August 2025 
In this VETgirl online veterinary continuing education blog, Tiffany Gendron, CVT, VTS (ECC), VETgirl’s CE Specialist, explains the options and the importance of monitoring blood pressure in veterinary patients. This is a vital aspect of patient care that is frequently performed by veterinary technicians! Learn why a blood pressure measurement should be obtained alongside your TPR.

Understanding Your Role in Blood Pressure Monitoring

by Tiffany Gendron, CVT, VTS (ECC), VETgirl CE Specialist

Monitoring blood pressure in veterinary patients is a vital aspect of patient care. A patient’s blood pressure (BP) provides critical insights into a pet’s cardiovascular, renal, and endocrine health. Whether in routine wellness exams or during treatment of specific diseases, accurate blood pressure monitoring helps guide diagnostic and therapeutic decisions. For this reason, I believe a BP should be obtained alongside your TPR in all patients presenting with an illness and in any geriatric patient (e.g., feline patient > 7-8 years of age; canine patient > 5-7 years of age, breed-size dependent) as part of routine healthcare monitoring.

It is essential to know when we can expect changes or alterations in blood pressure and what clinical implications hypertension (e.g., high blood pressure) and hypotension (e.g., low blood pressure) can have on our patients. Of equal importance is to understand “what is blood pressure?” Blood pressure is a measurement of force exerted by blood on the arterial wall.1

There are 3 Components of Blood Pressure:

  1. Systolic Arterial Pressure (SAP): This is what you hear when getting a Doppler BP “the woosh, woosh” sound.
  2. Diastolic Arterial Pressure (DAP) is generally not reliable (or audible) when using a Doppler and, as such, typically isn’t recorded when performing a Doppler BP. Fun fact: Although not clinically relevant, DAP can be audible in some patients (e.g., a large breed dog with a slower heart rate).
  3. Mean Arterial Pressure (MAP) looks at the average arterial pressure over time (milliseconds). NOTE*: It is not the “true mathematical” average of SAP and DAP – remember diastole is a longer phase of the cardiac cycle, so an “average” of SAP and DAP would not provide an accurate reflection of mean arterial pressure.

 

Methods of Measurement

  1. Indirect or Non-Invasive Blood Pressure (NIBP) Measurement
  • Doppler Ultrasonography
  • Oscillometric Devices
  1. Direct Arterial Blood Pressure Measurement (dABP)

Although direct arterial blood pressure (dABP) is considered the “gold standard,” there are several factors that may prohibit its use in practice, including:

  • Technique of placement, especially in cats
  • Technical difficulty
  • Sedation/local anesthetic +/- general anesthesia for placement
  • Equipment
  • Supplies for placement and maintenance
  • Interpretation and utility of results
  • Requirement for 24-7 care (if it disconnects, the patient can exsanguinate)

However, if you need a “how-to” video for placing an arterial catheter, check out this VETgirl video to learn how to set up a dABP. Need to set up a pressure transducer? Check out this video, too.

It is likely a fair assumption that it is far more common for hospitals to have the staff and resources available to perform indirect arterial blood pressure or noninvasive blood pressure (NIBP) monitoring using either Doppler or oscillometric devices. To ensure the results obtained are reliable, a protocol for blood pressure measurement should be used. Recommendations and a protocol for obtaining NIBP’s were developed by the American College of Veterinary Internal Medicine (ACVIM).

Here is a summary of the ACVIM recommendations:

  1. Ensure the unit is routinely calibrated.
  2. Patients should be with the owner, if possible, in a quiet room (ideally, with no sedation, although this may not always be possible) for 5-10 minutes prior to obtaining reading.
  3. Gentle restraint of the patient should be done in ventral or lateral position.
  4. The cuff size should be approximately 40% of the circumference of the cuff site in the dog, or ~ 30-40% of the circumference of the cuff site in cats. Typically, the limb or tail is used.
  5. Record cuff site and patient recumbency—ideally performed by the same person for serial management.
  6. 5-7 consecutive measurements should be performed – typically, the 1st reading is disregarded.
  7. Average the remaining values to obtain the average BP reading.

Doppler Blood Pressure

Pros:

  • Ideal for small patients such as cats and small dogs
  • Effective in detecting blood flow in small arteries of cats and small dogs, where oscillometric devices may fail
  • Potentially more reliable in patients with arrhythmias
  • Non-invasive
  • Audible feedback helps in quickly identifying systolic pressure

Cons:

  • Diastolic and mean arterial pressures are not always accurately measured
  • Requires user experience to use correctly, variability in cuff placement, and interpretation (e.g., incorrect cuff size or placement and animal positioning can result in inaccurate readings)
  • Stress of handling affects readings, especially in nervous or aggressive animals

Oscillometric Blood Pressure

Pros:

