While the research into cat separation anxiety is just at the early stages of understanding, many have been noticing the signs. I will retell the story of my two cats, Bubba and Charlie.
Charlie was my future wife’s cat of 4 years. Some 6 years ago, when we moved in together, Charlie was aloof and prevented me, at least at first. Once she realized I was here to stay, she started accepting me. Initially, a bit stand-offish, but slowly accepting me to the point that she’d lay on my lap to the dismay of my wife. My work at the time was on the street, with periods of time in the home. We soon noticed that when I was away, Charlie would groom herself excessively, to the purpose of producing a bald spot on her flank. On my retirement, the only time we were away was every 2 months, my wife had to come back to the hospital she worked for to do their payroll. We would be away for 2 -3 days every 2 weeks. On our return, we would find that Charlie had vomited all around the home, and on our bed. The reason we know this, once on birth at home, we walked in on her vomiting. Whenever we brought out our suitcases to pack for our trip, Charlie would hide out, under the bed, the sofa, or under the dining table to prevent us.
Bubba, on the other hand, was a stray that I adopted about a year after I had moved in, my best guess was that he was about a year old. It took a while but Charlie and Bubba became great buddies. The only sign with him was on our return he would not let us out of sight. If you went to the restroom, he had to be there. He would walk with me, rubbing up against me, to the extent as to almost trip me.
In doing research, these are all symptoms of separation anxiety in cats. Some say being orphaned or being weaned early can predispose the development of separation anxiety. As this topic gets more study, there could be more information garnered.
Things to do would be subjective. The first thing would be to get the veterinarian do a complete physical to make sure the behavior is not due to some underlying physical issue. This will maybe involve blood work, urinalysis, thyroid testing, or a blood pressure test.
Some other suggestions include making the time of passing less stressful by making changes in the normal routine. Some experts suggest that for 15 minutes prior to leaving and upon return home, the operator should dismiss the cat. Leaving a distracting toy can be helpful. Someone suggested hiding tasty treats in a variety of places in the house. Making the environment more stimulating may help. A cat tower with toys attached close to a window could help. Sometimes they simply enjoy seeing what is going on outside.
Some experts have stated that in some situations the short-term use of anti-anxiety medications may be needed. You must be aware that these are not labeled specifically for use in cats and should / must be prescribed and monitored by your veterinarian.