As a dog owner, I’d offer to pay for any damage to be repaired or replaced. It’s just the kindest thing to do.
On the flip side though, if I’m going to a home with a dog in it (or any pet) I don’t wear my expensive posh stuff as animals can be arses.
Any animal can exhibit unusual, unpredictable behaviour. One of mine spins around in the air when my twin sis comes round, even if for every other visitor he’ll get a toy & sit to present his ‘gift’ to them. I had a Yorkie who’d pretend to have an epileptic fit when my best mate would come round. Only to him, he ignored everyone else! Thousands on scans, neuro consults, blood tests to be told he was being a drama queen!
I’ve lost too many pairs of tights and cheapo leggings & tights to a jumping creature, be it cats (the killers of many a 100 denier pair), dogs, even a Guinea pig who had a nibble on my t-shirt as it sat on my lap. I usually say, if my host offers to replace the damaged item, not to worry about it; it’s just what some animals do sometimes (as I said, all animals can be arses).
If they don’t offer to replace the jeans, or refuse to offer, or can’t afford to buy a pair at full purchase price, then I’d suck it up for the sake of family peace, as gutting as it is to have something you treasure being damaged.