The cat's voice is hoarse and it can't meow.
If a cat's voice is hoarse and it can't meow, it might be due to heatiness or a cold. In this case, pay attention to a light diet, ensure it drinks plenty of water, and give it cold medicine. If it also has a cough, it might be bronchitis caused by the cold, in which case you'll need to give it anti-inflammatory medication. Hairballs in a cat's stomach can also cause this; in this case, you should give the cat hairball remedy or cat grass. 
1. Getting internal heat
If you find that your cat's voice is hoarse and it can't meow, it may be due to internal heat. In this case, you should give your cat more water and feed it some cooling fruits, such as apples. During this time, be sure to keep its diet light.
2. Common cold
When a cat catches a cold, it may become hoarse and unable to meow, and it may also have a dry nose and runny nose. In this case, you should give the cat cold medicine, and make sure to give it plenty of warm water and keep it warm.
3. Bronchitis
If you notice your cat is unable to meow and is accompanied by symptoms such as a runny nose and cough, it may be due to bronchitis caused by a cold. In this case, you can give your cat cold medicine and anti-inflammatory drugs to relieve the cat's symptoms until it recovers.
4. Hairballs
When a cat has a foreign object in its throat, such as a hairball, it can become hoarse and unable to vocalize. This usually happens during molting or shedding season. In this case, you can give your cat cat grass or hairball remedy to help it expel the hair.
