Cat Aging and Weight: What the Scale Tells You
Weight changes in cats are often the earliest visible sign of an age-related health condition.
Ideal Weight Ranges by Age
Most domestic cats should weigh 3.6-5 kg (8-11 lbs). Large breeds like Maine Coons can healthily reach 6-9 kg. Body condition score (BCS) on a 1-9 scale is more meaningful than weight alone; a score of 4-5 is ideal.
| Life Stage | Age | Weight Trend | Key Risk |
|---|---|---|---|
| Kitten | 0-1 yr | Rapid gain | Underweight |
| Young Adult | 1-6 yrs | Stable | Obesity (post-neuter) |
| Mature Adult | 7-10 yrs | May gain | Obesity; early organ disease |
| Senior | 11-14 yrs | Slight loss | Hyperthyroid weight loss |
| Geriatric | 15+ yrs | Declining | Muscle loss, CKD |
Obesity and Accelerated Aging
Obesity — more than 20% over ideal body weight — significantly increases the risk of:
- Type 2 diabetes mellitus
- Hepatic lipidosis (fatty liver)
- Osteoarthritis and joint pain
- Lower urinary tract disease
- Reduced lifespan (2-3 years shorter)
- Respiratory problems
- Reduced immune function
- Increased surgical risk
Weight Loss in Senior Cats: Never Ignore It
Hyperthyroidism: Weight loss despite good appetite. Affects ~10% of cats over 10.
Chronic Kidney Disease: Nausea, reduced appetite, muscle wasting. Very common over 12.
Diabetes: Weight loss with increased thirst and urination.
Monitor at Home
Weigh your cat monthly. A consistent loss of more than 0.5 kg over 1-2 months warrants a vet visit. Also do a rib check: you should feel ribs easily without pressing hard, but not see them visibly.