Glad to hear Fish is ok, well worth the money.
I treat all my dogs myself, but worked in a vets for many years and have had a lot of experience, btw don't shoot my cattle with broken legs unless its in a place where it can't be repaired, stuckie on all the way. I will go to the vets when it is something I can't handle, and I will pay, last week my NI went to the vets with a twisted gut, had rung the vets and told them what it was and they prepped for surgery immediately, had a phone call to say operation would be £800-£1000 would I like her put to sleep, my answer was no continue, she is now home with me and healing gradually. I can understand the mentality of some people not wanting to pay that sort of money to keep an animal alive however its a personal choice and also depends on how you look at the animals in your life. I know a lot of farmers that would put the dog/cat to sleep without a second thought, then others that would spend a fortune.
I wouldn't use cattle or sheep medicine on my dogs, although there are some that are the same as would be used to treat them, but would ring the vets and get what I need for them, they will give me what I ask for unless it is a medicine that needs to be administered by a vet like Mycotel for cattle, due to farmers injecting themselves and having heart attacks!
It's all about how confident you are in treating you animals yourself and recognising the signs of what is wrong. If ever in doubt go to the vets that's what they trained all those years for.