Keep the dog outside the home---in the backyard---in its own house. Remember that a dog needs his own space too, so don't worry that you might seem cruel by keeping it outside. It is essential to realize that the inside of the house is a pet-free area, especially if the allergic reaction is particularly strong. Also, bear in mind that if the allergic reaction is too severe, it might be necessary to dispose of the dog completely. Consult a doctor to determine the severity of the allergy in order to decide what to do.
Remove the parts of furniture fabric that can be stripped from the cushions and the pillows, such as coverings and wrappings.
Wash the coverings in a washing machine, setting the temperature to a level suitable for that particular type of fabric. Use a quality laundry detergent for this part of the task. If the dog used to sit on the piece of furniture in question, wash the fabric twice in a row, making sure to get all the allergens out. When the fabric from the furniture is washed, dry it and iron it to have it ready for later.
Vacuum the parts of the furniture that can't be stripped and washed separately. Use a quality vacuum cleaner with a filter for allergens.
Clean the surfaces of the furniture that are not covered with fabric. If the surfaces are wooden, use a multipurpose cleaner with a scrub sponge dipped in warm water. Then treat the wooden surface with a cloth dampened with wood polishing liquid.
Place the coverings back on the furniture piece. Close the zippers and assemble all pillows and cushions.
Disinfect the surface of the furniture by spraying a cleaning and disinfecting solution to its surface. You can use a common spray or disinfecting spray.