The animal expert’s family revealed the 74-year-old’s fight with dementia “has progressed much faster in the last few months.” READ MORE: https://gma.abc/3rVjBSY Subscribe to GMA’s YouTube page: https://bit.ly/2Zq0dU5 Visit GMA’s homepage: https://www.goodmorningamerica.com Follow GMA: TikTok: tiktok.com/@gma Facebook:facebook.com/GoodMorningAmerica Twitter: twitter.com/gma Instagram: instagram.com/goodmorningamerica #JackHanna #Dementia #ColumbusZoo #GMA