her nose. She also started to rapidly drop weight. I spoke to my vet (whom I worked for at the time and is fantastic) and he said go ahead and start her on SMZs.
We did this with no improvement and meanwhile she starts streaming milk so I think that she is going to foal early/abort. She streams and drips for about 10 days, won’t lay down, still eating and drinking normally, and finally aborts a smallish foal with a very thick placenta and umbilicle cord.
Normally we would send this to the lab but by this time it was obvious that that was the least of our problems. She has dropped approx. 300 pounds in less than a month and the muscle is just wasting to nothing despite a feed and hay increase. The snotty nose was no better despite changing antibiotics several times. The strangest symptom is that she now required huge amounts of water. She was in a small lot with a run in and a 20 gallon water tub. You could fill it in the morning and before noon she had not only drained it but would stand at it licking the bottom for as long as you let her. She would drink easily 50 gallons of water per day which as pretty alarming (this was mid spring and not hot weather).
Next step was to restrict her water intake. If I am relaying this correctly that was in case she had a psychological problem (in addition to whatever else was going on) and was obsessively drinking. This could cause the level of urea in her kidneys to get off kilter which would cause her to keep flushing them out with water. Basically the problem would keep making itself worse and worse. This was heartbreaking because she would just stand and lick the water tub between waterings.
She finally developed pitting edema on all four legs and got so skinny that we knew that she was done. This was after about a dozen trips to the clinic and everything from ultrasounds to lots of bloodwork to tapping her belly. The last option was exploratory surgery that would still likely end with euthanizing her on the table. We elected to euthanize and on necropsy discovered that although she had no outside masses that we could find, her uterus, broad ligaments, ovaries, kidneys, some bowel, and who knows what else were just eaten up with cancer.
Sorry this is such a long post and not very uplifting, but this was my experience with lymphosarcoma. The entire thing from first noticable symptom to euthanasia was about two months. I hope that your horse has a drastically better outcome, jingles for her.
Lindsay
Unfortunately, we had an Arab who started losing weight. The vets did every test there was, belly taps, ultrasounds, everything, and couldn’t figure out why he was so thin. We kept bringing up cancer, but all the tests said no. He wanted to eat but wouldn’t. He would take a bite and then just stop. We finally put him down, and once they opened him up, they found cancer EVERYWHERE in his belly. The opening to his stomach, which was full of ulcers, had shrunken down to about the size of a dime.
It was awful, and the only reason we waited so long to put him down was that the vets kept saying it was NOT cancer and they just wanted to try one more thing that they were sure would work…
It seems that once they start dropping weight and there’s no improvement, it’s usually cancer. What’s bad is that they can’t always find it. Wish I had better information for you.
ETA: This was a 19 year old chestnut gelding, and from the time he started losing weight until we euth’ed was probably about 6 months.
I have NO idea if this is proper protocal for horses… so ask your vet, but…
we are worried my best dog in the world could have lymphoma. We were just at the vet’s again tonight, he’s looking into some more advanced diagnostics and the pros/cons before we run them. We decided against chemo if that’s what it is. He’s asymptomatic now.
One protocol for keeping dogs with that comfy is prednisone. I’d ask your vet about Pred or something like Winstrol. For dogs, Pred doesn’t increase the life span, just makes them feel better.
I rescued a skinny, neuro-looking old old intact Rotti from a shelter at Christmas time once as my Christmas present to the dog world 
It made room for one more at the shelter that night, and I swear I saw a smile on his face in the back of the car on the ride home. We found he came with Osteo in his skull. We finally went to pred (which fixed his neurological like back issues). Tommy had a few good weeks of running and playing like a dog. I was there when he tried to leap onto the deck- missed- and landed on his shoulder. I called my vet (good friend) right away, and she said, it’s been a few weeks and that’s about as long as it takes… it’s the osteo. The old Tommy would never stop eating. You could tell he just really loved his new life. Too bad it was only for 6 weeks… the Pred made it a great few weeks.
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sid, I wish I had more insight for you. I understand the frustration and helplessness you must be feeling as you search for answers and there’s just nothing specific to be found at this point.
