Stubborn Flea Problem

Hi guys,

One of my dogs spent a few days at the vet in December and came back with fleas, but I didn't notice until like a week after she was home. We've been battling with a flea problem ever since and although it doesn't seem to be an infestation anymore, it's still enough that I am being bit badly. One of my dogs got bit real badly but she's over it now. I put a flea ointment on them once I noticed.

I have five dogs and I've only noticed fleas on one of them in the last week (as evidenced by daily fur searches and, this morning, baths). Three fleas came off one dog only.

I put flea powder on the dogs, our bed and couches weekly, on their bedding weekly and I also wash all blankets and throws every second week and everything is tumble dried for good measure.

Yet this still doesn't seem to be enough to rid ourselves of the problem. I can't bomb the house because we have birds. Diatomaceous Earth is out of stock everywhere at the moment so I can't use that. I'm not sure what else to do.

Any ideas? We are coming up to winter but I don't want to take for granted that will kill them off because our temps don't drop to freezing / below freezing often enough, only at night maybe.