Introducing an FIV+ Cat to a FIV- Cat

When Caring For Creatures first opened its doors in 1988 there was no diagnostic testing available for determining if a cat had contracted the FIV virus. When the test became available and we received our first cat that tested positive, we had to make a decision. At the time we had a special area for cats testing positive for leukemia, but no space was available for the FIV positive cats. Our veterinarian explained in detail about the virus and that it would not pass just through general contact like the feline leukemia virus. Typically the virus was passed through bite wounds – think unaltered male cats fighting for territory or over female cats in heat. We were advised that if positive and negative cats were compatible, i.e. not fighting, the likelihood of the virus passing was nonexistent. The important aspect was properly introducing the positive cat to the existing population; this is true for introducing any cats, positive or not.

For over 10 years we kept FIV+ and FIV- cats in the same area; mostly because we did not have any other place to separate them! With our new cat residence that was completed in 2003, we do now have a room for FIV+ cats – mostly so we can track them better and if we want to give special food or supplements, it is a little easier to do it this way. But we never had a negative cat turn positive during the long period we had them together and we regularly did spot testing and re-tested negative cats should they become ill suddenly, etc.

The key to having positive and negative cats together is to do a very slow introduction period – this could mean weeks/months depending on the cats. FIV is not transmitted through general contact, but rather, by bite wounds; so it is important that the cats get used to being around each other on a slow basis (this would be true for introducing two negative cats as well!). Our procedure for introducing an FIV cats into a general population of negative cats was as follows (by the way, we also use this procedure when we introduce a new cat into any of our existing colonies/rooms):

We place the new arrival(s) into what we call cat condos – they are tall cages that are perhaps 4′ tall, with two shelves and a lower area for litter box, food/water and a bed. We typically take a sheet and cover the top, back and two sides (we use binder clips to attach sheet to cage). We would leave the front of cage (that has doors) open. This gives the new cat(s) a feeling of security – they can observe their surroundings without feeling threatened. The existing cat can also observe and get a feel for the new cat(s) without having a strong urge to attack the new arrival who is in their territory. Sometimes we also use a product called Feliway – it comes in a spray bottle and is a pheromone product; it is a calming scent to cats and is similar to the scent a cat leaves when rubbing up against your legs, furniture, etc. Bottom line – it is a “positive” scent. You can spray Feliway on the sheet covering the cage and even spray some on your hands and then rub the fur of the cats.

Here at the sanctuary, the new arrivals remain in the cage from one week to a month or more; it really depends on the cats involved and how the interactions are going with the other cats. Once the new cat calms down a bit, sometimes we let the cat out into their room to be with the other cats when a staff person is in the room cleaning to observe interactions. The cat is returned to the cage for the overnight period so there are no incidents during un-monitored times. It’s also a good way to make sure the cats are eating, drinking and eliminating properly. If things go well, we let the new cat remain out of the cage to mingle with the other cats.