Liability when selling a dog: Legal advice

Questioner

As a consumer, I received a litter of Chihuahuas and subsequently sold them via Marktplaats. One of the puppies was sold and the first 1.5 weeks went well with the new owners. After this period I got a phone call that the puppy showed aggressive behavior and that they would take blood to find an explanation for this behavior. Nothing came of this blood test and they continued with the investigations. In the meantime I was asked to make a financial contribution for the costs incurred. I indicated that I would think about this. The second examination was an ultrasound to see if the dog was in pain somewhere to explain the behavior. After this I was called by the buyers and they told me that nothing was found in the body, but that there was probably something wrong in the head. The next day I received another phone call stating that the vet had advised putting the dog to sleep because the development of the cerebellum was not good. I have received the report of this research. It does indeed state that there is probably something wrong with the development of the small brain, but with the final conclusion that this does not explain the complaints! I spoke to my own vet and he said that this was a very drastic decision. I then made the buyers the proposal to give half of the purchase price back and to pick up the dog again and give it a second chance here. This proposal was immediately rejected, they wanted to 'finalize' it together and had the dog put to sleep the same day. Now a week later the buyers are demanding the full purchase price back from me. If I do not agree to this they want to take this case to court and claim back all costs incurred. My question is the following: To what extent am I as a private individual liable for the above? Any defect in the dog normally gives completely different complaints (drunken gait and motor disorders). Both here at home and with the new owners there were in principle no problems. The investigations also provide no explanation for the problem. Also, it's not a 'hereditary' thing that I could have known about. My proposal to take the dog back and refund half of the purchase price was not accepted, no counter-proposal, nothing. There is no sales contract, but the proposals I made were made in writing.

Lawyer

As a private individual, you can be held liable for the damage if there is a shortcoming that can be attributed to you. It depends on the care you provided to the dog and whether you knew about the condition. For example, if it is a rare disease that you could not have known about, then in principle that cannot be attributed to you, as you already indicate. This means that you are not liable for the damage and the buyer cannot claim it because he does not want to return the puppy. Also because you made a proposal that was not accepted by the buyer and the buyer has a duty to investigate the purchase, while you otherwise have a duty to inform the buyer.

Lawyer

The buyer's claim is unjustified on both medical and legal grounds, as the diagnosis does not explain the dog's behavior. You have made the offer to take the dog back. Although it would have been better to refund the entire purchase price, the buyer apparently did not want to cooperate in any way with returning the dog. This means that there is a forfeiture of rights and they cannot legally institute a claim against you.