I write this immediately after watching #57 on the list, Nosferatu: Phantom der Nacht, which I enjoyed, by Werner Herzog, whose movies I always like. The explanation of the animal cruelty in Nosferatu is taken from Wikipedia:
Dutch behavioural biologist Maarten 't Hart, hired by Herzog for his expertise of laboratory rats, revealed that, after witnessing the inhumane way in which the rats were treated, he no longer wished to cooperate. Apart from travelling conditions that were so poor that the rats, imported from Hungary, had started to eat each other upon arrival in the Netherlands, Herzog insisted the plain white rats be dyed gray. In order to do so, according to 't Hart, the cages containing the rats needed to be submerged in boiling water for several seconds, causing another half of them to die. The surviving rats proceeded to lick themselves clean of the dye immediately, as Hart had predicted they would. Hart also implies sheep and horses that appear in the movie were treated very poorly, but does not specify this any further.
In 2010, 't Hart talked in the TV program Zomergasten about his involvement as expert for rats in Nosferatu. According to 't Hart, Herzog ordered 12,000 white rats from Hungary to the Netherlands, where they were to be used for a pest scene. The transport lasted three days, during which the rats were not fed nor soaked; therefore, they began to devour each other. After their arrival, Herzog decided to color them black. For this process, the animals were put into boiling water, whereby half of them died. 't Hart then withdrew from the project. In the TV program, he called the process "immoral".According to my perspective on art, we should care primarily about the work's consequences on the world. This perspective does not discriminate between the work itself and the process of its creation. Therefore, animal cruelty during the production phase should be subtracted from the actual value produced by the finished project. In the case of mistreating 12,000 rats (plus some horses and sheep), the suffering caused might be enough to outweigh the positive effects of the film.
Based on my anecdotal experiences and my old beliefs, most people would argue that, although animal cruelty is regrettable, that it should not factor into our judgments of an artwork's value. This is true for several theories of artistic value, none of which make sense to me. It is true, however, that there are many elements in the film from which the animal cruelty cannot take away from. For instance, if you want to praise the film for its innovation, technique, ideas, or entertainment value - which is what most people care about - you could still do so regardless of animal cruelty. But if you want to argue that the film deserved to be made - that is, that it helped the world more than it harmed the world, then you cannot leave out the fact that thousands of rats were abused. However, in most cases, the film itself can be made without that cruelty, so the cruelty itself isn't a reason to hate the movie's ideas, but rather a red flag about the artist's priorities. We could also consider positive consequences of the creation process such as the fact that the film gave all the crew members jobs, work experience, and (maybe) fun times and new friends.
Nevertheless, we shouldn't forget that the animal cruelty is in the past. No matter how many times the film is rewatched, distributed, or praised, only 12,000 rats were harmed. In contrast, the positive value of the work likely increases over time as it accumulates views.