As I read this thread it rings a bell with what I dealt with for two dogs with canine lymphoma. There were symptoms that no matter how many trips to the vets we took and lab work we did we still didn’t get a definitive answer related to cancer until soon before we lost them. My little voice kept telling me something was seriously wrong long before we had those answers.
I added this because I realized what’s consistent in all these instances is that we each felt something was seriously wrong even when lab work didn’t show that. I think we should always listen to our intuition.
With that said, I know my heart was in my throat as we processed information for my mare, as I’m sure each poster writing about their experiences has dealt with, but my mare is happy and healthy now so there can be happy endings.
sid, I think if it were my horse I would check blood work again hoping that it could implicate the problem, but might leave you still in the dark as to the reason for the rapid weight loss. I do hope the situation resolves itself like it has for my mare. Please keep us abreast of what’s going on.
Sid I am so very sorry you are going through this with your mare. I remember well chatting with you about your other horse and her lymphosarcoma.
I do very much think that cancer is more common in horses than any of us realize, and that it often goes undetected until the horse is put down or passes away due to a secondary issue like colic or bleeding or something.
Go with your gut on this… Bloodwork may be a good place to start if you’ve not done it already. I know it is hard, because if she does have cancer, what can you do?
My 21 y/o TB has numerous lumps and bumps and I worry every day… I know if he’s got them on the outside, he’s probably got them on the inside too.
Anyway hugs to you and jingles for your mare. Hope she perks up a bit for you…
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The vet just left (called the back up to my regular vet – just wonderful). Explained the history and she took one look at her and said “oh my”. Really can’t be anything other than cancer, considering that melanoma on her throatlatch. I had read this and she confirmed melanomas in dark horses are rare, but very aggressive. Pulled blood and should have results back today. May show nothing, but I want to avoid some catastrophic event that may show is pending through the results.
She’s comfortable, eating no hay, but still eager for good “scritchies” and her senior feed, which she said to feed as much of as she wants. I’ll keep close eye on respiration, temp, hr, manure, etc. I hope she’ll hang in until my regular vet gets back, but if she starts to become obviously depressed or becomes painful I’ll do what I need to do quickly.
This is so heartbreaking…. These years ahead were supposed to “our” years…just she and me to teach me as I get back in the saddle. Candy Allen was her trainer and Calli was always the favorite --a happy “workaholic” for many dressage enthusiasts who lessoned here years ago. A powerhouse, an athlete with the kindest soul. She was special from the day I delivered her.
Thanks for all the input.
Sid, I am so sorry. You hang in there. That ol’ gal is lucky to have you.
I’m so sorry. I leased a horse that had about the same exact story as Seven-Ups post (blood bay TB). Rapid weight loss and anemic (he was bleeding out internally) were the only two signs. I still can’t talk about it without tearing up (like right now).
[[[[[HUG]]]]]
Bloodwork back – nothing significant except that she is losing protien somewhere. As long as she’s not suffering, we’ll take it a day at a time.
I want to share that I lost my beloved Springer, Shelby, to lymphoma- BUT, we lost her because she also had bone marrow cancer. My regular Vet, who is wonderful, did NOT test her, and we treated her for the lymphoma, and couldn’t figure out why her bloodwork wasn’t improving. I took her to the Vet who literally wrote the book on Veterinary Oncology, Dr. Jeglum, and she tested her for bmc, and she came back positive. My regular Vet did not know about the correlation.
I am so sorry to hear about your mare, sid. I have followed you trials with your stallion, and I appreciate how proactive and loving you are with your horses. I hope you can find something to help your girl.
I’m so sorry to hear this. Taking it one day at a time is the perfect plan for you and your special mare. She sounds like a real gem.
I feel your pain on a very personal level. Lymphosarcoma took my beloved Alibar last year with devastating speed (story here). Not the same as your query since he never had a melanoma- the signs I saw were a decrease in appetite, decrease in energy level, and labored breathing. Alibar was an iron horse- he was “himself” even on the very last day, but the toll it took on his body was devastating.
I too believe that cancer is a bigger enemy to horses than we might think, due them colicking, etc before being diagnosed.
