Dogs' fear of noise, smells or changes in the environment is common. Here are some possible reasons why your dog is scared when you wash the house:

1. The noise of the devices
Vacuum cleaner or washing machine: the dog can be sensitive to the noise these devices make. Loud or sudden noises may stress him.
2. Changes in routine
Change in environment: When you wash the house, the dog may feel that his routine changes. Dogs like routine, so changes can discourage them.
3. New smells
Detergents: Detergents may cause strong or unfamiliar odors to the dog, which may deter him.
4. Feeling insecure
Disturbance of the familiar place: dogs talk about a sense of territory. When the house is washed, they may think that their familiar environment changes or becomes uncomfortable.

5. Previous experiences
Bad experiences: If your dog has previously had an unpleasant experience related to noise or water, he may feel fear every time you wash the house.
what to do
Use mild detergents: If you use strong detergents, try to find less scented substitutes.
Gradualness: While you wash the house, allow the dog to be in a quiet and calm place, or even in a separate room.
Distraction: Give the dog favorite toys or snacks to distract him while cleaning.
Gradual exposure: Allow the dog to get used to the noise of the devices by playing them for a short time and gradually increasing the time, while giving positive reinforcements when it is quiet.

Dogs' fear of devices such as a mop is a common phenomenon, and there are several possible reasons for this:

6. Noise and traffic
Noise: The mop can make noises that scare the dog, especially if it sounds like other devices that he doesn't like.
Unexpected movement: The movement of the mop can appear to the dog as unexpected or threatening, which can make him fear it.
7. The context of water
Fear of water: If your dog does not like water or has had a negative experience related to water, he may associate the mop with water and feel fear when he sees it.

8. Previous experiences
Bad memories: If your dog has had an unpleasant experience in the past related to a mop or similar devices, this can make him afraid of them.
9. Feeling insecure
Lack of control: When there are foreign devices in motion, the dog can feel that he has no control over his environment, which will make him feel anxious.

What to do to help the dog?
Gradual exposure:

Allow the dog to get used to the mop by presenting the mop to him in a calm manner. Place it next to the dog when it is off and let it smell and approach it at its own pace.
Positive reinforcement:

When the dog is behaving calmly near the mop, give him a treat or positive attention. This way he will start to associate the mop with good experiences.
Distraction:

While you mop, allow the dog to play with favorite toys or engage in some other activity to distract him.
Using a silent mop:

If possible, use a quieter mop or do the washing while the dog is in another room.

Additional support:

If the fear persists or worsens, you should consider contacting a dog behaviorist for further advice.
It is important to be patient and remember that every dog ​​is different, so what works for one dog may not work for another.