In the late stages of heartworm infection in dogs, they will have symptoms such as loss of appetite, weight loss, body shaking, and lying on the ground. These symptoms are usually caused by mosquito bites and infection. The dog needs to be sent to a pet hospital for examination and treatment immediately. Provide a quiet resting environment for the dog, provide the dog with nutrition in a timely manner, replace the fresh water source, and do not take the dog to play in dirty and messy places to reduce infection.