Final answer:
Changes in a family that can affect a pet's pruritus include stress, dietary changes, new cleaning products, and the hygiene hypothesis which proposes a lack of exposure to antigens leading to allergies. These factors can contribute to the development or exacerbation of conditions such as eczema in pets.
Step-by-step explanation:
Changes in a family can affect a pet's pruritus, which refers to an itchy sensation that provokes the desire to scratch. Factors such as stress from a new environment, alterations in diet, changes in household cleaners or laundry detergents, and fluctuations in attention or routine can all cause or exacerbate an animal's itchiness. For example, a dog may develop eczema, a condition characterized by dry, itchy patches of skin that can be triggered or worsened by environmental allergens, which might be more prevalent in a new residence or due to the use of different cleaning products. Stress can also weaken an animal's immune system, making them more susceptible to allergies and skin infections leading to pruritus. Another example is the hygiene hypothesis, which suggests that a lack of early exposure to diverse antigens in overly clean environments can contribute to the development of allergies in pets, just as it can in humans. This can lead to an immune response to harmless substances such as dust mites or pet dander, causing pruritus.