Not all veterinary hospitals, surgical suites, and their standards of care are created equal! We, at Butler Creek Animal Hospital, strive to give our patients and their owners superior care and support that extends beyond the examination rooms. When you're facing an impending surgery for your pet, it's essential to us you have some peace of mind throughout the process.
It’s essential that the veterinarian knows as much as possible about your pet prior to surgery. This means that we should have a copy of the records from any previous veterinary visits and that your pet’s surgeon will perform a complete physical examination of your pet before beginning any part of the anesthetic regimen. This is crucial; pets with certain health conditions can be high-risk patients for anesthesia.
The pre-anesthetic examination is done on the day of surgery by the veterinarian performing the procedure and are at no additional cost. These exams generally consist of:
Systematic visual inspection of the pet's head, face, eyes, ears, mouth, limbs, and body
Palpation (feeling with the hands) of the body's outer surface (skin, fur, muscles, etc.), and internal abdominal organs (liver, kidneys, intestines, bladder, etc.)
Auscultation (listening with a stethoscope) to the heart, lungs, and gastrointestinal system.
An examination before surgery will reveal potential problems and allow the veterinarian to investigate any potential problems if necessary. If he or she has examined your pet several times over the course of puppy or kittenhood, chances are they will already know about any potential pitfalls.
Pre-surgical Blood Testing
Doing blood work prior has plenty of advantages! Even young puppies and kittens coming in for a routine spay or neuter can benefit from running pre-surgical bloodwork. “How so?” you may ask. The veterinarian can spot early signs of countless diseases this way and can get a better idea of how anesthesia may affect your pet. These signs will often show up on blood work before you notice any changes on the outside, so even they may seem completely normal to you there could be something going on inside their body. If they do see anything concerning, they may want to cancel or postpone the surgery and deal with that problem first to make surgery and anesthesia as safe and successful as possible for your companion.
Knowing how your pet is functioning internally also gives the veterinarian a chance to potentially alter their typical drug protocol for sedation and anesthesia to a combination of different medications that are tailored for your specific pet.
Even young puppies and kittens coming in for a routine spay or neuter can benefit from running pre-surgical bloodwork. The veterinarian can spot early signs of countless diseases this way and can get a better idea of how anesthesia may affect your pet. These signs will often show up on blood work before you notice any changes on the outside, so even they may seem completely normal to you there could be something going on inside their body. If they do see anything concerning, they may want to cancel or postpone the surgery and deal with that problem first to make surgery and anesthesia as safe and successful as possible for your animal.
Pre-surgical bloodwork typically consists of two different blood analyses:
The first test is called a Complete Blood Count (or CBC) - This basic blood test shows us the levels of red blood cells, white blood cells, and platelets, which can be helpful in diagnosing anemia (low red blood cells), systemic infections, and potential blood clotting deficiencies.
The second is the blood Chemistry - This tells the veterinarian how the kidneys and the liver are working. These organs especially do not usually start to show noticeable symptoms of disease outwardly until quite advanced. The kidneys and the liver play a huge part in how the body metabolizes all of the sedative/anesthetic medications will be administered/prescribed to the animal before, during, and after surgery. Because of this, it is very important for us to know there are no significant kidney or liver issues before we put your pet under anesthesia, especially if they are older.
For even more information on blood work and what it tests for please visit our diagnostic bloodwork page!
Pre-surgical Antiemetic & Analgesics
If you've ever had surgery, you've probably experienced the unfortunate side effect of nausea, and sometimes vomiting, caused by anesthesia. In the past, regurgitation by a pet during and post-procedure were all too common. Even once returning home, pets sometimes would continue to vomit and often lacked a regular appetite for days. Inappetance often may prevent the owners from being able to give the medications prescribed post-op since many antibiotics and pain medications are supposed to be given in conjunction with a meal.
For these reasons, we implemented the use of Cerenia, an antiemetic injection that lasts 24 hours, as part of our surgical routine. An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of opioid analgesics, general anesthetics, and chemotherapy directed against cancer. Since starting this, we've seen a dramatic decline in regurgitation by patients while in the hospital and owners often report that their pet is eating normally by the next day.
The results of a study that followed patients after surgery (displayed on the right) speaks for itself. Half of the study group were given maropitant citrate (Cerenia) prior to anesthesia and the other half were given placebos.
Ramsey, D, et al. "Cerenia Prevents Perioperative Nausea and Vomiting and Improves Recovery in Dogs Undergoing Routine Surgery." Intern J Appl Res Vet Med. 12.3 (2014): 228-37. Web.
