Feline distemper, also known as feline panleukopenia and feline infectious enteritis, is an acute, highly contagious disease of cats. Clinical manifestations are characterized by sudden onset of high fever, intractable vomiting, diarrhea, dehydration, circulatory disturbances and a dramatic decrease in white blood cells. Inadequately vaccinated or unvaccinated cats are susceptible to feline distemper, especially in young cats between 3 and 5 months of age. The main method of acquiring antibodies to feline distemper is vaccination. Each cat has a different level of antibodies, and the higher the concentration of antibodies, the lower the chance of contracting feline distemper virus, so it is necessary to test the concentration of antibodies in the cat.