If your animals have as heavy a load as you imply, it may be better to go with an injectable. Especially since you said they are off their feed... they probably wouldn't eat it anyway. The vet reported a heavy load... did he/she recommend a dewormer? You might call and ask.
Hope it all works out and you've caught this in time. Pics of them would be nice also, pls and thanks.
Hope it all works out and you've caught this in time. Pics of them would be nice also, pls and thanks.