Senior Pet Bloodwork: Why Annual Screening Matters for Older Dogs and Cats

If your dog or cat is getting up there in years and still seems fine, you might wonder whether bloodwork is really necessary. I hear this from clients at Hearthstone Animal Clinic in Cypress, TX every week: "She's eating well, she's still playful, why would I put her through that?" The short answer is that by the time you notice something's wrong with a senior pet, the disease has often been progressing for months or years. Bloodwork lets us catch problems when they're still manageable, not when they've become emergencies.

What counts as a senior pet?

Dogs and cats age faster than we do, and the threshold for "senior" depends on size. For cats and small dogs under 20 pounds, I consider them senior at around 10 years old. Medium dogs (20 to 50 pounds) hit senior status at 8 or 9. Large and giant breed dogs, like Labradors, Golden Retrievers, and Great Danes, I start treating as seniors at 6 or 7 years old.

This isn't arbitrary. Larger dogs have shorter lifespans, and their organs show wear earlier. A 7-year-old Great Dane is roughly equivalent to a 55-year-old human, metabolically speaking. That's the age when screening starts to pay off.

Why can't I just watch for symptoms?

This is the part most owners get wrong, and it's not their fault. Dogs and cats are hardwired to hide illness. In the wild, showing weakness gets you eaten. Your pet's survival instincts work against early detection.

Kidney disease is the clearest example. By the time a cat starts drinking more water and losing weight (the classic signs), they've typically lost 65 to 75 percent of their kidney function. That damage is permanent. But a simple blood panel catches the early rise in kidney values when we can still slow the progression with diet changes, hydration support, and medication.

The same applies to:

• Diabetes: Elevated glucose shows up on bloodwork long before the excessive thirst and urination that owners notice
• Hyperthyroidism in cats: The thyroid level spikes months before weight loss becomes obvious
• Liver disease: Enzyme elevations appear early, jaundice appears late
• Anemia: Subtle at first, life-threatening once severe

I'm not trying to scare you. I'm explaining why "she seems fine" isn't the same as "she is fine."

What does senior bloodwork actually test?

A standard senior pet bloodwork panel at Hearthstone includes several components, and each one tells me something different about what's happening inside your pet.

Complete blood count (CBC)

This measures red blood cells, white blood cells, and platelets. It tells me if your pet is anemic, fighting an infection, or has a bone marrow problem. Low red cells in an older cat can point to kidney disease or a hidden cancer. High white cells might mean a tooth abscess or something more serious.

Chemistry panel

This is the organ function screen. I'm looking at:

• BUN and creatinine: Kidney values. Elevations mean the kidneys aren't filtering waste effectively.
• SDMA: A newer kidney marker that catches disease even earlier than creatinine
• ALT, ALP, and bilirubin: Liver enzymes and function markers
• Glucose: Diabetes screening
• Total protein and albumin: Nutrition status and liver function

Thyroid level (T4)

Essential for cats over 8. Hyperthyroidism is extremely common in older cats and causes weight loss, vomiting, heart problems, and high blood pressure. It's also very treatable once we diagnose it. In dogs, I check thyroid if there's unexplained weight gain, lethargy, or skin changes.

Urinalysis

Bloodwork tells me what's in the blood, but urine tells me what the kidneys are actually doing with it. Dilute urine in a cat with normal blood values can be the first sign that kidney function is slipping. I catch a lot of early problems this way.

How much does senior pet bloodwork cost?

At Hearthstone Animal Clinic, a comprehensive senior panel typically runs between $150 and $250, depending on which tests are included. A basic chemistry and CBC is on the lower end. Add thyroid, urinalysis, and SDMA, and you're at the higher end. Some owners opt for our wellness panel packages, which bundle these tests at a lower cost than ordering each one separately.

Is it worth the money? If this was my dog, I'd say yes. Catching early kidney disease in a 10-year-old cat can add two to three years of quality life with the right management. That same cat presenting in kidney failure at 12 has far fewer options. The math works out.

What happens if something shows up on the bloodwork?

An abnormal result doesn't always mean disaster. Context matters. Here's what I tell clients when I'm reviewing results:

Mild elevations sometimes just need monitoring. A slightly elevated liver enzyme in an otherwise healthy dog might just need a recheck in three months. It could be a medication effect, a fatty meal before the blood draw, or nothing at all.

Significant abnormalities usually need further workup. If kidney values are climbing, I want to do a urinalysis, blood pressure check, and possibly an ultrasound. If the thyroid is high in a cat, we discuss treatment options (medication, radioactive iodine therapy, or a prescription diet).

The goal is staging, not just diagnosis. Knowing your cat has early stage 2 kidney disease according to IRIS (International Renal Interest Society) guidelines tells me exactly what interventions make sense right now and what to watch for going forward.

How often should senior pets get bloodwork?

For most senior dogs and cats, I recommend annual bloodwork as a baseline. For pets over 12, or those with known chronic conditions like diabetes or kidney disease, every six months makes more sense. The changes happen faster at that age, and catching a shift early gives us more time to adjust treatment.

I also recommend bloodwork before any anesthesia, even for minor procedures. A dental cleaning in a 12-year-old dog is routine, but I want to know those kidneys can handle the anesthesia drugs before we start.

What signs should prompt bloodwork sooner?

Don't wait for the annual visit if you notice:

• Increased thirst or urination
• Unexplained weight loss (even 1 pound in a cat is significant)
• Decreased appetite or changes in eating habits
• Vomiting more than once a week
• Lethargy or reluctance to play
• Bad breath (can indicate kidney disease or dental problems)
• Changes in coat quality or new lumps

These aren't just "getting old." They're symptoms that deserve investigation.

Schedule your senior pet's bloodwork in Cypress

If your dog or cat is approaching senior status, or if it's been more than a year since their last blood panel, now is a good time to get a baseline. Early detection isn't about finding problems to worry about. It's about finding problems we can actually fix. If you're in Cypress, TX and want to get your older pet screened, schedule a visit at Hearthstone Animal Clinic or give us a ring at (281) 859-9244. I'd rather tell you everything looks great than catch something too late to help.