Managing Feline Stress Through Diet

Cats are susceptible to external stressors (eg, environmental changes, forced confinement, unpredictable handling by unfamiliar humans, changes in routine, continued exposure to high-frequency sounds). Studies have shown that cortisol secretion increases when cats are exposed to these events chronically. Ingestible, bioactive peptides (eg, alpha-casozepine, tryptophan) have been reported to have a calming effect on humans. Alpha-casozepine is derived from a major protein in milk, which is believed to cause an anxiolytic effect by binding to gamma amino butyric acid (GABA) receptors. Tryptophan is the precursor for the neurotransmitter serotonin (5-HT) and kynurenine. The anxiolytic effects of dietary tryptophan are likely facilitated by central 5-HT synthesis and signaling. 

In this study, 21 healthy, client-owned cats were divided into 2 groups. The control group (n = 11) was fed a balanced commercial diet, and the study group (n = 10) was fed a novel balanced prescription diet that contained alpha-casozepine and tryptophan. Plasma and urine cortisol levels were measured before the study and after 8 weeks. Plasma cortisol levels served as an indicator of acute stress. Urine cortisol levels were used to estimate change change in cortisol over the 8-week study period. There was no significant change in plasma cortisol levels in either group. The cats treated with the study diet had a 40% reduction in urinary cortisol levels after 8 weeks, whereas those in the control group had no significant change in urinary cortisol levels. 

The concept of feeding diets to reduce stress is novel in veterinary prescription nutrition. It is an ancient concept in Traditional Chinese medicine, in which certain foods or herbal medicine can be given to treat stress. This study points out that by elevating levels of certain compounds (eg, an essential amino acid), a client can possibly change the biochemical nature of the cat’s central nervous system so that it reacts to stress differently. These types of interventions may be useful in the management of the indoor-only cat and especially in stress-mediated conditions (eg, feline idiopathic cystitis). Further studies are warranted to evaluate foods and supplements to better understand how they work and the clinical situations in which they would be most beneficial.—Heather Troyer, DVM, DABVP, CVA, CVPP