Now Playing: Mad Cow Disease Discovered in U.S. Dairy Cow
Now Playing: Mad Cow Disease Found in California
Now Playing: Closer Look at Mad Cow Farm
Now Playing: What is Mad Cow disease?
Now Playing: Exploring treatment options for teens addicted to e-cigarettes
Now Playing: Veteran who lost both legs in Iraq war finds healing in yoga
Now Playing: Girl with cochlear implants gets classroom elf just like her
Now Playing: How IVF grants are helping some families afford the gift of life
Now Playing: What to know about the new test for breast milk
Now Playing: New warning issued on e-cigarettes and young people
Now Playing: Student records ‘1 second of positivity’ each day and the results are amazing
Now Playing: Number of teens using e-cigarettes has doubled: Study
Now Playing: What is Rift Valley fever?
Now Playing: The Future of Medicine
Now Playing: Vaping use skyrockets among kids, report finds
Now Playing: Texas judge rules Obamacare ‘unconstitutional’
Now Playing: Man says he feels ex-girlfriend used him to kill her mom: Part 6
Now Playing: Did Gypsy Blanchard’s mom have Munchausen syndrome by proxy?: Part 5
Now Playing: Woman once praised for battle with illness revealed to have never been sick: Part 4
Now Playing: Gypsy Blanchard on what happened the night mom was stabbed to death