Sarcoids & melanomas

nikicb

nikicb

Well-Known Member
Joined
15 June 2009
Messages
7,702
Location
Was Surrey, now West Berkshire
www.facebook.com
Sorry if this is a stupid question.....

Can someone tell me about the differences between sarcoids and melanomas or refer me to something to read. Out of interest really. My grey pony has a few melanomas which have been checked out by the vet and we're leaving at the moment. But for my own learning I'd like to understand the difference between the two.
Thanks for any help.
 
They're both forms of cancer though sarcoids sort of blur at the edges of the definition of "cancer". They can both have l-o-n-g spells of time when absolutely nothing happens to them and they stay small, localised and harmless. By and large, sarcoids tend not to metastasize (spread to other sites inside the body). Melanomas are much more dangerous and can and do spread to other sites within the body which will eventually cause death from organ failure of one sort or another. Grey horses are almost 100% certain to have some melanomas by the time they reach old age as it is also linked to melanin that makes the skin of grey horses grey. Sarcoids are linked to the spread of a particular virus by flies, so if a horse has 1 sarcoid it is possible that it could develop more if flies land on the raw tissue of the sarcoid. It is thought that they can also be spread from horse to horse by this same mechanism. Like all cancers, melanomas arise (very, very basically) from an error in the horse's own cell repair/reproduction mechanism. Try not to worry too much about your horse's melanomas unless you observe changes in them or other symptoms occur x
 
Thanks BoF. That's very helpful and clear. I'm trying not to get too worried about the melanomas my pony has as there's not really anything I can do about them. He's 18 so not young, and seems perfectly well in every other way. They aren't causing him any issue (under his tail), and the vet said we should just leave them be unless they get big and start interfering. He has a small pea sized one on his face, but has had that for as long as I can remember (we've had him 10 years) and it hasn't changed. In fact I thought it was just a wart until I saw the ones under his tail and checked with the vet. I just really wanted to understand the differences between the two. Thank you. :)
 
Sarcoids are NOT a form of cancer, they are a wart, thought to be caused by a virus. They can be treated by excision or 'Liverpool' cream neither method is always successful and the sarcoid can grow back.

Melanomas are growths and 98% of grey horses will have at least one, they are technically a carcinoma but most are benign. Melanomas come about in grey horses because the melanin no longer diffuses the hair shaft and has to go somewhere, it can cause nodules on (mostly) the mucous areas of the horse, ie around the anus/eyes/mouth etc, but can form elsewhere. Melanomas also attach themselves to internal organs. Melanomas only become a problem if they a) grow aggressively or b) obstruct the airways (in the throat for instance). A melanoma on a non grey would be very concerning. Melanomas can be treated by excision, but this is very hit and miss as they can often be in very difficult to get to places and very often grow back. Cimetidine is another way, this is a drug used to treat ulcers by shrinking them, it was accidentally discovered that Cimetidine sometimes caused melanomas to either shrink or stop developing further, again it is quite hit and miss and does not always work.

I am an expert on these as all my horses are grey and one of them is actually being treated for aggressive melanomas at the moment.

Try not to worry, my 31yo had one melanoma under her tail which did not change for years and years, she does have several more now but she IS 31 and in the rudest health ever!
 
Thanks Sirena, that's reassuring. I guess I just have to keep an eye on them to make sure they aren't growing really quickly. One further question. I lunge my pony to exercise him (he's a sec A and used for lead rein but lunge to keep him fit). He has to wear a crupper as the roller slips forward. It doesn't seem to rub him, but should I be careful not to chafe the melanomas and put some extra padding on it? He doesn't seem to worry and they are quite hard and flattish bumps, but I wasn't sure if it was a problem. The crupper is very smooth rounded leather, so no rough edges that could catch, but didn't want to aggrevate them.
 
Yes it is a good idea to just keep an eye on them, perhaps take a photo, then, if they do change you will be able to tell easily.

As for the crupper, it does make sense to minimimise chaffing, so, unless the melanoma is very small or not near the crupper it won't hurt to add some extra padding.
 
I was gonna post on this subject as me-laddo has 2 lumps under his tail. I am watching them closely, he started the summer with just 1. Though he had one on his back last winter and one day it just vanished!
I wondered if there are herbal/homeopathic supplements that can help?
 
You must log in or register to reply here.
Top