Hound Labs  is an American breath diagnostic company specializing in technology that measures breath.
The company was founded in 2014 Oakland, California by ER physician and venture capitalist Dr. Mike Lynn, Kuni Oh (a patent attorney with a background in science and engineering), and Jenny Lynn (a business executive who specializes in launching new ventures). They have received $8.1 million in funding from Benchmark. 
Hound Labs developed the first ever marijuana breathalyzer. Their patented technology is one billion times more sensitive than most other breathalyzers, allowing detection of minute particles that only exist on the breath for a few hours after marijuana inhalation. The HOUND® Marijuana Breathalyzer will show if someone has smoked marijuana recently and unlike a blood test or urine test, it is primarily effective in determining whether someone is high at that moment.
Hound Labs feels that this is an opportunity to combat the problem of stoned drivers. In a Venturebeat article Hound Labs announced that clinical trials were being launched in San Francisco and they will be carrying out field studies with law enforcement agencies across the US. Mitch Lasky, a Benchmark general partner who is on their board of directors, said: 
Cannabis legalization has created a new global market for employee and law enforcement testing. In the past, employers and law enforcement professionals focused on possession and use. After legalization, impairment — whether behind the wheel or on the job — becomes the new enforcement paradigm. Groundbreaking science is necessary to make an accurate measurement of recently used cannabis, and Hound Labs is uniquely positioned to deliver a solution to the market that respects the needs of the enforcement community as well as the rights of legitimate cannabis users.