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Bacterial Infection (Streptococcus) in Dogs

Streptococcal Infections in Dogs

Streptococcal infection refers to a bacterial infection caused by streptococcus. Puppies and older dogs are most suscetible to developing this disease, as their immune systems are not fully developed or have declined.

The condition described in this medical article is common in both dogs and cats. If you would like to learn how it affects cats, please visit this page in the PetMD health library.

Symptoms and Types

Some of the common symptoms of this infection include:

  • Pain
  • Fever
  • Arthritis
  • Lethargy
  • Coughing
  • Pneumonia
  • Abscess(es)
  • Difficulty swallowing due to swelling (tonsillitis)


Age often determines the propensity for developing this bacterial infection. Both the oldest and youngest dogs have less developed immune systems -- the youngest because of the lack of antibodies to fight infection, and the oldest because of a decline in antibodies and a weakened immune system.

Some of the causes for infection are viruses, bacteria, fungi, and protozoa, often resulting from recent exposure through a wound or surgical procedure.


A medical condition in which the tonsils are inflamed


A group of organisms made up of only one cell; a one-celled animal