1. Methods of Measuring Animal Blood Pressure

　　There are invasive and non-invasive methods for measuring animal blood pressure. The invasive method involves anesthetizing the animal and surgically implanting a blood pressure monitor into the blood vessel, which provides more accurate measurements. However, due to the need for anesthesia, it is not very practical in clinical applications. Among the non-invasive blood pressure meters, the Doppler blood pressure meter is widely used because of its ease of use, accurate values, and reasonable price. Before measuring blood pressure, the animal should be calmed and familiarized with the environment. Before deciding on high blood pressure, false positive results caused by the animal's clinical anxiety must be ruled out.

　2. Applications of the Doppler Blood Pressure Meter

　　1. The Doppler blood pressure meter can be used as a tool for cardiac ultrasound selection. Blood pressure and heart sound auscultation can be included in routine health checkups. Blood pressure represents the pressure value of blood pumped by the heart against the inner wall of blood vessels. If the blood pressure value measured by the Doppler blood pressure meter is high and heart sounds auscultation is abnormal, it indicates a serious cardiovascular disease condition requiring cardiac ultrasound examination or regular follow-up.

　　2. Tracking Antihypertensive Drug Use

　　For animals with heart disease or hypertension, blood pressure should be remeasured three days after taking medication to determine whether the blood pressure has returned to normal or to adjust the drug dosage based on the blood pressure value. If the blood pressure is normal, it should be remeasured 3–7 days later for follow-up, and then at least every 3–6 months.

　　3. Pre-surgical Evaluation

　　Measuring blood pressure in animals before surgery. If pre-surgery blood pressure is low and albumin is low, surgery is not advisable. If surgery is forced, shock during surgery is hard to rescue. During surgery, systolic pressure should preferably be maintained between 80–100 mmHg to ensure sufficient blood perfusion to body tissues. Post-surgery, measuring the animal’s blood pressure is also necessary to avoid low blood pressure, insufficient blood supply to the heart and kidneys, tissue hypoxia, decreased resistance, and susceptibility to infection.

　　4. Emergency Care

　　When animals experience shock or respiratory arrest, the Doppler blood pressure meter can be used during emergency care to measure blood flow, allowing monitoring of pulse and blood circulation.

　　3. Measurement Process with Doppler Blood Pressure Meter

Animal waiting for blood pressure measurement

　　1. Blood Pressure Cuff and Placement

Inflated bladder of blood pressure cuff, available in different sizes.

　　The length of the blood pressure cuff bladder must be more than 60% of the circumference it surrounds, with a width of 40–50% of the circumference. It cannot be too long or too wide. If the bladder is too short, it will bounce off after adhesion and blood pressure measurement will be impossible. If too narrow, it will cause excessive pressure and falsely high readings. Generally, the cuff is placed between the elbow and wrist joints, avoiding bony prominences.

Doppler blood pressure meter probe.

　　The core part of the Doppler blood pressure meter. The probe is placed under the cuff. It determines arterial blood flow by emitting or receiving sound waves reflected from the vessel wall; changes in frequency are converted into audio signals. The probe placement area requires shaving and use of ultrasound coupling gel to reduce air interference between the probe and placement site. The probe can generally be taped to prevent interference caused by movement.

Control buttons of the Doppler blood pressure meter, including volume control, on/off switch, etc.

Handle and dial panel to inflate the bladder, with the final blood pressure value displayed on the dial. After inflation, pressing the button deflates the bladder.

Another Maltese dog having blood pressure measured.

　　This dog was agitated during the blood pressure measurement, resulting in difficulty during the process and inaccurate results. Animals being measured for blood pressure for the first time are sensitive; initial data may be disregarded. After acclimation, measurement should be repeated. To reduce error, at least five measurements should be taken and the average value used as the final reference.