Feline Leukemia shot?

So has anyone run into this. I have a 7 year old kitty who has only had 2 feline leukemia shots in her life. The first one when she was about 4 months the 2nd being the follow up shot. The leg she got the 2nd shot in she couldn't walk for about 2 days after maybe 12 hours after getting the shot. I thought she had been stepped on or hit by a car. She cried in pain all night. Rushed to the vet the next morning first thing. They took an x ray saw nothing when the vet realized it was the leg he had given her her shot in. Since he has not given her the shot. I worry a little that she could contract Leukemia but thank goodness she is not a fighter at all (except with her brother). Has anyone had something like this?

For whatever reason, the ages when cats contract the feline leukemia virus are shaped like a big bell - with the youngest and the oldest being the most susceptible. We think this is because of the weak immune systems of both groups. It's not impossible, but it is unlikely that an otherwise healthy, 7-year-old cat would contract FeLV, vaccinated or not. It is spread through saliva, and apparently it takes quite a whopping dose of it over a period of time before infection occurs. This is why kittens are routinely tested - their mothers with the virus spread it to them while caring for them in infancy. It can also be spread by biting, but it is more well known as the "nice cat" disease because of its spread via mutual grooming. Even kitties who are indoor/outdoor or outdoor only - once they get into adulthood and before they reach their senior years - are unlikely to contract the disease.

Many animals experience the vaccine reaction you report. All of our vaccines are meant to go subcutaneously, meaning under the skin but not into the muscle (a space humans do not have in as significant quantity as other mammals). Sometimes the vaccine can be partially injected into the muscle because the animal squirmed or the skin is really thick and the needle jabbed a little too deep. The vaccine being in the muscle doesn't change its efficacy but certainly it cause a lot of inflammation in the muscle tissue when deposited there. The FeLV vaccine I use is given via transdersmal injection - a special device is used to load the vaccine and deliver it into the dermis (the lowest layer of the skin) - and so this reaction is minimized (although there was a report out a while ago about stupid vets who were breaking femurs with it because they were giving the shot over the bone and not over the muscle...).

In my patients, I don't worry too much about the FeLV vaccine, especially if they are middle age, spayed/neutered and indoor only. My older kitty is not vaccinated for it, but my younger one is. Remember that young cats who get this disease are all mostly dead from lymphoma/leukemia by age 1 and by age 3, 99% of the rest have succumbed - so contact with older cats (>3 years) is unlikely to be a risk factor for disease transmission, unlike with FIV (because cats of any age could be infected with that virus).

My recommendation to you would be to weigh the risk factors for your individual household and act accordingly. And always, if it puts your mind at ease, vaccinate. I have many clients who would not be able to sleep at night thinking their kitty could be at risk despite living situations which would preclude disease transmission who vaccinate anyway. Call your vet if you are worried - that's what we are there for, I promise. You are never a bother and our job is to educate you about your pet's health so you can make the best choices for them.

Thank you so much. It was a very good explanation and much appreciated. To be honest I wanted a 2nd opinion. My vet and I have weighed the good and the bad. It is nice to know varying opinions.
I love my vet. He is dry but I get him. And he has been my vet for 19 years now.