One of my puppies is going abroad, he is therefore staying until he is 4 months and he has his pet passport. The actual sale is taking place when he is 8 weeks old and I will just be in effect, boarding him until he is good to travel.

I have been thinking about whether I will possibly need another contract for whilst he boards with me- mainly in case of emergencies such as he has an accident or illness - to stop any disagreements over vet fees etc.

What do others do in these circumstances?

I think you can never go wrong by putting things in writing. 
Would suggest liaising with the other party to ensure each has the areas covered that they would like to then everyone should be happy.
You will need to consider insurance too I would think.

I keep pups for extended periods for overseas buyers but I dont take money until they are about to fly...so the puppy belongs to me and I accept all eventualities.
The risk of being let down is balaced out by my freedom to change my mind right up till the last minute.

When I bought from abroad, I paid in full the asking price on my first visit, and  agreed to pay any costs incurred for food and vets for the 10 months following, which I settled up at the time I collected her.

Drover, putting myself in the buyers position...

Although I can see the merit for a breeder in Tooolz position, I'd like to know the pup is definitely mine - and you won't change your mind - so I'd appreciate the sale going through at 8 weeks.

From that point on I'd expect to pay for board and insurance, and would cover all the other costs that would normally be incurred if the pup had come home with me at 8 weeks.  Worming, vaccination, training classes (if relevant), and any insurance excess that might be payable in the event of illness (perhaps you will pay in the event of accident?).

Having nearly been caught out by an early medical condition that the insurer 18 months later decided was a recurrence (it wasn't but that's another story!) I would really stress the importance of insurance.  You might need to take it out in your name, and maintain 'ownership' of the puppy until 4 months BUT it could save you and the owner a lot of heartache and £'s should something arise whilst the dog is still in the UK.

I'd leave it to you to decide whether you wanted payment in advance but I think I'd expect to pay for the pup at 8 weeks, and buy the insurance at the same time.  I'd then arrange to pay monthly in advance for other costs with incidentals being settled as we go along including the medical expenses associated with overseas travel.  I'd welcome a written contract if only as a prompt for the discussion we would have about expected costs.

As a buyer I know full well how much effort and hard work goes into raising a litter, and a young puppy, so I'd be keen that you didn't feel 'put upon' by asking you to keep my puppy a bit longer.  BUT I hope that you wouldn't overcharge me for the privilege :)

Thanks. The sale will go through at 8weeks. I am very happy with them and I understand their need for reassurance that the puppy is theirs.

I am definitely not overcharging- they are paying the purchase price (obviously :) ) and an extra £167 for the pet passport and I am charging them £5 per week board for the puppy for the 7 weeks extra he is staying, that covers food  and I have loads of extra wormer that will just go to waste so not charging them for that.

My main concern is if there were an accident or illness - I would hate for things to be a bit mirky and neither clear on what happens if there is and who pays vet bills etc.