Analgesics are a class of medications designed specifically to relieve pain and are a very important part of our pre-surgical protocol. Analgesics sit on the pain receptors and help prevent the pain response. By giving pain medications before the pain signals are ever sent to the patient's brain we significantly reduce the amount of pain experienced after surgery. Analgesics sit on the pain receptors and help prevent the pain response. In some cases is the same drug can act as both a mild sedative and an analgesic (e.g. morphine).
Most animals in the hospital, just like many of us humans, experience some anxiety. If there is a lot of adrenaline rushing around the body it can affect the way the anesthetic drugs work, as well as making the heart more sensitive to some of the drugs. To counter this and make the pet more comfortable, a sedative should be given before anesthesia. With a good sedative on board the animal will need less anesthetic agent and will have a smoother induction and recovery from anesthesia
Just like with humans, patients undergoing general anesthesia must have an intravenous catheter in place before anesthesia is induced. There are two critical reasons for this: the first is that the intravenous catheter provides a route to give drugs quickly into the circulation in case of an emergency. If something happens and the blood pressure falls, it is extremely difficult to raise a vein and place a catheter after the fact. By the time the catheter is in place, it may be too late. With a catheter already in place, emergency drugs can be given rapidly and easily with no loss of precious time, potentially saving the animal's life.
The second reason to have a catheter is that for most elective surgeries an animal should be receiving intravenous fluids for the duration of the anesthetic period. We are giving a number of drugs that can affect blood pressure. Most will cause the blood vessels to relax, the heart to slow, and consequently the blood pressure to fall. Intravenous fluids help to keep the blood pressure above critical levels. This ensures that oxygen and nutrients continue to reach the organs that need them, including the brain and kidneys. It can be dangerous to anesthetize an animal of any age without providing blood pressure support in the form of fluids.
The induction of anesthesia refers to the process of actually making the pet unconscious by administering anesthetic agents. This is the step in human medicine where the anesthesiologist asks you to count backward from 100 as he gives you an injection. Generally, moderately deep anesthesia is accomplished very quickly when injectable drugs are used. This is the same procedure that should be used for all animals.
There is the option to use inhalants to induce anesthesia. This is usually called "masking", as the gas is delivered to the patient via a face mask. This is not the safest method for many reasons, although some vets may tell you it is. It takes approximately 4 to 5 minutes before the pet is anesthetized enough to be intubated. During that period there is no control over the airway; that is, if the pet regurgitates, fluid can be inhaled into the lungs. This is also a very stressful and frightening thing for most pets. They have a large mask placed over the muzzle and they are forced to inhale a strong-smelling gas while being physically restrained. As the gas begins to make them feel dizzy, they try to escape it. There is a large release of adrenaline, which can cause heart arrhythmias. There is also a lot of waste anesthetic gas that escapes around the mask, exposing the veterinary personnel.
Instead, check that the veterinarian is using injectable agents to induce anesthesia. These act very rapidly, in 30 seconds to 2 minutes generally. They allow excellent control of anesthetic depth and allow the airway to be intubated quickly, avoiding most of the risks of aspiration. With an IV catheter, the pet does not even realize the drug is being administered and just falls asleep with little or no excitement. Overall the effect is a much more peaceful, safer induction.
It is important to have control over the pet's airway as quickly as possible and to protect it at all times. Oxygen must get to the lungs in order for animals to live! Some breeds are predisposed to airway trouble. “Brachycephalic” dogs and cats are those with short faces, like Bulldogs, Persians, Boston Terriers, Pugs, Himalayans, and Pekingese all have long soft palates and small nostrils that will interfere with air flow. Even in animals with "normal" anatomy the airway can become obstructed inadvertently, but without proper attention and care the brachycephalic animals are higher risk.
We "intubate" a pet in order to have control over the airway. We pass a special kind of tube called an endotracheal tube through the mouth and into the trachea, or windpipe. This tube has fairly rigid walls and cannot be collapsed. This bypasses all of the soft structures that could potentially flop into the airway when the pet is unconscious and allows us to deliver fresh gas and anesthetic right to the lungs where it is absorbed. The endotracheal tube has a cuff on the end, which effectively seals the airway. In addition to preventing anesthetic leaks, this also protects the patient from inhaling any gastric fluid that might be passively regurgitated during anesthesia.
Gas anesthesia is reliable and safe when delivered by an experienced anesthetist. We prefer them to injectable anesthetics (for maintenance) because the depth of anesthesia is much easier to control. This is particularly important when an animal becomes too "deep" under anesthesia and we need to lighten the anesthetic plane. With inhalant or gas anesthetics we are able to do this relatively quickly since the anesthetic is expelled by breathing. With injectable anesthetics, if the pet is too deep after the anesthetic, we have to wait for the body to metabolize the drug and eliminate it. With some drugs, this can take up to an hour. Gas anesthetics should be used when an anesthetic period will be longer than 5-15 minutes.
