Breeding a mare with a melanoma

[PhoenixFarm]

Just an anecdote about the external melanomas being the tip of the ice burg:

When I ran a kids riding program, I was given a gray welsh mare that had a monstrous amount of melanomas on her vulva and dock. The owners had been told what has been stated before: if that’s what the outside looked like, then she was surely dead horse walking internally. They couldn’t bear the idea of euthanizing her, so they have her to me with full disclosure and the belief we’d have to euthanize within the year. The mare was 19 when she walked in my door.

Well, wouldn’t you know , she worked happily until she was 30, never had issues, was an easy keeper, and after we retired her at 30 she lived another five years before she passed away quietly in her sleep.

Now, of course one experience is just that, but external doesn’t always mean internal death is lurking.

My heart horse is an 18 yo gray, and every time he gets a bellyache, I try not to go immediately to “it’s a tumor”. Not sure I could take that added stress with a broodie.

[oldernewbie]

I’m not a breeder, but I do own a horse with a melanoma. He is young (7) and the melanoma is in his eye. So far we are controlling it pretty well with cimetidine and a weekly shot of Zylexis. This is not a cheap regimen (mostly because of the Zylexis) but he is worth it.

One of the things that has fascinated me about this condition is that there seems to be relatively little good, solid, scientific advice or information for the horse owner. I don’t know if melanoma is one of those things that hasn’t (until recently) generated a lot of research interest or if there hasn’t been much of a demand for more information. In any case, this thread is a perfect example of the information lack - some first hand experience, but relatively little decent information to help the OP, including no concrete info about who to contact.

Maybe, instead of posting scary stories, (which are especially scary to me as I compulsively check my horse’s eye every day), we could give the poster more names of people who know something about melanoma. It would help a lot of people.

So - who do you know? The guy in TN is mentioned above, as is the study in FL currently being run by U of F. When it comes to ocular melanomas I know my vet at Rood & Riddle knows a lot, but that doesn’t help breeders much. (BTW she has mentioned treating several broodmares with ocular melanomas who get along just fine)

So who else is out there? Where is the solid information?

ETA: OP, you might try searching the rest of the COTH forums about melanoma.

[Graymaresrule]

There’s this
http://www.thehorse.com/articles/28888/new-cancer-vaccine-for-horses-in-the-works-aaep-2011

There are a lot of gray Irish horses, both Draughts and Connemaras.

I was given a broodmare three years ago, supposedly half Connemara half Trak by Falke (never have been able to prove it) She was carrying her fifth foal. I worried the whole time but she foaled out fine. I had her put to sleep last fall at age 22 or so.

ETA:She was homozygous or gray. Falke was heterozygous for gray.

[alto]

@oldernewbie;6980481

One of the things that has fascinated me about this condition is that there seems to be relatively little good, solid, scientific advice or information for the horse owner. I don’t know if melanoma is one of those things that hasn’t (until recently) generated a lot of research interest or if there hasn’t been much of a demand for more information. In any case, this thread is a perfect example of the information lack - some first hand experience, but relatively little decent information to help the OP, including no concrete info about who to contact.

Maybe, instead of posting scary stories, (which are especially scary to me as I compulsively check my horse’s eye every day), we could give the poster more names of people who know something about melanoma. It would help a lot of people.

Did you read the open access article I linked - it has a lot of good information in there including some indications of why this is not a straightforward concept - current understanding is that it’s multi-gene/foci dependent with modifying factors.
This study spanned 9 years & over 1100 horses: read it!
If the techno-speak is an issue, ask your vet to translate :yes:

So who else is out there? Where is the solid information?

Read the scientific journals, look at the references - these are all names of people working in same or related fields, send emails, you will get some replies back …

If you wait for someone like The Horse to relay the information, the data will always be 3 - 5 years behind the leading edge of technology.

[CrowneDragon]

The weird thing with melanomas is their growth seems to wax and wane. There may be some kind of immune suppression of tumour growth, so it seems possible that an event that upsets the apple cart (illness, pregnancy, whatever) could cause an increase in growth. Or a decrease in growth. :-/ I worked with a lot of grey mares when I worked at a TB breeding farm and never noticed any correlation between tumour growth and pregnancy.

