What is EGUS and how are ulcers treated in horses?

used just for pleasure riding. 
The additional risk factors for developing EGUS include
A high concentrate ration in the diet
Not enough roughage in the diet
Going long periods of time without eating or starvation
Not drinking enough water
In foals weaning can be a factor too.
How is EGUS diagnosed?
When we suspect a horse is being affected by EGUS or we want to rule it out the test of choice is gastroscopy. This is where we use a camera to look down the oesophagus and into the stomach. It shows us what is happening to the stomachs mucosa. Following gastroscopy the vet will often give the ulcers a grade and this is dependent on how severe the lesions are. 
How can it be treated?
The approach to treating EGUS is twofold. 
First medication is given for a period of time to reduce the stomach acidity. 
Routinely we use a drug called omeprazole this inhibits stomach acid secretion for about 24hours. It is normally given for one month and the response to treatment is monitored using gastroscopy to see if the ulcers are getting better.
The second aspect of treatment is reducing the risk factors for developing EGUS. 
This means making changes specific to the individual horse. These changes may include minimising any stress increasing foraging behaviour through access to pasture or providing regular haynets when stabled maximising the fibre content of the diet adapting the horses activity program maintaining consistency in routines and ensuring constant access to water. These horses will often benefit from being fed a small handful of hay before exercise to help buffer any stomach acid that gets splashed around.  
So whats the long term outlook?
EGUS can take some time to get on top of and there are horses that will suffer from it chronically or have repeated episodes during their lives. There are still parts of EGUS that we dont completely understand and theres research underway to help us treat and manage it better. Wherever possible prevention is better than cure so try to make sure your horses lifestyle minimises the risk of EGUS. If you have any concerns get your vet to take a look to make sure he isnt being affected.