There is no reason to conduct cruel tests on animals. Results from animal experiments have proven inaccurate when extended to human health conditions and diseases. Thankfully, many humane charities that fund only humane, non-animal-based research exist.
If you are unsure whether a health charity funds animal experiments, call the organization. If the charity representative is unsure, politely but firmly insist that they look into it. Every call health charities receive has an impact and makes it clear that animal use in research is an important issue.
If you cannot find a charity that does not conduct animal research in the area you want to support, at the very least please ensure you earmark your donation for non-animal research or that your gift is used to develop alternatives to the use of animals.