Hi-Oc (JC "High Octane") is my soon-to-be 24yo OTTB gelding, and the origin of my username. I've owned him since just before he turned 8...so 16 years. Time flies. He was first diagnosed with EOTRH 5 years ago, by my vet, Dr. John Zaccardi of Mount Vernon Veterinary Hospital. What we thought was a hole in his gum caused by a piece of hay, ended up being a fistula - a hallmark of EOTRH. Fistulas are draining tracts, and an outward sign that an infection is brewing in the gums.
In EOTRH, the body attacks the tooth root, and "resorbs" it. It can also try to remedy this by forming excess cementum (the hypercementosis part). Usually, horses go either way - the resorption lane or the hypercementosis lane, and the disease starts on the "outside" incisors and works its way towards the middle ones. The resorption causes more pain, and is readily apparent on radiographs. The hypercementosis is more obvious, causing large growths on the tooths at the gum line. This doesn't seem to bother the horse. I was informed that Hi-Oc seemed to have the latter, and to only monitor him for signs of pain. He didn't start to show any until December 2016.
In the photos below (dated 2/21/16), you can see the fistula above tooth #201...it's the red dot.
![Image](http://i85.photobucket.com/albums/k61/Junolalo/Mobile%20Uploads/2016-02/4DE2AAAA-3363-4C06-90E6-4F2AA956AF4E_zpsqquvqgld.jpg)
You can clearly see the hypercementosis around tooth #202...and if you look where the piece of grass is pointing, the red, mottled look of an angry gum.
![Image](http://i85.photobucket.com/albums/k61/Junolalo/Mobile%20Uploads/2016-02/636BEA35-1E07-4958-926D-794650F7B979_zpsnepwj3r2.jpg)