Boxers/fainting or seizure or heart
My boxer of four years old and twice in the last three days he has had episodes of the color draining out of his tongue and gums. He seems less then coherent and stares at me. He was a rescue so he normally jumps at the slightest noise. I had to beat on the floor and he seemed to not be with me. He seemed to be trying to come back to be alert more through his legs and sitting up but can't get his eyes to come into focus. He seems to be over within 5-10 minutes and the color comes back and he is fine. I am not sure what to think, I made an appointment for the vet and then he seemed fine so I didn't take him. Then it happens again on Sunday after the initial on Friday night. He seems hungry after the incident and thirsty. I don't know what to ask the vet to do so as to keep the cost down in not exploring everything under the sun.
I'm sorry to hear about your boy's troubles. With Boxers, the first thought with fainting and pale gums is the heart. Seizures are certainly a possibility, although often the gums get bright red rather than pale. I would suggest a visit with a board-certified veterinary cardiologist, ideally one that is familiar with Boxer heart issues. You'll want to have an auscultation, and if there's a murmur a Doppler echocardiogram done, and you'll also want a holter monitor put on him.
The holter is basically a 24-hour EKG. Boxers are prone to a cardiomyopathy (ARVC) that is characterized by abnormal heartbeats; if too many of them occur in a row, the heart doesn't pump blood to the brain and the dog will pass out. There is a lot of variability in the beats and so a normal 2-3 minute EKG often doesn't usually catch them. Sometimes even the 24-hour monitor won't catch them, but in a symptomatic dog the odds are higher.
Unfortunately often the first symptom of ARVC is sudden death, so I personally would not want to delay the holter. If you can't get in to see a cardiologist soon, you can rent holters from some Boxer clubs, breeders, or cardiac companies. (A web search for "holter rental" should bring up some options for you.)
It could be other things, too, like low blood sugar, anemia, thyroid issues, a worm infestation -- but with Boxers, probably 8 out of 10 times it's the heart.
Most dogs with ARVC respond well to medication, once the dosage is fine-tuned; our cardiologist here has had dogs doing well on meds for 8+ years. Good luck, and I hope you get things figured out quickly!