Falkirk Council took the decision after a visual inspection of the bridge yesterday (Thursday).
A spokesperson said: “We have taken the decision to shut the bridge until a formal safety inspection can be carried out early next week by our bridge engineers.
“This is in the interests of public safety.
“The timber decking and handrails appear to be in a poor condition and there is a risk that people and their pets could injure themselves whilst trying to cross it.”
Fencing will be erected to close the bridge as soon as possible.
Meanwhile, people are being asked to use a different route.
Diversion signage will be put in place highlighting the bridge closure and suggesting alternative routes into the Carron Glen SSSI via Herbertshire Castle Park.
The area is popular with dog walkers and outdoor enthusiasts.