What is the ruling on a veterinarian helping owners of ornamental dogs to determine the estrus cycle of their female dogs in the following cases: if the dogs are solely for ornamental purposes, if ornamental dogs can be crossbred to become guard dogs, or if the ornamental dogs were originally hunting dogs?

It is not permissible to keep dogs for ornamental purposes or for hunting by one who does not hunt with them. The impermissibility of keeping them does not change by virtue of their ability to give birth to guard dogs or if they were originally hunting dogs. The consideration lies in the need and purpose of acquisition. As for one who keeps a dog without need, such as for ornamentation or boasting, it is Haram without dispute. Regarding keeping a hunting dog by one who does not hunt with it, the preponderant opinion is that it is forbidden. Therefore, assisting those who keep such dogs is Islamically prohibited.