  • Ideal for small to larger dogs
  • Automatic, non-invasive, easy to use, less operator-dependent
  • Measures systolic, diastolic, and mean arterial pressure (MAP)
  • Can be programmed for timed intervals for continuous monitoring, if needed
  • Requires less patient handling (e.g., advantage for nervous patients, although the sound and pressure exerted on the limb can cause excitement)

Cons:

  • Less reliable in restless/moving animals
  • More expensive than Doppler
  • Prone to errors due to movement or incorrect cuff placement
  • If heart rate on the machine does not match the heart rate of the patient, generally considered to be inaccurate reading
  • Less reliable in patients with arrhythmias

Tips for Getting an Accurate BP

  • Use the correct cuff size (width = 30–40% of limb or tail circumference). Cuff selection matters! If you choose a cuff that is too small, you will falsely elevate your reading. Conversely, if you use a cuff that is too large, you will obtain falsely decreased measurements. Always remember to fully deflate the cuff between measurements!
  • Seek alternate locations for measurement, such as the tail in dyschondroplasic breeds (Dachshunds and bassets, we are talking about you!).

    Dyschondroplasic breed (left), canine mix breed dog hindlimb (right). Photos courtesy of Tiffany Gendron.

  • I know you’re all thinking it. What about using tape to secure the cuff? We have all done it, guilty as charged. A 2024 study published in JAVMA suggested that adding that piece of tape results in variability in systolic readings. Ideally, try not to use tape since it’ll change the blood pressure reading.
  • Poor positioning or limb selections can provide you with unreliable results as was demonstrated in this 2013 JAVMA study. Higher readings are obtained when sitting as compared to laterally recumbent. The value also varied more from one reading to the next when not in lateral recumbency.
  • Low stress handling is helpful because getting a blood pressure reading should not cause undue stress in our patients. We may need to be flexible and recognize that although our results may not be an accurate reflection of what true blood pressure is. However, if paired with other clinical parameters, we can use a global assessment of the patient to aid the veterinarian in treatment and intervention options. It is best to have our patients in lateral recumbency, relaxed and not moving. We all know this is best, but it may not always be achieved.
  • Allow the animal to acclimate to the environment before measuring (if possible). In the ER/ICU settings, this is not possible due to patient status and the stress of this environment. The important things to consider in these cases include:
    • Additional monitoring and devices (physical exam, ECG, blood work)
    • Comparison of pulse rate to heart rate to ensure they match.
    • Most skilled people should obtain BP’s because the physiological state makes readings less reliable, even in the hands of our most skilled veterinary professional.
  • Take multiple readings and use an average (ideally 5-7 measurements). What if the measurements trend down as you’re getting your readings? In this case, continue with measurements until you reach a plateau, then record (5-7 measurements).
  • The cuff should be as close to the level of the right atrium as possible to obtain the most accurate blood pressure measurements. (This is why lateral or sternal recumbency is so important!)
  • Know your normal values below:5

Check out this video that walks you through cuff selection and some tips and tricks you need to know to get repeatable, reliable, and accurate blood pressures!

 

Conclusion

Blood pressure monitoring in small animals is an indispensable diagnostic tool in both routine and emergency care. While each technique has its pros and cons, understanding their limitations and applications allows veterinary professionals to choose the best method for each patient. Whether you’re monitoring a hypertensive cat, a hypotensive dog, or an anesthetized patient, accurate BP assessment can significantly impact outcomes. Please remember that repeatable, reliable, and accurate blood pressures are the goal. Happy monitoring!

References:

    1. Kirby R., Linklater A. Monitoring and Intervention for the Critically Ill Small Animal: The Rule of 20.  John Wiley & Sons; 2016, Ch 3:29-39.
    2. Rondeau DA, Mackalonis ME, Hess RS. Effect of body position on indirect measurement of systolic arterial blood pressure in dogs. J Am Vet Med Assoc 2013; 242:(11)1523-7.
    3. Acierno MJ, Brown S, Coleman AE, et al. ACVIM consensus statement: Guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats. J Vet Intern Med. 2018;32(6):1803-1822.
    4. Cooper E, Cooper S. Direct systemic arterial blood pressure monitoring. In: Burkitt Creedon JM, Davis H (eds). Oxford: Wiley-Blackwell; 2012.
    5. Williamson JA, Leone S. Noninvasive arterial blood pressure monitoring. In: Burkitt Creedon JM, Davis H, eds. Advanced Monitoring and Procedures for Small Animal Emergency and Critical Care. John Wiley & Sons; 2012:134-141.
    6. Waddell L, Brown A. Hemodynamic monitoring. In: Silverstein D, Hopper K, eds. Small Animal Critical Care Medicine. 2nd ed. Saunders; 2015:957–962.
    7. Martinez A.B.P., Cochran L.A., Ishak A.M., et al. Secondary fastener (tape) placement on a blood pressure cuff causes interindividual Doppler blood pressure measurement variability in healthy large-breed dogs. J Am Vet Med Assoc 2004;262(12),1686–1691.

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