By the end in Polka-Dot Puss, both Tom and Jerry are covered in spots from head to foot and being quarantined by Mammy Two Shoes herself. Tom pouts and glares at Jerry for making him get measles.
Jerry tests Tom's reflexes and uses a hammer by almost bludgeoning him, and he shoves a thermometer in Tom's mouth, where (out of Tom's view) Jerry holds a cigarette lighter underneath the thermometer, causing the temperature to rise, expanding the thermometer, such that it explodes in movie Polka Dot Puss.
In Polka-Dot Puss, Jerry consults Dr. Quack's medicine book and does a number of unorthodox treatments to the now hypochondriacal cat, such as placing a stethoscope next to a ticking alarm clock to intensify Tom's apparent heartbeat and setting off the alarm shortly afterwards.
Polka-Dot Puss is a 1949 one-reel animated cartoon and the 39th Tom and Jerry short produced in 1948 and released on February 26, 1949. Polka-Dot Puss short was directed by Tom and Jerry's creators, William Hanna and Joseph Barbera.