Brittny Mejia Los Angeles Times Dogs are being trained to sniff out people who are COVID-19 positive by picking up the particular smell of sweat from their armpits. Veuerâs Sean Dowling has more. In her quest to overcome one of COVID-19's strangest symptoms, Mariana Castro-Salzman was willing to try anything. The 32-year-old visited an oncologist and got a CT scan of her head. She saw an ear, nose and throat doctor. Took steroids. Went to a neurologist who put her on anti-anxiety medication. She began sniffing essential oils every day. A homeopath prescribed bath flowers, supplements and chaga mushrooms.