Funny anecdote for you: We had an older mare that was riddled with melanomas. She had produced several nice horses (I owned one), and in the spring she was sent out to be bred for the umpteenth time. After she got to the farm she was checked and their vet said breeding her was pointless; she was so full of melanomas that she would never get pregnant. They tried some pretty aggressive treatments to try to decrease the tumour burden in her uterus with no luck, so she was sent back to us unbred.
Several months went by (11, to be exact ) and wouldn’t you know she’s foaling out in the pasture. Since she was assumed to be infertile she was living out with the retirees, and had been bred, through the fence (with electric wire on top!), by a yearling :lol: Threw a GORGEOUS chestnut roany colt, too!

[Daventry]

[QUOTE=goodpony;6979593]
14 is a more typical age for a grey to begin showing the first signs of melanoma. A horse riddled with Melanoma by age 7 I suspect is somewhat atypical. Still its a terrible story–so sorry TC. Some breeders believe the Homozygous state may have something to do with it—versus one copy of the grey gene and or very late greying individuals.[/QUOTE]

I have to agree. My heterozygous grey broodmare had two small melanomas show up just under her tail when she was around the age of 12. She was bred every single year without a problem until she was 20 years old. I’ve done lots of research on melanomas over the years, and the consensus seems to be that, although greys are more prone to melanomas, they tend to be benign (non-cancerous). Non-greys who develop melanomas tend to be malignant (cancerous). What often ends up happening with melanomas in greys is that they tend to grows/spread and often surround or attach themselves to the organs…which is what eventually causes problems, not so much a cancerous melanoma.

[Lynnwood]

[QUOTE=Daventry;6981167]
I have to agree. My heterozygous grey broodmare had two small melanomas show up just under her tail when she was around the age of 12. She was bred every single year without a problem until she was 20 years old. I’ve done lots of research on melanomas over the years, and the consensus seems to be that, although greys are more prone to melanomas, they tend to be benign (non-cancerous). Non-greys who develop melanomas tend to be malignant (cancerous). What often ends up happening with melanomas in greys is that they tend to grows/spread and often surround or attach themselves to the organs…which is what eventually causes problems, not so much a cancerous melanoma.[/QUOTE]

Had an older TB mare as a schooling horse with a BIG plum sized melanoma on her shoulder one up on her neck one by her thyroidish area looked almost to be a connected track. She was given to us to use as a schooling because she was thought to be barren had foaled something like 7ish foals previously and then spent two seasons not getting in foal. Surprise surprise when around Oct she started looking really round for kicks we had her checked and to quote the vet "this space is occupied ". Previous owner was not really sure of a breeding date she’d been living out with the stud as his companion. She foaled a nice big colt on Christmas Eve. Never saw a change in her Melenomas while bred.

However about a year later she collapsed about 10 mins after walking into the ring dead of an aortic aneurysm found during necropsy she had several heart based tumors and the vet said they contributed to her death. She was 22ish at the time.

[VirginiaBred]

@Daventry

I’ve done lots of research on melanomas over the years, and the consensus seems to be that, although greys are more prone to melanomas, they tend to be benign (non-cancerous). Non-greys who develop melanomas tend to be malignant (cancerous). What often ends up happening with melanomas in greys is that they tend to grows/spread and often surround or attach themselves to the organs…which is what eventually causes problems, not so much a cancerous melanoma.

^^THIS^^ is exactly what I’ve been told as well.

[oldernewbie]

[QUOTE=alto;6980694]
Did you read the open access article I linked - it has a lot of good information in there including some indications of why this is not a straightforward concept - current understanding is that it’s multi-gene/foci dependent with modifying factors.
This study spanned 9 years & over 1100 horses: read it!
If the techno-speak is an issue, ask your vet to translate :yes:

Read the scientific journals, look at the references - these are all names of people working in same or related fields, send emails, you will get some replies back …

If you wait for someone like The Horse to relay the information, the data will always be 3 - 5 years behind the leading edge of technology.[/QUOTE]

Yes, I did read the article. It was very interesting but doesn’t address the OP’s question or any practical issues. Don’t need an interpreter, have a biology degree.

My issue is that IF there is good research going on re: the issue, it is not filtering down to even very skilled and knowledgeable practitioners, much less to the melanoma horse owning public. Just thought I would put out a call for more information if people had it.