I have $10,000 tack coverage included with my horse trailer policy. Some of my tack is in the house and some in the trailer.
My trailer values at $17,000, $10,000 tack and I think my premium is $450 a year, $500 deductable. You can get additional coverage for tack which I did, but I forgot the increments of pricing. (The tack must be in the trailer for it to be insured if stolen or damaged) It was cheaper than going through my auto insurance and it didn't cover tack, just the trailer itself.
I believe the insurance is through The Creelman Agency.
I DON'T LEAD 'EM AND FEED 'EM, I RIDE 'EM AND SLIDE 'EM.