I have a cat who was born on a farm and had been through practically everything imaginable, so when he was diagnosed with feline leukemia at 4 months old I was determined to beat it. I came across Transfer Factor - the human formula - and started administering that twice a day with vitamin c and a high protein diet. When he was retested 3 months later the results were negative.. and I was thrilled! He is now just over a year old and perfectly healthy and happy.