In some rural areas bacon grease is used to poison/kill dogs. A person would get rid of a pesky neighbor's dog by saturating an everyday kitchen sponge in bacon grease and then tossing it to the offending dog. The combination of bacon grease and the expanding sponge would effectively kill the dog.
A small amount of olive oil added to a dog's food will help with digestion and improve the appearance of its coat.
KMA--glad to hear your dog is on the road to recovery.