non-formal garments for wedding in short length

I'm so in love with my sweet Benson. He has settled into our home and family like he's always lived here. He gives me hugs now and is the best retriever of toys I've ever had!
I'm concerned about his panting, his rapid heart rate. The day after he came to me i had our vet appointment and he got his full physical. I told her about this even then. She believed it was the stress of getting new family and surroundings. But here we are a month in and he is still a heavy panter when he lays down in bed to rest. He always has fresh cool water, lives inside with air conditioning and doesn't have to have been running or playing hard right before. non-formal garments for wedding in short length
Could it be the long hair?