What happens if a dog is over-vaccinated?

Over-vaccination stimulates the body to produce more antibodies and may cause an overactive immune response with adverse effects. Because vaccines are weakly virulent, an overdose can make the immune system attack the body’s healthy cytokines as if they were viruses, causing fever, vomiting, joint pain, lethargy, loss of appetite and convulsions.

So after a dog is over-vaccinated, the owner should closely observe its reaction, and if adverse symptoms appear, take it to a pet hospital promptly.