Acceptable if the three "R's" are applied.
The three Rs
The three Rs are a set of principles that scientists are encouraged to follow in order to reduce the impact of research on animals.
The three Rs are: Reduction, Refinement, Replacement.
Reducing the number of... animals used in experiments by:
Improving experimental techniques
Improving techniques of data analysis
Sharing information with other researchers
Refining the experiment or the way the animals are cared for so as to reduce their suffering by:
Using less invasive techniques
Better medical care
Better living conditions
Replacing experiments on animals with alternative techniques such as:
Experimenting on cell cultures instead of whole animals
Using computer models
Studying human volunteers
Using epidemiological studie