The kidneys, liver, and brain are among the organs most affected by aging in dogs. Early-stage organ decline is often silent—symptoms may not appear until significant function has been lost. This makes proactive monitoring at home, combined with regular veterinary blood work, especially valuable for dogs aged 5 and above.
Quick take
- Early-stage organ decline is often silent—symptoms appear late.
- Increased thirst, appetite changes, and lethargy are key warning signs.
- Canine cognitive dysfunction affects a significant proportion of dogs over 10.
- Baseline blood work gives your vet a reference point for detecting subtle changes.
Why Organ Health Deserves Attention in Aging Dogs
Unlike muscles or skin, internal organs don't give obvious visual cues when they're struggling. The kidneys can lose up to 75% of function before clinical signs appear. The liver has remarkable regenerative capacity but can develop chronic issues quietly. And cognitive changes are often attributed to "just getting old" when they may be addressable.
Kidney Health in Senior Dogs
Increased thirst, more frequent urination, decreased appetite, and weight loss can indicate kidney issues. Regular blood work—including BUN, creatinine, and SDMA levels—at least annually for dogs over 7, helps catch changes early when management is most effective.
Supporting hydration through wet food, bone broth, or water fountains is a simple but meaningful intervention.
Liver Health: What to Monitor
The liver has remarkable regenerative capacity, but chronic issues can develop quietly over years. Watch for changes in appetite, unusual lethargy, or yellowing of the gums or whites of the eyes (jaundice). Liver enzyme levels in routine blood work can flag issues early.
Track what matters. Download the free Longevity Scorecard — a 60-second weekly check-in for your dog's energy, appetite, comfort, and more.
Cognitive Health and Canine Cognitive Dysfunction
Canine cognitive dysfunction (CCD) affects a significant proportion of dogs over 10. Signs include disorientation in familiar places, changes in sleep-wake cycles, house soiling in previously housetrained dogs, and altered social interactions. Mental enrichment (puzzle feeders, scent games) and specific nutritional support (antioxidants, medium-chain triglycerides) may help slow progression.
The Value of Baseline Testing
Establishing baseline blood work values when your dog is healthy gives your vet a reference point for detecting subtle changes. A 10% shift in kidney values means little without knowing where your dog started. This is one of the most impactful things you can do for early detection—and it's as simple as asking your vet to run a comprehensive panel at your next wellness visit.
What to Do This Week
Monitor your dog's water intake this week by measuring how much water you put in the bowl and how much remains. Note any significant changes in your Longevity Scorecard. If you haven't had baseline blood work done, schedule it at your next vet visit.
When to See a Vet Urgently
See your vet urgently if your dog shows sudden excessive thirst or urination, yellowing gums or eyes, persistent loss of appetite, sudden disorientation or confusion, seizures, or abdominal swelling.
This article is for educational purposes only and does not replace professional veterinary advice. If your dog is unwell, please consult your veterinarian.