Our last 2 cats, (feral kittens, eyes barely opened, never spent a day outside, after I took them home) received their vaccinations, when they were spayed. Since they never went outside, the vet agreed, they didn't require outdoor cat's vaccinations. They were never kenneled, never saw another cat, but both of them died before they were 16 years old. One had spinal deformities and tumors, the other one just died of old age. She was losing weight, skin and bones, the vets talked a lot about quality of life. She didn't like to get pets or scricthes, life was no longer happy for her. Over the years, we've probably had around 18 cats, (I am 75 years old.) About 4 of those 16 outdoor cats who were fully vaccinated, lived to be 18+ years. Vaccinations did not make a negative difference in all of their lives.
Also, we've lived on the same street since 1982, beautiful 100 years old houses, where one very religious family didn't believe in birth control, even for their cats. Their house was a flipping stray cat factory. They didn't take care of them, didn't feed them. They came begging for food, it was awful. While the neighborhood tried to help, two wonderful neighbors got many of them spayed or neutered and kept bowls of food/water on their porches for them. The cat factory family is still there, but in the past ten years not many stray cats. They probably didn't vaccinate their cats either, just like they didn't feed them.
Your cats are lucky they have you. You are a responsible cat parent and doing what needs to be done. Please take care of yourself too.
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