There is not a slippery slope, as humans at present, do not value animals as they should. However, Animals should not be cloned for several reasons. Already on earth there are far too many human companion animals, and millions suffer from neglect and indifference. Also, at present, cloning is expensive, invasive, not the most simple method of producing an organism, and is largely misunderstood, like so many technologies in science.
Overlooking that the “slippery slope” concept is invalidated in science, it is not wise for humans to clone until they know more ramifications of all they are doing. By definition, in science, one does not know what one is doing until the data is all in, so taking some risks are more hazardous than others. People do not seem to understand that a clone is not “the” individual, any more than identical twins are the same person. Although one could create a beloved “copy” of Fluffy or Scruffy, the resulting creature is NOT Fluffy or Scruffy, but a new animal in a different time and place.
To have an exact copy of a person for example, would require that an organism’s total character and personality came from a frozen time. For example, to create a Martin Luther King would require a return to a time when civil rights were dismal. Or to create a Marilyn Monroe, one would have to have the Kennedy clan, more sexism, and a past culture that shaped her. It is the same for any other organism.
Belonging to the animal kingdom is useful and very instructive for humans, but the energy and knowledge of cloning should be studied in a total cultural context. For any given procedure, questions such as cost, total time, probable reaction, other ways of looking at solutions and more.
To look at the idea of cloning an endangered leopard, for example. Does it make any sense to have another gorgeous leopard, but no protected habitat for leopards in general? Doesn’t it make more sense to study the problem of human over-population and find ways to ease the destructive nature of too many people with too many domestic animals?
Other animals, just as human animals, are creatures who should be respected and appreciated for exactly what they are, how they make life possible, and how bio-diversity allows a continuation of all life only when one member is not over represented.
Cloning, even as an idea suggests that one animal, humans, have the wisdom and discrimination to make earth a better place. If so, they should begin soon.