Need some help! My 4month old puppy has red bumps on his belly!!!!

Riley has theses little red bumps or spots on his lower belly inside his thighs. He seems not be bother by them but im a little concern. He is a aussie but he has never been a hyper dog. He seems to be a little bit more lazy as of late but that could just be me. He is eating and drinking normally and he is also teething. Is there any other signs i should be looking for a sick puppy. If thats the case? Please give some advise!!!!
Thanks!

Can you take a photo of them?

Does he go swimming/wading around in water then run through bushs/long grass?

Blaze gets little red bumps from swimming and then running in grass and rolling ect.

doesn't go swimming but there has been a lot of rain around here and he rolls around and lays in the wet grass. I will try to get a pic. soon.

Turns out riley had a staph infection and is being treated and will be fine!!!!I guess if you feel like something is wrong with your dog ...dont think twice ..call the vet!

Good advice! I'm glad its treatable