Are you sitting down? Ralphie has HEARTWORMS.
Yep, that's right. A moderate to severe case at that. He spent the day at my vet's clinic the week following our emergency vet adventure. His EKG looked great (whew!) so they moved on to a chest x-ray that showed the right side of his heart enlarged. Doc could see the worms on the film.
Strange part? He tested NEGATIVE (for the THIRD time since we found him a year ago) that same day. Even though it's quite obvious he's infested. We now think that the worms either temporarily affected one of his heart valves or that the entire load shifted, basically causing him to pass out that Sunday.
Heartworms explain all of his cardiac symptoms perfectly, but they weren't even on our radar since he tested negative in April 08, again in October 08 and since he's been on preventative (that I now know could have killed him) religiously since we found him.
Ralphie received his first immiticide injection that same day (May 27th). He was out of commission for about 72 hours before returning to his old self. Which leaves us the difficult task of keeping him calm. Sadly, he's spending a lot of time in his crate these days. But it's only temporary.
I guess if I had to choose between a treatable case of heartworms or getting to know our local veterinary cardiologist on a first name basis...I'd pick heartworms. His treatment will be over in 8-10 more weeks and there should be no long term effects.