What bloodwork does a senior dog need, and how often?
AAHA's senior care guidelines recommend a CBC, a chemistry panel, and a urinalysis every 6 to 12 months, with a thyroid test and blood pressure check once a year. Your veterinarian adjusts that list for your dog.
The short version
- AAHA recommends a CBC, chemistry panel, and urinalysis every 6–12 months for senior dogs, and T4 and blood pressure annually.
- AAHA defines senior as the last 25% of estimated lifespan, with no single age that fits every breed.
- IDEXX reports SDMA rises with about 40% loss of kidney function on average, while creatinine may not rise until up to 75% is lost.
- A baseline taken while your dog is healthy lets your veterinarian spot a trend before a value leaves the normal range.
The American Animal Hospital Association (AAHA) recommends a complete blood count, a chemistry panel, and a urinalysis every 6 to 12 months for senior dogs, plus a thyroid test and a blood pressure check once a year.1 We are not veterinarians. Below is what the guidelines say, what each test looks at in plain words, and what to ask at the next visit.
What do the AAHA senior care guidelines recommend?
The 2023 AAHA Senior Care Guidelines include a table of tests and how often to run them. For dogs:1
| Test | AAHA recommended frequency |
|---|---|
| Complete blood count (CBC) | Every 6–12 months |
| Chemistry panel (includes SDMA if available) | Every 6–12 months |
| Urinalysis | Every 6–12 months |
| Thyroxine (T4) | Annually |
| Blood pressure | Annually |
| Heartworm and tick-borne disease tests | Annually |
The guidelines also recommend a medical workup for senior pets once or twice a year.2 AAHA's guidance for pet owners is more specific: senior pets should be examined by their veterinarian every six months.7
This is a guideline, not a prescription. Your veterinarian may add or skip tests based on your dog's breed, history, and exam.
When does a dog count as senior?
There is no single birthday. The AAHA guidelines define the senior stage as the last 25% of a dog's estimated lifespan and say there is no specific age for senior status, because aging varies by species and breed.3 As a working rule for owners, AAHA describes senior dogs as those older than 7 years.7 Ask your veterinarian where your own dog falls.
What does each test look at?
- CBC. Counts the cell types in the blood: red blood cells, which carry oxygen; white blood cells, which fight infection and respond to inflammation; and platelets, which help blood clot.5
- Chemistry panel. A group of tests that gives information about the organs and tissues and helps detect diabetes, kidney disease, liver disease, and other disorders.5 AAHA's list for the panel includes total protein, albumin, the liver enzyme ALT, glucose, the kidney values BUN and creatinine, sodium, potassium, and calcium.1
- Urinalysis. Reports the chemical and microscopic properties of urine. It shows how well the kidneys are working and can identify inflammation and infection in the urinary system.5
- Thyroid (T4). A screen for hypothyroidism, which VCA Animal Hospitals describes as the most common thyroid disease in dogs. It occurs when the thyroid gland does not produce enough hormone.5
- Blood pressure. AAHA notes that high blood pressure is common in senior pets.7
What is SDMA, and how is it different from creatinine?
Both are blood markers of kidney function. Creatinine is the older one. SDMA (symmetric dimethylarginine) is a newer test, and AAHA lists it within the senior chemistry panel "if available."1
The figures below come from IDEXX, the laboratory company that offers the SDMA test, so read them as the manufacturer's data:6
- SDMA increases with a 40% loss of kidney function on average, and as early as a 25% loss.
- Creatinine does not increase until up to 75% of kidney function is lost.
- In dogs, SDMA increased 9.8 months earlier than creatinine on average, with a range of 2.2 to 27 months.
- Creatinine is a breakdown product of muscle, so it is affected by lean body mass. IDEXX states that SDMA is not.
An SDMA result is one data point. What it means for your dog is a question for your veterinarian, who will read it alongside creatinine, the urinalysis, and the exam.
Why does a baseline while healthy matter?
Lab reference ranges are built for dogs in general. Your dog has its own normal. The AAHA Canine Life Stage Guidelines say it is useful to establish a baseline for each individual dog before hidden disease develops, and that some diseases are identified by an increase over the dog's previous levels before a value leaves the normal range.4
The same guidelines cite a study of 1,421 apparently healthy dogs of all ages in which significant abnormalities were present in 39.5%.4 VCA makes a related point: dogs are very good at masking illness, and regular monitoring makes it easier for a veterinarian to detect minor changes.5
Check tonight
Find the date of your dog's last blood and urine tests. Look in your clinic's app, your email, or the paper folder. Write down the date and whether the report lists a CBC, a chemistry panel, a urinalysis, and a T4. If you cannot find it, add "ask the clinic for a copy" to your list.
What should you ask your veterinarian?
- Is my dog in the senior stage for its breed and size?
- Which of the AAHA senior tests has my dog had, and when?
- Does our chemistry panel include SDMA?
- How do these results compare with the last ones? Is anything trending, even inside the normal range?
- Should we test every 6 months or every 12?
- Can I have a copy of the full report?
When to call your veterinarian
Do not wait for the next scheduled panel if something changes between visits. VCA lists unexplained weight gain, lack of energy, recurring skin or ear infections, and hair loss as reasons a veterinarian may test thyroid function.5 Tell your veterinarian what changed and when, and ask: "Is this worth a visit and bloodwork now, or can it wait for the next checkup?"
Quick answers
How often should a senior dog get bloodwork?
The 2023 AAHA Senior Care Guidelines recommend a complete blood count, chemistry panel, and urinalysis every 6 to 12 months for senior dogs, with thyroid (T4) testing and a blood pressure check annually. Your veterinarian sets the schedule for your dog.
At what age is a dog considered senior?
AAHA defines the senior stage as the last 25% of a dog's estimated lifespan and says there is no specific age, because aging varies by breed. In its guidance for owners, AAHA describes senior dogs as those older than 7 years.
What is SDMA on a dog's blood test?
SDMA is a blood marker of kidney function. IDEXX, the lab that offers the test, reports that it increases with about 40% loss of kidney function on average, while creatinine may not increase until up to 75% is lost.
Sources
- American Animal Hospital Association (2023). 2023 AAHA Senior Care Guidelines: Diagnostic Tests and Recommended Frequencies for Senior Dogs and Cats
- American Animal Hospital Association (2023). 2023 AAHA Senior Care Guidelines: Evaluating the Healthy Senior Pet
- American Animal Hospital Association (2023). 2023 AAHA Senior Care Guidelines: Defining the Senior Patient
- American Animal Hospital Association (2019). 2019 AAHA Canine Life Stage Guidelines: Baseline Data
- VCA Animal Hospitals. Wellness Testing for Senior Dogs
- IDEXX Laboratories. IDEXX SDMA
- American Animal Hospital Association. Supporting Your Senior Pet: Veterinary Care Recommendations
Written by the Tailwise editorial team from the sources above. We are not veterinarians, and this article is not veterinary advice. If something here matches what you see in your dog, talk to your veterinarian.
More years. Better years.
