My dad wormned his dog with zimectrin gold it slipped and he gave her enough for a 1000 pound horse,she is blind this morning wobbely and slobbering will she be okay

I don't know of a better reason to get your dog to a vet NOW; I don't know why you would not have taken her to a vet sooner instead of posting here and waiting !

Why the hell would your dad de-worm a dog with horse medication?

No, she won't be okay! You need to get her to a vet if she has any hope of surviving. The blindness is likely permanent, and she'll be very luck if that's the only thing she suffers because of this.

What was your father thinking? Was he thinking at all?

I am going to go out on a limb and guess this isn’t the first time your dad has used horse meds to treat other animals? I do know that a lot of farms share meds between the animals (not saying it is OK or right, just saying it does happen quite often). The amount needed for a dog is tiny, 1 container would literally last 10 years, if the shelf life wasn't less than 2 years. A horse is wormed on a 100lbs scale and dog is wormed on a 10lbs scale.. Huge difference, especially when you’re talking about an 800lb horse to a 35 lb collie. If the wormer did contain ivermectin, blindness is a side effect of an overdose. And so is death! Your dog needs to see a vet asap. In the meantime you need to hydrate the dog. Even force feeding pedealite by eye dropper. It can take most dogs weeks to overcome an overdose, and that’s usually with IV fluids. Ivermectin has also been known to cause death in some breeds such as collies and shelties. So your work dog now being rendered “useless” leaves you with what options? Will your dad do the right thing and take the dog to the vet for the long term care he/she will need? Sadly no one here knows if your dog will be “all right” .

Have a look at this link:
Ivermectin Toxicity in Dogs and Cats

So... no one in this family thought once to call a vet or a friend who is very animal savvy and ask what to do if given too much wormer? Instead just let the dog digest all of that dewormer and hope for the best? People like you need to not ever own a dog... or cat or possibly even a horse.

Is there a reason why you dewormed with an ivermectin based de-wormer?