According to several recent studies, not only do cats feel stress but they are also susceptible to the negative physical and mental effects of it. A summary of papers presented at the NAVC Conference 2010 in Orlando was published in a supplement by the professional journal Clinician's Brief. Both papers presented in the supplement Stress - The Silent Player in Feline Disease discuss how cats' stressor responses are related to their evolutionary make up and how they do - or don't - adapt to being brought indoors. The success of their adaptation to being our indoor companions relates to their ability to handle stress and whether or not it will effect them physically and mentally.
In his paper Internal and External Influences on Disease Risk, Tony Buffington of Ohio State University states that indoor cats will still behave as if they were in the wild in terms of their drives to hunt, hide and defend their territories. If we don't understand these behaviors for what they are, we frequently misinterpret the meaning behind them, thinking they are acts of deliberate hostility or spite. The behaviors most commonly misinterpreted are biting, scratching, climbing and marking. In our misunderstanding, our responses to these behavior can create external sources of stress for cats, which in turn can create internal problems. Dr. Buffington concludes his paper saying that because our current knowledge base is limited with regard to the internal factors that cause physical stress, we as owners need to focus on the external factors that we can control and positively enhance.
Sarah Heath, a veterinarian and behaviorist from Chester, England, discusses in her paper Happy, Healthy Cats: How to Minimize Stress in the Modern Domestic Environment, how being indoor companions can actually compromise natural behavior for a cat. These lead to creating stress for cats, and again, can have a direct impact on their health. Dr. Heath discusses our preference for multi-cat household consisting of unrelated cats, as well as how people have different interaction expectations from cats versus how cats are more accustomed to interaction amongst themselves. Even if there is not outright aggression or fighting amongst cats in a multi-cat household, low-grade stress and tension can still be present, which can lead to behavioral issues and may even contribute to physical illness.
While it might seem that the best answer would be to let your cat roam unsupervised outdoors to relieve his or her stress at being indoors, this is definitely not the answer. The outdoor presents many dangers for cats including parasites, diseases, predators and cars. Keeping cats indoors is still the best option for a long and happy life.
Both Dr. Buffington and Dr. Heath offer suggestions for helping reduce external stressors for cats by providing proper environmental enrichment in the home. These include each cat having his or her own space away from other cats in the house; providing several "food and water" stations around the house so there isn't a sense of competition for these; providing several litter boxes, again to reduce a sense of competition, and maintaining the cleanliness of the box; and providing adequate physical and mental exercise that stimulates their normal "in the wild" behaviors. More suggestions can be found at the Ohio State University's Indoor Cat Project. Because cats can be so skilled at hiding signs of tension or stress until the effects have become detrimental, here at Scottsdale Cat Clinic we recommend implementing these environmental enrichments. Even if your cat is happy and healthy, these are wonderful ways to ensure she stays that way.