The onset of kitten season is one of the most dreaded times for animal shelters. Kitten season is one of the greatest factors that makes or breaks an animal shelter calling itself a no-kill shelter. And demonstrates the nasty side of mother nature by flooding the animal shelter with kittens two to four times each year, many of the kittens being neonatal (unable to eat without assistance). Factors that regulated the severity of kitten season are access to food, climate, and communicable diseases.
Although population is the primary limiting factor in are area’s carrying capacity, providing an additional food source will extend the carrying capacity beyond its natural limits. As long as there is an adequate food source, cats will breed. People who are feeding outside cats are providing the cats with incentive to continue to reproduce.
The northern states are more likely to have fewer breeding cycles due to harsh weather. Freezing temperatures serve to discourage a breeding cycle or kill any young offspring. The fewer breeding cycles provide the shelter with few incidents of shelter overcrowding.
Communicable diseases (usually feline panleukopenia) will usually kill off many kittens shortly after birth. The disease also presents a major risk to the animal shelter as the community and local animal control officers bring in diseased cats at a time when the shelter is at its greatest capacity. It is not uncommon to read new reports of animal shelter having to euthanize their entire cat population to rid the shelter of potential vectors while the shelter undergoes a disinfecting process.
All of these factors will cause the increase in euthanasia at the animal shelter. If the number of euthanasias drive the number of total deaths over ten percent, the shelter loses its right to call itself no-kill.