I tell you what I do which helps cool my dog down in very hot weather. I put tepid (not very cold) water on her. I start by putting a little water on the back of her neck, then work a little more down her back, and so on, until she is really wet. I do it gradually, so it doesn't come as a shock. She always stops panting so much after I've done this. The wet fur will help to catch any breeze, and help to cool her down.
Another thing is don't let them run around too much in the heat. The best time for hard exercise is at either dawn or dusk. And if it never really cools down at night (depending where you live) -then hard exercise may be out of the question.
Also, if they are long-coated dogs, this might sound a little brutal, but I would consider having their fur cut. It will look strange, but they will be cooler, and the fur will grow back given time.
Some nice "chillout" place for them to lay down when they come in will help. If you don't have air-con, how about a fan?
When I was a kid, if I was too hot, my mother used to give me a "hot-water-bottle" with crushed ice and ice water in it to hug....I loved it! I don't know if that would be possible, or if you could improvise, but a few of those, covered over with a thin dog-bed, for them to lie on would be such a cool idea!
Thank you for your response - no chance of pregnancy. I think you are right it's just the heat. I will have bloodwork done next time we take them to the vet. Thanks again.
Both dogs have the same issue? (well, they both have the heavy breathing?)
Are they related? The one who is hungry all the time...is she spayed? Could there be any chance she is pregnant?
OK maybe not....I just had to mention that possibility.
I would get them both checked out with a vet. It might be a good idea to run a full blood-work on both of them, which should show up if there is any infection (causing fever) or any other things going on.....get their hearts checked, and also check them for any Thyroid problems.
Another consideration. Even if they have been in the air all day, if it is extremely hot outside, they could still be feeling the heat. And the only way dogs have of cooling themselves down is by panting. Also, it can be warmer inside the house, if there is no air-conditioning, so they could still feel too hot when they come inside later in the day. Remember, dogs don't have the option of taking off their fur-coats!