Adopt a kitten from a breeder that offers a clear and precise guarantee.
Do not hesitate to ask questions. What will happen if my kitten gets sick in the days following adoption? Who will pay for veterinary expenses? What will be the modalities? What will happen if my kitten develops a genetic disease? A congenital disease? What will happen to my kitten? What will my options be at that time? Remember that these are often very emotional decisions and it is easy to play with the feelings of people when unfortunate situations arise.
Did you know that a viral, bacterial or parasitic infection can go unnoticed and that a simple stress can activate / reactivate it? Your breeder should be able to tell you openly and his guarantee should be based on the risks to which the kitten is exposed to the cattery but also in his future environment. Aim for a guarantee for infectious diseases of 10 days and more.
Did you know that the terms 'genetic' and 'congenital' do not mean the same thing? Genetic means that the disease is transmitted by the genes of the parents, whereas congenital means that the disease is present at birth (manufacturing defect during the development of the kitten in the uterus).
Did you know that several protozoa / viruses / bacteria can contaminate cats stools and that only DNA-based tests can detect them? Simple conventional stool tests only identify a very limited number of these infectious agents.
You must be comfortable accepting the terms of the contract, otherwise your only recourse will be small claims court in case of litigation.