as a vet nurse my favourite product for flea problems is 'comfortis' this is really good for dogs who have allergies or really sensitive skin as its a chewy once a month. Internal tablets will help with less reactions as there isn't any topical spot on going through the skin. as for worms and heartworm you can continue using sentinel as extra (double flea treatment wont hurt) you can change to interceptor instead ( same brand of sentinel) but this will only do heart worm and intestinal worms. with these two products you WONT EVER have a problem with fleas... you need to treat every pet in the home.
With treating the environment that is useless.. BUT the environment is more of the problem not the pet. 5% of fleas are on the pets the rest is inside/outside. If the pets are on flea treatment they are the treatment for the environment. when the fleas hatch they will jump on and die. treat your dogs as if they have to go outside to pick up the fleas. They can lay dormant in the environment for up to 6months so don't forget treatments or you back at square one. washing your pets wont remove any fleas ! thats very hard. as long as your on a good product your fine.. with sentinel because it only sterilises the eggs and doesn't kill the flea you need to use 'capstar' with it, this will kill any fleas on the animal within 20 min but is only short term.
goodluck.
as a vet nurse and puppy trainer.. this problem would most likely be due to the puppy not having any teeth to hold the tongue in. A lot of older pets that have their teeth removed from infection have this problem. i wouldn't be concerned. the tip of the tongue may get a little dry haha ;)
hi there, as a vet nurse i would get a vet check and a blood test.. weight loss could be a lot of reasons, some cancers, stress, not eating. in the meantime start some puppy food as thats very high in fat.