Pre-anesthetic bloodwork, recommended before most procedures requiring general anesthesia, isn't a routine formality but a genuine screening step that identifies specific factors affecting how safely and appropriately anesthesia can be administered to your individual cat.
Kidney and liver function specifically
Since these organs process and eliminate anesthetic drugs from the body, reduced function can mean drugs remain active longer than expected, requiring dose or drug choice adjustments — identifying reduced function beforehand allows your vet to modify the anesthesia protocol accordingly rather than discovering this mid-procedure.
Red and white blood cell counts
Anemia or other blood cell abnormalities can affect how well a cat tolerates the physiological stress of anesthesia and surgery, and identifying these beforehand sometimes changes the timing or approach to a planned procedure, particularly for elective surgeries where postponing until an underlying issue is addressed is a reasonable option.
Blood glucose and electrolyte levels
Significant abnormalities here can affect anesthesia safety and recovery, and correcting an identified imbalance before proceeding, where the procedure's urgency allows for this, reduces complication risk compared to proceeding with an unaddressed abnormality.
Why age affects the pre-anesthetic bloodwork recommendation
Older cats face higher baseline likelihood of age-related organ function changes, making pre-anesthetic bloodwork increasingly important with advancing age even for a relatively routine procedure — many vets recommend this screening more strongly, or as a firm requirement rather than optional add-on, for senior patients specifically.
What happens if bloodwork reveals a concern
Depending on what's found, your vet might adjust the specific anesthesia protocol, recommend addressing an identified issue before an elective procedure, or in some cases recommend additional monitoring during the procedure itself — this is a genuinely useful, individualizing step rather than a step that typically prevents a needed procedure from happening.
Modern anesthesia monitoring beyond bloodwork alone
Beyond pre-procedure bloodwork, ongoing monitoring during anesthesia — heart rate, blood pressure, oxygen levels, and body temperature — has become increasingly sophisticated and standard, meaningfully improving overall anesthesia safety beyond what pre-screening bloodwork alone provides, worth asking about if you're evaluating a specific clinic's anesthesia protocols.