Indoor cats can get colds if they come into direct contact with infected discharge from another cat who has got a cold. Or they come into contact with contaminated litter boxes, water bowls and human hands. The disease is also transmitted by airborne droplets. The virus can be stable for as long as 10 days outside of the host depending upon the ambient conditions.
There are two main viral groups that caused the common cat cold namely the herpesvirus group and the calicivirus group.
I’ll describe some possible scenarios under which an indoor cat (and therefore protected to varying degrees from infection) might get a feline cold.
If an indoor cat lives in a multi-cat home and one of the cats is new to the home they may have brought the virus into the home allowing it to be transmitted to other cats.
If an indoor cat is taken to a veterinary clinic there would be opportunities at the clinic for the cat to pick up the virus that causes a cold. It might be on the hands of the veterinarian or in the atmosphere at the clinic. They would bring it back to their home.
If an indoor cat has the luxury of a catio or outdoor enclosure, it is possible it seems to me, albeit difficult to visualise, that contaminated air droplets could enter the catio and infect the cat inside it. The water droplets might come from a stray cat just outside the catio.
The indoor cat’s owner visits a neighbour’s home and in that home is a cat with a cold. She handles the cat. The virus is deposited onto her hands. She returns to her home and handles her full-time indoor cat. She deposits the virus onto her cat. Her cat gets a cold.
The owner of a full-time indoor cat is also a cat foster carer. Her foster cat or cats are outside in pens as directed by the rescue organisation. One of the foster cats has a cold who she is caring for. It is possible that she could become the vector and transmit the disease from a foster cat to her full-time indoor cat despite the individual cats being permanently separated by a considerable distance.
The feline cold is contagious as described. There has to be some sort of transmission of the virus from one cat to another and there maybe an intermediate vector. Clearly an indoor cat living alone with their owner is much less likely to get a cold than a free-roaming cat if but there are opportunities to catch one. I’ve described some situations where it might happen.
It seems to me that the lessons that we have learned during the coronavirus pandemic about minmising the risk of infection might be usable in minimising the transmission of the virus which causes the feline cold to indoor cats. I’m thinking of washing hands when coming inside and taking other general precautions to minimise disease transmission. In fact the coronavirus pandemic may well dramatically reduce the incidents of the common cold in people this winter. The rules under which we currently live such as wearing masks and social distancing may become part of our lives and it may be a good thing in terms of health but a bad thing in terms of socialising (which humans in general need).