Reasons why a Ragdoll cat's back fur becomes stiff:
1. Eating too much salty food. A Ragdoll cat's fur will become dry and rough if it eats too much oily and salty food. It's recommended to cook your cat's food separately, using less oil and salt, and avoiding other seasonings. Keep it as bland as possible; this is better for its skin and fur.
2. Incorrect bathing method. There is a big difference between cats' and humans' skin and fur. If you are bathing your Ragdoll cat at home, it is best to use cat shampoo and conditioner.
3. Nutritional deficiency. To improve a Ragdoll cat's coat, it's recommended to start with its diet. Feed your Ragdoll cat more eggs, chicken, fish, vegetables, and fruits. You can also give it some pet nutritional supplements specifically for coat health. 
Ragdoll cat grooming methods:
1. Brush their fur daily. Ragdoll cats have relatively long fur, so it is recommended that pet owners use a special fur brush to brush their Ragdoll cat's fur 1-2 times a day.
2. Regular bathing. Bathe your Ragdoll cat regularly, but not too frequently, nor too infrequently. Bathing once every 1-2 months is sufficient, and dry them thoroughly afterward.
3. Use a special shampoo. When bathing a Ragdoll cat, you need to use a special shampoo. You can choose a shampoo with coat-enhancing effects to make the Ragdoll's fur smoother.
4. Pay attention to diet. The healthy coat of a Ragdoll cat mainly comes from consuming enough protein, and it is also important to pay attention to a light diet. For a Ragdoll cat with a healthy coat, it is recommended to choose cat food that is high in protein and contains fish oil.
