Yvonne and Snaffles (pictured) were being ridden in Shepherd’s Bush Green on Monday at 11.30am when the incident happened.
The dog chased the horses and repeatedly made attempts to bite their legs while the owner struggled to get the pet back under control.
Members of the public had to step in to help detain the dog.
Yvonne and Snaffles are recovering well at their stables with minor injuries and the officers were unharmed.
Sergeant Astley, from the Met Police’s Mounted Branch, said: “What should have been a routine patrol turned out to be unexpectedly eventful, where our hardworking police horses were sadly injured in the course of their duty. Fortunately Yvonne and Snaffles are recovering well and being looked after in their stables.
“We know horses are not a common sight in the capital but we urge all owners to keep their dogs under control to prevent this happening again.
“We’re appealing for any witnesses of the incident to come forward by calling 101 quoting CAD2691/28APR25.”
