A study led by the University of Bristol, published in 'Scientific Reports', found that dogs can experience emotional contagion from the smell of human stress.

Dogs exposed to stress odors were found to make more 'pessimistic' choices in a trial, indicating a negative emotional state.

The research suggests that human stress impacts dogs' emotional state, affecting their learning abilities and well-being.

These findings have implications for the care and training of dogs, particularly in environments like kennels and for assistance dogs.

Further research is needed to fully understand the effects of human stress on dogs.