If you buy a dog from a breeder, you can do one simple thing to avoid problems: get your agreement in writing. Even if you think you and the person you're dealing with agree on everything, it is always useful to spell out the understanding on each side. You may not know until you sit down with pen and paper that the other person expects something quite different from what you do.
What belongs in a contract depends on why you're buying the dog. If you want a purebred dog that can be registered with the American Kennel Club, that belongs in the agreement. If you just want a healthy mixed-breed dog, obviously there's no need to worry about pedigrees. If you're adopting a rescue dog, you aren't technically making a purchase, but you'll still want to make sure you have answers to all same questions about the dog.
People who are in the business of buying and selling dogs may have their own contracts, covering all the subjects they've found important over the years. If you're not in the dog business, the checklist below lists areas to think about when drawing up an agreement.
Health. The seller should set out any health problems the dog has or may have, and should guarantee that the dog is otherwise healthy. Has the dog been examined by a veterinarian? Can you return the dog, or get reimbursed for your vet bills, if the vet finds a serious problem within a couple of weeks?
Vaccinations. List the vaccinations the dog has had and when they were given. It's also helpful to say what further vaccinations the dog will need, and when. List the veterinarian or clinic that gave the vaccination in case you need documentation—which may be the case when it's time to buy a dog license.
History. Where did the dog come from? You don't want a dog from a puppy mill, where inhumane conditions are the rule.
Training. If the dog is supposed to be trained for a particular purpose (hunting, obedience), document the extent of the training.
Pedigree. If the dog's lineage is important, spell it out and attach a copy of the parents' pedigrees.
Quality. If the dog is purebred but of only "pet quality"—that is, not up to competition in dog shows—specify that in the contract.
Price. Does it include vaccinations, or the cost of spaying or neutering?
Warranties. What kind of guarantees is the seller making about the dog?
Here is a sample bill of sale that may be modified for your needs. It's adapted from the bills of sale in 101 Law Forms for Personal Use , by Robin Leonard and Ralph Warner (Nolo).