Behaivor toward new pet

Today I got a puppy, and my 3 cats are scared of it. Normally they would all hiss if I got a new pet, whatever the new pet was, but this time they run away. The puppy is still very much smaller than my cats. I think it is strange that they are all scared of it, but it is the first time I have had a dog.

Does anyone know how I could help my cats? Any info would be helpful.

I would, and I did of course teach the dog not to go after them, but while they were trying to adjust I would put the dog in his crate for an hour or so and let the cats investigate. I would do this throughout the day as well as during the night. It gave the cats a chance to sniff and look at the dog without fear. It actually worked in two ways, the dog got potty trained and the cats got to know the dog. It took about 5 months, but out of 11 I only have one that really hates the dog.

Thanks for the help, Sandie. I'll try it.