The answer to 'why is my pressure washer pet stains' is that your pressure washer may not be effectively removing pet stains. Pet stains can be difficult to clean because they often contain proteins, oils, and other organic matter that can get deeply embedded in surfaces. Over time, these stains can build up and become more difficult to remove with just a pressure washer.
Some common causes of pressure washer ineffectiveness on pet stains include: using the wrong cleaning solution, not letting the solution sit long enough, or not using the right spray pattern or pressure. To effectively remove pet stains, you may need to use a specialized pet stain remover or deodorizer, let it soak in, and then use the pressure washer at the right angle and distance to lift out the stain.