[CivilWarBrewing]

Our dog’s tongue changes color throughout the day. The vet told us her heart is strong and functioning normally but some dog’s tongues just do that.

[Spunky]

My sweet little Misty was in heart failure. She wasn't getting oxygen. As long as they had her in the Oxygen chamber she was not to stressed, but the minute they started cutting it down she went into stress her tongue started turning blue and her breathing was very labored. We made the decision this afternoon to have her put to sleep. At my age I will never get another pet as I love them to much and it is to stressful for me to make that decision.

You asked about the Viagra. That pill was first made for certain heart conditions, but they discovered what one of the side effects was (for men) and that would make the pharmaceutical company millions more dollars by marketing it for that instead.