Red raised bumps on cats without hair loss may be caused by mosquito bites, bacterial and fungal infections, allergic rashes, or eczema. You need to take the cat to the pet hospital for examination to confirm the specific cause and then carry out targeted treatment. , to avoid worsening of the condition. At ordinary times, you should pay attention to bathing and deworming cats regularly to prevent cats from being infected with parasites, and dry cats in time after bathing.