Smells fishy

Hello,

Puppy, approx 5 months old, has started to have a fishy smell.
I've done some searching and it seems it is anal glands. there's lots of info, but I wondered if someone could help me make sense of it.
Some say go to the vet, others to the groomer. iF I could sort it by diet i would much prefer that.
It tends to come and go throughout the day.

Thanks all!

 

We feed her rice and mince - chicken or beef and broccoli or carrot. plus a bit of royal canin as a topping.
we bought the most enormous bag of royal canin and we're trying to use it up, but prefer cooking her food.
Her poos seem ok ... some times she goes and then does another. not sure if she has to push.
she does the scooting thing but not often - every few days.

 

Thanks Josie. The dreaded fishy bum indeed.
Is it likely to go away unaided or is there anything we can do?
it's interesting what you say about getting scared as she has had a couple of stresses recently - like new people to bark at outside the house which didn't use to bother her but she has become more aware recently.