Just a whiff of tuna can jolt my cat, Shaka, from a sound sleep.  The aroma enters his nostrils and they begin to quiver.  The next thing I know, he is there to share my lunch.  Some cats get trained to the sound of can openers, but others, such as Shaka, use their keen sense of smell to alert them to important items such as the opening of a tuna package.  Smell plays important roles in eating, friend or foe recognition, elimination, and sexual behavior in cats.

Smell, also known as olfaction, is a highly developed sense at birth in cats.  Newborn kittens establish a nipple preference on the nursing queen, and smell is used to guide a kitten back to his chosen site.  If a young kitten wanders from his “nesting” area, olfactory cues will be guide him back until vision becomes the main guide at 3 weeks of age.  During the weaning process, from 4-6 weeks of age, a kitten will utilize smell to find food, and distinguish between edible and inedible objects.

An interesting aspect of smell in cats is the vomeronasal organ, which is responsible for pheromone communication between cats.  Pheromones are chemical communicators; odors produced by one individual and detected by another of the same species.  Canals are present in the mouth that channel pheromones to the paired vomeronasal organs in the hard palate.  Special olfactory cells in the organs transmit “smell” messages to the brain.

Flehmen is a behavioral response to vomeronasal stimulation. A cat exhibiting Flehmen will raise its head, draw its lips back, wrinkle his nose, and hold his mouth partially open.  This allows the odors to enter the oral canals and reach the vomeronasal organ.  Many of you have observed this behavior in your own cat without knowing what it was.  Situations that could initiate a cat’s Flehmen response are being around a female cat in heat, smelling urine of an unfamiliar cat, or smelling where another cat has rubbed and left its oily secretions.

Social interaction between cats starts with the olfactory information obtained when cats first approach face-to-face, and then face-to-anus. A cat will identify familiar cats and greet non-hostile, unfamiliar cats this way.  When a cat is greeting a human, the same behavior pattern can be observed.  The cat will approach and smell the person, then turn and present his hind end.

Smell plays a role in elimination behavior.  Urine and fecal odor buildup can be important factors in feline housesoiling. A cat may find his own odors offensive when a litter box is not kept clean, and then choose another location to eliminate.  In a multiple cat household, several litter boxes are usually needed to prevent smells from discouraging litter box use.  The scent of the litter itself can affect litter box usage.  Most cats detest perfumed litter and prefer the plain types.

Neutralizing urine odors helps eliminate behavioral housesoiling.  Although this may not stop the problem, it will reduce the factor stimulating a cat to return to the same location.  A cat’s sensitive sense of smell will draw him back to a previous site unless sufficient neutralization is achieved.  There are numerous products on the market, including white vinegar that may work.  The point to remember is that there is ammonia in cat urine, and if you clean with products containing ammonia, you will actually intensify the urine odor.

The sense of smell is crucial in the feeding behavior of cats.  Cats that are unable to smell may not eat.  Cats that are sick with upper respiratory infections and have congested nasal cavities often lose their appetites.  Pet food companies research the odors that stimulate appetite along with tastes to develop their products.  Cats will approach food and sniff it before eating.  When cats are presented with an unfamiliar item, they will sniff it, and if not stimulated favorably, they will not try tasting it.

Researchers have identified 14 chemicals that affect cat behavior when inhaled.  The most notorious of these is catnip, an herb in the mint family. About 60% of cats possess the gene responsible for catnip sensitivity. Catnip is considered hallucinogenic, and prolonged use could lead to a general decrease in awareness.  Overall, catnip is considered a safe substance. A cat may smell, lick, chew or eat catnip when presented with it. Some like to roll on and hold the catnip containing item in their paws. This releases the volatile oils in the leaves, which the cat smells.  The effects of catnip can last 2-15 minutes.  Age and previous exposure affect response to catnip. Stressed or fearful cats and kittens under the age of 5 months are not very responsive to catnip.

Smell is a very interesting sense in cats, but I sometimes wish I could eat a tuna sandwich in peace.

Written by Dr. Wexler-Mitchell of The Cat Care Clinic in Orange, CA
Copyright © 2011 The Cat Care Clinic