Contraction

• Small breeds may contract tonsillitis for no reason. But chronic vomiting and coughing will allow bacteria onto the tonsils. Tartar on the teeth can also cause infection, leading to bacteria as well.
  
  

Swollen Tonsils

• The tonsils will become swollen enough that the dog may gag or act as though something is stuck in his throat. He may eat less because of the pain from the swollen tonsils.
  
  

Fever

• According to peteducation.com, a normal temperature for an adult dog runs between 100.5 and 102.5 Fahrenheit. If your dog is running a fever along with other symptoms, it may be tonsillitis. Not all affected dogs will have a fever.
  
  

Lethargy

• A dog with tonsillitis may act tired or depressed. He may walk to his food bowl but not eat from it. He may also vomit and cough repeatedly, making him more listless.
  
  

Treatment

• A veterinarian will find what caused the tonsillitis. Treatment may consist of giving antibiotics, dental cleaning or even removing a foreign object from the throat.