Bloodwork & Lab Diagnostics

Many serious conditions — kidney disease, liver disease, diabetes, thyroid dysfunction, anemia, and infection — produce few outward signs in their early stages in dogs and cats. Bloodwork is recommended in several situations:

• Before anesthesia to confirm the liver and kidneys can safely process anesthetic drugs
• When a pet is lethargic, vomiting, drinking excessively, losing weight, or showing any sign of illness
• As part of annual wellness care in adults and semi-annual screening for seniors (dogs and cats over 7)
• Monitoring known conditions — diabetes, kidney disease, hyperthyroidism, Addison's disease — and the medications used to treat them
• Screening for infectious diseases such as heartworm, tick-borne illness, and FIV/FeLV

Different panels provide different information:

• CBC (complete blood count): red blood cell count and morphology (anemia, blood loss), white blood cell count (infection, inflammation, immune disease), and platelets (clotting ability)
• Chemistry panel: kidney values (BUN, creatinine, SDMA), liver enzymes (ALT, ALP, bilirubin), blood sugar (diabetes), protein levels, electrolytes, and more
• Urinalysis: kidney concentrating ability, glucose, protein, blood cells, bacteria, and crystals — a critical partner to the chemistry panel for kidney assessment
• Thyroid (T4): essential for cats over 7 years (hyperthyroidism is extremely common) and for dogs with weight gain, lethargy, or skin changes
• Cytology: microscopic examination of cells from skin masses, ear discharge, lymph nodes, or body fluids to identify cancer, infection, or inflammation

Most blood samples are collected from the jugular vein in the neck or the cephalic (front leg) vein — a quick, minimally uncomfortable stick that takes only seconds. For most patients, no sedation is needed:

• A small area of fur is clipped and the skin disinfected
• A needle is inserted into the vein and a small volume of blood (typically 1–3 ml) drawn into collection tubes
• The sample is spun in a centrifuge and run on our in-house chemistry and hematology analyzers
• For urinalysis, a urine sample is collected via cystocentesis (a needle passed through the skin directly into the bladder — the cleanest collection method) or as a free-catch sample
• Cytology slides are made from fine-needle aspirates (FNA) of masses or fluids, stained, and reviewed by our doctors — or sent to a veterinary pathologist for complex cases

Preparation depends on the specific tests ordered:

• Fasting: a 6–8 hour fast before a chemistry panel is ideal for accurate lipid and glucose values; for most other tests, fasting is not strictly required but is helpful
• Water: water is almost always fine up until the appointment
• Medications: some drugs affect lab values — let us know everything your pet takes, including supplements, so results are interpreted accurately
• Urine samples: if collecting a urine sample at home, use a clean container and bring it within 2 hours; a first-morning sample is most concentrated and most informative

Blood collection is fast — most pets tolerate it well with minimal or no restraint. The stick itself causes a brief moment of discomfort comparable to a vaccination. Results from our in-house panels are typically ready within 20–30 minutes. Our veterinarian will review the findings with you and explain what is normal, what warrants monitoring, and what requires follow-up or treatment. Some tests — specialized endocrine panels, pathologist review of cytology, culture and sensitivity — are sent to an external reference lab and take 1–3 days. We contact you directly with those results.

Blood collection is extremely safe for dogs and cats of all ages and health conditions — it is one of the least invasive diagnostic tools available. The quantity of blood drawn is a tiny fraction of the pet's total blood volume and causes no meaningful physiologic effect. There is no anesthesia involved for routine venipuncture. Pets with clotting disorders require care, but the sample volumes used in standard diagnostics are unlikely to cause complications. In critically ill patients, the diagnostic benefit of bloodwork vastly outweighs any minor procedural stress.