Kingfisher likely hit it. More than likely related to the move, exposure to new 'bugs' from any cattle they were around at the salebarn and now at hg's place - not to mention that it sounds like...nutritional state was not optimal wherever they came from...
He 'looked to have worms real bad'... how does that look, highgrit? Just wondering...without doing a fecal egg count, how do you know the difference between 'wormy' and 'starved'? Inadequate nutrition is usually a bigger problem than worm burden.
With cattle, you can usually feed your way through a worm problem, but you sure can't deworm your way out of a feed deficiency.
At the risk of POing you...y'all are just propagating old BS.
Killing ALL the worms is what you need to do - dead worms(I'm not talking warble larvae) don't cause nearly the damage or drain on the animal that the live ones do...as they continuing to feed on the animal. Giving half a dose...more BS; it just contributes to selecting for worms with resistance to that class of dewormers.
If an animal goes down or dies because you killed all the worms at one fell swoop, it's not because you killed all the worms - it's because you didn't kill them soon enough.
Margin of safety for most all the dewormers is pretty wide - exception is levamisole - you might have to go 5X-10X to see signs of toxicity with most of them...but, other than accidentally, why would you want to waste the $$ doing so. Better to overdose a little than to underdose.