I Am Afraid of Anesthesia for My Pet PART 1 Sandra L Waugh VMD, MS
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hen we discuss a dental procedure with a client they almost always express a fear of anesthesia, especially if their pet is very young, very small, or elderly. In this series of articles I will address what anesthesia is, the important risk factors, types of drugs used, equipment used and the importance of staff training. While I can’t make the risk of anesthesia go away, I hope I can relieve much of your anxiety. In order to do any involved dental procedure we need to induce a state of unconsciousness so the pet holds still, doesn’t react to what is being done and does not feel any pain during the procedure. Different drugs can be used to maximize the efficiency of this procedure and can be tailored to the specific needs of an individual patient. The first step is to give preoperative medications to relax the patient and provide relief from pain. At Windsor Pet Dental this usually consists of a narcotic for pain relief and a low dose of tranquilizer to relax the patient. After a 15-20 minute wait the patient is ready for the induction of anesthesia. Induction consists of giving drugs that quickly cause a state of unconsciousness sufficient for an endotracheal tube to be placed into the windpipe. These drugs don’t last very long in the body. An intravenous (IV) catheter is placed because induction drugs are designed for IV use and because during the dentistry we give IV fluids and other drugs IV as needed. 40 4 Legs & a Tail
There are many different drug combinations for this but we use alfaxalone and midazolam. These drugs are given to effect, meaning that the drugs are given until the desired effect is reached rather than by a fixed dose. We then connect the pet to an anesthesia machine which delivers an anesthetic gas called isoflurane dissolved in oxygen which the pet breathes.
“I weigh all of 5.8 pounds and my owners worried that I was too small for anesthesia. I did just fine, though, and my mouth feels so much better.” 11 year old Maltese
“My teeth were causing me pain and I really wanted to get them fixed but my owners worried that I was too old for anesthesia. But I wasn’t and now am much happier with my mouth.” 14 year old Jack Russell Terrier. We can change the amount of anesthetic inhaled during the dental procedure by turning a dial which increases or decreases the percentage of anesthetic gas depending on the level of anesthesia the pet is showing. We can increase the amount of inhaled gas if the pet is light and we see muscle movements such as swallowing or moving of the jaw or (for example) if the blood pressure goes below a minimum value indicating the patient is too deep we can turn the level of gas down. Changing the percentage of inhaled isoflurane provides a change within 20-30 seconds. Most people are unaware that anesthetic gas has poor pain relieving properties, which is why we started pain medicines at the beginning. If we are going to do a painful procedure such as an extraction we give a small initial dose of a narcotic or combination of pain medicines as an IV bolus in the catheter and then a slow drip of a low dose of the medicines via the catheter during the procedure. This is called a continuous rate infusion or CRI. Intravenous fluids are run in to maintain hydration and blood pressure. If the blood pressure is low the fluids are increased, if high the fluids are decreased. If any additional medicines are indicated they are also given via the catheter for quick effect. A local anesthetic is also given just like your dentist does for you. This is a combination of a local anesthetic plus Fall 2020
