Canine Penicillin dosage eighty pound dog?

Go to vet! don't experiment with your dogs health.

Some people can not afford care for their pet.

(Reply from a vet): The first answer is correct, you should only give prescription medicines when prescribed by a vet - if you end up giving the wrong dose the dog could develop a worse infection, and could be resistant to the antibiotic you have used. That will only result in a bigger vet bill!

There are many charities out there who will see people who can't afford to visit a vet - in the UK try the PDSA or RSPCA; you will usually just pay for the cost price of the drugs you are given. It's really important that a vet actually sees the animal - advice on here will not help you if the infection needs different antibiotics, or a long course - and if the infection is also causing pain you may need a pain killer as well (giving human painkillers to dogs can be VERY dangerous, and should never be done).