The following actions could be considered as illegal
B. Performing medically unnecessary surgery on an animal
Using an animal for surgery or medical purposes to create a medicine or treatment method is not illegal but if medically unnecessary surgery of an animal is performed it is insane and cruel and is considered as illegal.
C. Euthanizing a healthy animal
Animal euthanasia is the act of putting an animal to death or allowing it to die by withholding extreme medical measures. Reasons for euthanasia include incurable conditions or diseases, lack of resources to continue supporting the animal, or laboratory test procedures. But if a healthy animal is euthanized without these conditions then it can become illegal.
D. Not providing an animal with food and water
Not providing with food and water, an animal can die and it is cruel act therefore it is also illegal.