adelle has given some good advice.
In addition to this -
Please be very aware of basic hygiene. Handwashing /cross contamination.
If u can do the guineas first with all contact before the dog -to lessen the chances of passing the bacteria around.
Dont touch your face or mouth (or guineas)without washing your hands first.
I'm guessing the dog has started on antibiotics already? Ask the vet about probiotics for the dog to give him a few hrs after his antibiotics the same as can be done for the guineas to help replenish the good gut bacteria.
I had campylobacter a few years ago. I had my own cutlery &crockery &would wash all cooking utensils in very hot soapy water. I never passed on the bug to any others in the house.
Not even the guineas, but I hardly handled them &no kisses for the 'active' period though

I did struggle with it for about 6months &lost over 4stone in weight....
Never had a waistline before
I couldn't eat meals without disastrous effects for around 6months &after numerous different drugs pills n potions over that time, my digestive system was battered never to fully recover
So Give the dog a 'bland' easily digested diet to help him digest food properly as soon as possible afterwards.
Give him small meals often &gradually increase them in size &reduce in frequency.
Not too much wet food or high in protein foods as this will make him more loose with his bowel movements-which you definitely won't want!
Try not to wash the guineas &dogs bowls etc in the same water or just do the guineas ones first as a precaution.
Use disposable kitchen towels or an allocated towel for the dogs bowls &hands after dog washing.
...not that I'm paranoid about food poisoning now
Healing vibes Charlie dog &here's to a bug free household for the rest of you

Xx