Drivers are being warned to expect long delays on Wednesday morning as a result of the work.
Sections of the motorway will be closed across two separate weeks to allow a pedestrian footbridge to be cleaned.
Animal investigators have launched an appeal for information after the dog was found by a member of the public.
The new 20mph speed limits are to be enforced in the villages of Harthill and Woodall.
Traders in Harthill say they may not survive the fourth set of roadworks in 18 months.
Police say they are investigating a possible offence of causing unnecessary suffering to an animal.
A man has been arrested over the incident, which left a 26-year-old with life-threatening injuries.
The M8 was closed westbound for almost five hours following a crash in North Lanarkshire.
Archie Livingstone died at the scene of the collision in Blackridge, West Lothian, on Monday morning.
