Also called · 고양이 단맛 · 설탕 · 미각 · 쓴맛
What it looks like
- No interest in sweet treats
- No reaction to fruit
- Refuses bitter medicine absolutely
Why it happens
The gene is switched off
Detecting sweetness requires two proteins, T1R2 and T1R3, to pair up. In cats T1R3 is intact but the gene for T1R2 is broken. A 247-base-pair stretch is missing from an exon and a stop codon has been introduced, so the protein is never made. With no partner, the receptor is never assembled, and sweetness drops out of what can be detected. (PLoS Genetics, 2005)
It is not only house cats
The same defect has been confirmed in tigers and cheetahs. It appears common to the whole cat family, and is read as a function switching off once evolution toward obligate carnivory left no use for it.
Bitterness, on the other hand, is acute
Other senses fill the space sweetness left. Cats are far more sensitive to bitterness than dogs, which is thought to reflect the survival value of detecting spoiled meat and toxic plants. It is also why medicating them is difficult.
What to do
Do not try to tempt a cat with sweetness
Mixing in something sweet to improve palatability is meaningless for a cat. What a cat responds to is the smell of protein and fat, and temperature.
Medicate by masking bitterness
Given their sensitivity to bitterness, a tablet offered plainly meets strong refusal. Hiding it in strong-smelling wet food, or using a pill-giving treat, works better. Crushing it to powder spreads the bitterness instead.
There is no reason to give sweets at all
Neither dogs nor cats require sugar. Treats judged by human standards add calories and nothing else.
Watch out for
They simply cannot taste it — the effect on the body is unchanged. Chocolate and xylitol are dangerous regardless of taste. If anything it warrants more care, since there is no flavour to prompt refusal.
See a vet if
Suddenly stops eating and drools
Approaches food then flinches back — possible oral pain
Common questions
The cat is responding to the smell of fat and dairy, not to sweetness. Many cats cannot break down lactose, so it can lead to diarrhoea.
Grapes and raisins are off-limits. Otherwise a small amount is usually fine, though it is not a nutritional requirement and only adds calories.
Related behaviors
Was this useful?
General behaviour and nutrition information. It does not replace diagnosis or prescription. Similar behaviour does not always have the same cause, and the cause is not necessarily diet or environment — have a vet rule out illness first, and consult a behaviour specialist where needed.