Before discussing the strategies behind improving our feline friends' appetite, let's unravel the science regarding cats' uniqueness and why they are "picky" eaters compared to dogs who appear to anything – even if it isn't food!
Cats were domesticated more recently than dogs, about 9000 years ago.
Today, dogs are considered omnivores (can eat plants and meat), whereas cats have always been and will continue to be obligate or strict carnivores.
The features of cats that make them strict carnivores include:
Cats have long, sharp canine teeth with small incisors and molars and very short gastrointestinal tracts making them ideal for hunting prey, stripping meat from bones and digesting meat much faster than veggies.
Cats are used to hunting small prey often during the day, reflecting their preferences for eating frequent small meals.
Cats have much higher dietary protein requirements and amino acid requirements.
Cats lack certain enzymes that allow for specific nutrients and must acquire them through dietary animal sources. These include Vitamin A, niacin, taurine and arachidonic acid.
How palatable or appetizing a diet is, is extremely important to the appetite of cats. Studies have shown that cats will eat a less balanced diet over a complete and balanced one if the diet has high palatability, much like how people favour fatty foods that taste great but aren't always nutritious and healthy.
1) Taste of food
Cats have a relatively small number of taste buds (<500) compared to dogs (about 1,700) and humans (about 10,000), so they are less sensitive to taste compared to other species. Of the classic five basic tastes, cats lack sweet taste receptors and so show no sweets preference. They also respond negatively to bitter tastes, which is opposite to dogs' preferences. Fascinatingly, cats do not find water tasteless and can be quite picky about their water source.
2) Odour of food
To compensate for their weak sense of taste, cats use their heightened sense of smell to determine particular food preferences. A cat's sense of smell is 14 times that of humans. So the odour of food seems to be the most crucial factor for them when choosing food.
Cats have a unique organ called the Vomeronasal Organ (VNO) located at the roof of their mouth. The VNO connects to both the nose and mouth.
A cats' decision to taste food comes from the collective use of the mouth, nose and VNO.
The next three factors are very individual but play a role in food intake preferences:
3) Shape of food – many cats like star-shaped kibbles, but some cats prefer round kibbles, and to some cats, the shape of the kibble is irrelevant.
4)Texture of food – the preference for dry food versus wet food often comes down to texture preferences. Some kitties like the crunch factor, and others don't care.
5) Mouthfeel – mouthfeel isn't just about how the food feels in the cat's mouth, though that is a factor. Older cats with dental disease that are used to eat dry food can often appreciate having warm water added to their dry to improve the mouthfeel on their sensitive teeth.
Getting to know which shape, texture and mouthfeel your cat prefers is simply a matter of trial and error.
We can gain a much better understanding of how to make our cat's food more palatable by doing three things:
1) Understand the animal-related factors affecting food palatability
A cat's way of life and prior dietary experiences play a role in its food preferences. For example, cats fed a lot of dry food from 7 months of age to 23 months of age have a reduced acceptance of canned food later in life.
Taking a cat's age into consideration is also crucial as the receptors for smell and taste decline with age. Therefore older cats may need some encouragement to make their foods more palatable as they age.
Finally, cats will either prefer a novel food ("neophilia") when they have been fed a single food for a long time or reject it ("neophobia”). Rejection is most commonly seen when the cat is under stress (emotional, environmental or physiological). Introducing new foods under favourable circumstances is a good idea.
A fascinating fact that I have seen in my practice is the concept of "learned food taste aversion." If I say the word "tequila," many of you may already understand what I am referring to. Cats, if introduced to a new food when feeling ill may try it on day one and then never taste it again. They associate the taste of the novel food with how ill they feel at that moment, and that aversion can be long-term. I made this mistake myself once in practice after offering a cat that I had just diagnosed with a prescription renal diet with chronic kidney disease. I knew the diet would help their kidneys but forgot that I introduced a new food to them when uncomfortable with their surroundings and not feeling a hundred percent. It is no wonder why he wouldn't accept the new diet. Only introduce new diets or treats when cats are comfortable in their environment and feeling fine.
2) Watching your cat just before eating and during eating
Touching the food with their paws and biting at the food are good signs that your cat likes the food. During consumption, cats who are eating something they enjoy will have "half-closed eyes" and may lick their nose, protrude their dog or smack their lips. Signs of disliking a food include moving the tail to the left and right and grooming.
3) Understand the dietary-related factors affecting food palatability
However, these should not be routinely added to a food until you have discussed them with your veterinarian.
Perhaps my biggest tip for feeding your cats is to remember that they aren't omnivores like us and have many different preferences and needs regarding diet. Finally, if your cat goes a full day without eating, this is something that I wouldn't ignore and reach out to your veterinarian immediately. Plus, your veterinarian can help you choose which foods and additives are best for your cat's particular situation.
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