Unfortunately, I have treated my male erectus many times for GBD. Sometimes it is a simple microbubble issue and sometimes it is a bacterial infection creating gasses.
To evacuate I used a bobby pin (plastic tip left on).
If you choose this method:
Hold the horse underwater so that your thumb rests on the base of the pouch in a way that gentle pressure forces air up to the opening. Let him rap his tail around your finger.
While exerting mild pressure, gently tease the opening of the pouch open with the bobby pin. This takes some practice with gentle side to side and downward pressure. You are really trying to ease the two sides of the pouch open just a little.
The horse will clamp but with patience you will break the "seal" of the pouch opening enough to force the bubbles out.
The key is gentle but firm - never forcing.
My male had this as a recurring problem and I got to the point of being able to express the bubbles in moments. It really ****es off the horse though!
The members on Seahorse.org will recommend Diamox, a prescription commonly used for HACE (high altitude cerebral edema) and list sellers etc... The problem is they can't ship to Canada. I actually got a Pharmacist to prescribe some for me after explaining the problem. The meds are administered as a pouch flush and should clear the problem up.
Good luck with the horse.
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