Ok need some advice ladies!

I have a labrador that I've had for 3 years and she NEVER had fleas or worms once...

The other half got a husky in June and since then I can't get rid of the fleas on my poor lab and she has worms for the 2nd time yet she doesn't scavenge or bin raid or anything (husky never actually has them she just brings fleas into the house maybe found 5 on her tops and they've always been at the end of her fluff not near her skin)

I've treated them both every 4 weeks with advantage flea treatment and Drontal wormer (both recommended by the vet as best available) and got flea sprays and powders and the house has been scrubbed and treated and their beds are being washed weekly and I just don't know what to do anymore!!

Is there anything anyone can recommend to help!! I think I'm getting there with them and only find one or 2 dead fleas on my lab then a couple days later she's got like 10!!