Dog Anesthetic Side Effects and Risks
Any time medications are used, including anesthetic drugs, there is the risk of unpleasant reactions. Reactions can range from mild and no big deal, or catapult into catastrophic and even life-threatening situations.
However, in most cases, risk of death is more likely on the drive to the hospital than from dog anesthesia. Mild dog anesthetic side effects include injection site swelling or a faint decrease in a dog’s cardiac output. Catastrophic effects include anaphylactic shock or death.
Other adverse reaction risks to dog anesthesia include not making sure your pup has been fasting prior to being anesthetized. If the pet hasn’t properly fasted, your dog may vomit while unconscious and the vomit can be accidentally sucked into the lungs.
Sucking vomit into their lungs can trigger an episode of aspiration pneumonia which can be life-threatening. More rare reactions to dog anesthesia are side effects like seizures, visual impairments, clotting disorders (like von Willebrand’s disease in dogs), and system organ failures of the liver, kidney, or heart.
Known Risk Factors of Dog Anesthesia
Dogs that suffer from canine Cushing’s disease and Addison’s disease, hypothyroidism, diabetes, and also dogs that are obese or have kidney or canine liver disease should require extra caution and consideration before going under anesthesia. It’s important to discuss with your vet all of your dog’s potential risk factors and proceed from there. If the benefits of the procedure are larger than the risks of anesthesia to your dog, then anesthesia may be the way to go.
When using general anesthesia, there are certain protocols that are followed for all breeds of dog. Generally, a dog needs to undergo preparation and patient assessment before being given anesthesia to evaluate any potential risk factors. A dog must also be given premedication prior to general anesthesia, such as sedatives and pain medication. This is usually done an hour before the procedure.
Dogs may also be given induction drugs to propel them from being conscious into an unconscious state. Additionally, all dogs will be monitored during anesthesia, including monitoring their respiration, heart rate, blood pressure, body temperature, and other central nervous system functions.
And finally, all dogs are monitored during recovery as well. This process is usually overseen by staff that are trained in detecting any recovery problems specifically related to anesthesia and its effects on an animal’s system.
Another thing to keep in mind is that not all dogs are a good candidate for anesthesia. Different breeds have genetic differences, as well as body conformation differences that can play a very important role in delivering the anesthetic drugs to their system safely.
There are certain breeds that are more responsive to anesthesia, which puts them at a higher risk for overdose because less of the drugs are needed to put them under. Other breeds, such as Boxers with smushed-in noses, run the risk of airway an obstruction. Their risk of course, is greater than dogs with longer snouts, because dogs with longer snouts have better-formed airways.
Certain breeds take longer to recover from anesthesia than others as well, and breeds that are considered high risk already tend to also suffer from metabolic disorders. These breeds pose an even greater risk under anesthesia.
Dogs with heart disease, whether their disease is acquired or congenital, are risky too. A consultation should be done before any dog anesthetic is given and any procedure is performed for all dogs for maximum safety and no lasting dog anesthesia side effects. Every dog’s experience under anesthesia must be customized and tailored specifically for them.
Are there things that can be done to minimize the risks?
Pre-surgical physical examination, preoperative blood and urine tests and radiographic examination may detect clinical and sub-clinical medical conditions that could increase the risk associated with anesthesia. These conditions include heart disease, liver disease, kidney disease, diabetes mellitus, anemia, dehydration and certain infectious diseases, such as heartworm disease.
Blood tests increase the chance of detecting a hidden problem that could prove to be life threatening. In older animals, chest radiographs and an electrocardiogram (ECG) are often recommended to ensure there is no pre-existing pathology in the heart or lungs that might increase the risk of an adverse reaction.
Immediate intravenous access for emergency drug administration is one of the most important factors in the successful treatment of cardiovascular or respiratory failure. By placing an intravenous (IV) catheter and line before anesthesia, your veterinarian can ensure that this lifeline is already in place, should the need arise. Anesthetics, fluids and emergency drugs can be administered through the IV line.
Intravenous fluids help maintain blood pressure in the anesthetized patient and replace lost fluids (During surgery, fluids are lost through evaporation from body cavity surfaces, through bleeding and in any tissues that are being removed). Upon completion of the procedure, intravenous fluid therapy speeds the recovery process by diluting anesthetic agents circulating in the blood stream and enhancing their metabolism and elimination through the liver and kidneys. Patients that receive IV fluid therapy generally wake up faster than those that do not.
Additionally, studies have shown that 0.9 – 2% of all patients that receive general anesthesia will develop kidney dysfunction 7-14 days after anesthesia. This risk is significantly reduced in patients that receive peri-operative intravenous fluid therapy. Although 98% of all pets will have no problem, your veterinarians goal is to eliminate that unknown 2%.
For these reasons, all surgery patients should receive intravenous catheterization and fluid therapy.
You should ensure that your dogs complete medical history is available to your veterinarian, especially if your dog has been seen at another veterinary clinic. Before anesthetizing your dog, your veterinarian needs to know about any medications or supplements that your dog has received in the past few weeks, any pre-existing medical conditions, any known drug reactions, the results of previous diagnostic tests, and whether the dog has undergone any anesthetic or surgical procedures in the past. Other useful information includes the dogs vaccine status and reproductive status, (i.e., when was its last estrus or heat cycle).
What to Expect After General Anesthesia
Whether you have a young dog and you’ve scheduled routine neutering, an old dog who needs dental work, or an active dog who has torn a ligament – you may be scheduling a veterinary procedure that requires anesthesia.
There’s a risk involved any time a dog is given drugs to put him under for surgery. So it’s important for responsible dog owners to be aware of potential complications, have a plan in place beforehand, and work with a veterinarian to ensure your pet’s safety.
When it comes to routine procedures, what pet owners least expect is a call that something’s gone wrong. But that’s exactly what happened to first-time pet owners Lisa Marchese and Gudry Genao after they brought their five-month-old Havanese puppy in for neutering procedure. Minutes after the procedure began, their beloved Petey died.
“We weren’t nervous about the neutering; if anything, we felt bad for what we heard he was going to experience afterwards,” says Marchese. “It never crossed our minds something would happen.”
Although anestheia-related deaths are rare, they can occur. Approximately 1 in 2,000 healthy dogs die under anesthesia each year, says Preventative Vet author and veterinary anesthesiologist Dr. Heidi Shafford.