Progressive veterinarians recognize the benefits of delivering pain medications continuously during surgery. Often this takes the form of a constant rate infusion, or CRI. A CRI is a simple concept a drug is diluted in regular intravenous solution and delivered continuously during the surgical procedure, and often after it as well. Drugs used may include morphine, hydromorphone, fentanyl, medetomidine, lidocaine, or ketamine. Ketamine is an interesting drug, in that we use it as an anesthetic induction agent, but at very low doses acts to enhance the pain-killing properties of opioids like morphine. By giving ketamine in a CRI during surgery we get very good pain relief.
We employ a registered veterinary technician who assists the doctors in surgery, monitors the patients under anesthesia, and assures every patient and client is treated the way we would want our own pets treated. The most important piece of “equipment” any veterinarian can have is a properly trained and educated Registered Veterinary Technician (RVT). They are the Registered Nurses of the veterinary world that often fill multiple roles including radiology technicians, dental hygienists, pharmacy technicians, and educators. Licensed Technicians have received years of education from an accredited college, have to take the VTNE (Veterinary Technician National Examination), and are required to earn continuing education hours to maintain their licensure. Check to see whether your veterinarian employs an RVT who has graduated from an accredited college.
While all the latest monitoring technology is great, having that college-educated, experienced person with eyes and ears monitoring your pet is the best protection you can get. A stethoscope on the chest and a hand on the pulse can tell us a lot more than a device clipped to the toe or tongue. An experienced RVT will notice trends in pulse rate and quality, respiration, and blood pressure and take steps before a problem occurs. They will be present during surgery in case of an emergency. And they are with your pet during the entire anesthetic period and throughout their recovery.
The most important piece of physical equipment to have when monitoring anesthesia is the ability to measure blood pressure. As previously mentioned, low blood pressure can result from many of the drugs we use as sedatives and for pain control. It is also an extremely common consequence of the 12-hour fast we require before surgery. Pets come into the hospital without food, but most also don't drink very much the night before surgery. They are in a state of marginal hydration, and this lowers the blood pressure. We add drugs on top of that, and many patients (especially cats) become quite hypotensive.
If low blood pressure continues for too long, organ damage can result. This is especially a concern for the kidneys, which need a minimum blood pressure for proper perfusion. If there is no blood pressure monitoring, the veterinarian will never know whether vital organs are being supplied with nutrients and oxygen. He or she will never know whether the intravenous fluids need to be increased, or whether the pet needs a large amount called a "bolus" to correct the hydration right off the bat. Falling blood pressure can tell us that an animal is getting to deep under anesthetic, and we can correct it quickly. If we are not monitoring the blood pressure trend, how do we know if it is falling? Again, this is where an experienced RVT monitoring the situation comes into play. They can take into account the blood pressure, respiration, heart rate, reflexes, medications given, and the overall picture that your pet presents to make a determination as to the animal's state. In concert with the veterinarian, the RVT makes changes to fluid rates, anesthetic rates, oxygen flow, and medications delivered in order to keep your pet at a safe, quiet, pain-free plane of anesthesia.
Other equipment like ECGs and pulse oximeters are also useful as ancillary monitoring equipment but can never replace a registered RVT during routine procedures. They do give some warning of impending problems, but usually lag behind the observations of the human "monitors".
In the past, human and animal doctors alike used to do surgery in a less than sterile manner. Post-operative infections were relatively common, and post-surgical mortality rates were high by today's standards. Fortunately, things have changed over the last 50 years, or certainly should have! Today, the quality of care standards for veterinary surgery in a hospital like ours are very close to those of human surgery.
All clinics should have an operating room that is physically separate from the rest of the clinic and used only for surgery. This room should be kept as clean as possible, without foot traffic. All surfaces in the room should be disinfected weekly, and the majority of the surfaces daily, before surgery. The patient should be prepped for surgery in another room so that hair and dirt contamination of the operating room is minimized. No animals should enter the room unless they are anesthetized and about to undergo a surgical procedure.
The surgeon should be capped and masked and gowned in a new, sterile gown. Sterile surgical gloves (not exam gloves) must be worn. An unopened, autoclave-sterilized instrument set should be used for each surgery. New suture material should be used for every surgery.
Some of these things seem very basic but as amazing as it seems, some veterinarians do not do these things. You need to check into the procedures at the hospital you select to do your pet's surgery. Of course, it goes without saying that a veterinarian should perform the surgery itself. You need to confirm this as well.
