Depends on your stance on the matter and whatever other cars/trucks you have. Most dogs become 'family' as reported above. Some pets are cleaner and better behaved than others.
If your plan is to trade the truck off in a couple years and get the most out of it in terms of value, some dogs, esp those which track a lot of grime, and chew/scratch can almost ruin an interior. That's an extreme end of the spectrum. Not that interiors can't be cleaned up, but it takes quite a bit of time to *really* clean an interior thoroughly (not just spray Armour-all on it), and sometimes they damage interior parts, seats, etc. Some dogs really smell like 'dog' too. Anyway, it can give dealers a bit of a bargaining chip.
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