To clean an orthopedic foam dog bed, remove the outer cover by unzipping it. You can wash the cover in the washing machine at the cold temperature setting. Once you have added some detergent, switch the machine on. Now, fill the bathtub with warm water halfway. Add some laundry detergent to get soapy water. Use your hands to work the work the water into the foam. After emptying the bath tub, refill it using plain water and use it to rinse the foam bed. Make sure you squeeze the foam more than three times to remove the soap. Keep going until you can no longer see any suds. Dry the foam and the cover outside in the sun. When they are dry, place the foam inside the cover and zip it up.