A heartbroken owner has warned of the dangers of walking dogs in high temperatures after losing her beloved French bulldog.

Laura Kyle, 32, had taken her three-year-old dog Betty out for a walk near Livingston on Thursday, July 15, before she tragically died, the Daily Record reports.

Although Betty was fine while walking with Laura, a beautician and her other dog, a pug called Frank, it was after she returned home that things took a turn for the worse.

Laura gave the two pooches water and left them to their own devices but found Betty limp and unresponsive that afternoon.

Betty was rushed to the vets, who told Laura her French Bulldog was suffering from heatstroke and it had affected her brain, leaving it damaged.