Here's a post I wrote in response to a similar question on another site. I hope it helps.
AFAIK, there is no "best practice" where transporting dogs is concerned.
I've seen quite a few different types of doggy seatbelts advertised in
Dog World and
Dog Fancy, and here is what I can tell you based on that.
Are there doggie seatbelt?
Yes. They usually consist of a body harness of some sort that attaches to the vehicle via the seatbelt. I have seen one that claims to use the LATCH anchors instead.
Do they work with lap only and lap/shoulder belts?
Good question. The ads usually (always?) show the device attaches with a lap/shoulder belt, but that *could* be because outboard positions photograph better.
How much to they cost?
There seems to be a wide price range, from $20 to over $50. I don't remember off the top of my head for sure, though. I'll see if I can dig up a couple of websites.
Where do you buy them?
Try your local pet store. I've seen them on PetSmart.com. Also, most manufacturers have their own websites from which you could order.
Are they considered safe?
I would not expect one to save my dog's life in a crash. Looking at the design and having seen crash test videos for child seats, it just doesn't seem likely. I do, however, consider it a safety device. 1) It keeps the dog restrained while the vehicle is moving, which means the dog isn't going to be jumping out an open window (or door when you get to your destination) or moving around inside the vehicle, which could distract the driver. 2) It keeps the dog from becoming a projectile in a crash. 3) If your dog becomes injured in a crash, it keeps him restrained, so (hopefully) he cannot further injure himself or injure a person in his distressed state.
Here are some links*:
Ruff Rider's Roadie LX Vehicle Restraint ($80)
Ruff Rider site ($40-$75) - they make other models, not just the one above
Travelin' Dog Car Harness by Comfort Ride ($25)
Muttslinger ($40-$60)
Hold-A-Dog Seatbelt Harness ($27.95-$50.95)
PetBuckle has LATCH option ($40-$52)
SURVIVOR Big Dog Seat Belt System ($55)
The Ruff Rider looks the "best" to
me. They even provide a locking clip!
Seriously, though, some of those seem extremely flimsy. I really don't see a .5" nylon strap holding a 40 lb dog in a crash, and I doubt some of those buckles were made to withstand the several hundred pounds of force that are exerted during a crash, either. The Ruff Rider *seems* to be the best thought out and the most heavy-duty.
*These links are provided as a reference. Neither I nor this site endorse or recommend any of these products. Please do your own research before purchasing or using any such restraint in your vehicle or on your pet.