take the dog to a vet get them to sort the dog out then when it comes to the bill just say ui will have to pop in on my pay day as i havent got that much take 20 quid as a start and tell you will get the rest to them asap, any vet will understand use the vet you always go to as you say you have cover for your other dogs so he will no you will not rip him off,
do the best thing for the dog and dont do it ya self,
is there not a greyhound vet near you try him you never no mate
atb....lamp