Canine Anesthesia

Little Critters Veterinary Hospital

1525 N Gilbert Road Suite 101C
Gilbert, AZ 85234

(480)696-7744

www.littlecrittersvet.com

ANESTHETIC SAFETY

ANESTHETIC SAFETY

What you can do: You are your pet’s advocate and are directly responsible for making decisions to provide your pet with a safer anesthetic procedure. Some of these decisions include:

  • Choosing to have the procedure preformed with your regular veterinarian rather than the low cost clinic down the road. This is important for a few reasons, but most importantly is that your doctor knows your pet and therefore is better able to predict potential problems andpick the best anesthetic protocol for your pet. Additionally, while many low-cost clinics practice excellent medicine, unfortunately some are able to provide lower cost because they cut corners in other ways such as less expensive anesthetic gas, few injectable anesthetics, less pain control, reduced staffing and less (or no) monitoring of the pet under anesthesia.
  • Choosing to have pre-anesthetic blood work completed on your pet. Some hospitals will require that pre-anesthetic blood work be completed on all pets, some will only require it on geriatric (senior) pets, and some will leave the decision entirely up to you. Pre-anesthetic blood work provides the veterinarian with a picture of the health of your pet at the time of the procedure. The picture includes information on general organ status, potential infections, ability to clot blood, and anemia. Frequent problems identified include diabetes, liver disease, kidney disease and clues to infections or parasites. Young pets are generally assumed to be healthy and therefore owners often elect to forgo blood testing. Most of the time this is a relatively safe bet, but it is a gamble and occasionally even a young pet will have unidentified disease that will increase the anesthetic risk. If disease is identified the anesthesia may be postponed or the anesthetic protocol may be altered to increase the margin of safety for your pet. When asked to choose pre-anesthetic blood work for your pet, always ask yourself if you would want this checked on you prior to surgery.
  • Choosing to have an IV catheter placed and have your pet maintained on IV fluids Again, many hospitals require the pet be placed on IV fluids during the procedure, but you may be asked to make this decision for your pet at some hospitals. An IV catheter provides an immediate entry to a vein in the case of an anesthetic emergency and allows for the immediate administration of potentially life saving medications. Additionally, the catheter allows for the administration of IV fluids which support the pet’s blood pressure during general anesthesia and this helps to keep good blood flow to the kidneys which is important for all pets, but essential for those pets with early kidney disease.
  • Allowing for safer types of anesthetics recommended by your veterinarian

We are fortunate in veterinary medicine to have a large variety of anesthetics available to us which allows us to choose the safest anesthetic for your pet. As an example, some anesthetics are just inhaled and others are injectable. Often a combination of the two is used. Even the injectable drugs have large differences between them that can alter the safety of the procedure. Some anesthetics cause longer periods of anesthetic before the pet can awaken, some cause much more suppression on heart function and respiration, some have more of an affect on the liver or kidneys, and some shouldn’t be used in particular breeds of animals at all. At the time of this writing one of the safest and most adjustable anesthetic gasses is Sevoflurane. It is considered a human grade anesthetic gas and allows for very rapid changes in anesthetic depths.

Many times, if the veterinarian determines that your pet needs a specific type of drug it will just be implemented. However, occasionally a specific anesthetic will result in a higher expense and again you may be asked to make a decision depending upon the hospital olicy. Your veterinarian should always explain why a particular drug is recommended and provide you with the correct facts to help with the decision.

What Your Veterinarian Can Do:

Physical Exam and history

Your veterinarian will read through your pet’s medical chart to help determine the health status and any existing potential anesthetic problems or allergies. A complete physical exam will be done on all pets prior to anesthesia to again look for potential disease problems which may alter the anesthetic protocol needed. As an example, short nosed breeds of dogs (pugs) & cats (Persians) will have a delayed extubation which means that the breathing tube will be kept in the pet as long as possible when the anesthetic gas is shut off and the pet is maintained on oxygen. Brachycephalic or short nosed breeds are likely to have more problems breathing when awakening from anesthesia and delayed extubation resolves those problems by providing an open airway until the pet is more awake and better able to breathe normally.

Anesthetic choices

Veterinarians have various means of providing general anesthesia for your pet and this allows us to determine the safest choices for him/her.

The choices can include:

  • Using gas anesthesia to induce (cause the pet to sleep) the pet vs. using injectable anesthesia to induce the pet.
  • Injectable induction is the most common method and is the fastest and easiest on your pet.
  • Pets with liver or kidney disease may be induced with gas alone via a mask or an induction box. Pets maintained on gas alone will awaken quickly, but also take a little longer to induce and their blood pressure must be monitored very carefully.

Types of injectable anesthetics used

Again, there are many choices here as well. At our hospital we typically will induce with telazole or a combination of ketamine and valuim. These both have proven very safe for us and have minimal suppressive effects on cardiovascular or respiratory function.

  • For very short anesthetic procedures in which we would like the pet to be able to go home quickly, or for geriatric pets with organ disease, we will often use a drug called Propofol. This anesthetic is very safe and extremely short acting. Pets will typically awaken fully in 5-10 minutes and they awaken easily as if they had just been snoozing.
  • Other injectable anesthetics include those that provide a combination of pain relief and anesthesia and allow for reversal of the anesthesia with a second injection. These can have some suppression of blood pressure and are only reserved for young healthy pets undergoing very short procedures.

Types of anesthetic gasses used

Once again, veterinarians have the ability to choose the type of anesthetic gas used on your pet. Some of the older anesthetic gasses are much less expensive but also can cause problems in older pets, can result in liver disease and cause slower changes when the pet’s level of anesthesia needs to be adjusted. An example of an older type of anesthetic gas is halothane. The newer and of course more expensive anesthetic gasses include isoflurane and sevoflurane. These gasses are extremely safe and are commonly used in geriatric pets. They also provide the ability to quickly change the depth of anesthesia. I recommend using only one of these gasses.

Monitoring (really the MOST important aspect)

Monitoring of your pet’s vitals (depth of anesthesia, respiration, temperature, heart rate, blood oxygen saturation, blood pressure) should be done by one designated individual throughout the procedure and the results should be recorded throughout the procedure. Monitoring allows the person performing the procedure to focus on completing the procedure to the best of their abilities without dividing their attention between the task at and and anesthetic monitoring. Good monitoring also allows for the correct level of anesthesia to be chosen throughout the procedure. Most hospitals will provide some way of monitoring your pet, but the way the pet is monitored and the values monitored may vary depending upon the equipment and the staff available.

Recovery from anesthesia

The recovery or awakening period is just as important as the actual anesthetic procedure. The pet should be closely monitored during this time, the temperature should be taken and warmth should be provided if needed, the pet should have delayed extubation if needed and the pet should be supervised until fully awake.