Maintaining Body Temperature
This is a simple concept. We try to maintain body temperature as close to normal as we can. There are many places in the anesthetic and surgery process where heat is lost. These include heat energy expended warming the air that is breathed in, and lost when the warmed air is breathed out, body heat lost from the skin to cold surgical tables or countertops, heat lost when the abdominal cavity is exposed to room air (during a spay, for example), heat energy spent warming room temperature IV fluids, etc.
When body temperature drops it affects the animal's metabolism, which also affects the way the body processes drugs. Anesthetics are cleared at a slower rate than in a normothermic animal. Hypothermia causes decreased immune function, slower wound healing (and this includes surgical "wounds"), and increased risk of bleeding. Older dogs and cats have poor thermoregulatory systems, and they do not start to compensate for heat loss until a much lower temperature than a young dog would. So, it is important that we do everything we can during the surgical period to keep the body temperature normal.
This is achieved in a number of ways. Anything placed between the pet and the operating table (which is stainless steel) will reduce heat loss. However, our operating tables are heated which is not commonplace in most veterinary hospitals. Other heat-loss reducers can be as simple as an insulated blanket, sheepskin padding, or insulated foam rubber padding. Forced air patient warmers like we have, are the latest in warming technology. These machines consist of a heater and a hose that goes to a thin "blanket" or pillow. Warm air is forced into the blanket and surrounds the patient. When protected with an insulated barrier below and an insulated blanket on top, this system helps keeps patient body temperature in the normal range. These machines are very effective at providing warmth without the risk of burning, which can occur with other external heating devices like oat bags and hot water bottles.
This is a very simple thing that is easy to overlook but is more important than most of the things we have already talked about. A healthy percentage of animals that do not survive surgery and the anesthetic period succumb to problems that arise after the animal is out of the operating room and into recovery. It is vital that someone is constantly watching your animal after surgery, when the anesthetic machines are off, to make sure that recovery is going well.
In the normal course of events, the gas anesthetic is turned off, the system is flushed with oxygen, and the pet is allowed to breathe 100% oxygen. As the anesthetic wears off, the pet regains protective reflexes (like the gagging, coughing and swallowing reflexes) that prevent things from entering the airways. Once these reflexes are re-established, the endotracheal tube is removed. The patient is generally awake enough to roll himself into sternal recumbency, or on his chest with his head up. The time from anesthetic off to head up is variable, but is usually somewhere between 5 and 20 minutes, depending on the premedications and pain medications given, and the depth and duration of anesthesia.
Once the pet is sitting up, constant, direct observation is generally not necessary after most elective surgeries. Most pets are returned to a recovery kennel and checked every few minutes once they can stand. RVTs check the patient’s condition periodically, making sure there are no signs of distress or surgical complications and that the body temperature is maintained.
Up until this point, we've controlled the patient's pain with injectables, but what about after? There is pain after abdominal surgery in animals for at least a 3-day period. Patients should be sent home with a supply of oral pain medication. Depending on the procedure and bloodwork results, this can be anything from morphine in more involved procedures to non-steroidal anti-inflammatory drugs like meloxicam or Rimadyl (carprofen). DO NOT give your pet anything for pain on your own without checking with your veterinarian. Many of the drugs people use for pain are toxic to dogs or require a very different dose to be effective.
Immediate Post-Surgical Home Care
Most veterinarians will send your pet home the evening of the elective surgery. This is done for a few reasons, chiefly because most clinics are not staffed overnight. Many veterinarians feel that the pet's interests are best served by being at home with someone watching them the night after surgery. On occasion, we may keep your pet overnight and release them the next morning. There is some benefit to this, even with no one at the clinic all night, because the patient is kept confined and can be kept on injectable pain relief. The decision to send your pet home or keep him depends on you and your veterinarian, and neither is wrong.
If, however, your pet is sent home the night of surgery, be sure that there is some provision for problems. What if your pet starts to lick the incision? What if they are in pain? We make sure that you have a discharge appointment set up when you come to pick up your pet. This allows the technician to go over the medications being sent home, post-operative care instructions, complications to watch out for, and emergency clinic contact information should any problems arise. It also gives you the opportunity to ask any questions that you may have thought of after intake earlier that morning. Most patients do very well post-surgery, but we want you to feel confident in your pet’s post-operative care.
As you can see, making an elective surgery like a spay or neuter safe for your pet is quite a complicated process. It involves several people, and a variety of specialized equipment. It is possible to "cut corners" and omit some of the things that we have talked about. It is possible to spay a cat like we did in the old days with an injectable anesthetic, without surgical gowns or even gloves, just bare-handed on a counter in the back of a clinic. This certainly would make the surgery cheaper! But for some things, cost should not be the driving force behind the decision. We have to consider safety and the animal's pain first, and costs a distant third.