Senior Dog Blood Tests: What Changes With Age

Older dogs benefit from wider blood and urine checks because the kidneys, liver, thyroid and blood sugar control can change slowly with age. A senior check may include a blood count, liver and kidney tests, a thyroid profile and a urine test. Your vet decides the list and how often to repeat it.

What changes inside an older dog?

Organs wear gradually, and many age-related problems begin without loud signs. You may see a dog sleeping more, drinking more, putting on or losing weight, getting a dull coat or having accidents in the house. Some dogs also lose interest in walks or food. These are easy to blame on old age, but some have causes that a vet can look for, so mention every change to your vet, however small.

Blood tests do not show stiff joints or pain, so your vet will still examine the dog with their hands. What blood and urine can show is how the inner organs are keeping up.

What does each test look at?

• The Complete Blood Count (CBC) counts the red cells, white cells and platelets. It can help show anaemia or signs of infection, both of which may be quiet in an old dog.
• The Liver Function Test (LFT) checks liver enzymes and proteins. Changes may indicate that the liver is under strain.
• The Kidney Function Test (KFT) measures waste products such as urea and creatinine. Raised values may indicate that the kidneys are not clearing waste well.
• The Urine Routine checks the urine for strength, protein, sugar, blood and cells. It can show kidney or urinary changes that a blood test alone may not.

For owners who prefer one booking, the Senior Pet Health Panel groups several of these with sugar, salts and thyroid checks for older pets. It is a bundle, so your vet can still add or remove tests.

What does the thyroid test add?

The thyroid is a small gland in the neck that makes hormones which set the body's pace. In dogs, an underactive thyroid is seen more often as they age. It may go with tiredness, weight gain, a dull coat or skin trouble, although other illnesses cause these signs too.

The Thyroid Profile (T3, T4 & TSH) measures the thyroid hormones T3 and T4 and a signal hormone called TSH. Other illnesses can change thyroid results, so a registered veterinarian reads them with the whole picture and may repeat the test later.

Why is a urine test part of a senior check?

Kidneys do two jobs: they clear waste, and they hold on to water by making urine strong. A kidney that is tiring may lose that second skill early, and only the urine shows it. Protein or sugar in urine can also give your vet a lead.

Urine is usually simple to collect from a dog: catch it in a clean, dry container while the dog passes it, or ask your vet or the lab how to do it. A blood test and a urine test answer different questions. Read together, they give a fuller picture of the kidneys than either would alone.

How often should an older dog be checked?

Your vet decides. It depends on the dog's age, size, earlier reports and any known condition. A dog with a health problem may be checked more often than a healthy older dog.

Compare each new report with the last one. A slow trend across several reports can matter more than one number on its own. Keep all reports together and ask your vet what has changed since last time.

A check is not a substitute for care when the dog is unwell. If an older dog stops eating, drinks far more than usual, struggles to breathe or collapses, see a vet promptly.

Read next

If your dog is not yet in the senior years, Yearly Health Check for an Adult Dog: Which Tests and Why describes the usual yearly check. When you are deciding between bundles and single tests, Choosing a Health Package for Your Pet or Farm Animal helps you ask the right questions.

Testing in Bhopal

An older dog may find travel tiring, so Bhopal owners can use the free home sample collection for blood and urine. Visit or call the lab at C-200, C Sector, Shahpura, or WhatsApp +91 88175 01118; when you book, the lab confirms the method, sample needs and reporting time. From other districts, send samples by courier or bus parcel, or let your vet do it.