I have a huge bottle of cattle strength injectable.

People are going to kill themselves or go blind trying to use it.

Dog puppy mills have killed and or blinded dogs from not diluting it properly.
The dose must be figured on the bottle label strength per ml and severely diluted down with propglycol to the end strength of those heart worm chewables.
And propglycol can't be injected, only given as an oral dose.
Dog mills use it because the heartworm chews are so expensive. It's the same drug.

It's extremely easy to fudge the math by not accounting the bottle strength per ml to begin with.

Personally. even knowing the right math. I'd have to be dying before trying it.