Weird noises

Question
Hi,
I'm not sure if you'd define this as medical or behavioral, because I'm not really sure what it is.  Our Australian Shepherd has spend most of last night and today making this strange noise.  It's like a honking/moose call like noise that is so loud, I can feel the floor shaking.  I don't think he's ill, because his temperature is normal, and his breathing is fine, but I don't know what's going on, and our vet is closed until Monday.  These episodes last about 30 seconds, and after that he runs around happy.  What's going on here?  The only thing that's changed in the past few days is we turned on the heaters.  Could the dust be bothering him?
Thank you for your time!

Answer
The description you offer sounds like reverse sneezing and could be environmentally caused (dust) by the heaters.  It could also be something lodged in his throat or the first presentation of something far worse.  He needs to see the veterinarian FIRST THING Monday morning.  If the condition worsens or becomes more frequent, take him to the emergency vet.