What is a sarcoid?

After seeing a skin lesion on my horse ear that possibly was a sarcoid I searched for more informations about it to understand better what I had to face. The first thing that I undestood was that there are six different types of sarcoids and that they are the most common skin tumors that can affect a horse. Recognizing them is not so simple and it is very tricky to find an everlasting solution or an effective treatment due to the fact that they may vary a lot from a horse to the other. It doesn't seem to be more common in one breed respect to another but it has been found that the percentage of male horses affected is higher than that of females. Thay can be found everywhere in the horse's skin even if they are more commonly situated around the eyes, the mouth, on the face or the neck but they can grow also on the groin, the sheat and the legs. There is no clear eveidence of their inheritability and the good news is that they do not metastasise but often a horse with a sarcoid can develop others. It's not easy to recognise them because their appearence can vary a lot and they can be single or multiple. Sarcoids classification is based on their form and appearence so there are those that have a verrucous form, a nodular form, an occult form, a fibroplastic form, a mixed form or those called malevolent. The mixed form is a "mix" (as its name suggests) of the other sarcoids forms and every form can change in time and develop into another one. One of the more common reasons for them to change from one form into a more aggressive one is related to an injury. 

Sarcoids can be very small and stay in this way for a long period of time but the best thing to do, when you find on your horse skin something that could be a sarcoid, is to call your vet and ask him for an advise.  Probably, if the tumor is small and it doesn't create any problem to your horse, he will tell you just to monitor it and call him in case there will be any significant change in its dimension. Biopsy is not commonly used because every injury or trauma can worsten the sarcoid condition. 

Is there any satisfactory treatment that can completely solve the situation? The likeliest answer to this question is no because it is not simple to understand which treatment will work at 100%. Some of the possible solutions are: surgery, sarcoid cream, cryosurgery, injections of drugs into the lesion or radiation. Having a good dialogue with your vet is very important because his experience will be very helpful.    

Sarcoid or not?

What do you think about that? Is that a sarcoid or not? It was on the front side of the left ear of a female Haflinger, 6 y.o. It started being very little and after few months it grew suddenly without any clear reason. It used to make a crust that always went of (you can see it from the images below) and then the formation usually improved until it became doubled and then tripled. Unfortunately I do not have any photo taken during the very first time of it but it was really small and difficult to see. What happened then? Maybe an injury caused this growth but to be honest I have no idea about that. As I knew that the best solution in these cases was not touch the sarcoid until he doesn't create any problem I waited to call the vet who saw it when it started to grow. He told me that probably it was a sarcoid but the only way to know it for sure was to take a little part and analyze it. The problem is that if you remove part of a real sarcoid it probably will improve his width so if you chose to remove it it should be done for the entire tumor. Talking with my vet he also told me that, if I wanted to surgically remove it, it wasn't the right period of the year (we were almost in summer and here there are plenty of little mosquitos that can bite the wound) and it was better to wait until autumn came. So as we were waiting and the believed sarcoid continued to grow I decided to cover it with cream to protect it from insects and moreover it made the crust softer so it wouldn't have broken so often. It's true that  sometimes a spontaneous regress of the sarcoid may occur even if you do not use any particular treatment. And it's also true that in my personal case we weren't so sure about it and if it was a sarcoid or not but the thing is that it started to reduce its diameter until he completely disappeared.