Dogs are living longer than ever, which is wonderful. Our goal is to help them remain comfortable, active and well for as long as possible.
Routine blood testing becomes more useful as dogs grow older because many health problems can develop quietly, before there are obvious signs that something is wrong.
Ideally, we want to detect these changes early, when we have more options to investigate them, manage them and support the dog more effectively.
Does every young dog need routine blood tests?
No. I do not routinely recommend annual blood tests for young, healthy dogs below five years old unless there is a health concern or another valid medical reason.
Of course, younger dogs may need blood tests if they are unwell, vomiting, having diarrhoea, undergoing anaesthesia or surgery, taking long-term medication or suspected of eating something toxic.
In general, routine blood screening becomes more useful during a dog's senior years.
How often should small dogs have blood tests?
| Age | My usual recommendation |
|---|---|
| Under 8 years | Only when there is a medical reason |
| 8–12 years | Once a year |
| 12–16 years | Every six months |
| Over 16 years | Every three to six months |
How often should large dogs have blood tests?
Large dogs tend to age earlier, so I usually begin routine testing sooner.
| Age | My usual recommendation |
|---|---|
| Under 8 years | Only when there is a medical reason |
| 8–10 years | Once a year |
| 10–14 years | Every six months |
| Over 14 years | Every three to six months |
How often should giant-breed dogs have blood tests?
For the purpose of this guide, giant-breed dogs are dogs that weigh approximately 45 kg or more as adults.
| Age | My usual recommendation |
|---|---|
| Under 5 years | Only when there is a medical reason |
| 5–7 years | Once a year |
| Over 7–9 years | Every six months |
| Over 9 years | Every three to six months |
Track what matters. A simple weekly check-in on your dog's energy, appetite, comfort, stools, sleep, and thirst makes changes far easier to spot.
Why not wait until your dog looks unwell?
Because dogs can compensate remarkably well. They may not show any outward signs of a problem until the disease is quite advanced.
When a disease is detected early, we usually have more options to manage it and help the dog stay comfortable and well for longer. If it is only discovered at an advanced stage, the changes we make may not have the same effect.
Kidney disease is a good example. If it is detected while the patient is still in Stage 1, the patient could potentially continue to live well for several more years with appropriate monitoring and management.
However, if kidney disease is only discovered at Stage 4, when your dog is very unwell and no longer eating, our options may be much more limited. We may still be able to improve their comfort and quality of life, but we are less likely to gain as much time as we might have if the deterioration had been identified earlier.
What does a routine blood test check?
A routine blood test generally looks at:
- Red blood cells
- White blood cells
- Platelets
- Kidney and liver markers
- Blood glucose
- Proteins and electrolytes
Depending on the dog, I may also check other parameters such as SDMA, thyroid levels or specific inflammatory markers.
The important thing is not simply whether every result falls within the normal range. We also compare the results with the dog's previous tests and look for changes over time.
Frequently Asked Questions
Are blood tests the only form of routine screening my dog needs?
No. A blood test should ideally be assessed together with a urine test. Depending on your dog's age, breed, examination findings and medical history, your veterinarian may also recommend imaging such as an abdominal ultrasound or X-rays.
These tests provide different types of information and work best when used together.
Can blood tests pick up cancer?
Blood tests cannot reliably detect or rule out cancer, but they may show signs that something is wrong in the body.
For example, a dog with significant anaemia may need further investigation to look for a possible source of internal bleeding. One potential cause would be a growth that is bleeding slowly and causing ongoing blood loss.
In this situation, your veterinarian may recommend imaging to look for the underlying cause. Normal blood results are reassuring, but they do not guarantee that a dog does not have cancer.
Can blood tests replace a physical examination?
No. Physical examinations are extremely important and cannot be replaced by blood testing.
A physical examination allows your veterinarian to assess your dog's heart, lungs, abdomen, lymph nodes, muscles, joints, skin and overall condition. It should be used together with blood testing to build a more complete picture of your dog's health.
What is the purpose of routine blood testing?
Routine blood testing is not about doing more tests for the sake of it. The purpose is to identify meaningful changes early, while we still have more options to investigate and manage them.
This may mean adjusting the diet, changing medication, arranging further tests or monitoring a particular result more closely.
Do we have to follow the testing schedules above?
No. These schedules are only general guidelines.
How often your dog should have routine blood testing should be discussed with your veterinarian. The most appropriate interval depends on your dog's age, overall health, underlying medical conditions, previous results and whether they are taking any regular medication.
What to Do This Week
Look at your dog's age, size, and health history. If they are due for screening, call your veterinarian this week to discuss a blood testing schedule that suits your dog. If you already have recent results, ask your vet to walk you through the trends rather than focusing only on whether each value is "normal".
When to See a Vet Urgently
Contact your vet promptly if your dog is unwell, vomiting, has diarrhoea, is losing weight, drinking or urinating more than usual, or if a recent blood test flagged any values your veterinarian wants to recheck.
This article is for educational purposes only and does not replace professional veterinary advice. If your dog is unwell, please consult your veterinarian.
Screening is one part of a wider picture; read more on helping dogs age well.
About the Author
Dr Kelly Yeo graduated from the University of Melbourne in 2009 and has extensive experience in companion animal medicine, with a special interest in geriatric care, chronic disease management, palliative care, and canine longevity.
Her work focuses on helping dogs live longer, healthier, and more comfortable lives through early detection, thoughtful nutrition, practical preventive care, and compassionate support for owners.
