At present, for example, it is often difficult to trace the history of a litter of puppies especially if they have been sold via animal dealers and pet shops.
Er enghraifft, mae’n aml yn anodd iawn olrhain hanes teulu o gŵn bach, ac yn enwedig os cant eu gwerthu drwy werthwyr anifeiliaid a siopau anifeiliaid anwes.