Anesthesia in Dogs: Risk, Preparation, and What to Expect

In brief

There are five things you should know about anesthesia in dogs. First: the risk is lower than many people fear – in large studies, depending on population, time window and definition, between about 0.1 and 0.7 percent of dogs died from causes related to anesthesia or sedation. Second, and this surprises almost everyone: the most dangerous stretch is not the surgery but the recovery period. In the British CEPSAF study, 47 percent of the deaths occurred afterward; in a worldwide study from 2024, it was 81 percent. Third: age alone does not decide the risk; a major factor is the dog's health status – in the CEPSAF study, the risk in dogs with severe pre-existing disease was roughly eight times the overall average. Fourth: sedation is not a "mini anesthesia"; it, too, can depress circulation and breathing, and it was counted in the analysis just the same. Fifth: heart findings that happen to show up under anesthesia must be confirmed in the awake dog before they become a diagnosis.

Few appointments frighten dog owners as much as anesthesia – and few places show such a wide gap between worry and actual risk. This article puts the numbers in context, explains what happens before, during and after, and shows you how to recognize anesthesia that is done well.

Note: This article is general information and does not replace an informed-consent conversation at your clinic. Questions about your dog's anesthetic risk, pre-existing conditions and medications should always be discussed with your veterinarian before the procedure.

👉 All about prevention and health: dog health basics at a glance

1. How high is the risk really?

For many years, the main reference was the British CEPSAF study, which analyzed around 98,000 anesthetized or sedated dogs. The result: the risk of an anesthetic- or sedation-related death within 48 hours was 0.17 percent – about one in 601 dogs (Brodbelt et al. 2008). Its data, however, were collected between 2002 and 2004.

Two newer large studies add to this picture. An analysis of UK general-practice records from the VetCompass program covered 157,318 dogs anesthetized or sedated between 2010 and 2013: 0.10 percent died within 48 hours and 0.14 percent within two weeks of causes for which the anesthetic or sedative could not reasonably be ruled out as a contributing factor (Shoop-Worrall et al. 2022). A worldwide study of 55,022 dogs from 405 veterinary centers in eight countries found an anesthesia-related mortality of 0.69 percent in the period from premedication to 48 hours after extubation (Redondo et al. 2024).

These figures cannot be read as a trend over time, nor can they be played off against each other: the studies differ in their populations and settings, in their time windows and in how they define an anesthesia-related death. What they have in common is the order of magnitude – well under one percent – and the finding that the risk is clearly higher in seriously ill patients; both newer studies also found a higher risk for emergency procedures.

On its own, though, none of these overall numbers tells you much, because each lumps perfectly healthy spay and neuter patients together with emergencies. What matters is the breakdown by health status: in the CEPSAF study, in dogs with severe pre-existing disease, the risk rose to 1.33 percent, or about one in 75. In healthy dogs, it was well below the overall figure. In the VetCompass data, eight of 89,852 dogs undergoing castration or spay died of anesthesia- or sedation-related causes within two weeks – 0.009 percent.

That leads to the single most important sentence in this article: the risk is closely tied to the patient's condition, not just to the anesthesia itself. That is exactly why all of the preparation revolves around knowing that condition as precisely as possible beforehand.

A word on these numbers, because they are easily misread in both directions. Whether roughly one in 1,000 or one in 150 – such figures sound reassuring to many people and threatening to some, but in fact they describe a group, not your dog. For a healthy young dog being neutered, the risk is well below it; for an emergency patient with unstable circulation, well above.

More useful than any of these numbers, then, is the question of which group your dog belongs to – and that is exactly what the classification in section 4 does. It is the reason an informed-consent conversation does not end with a percentage, but with an assessment of this particular dog.

2. The most dangerous part is recovery

Many owners assume the most critical moment comes during surgery. The data show, however, that the recovery period needs particular attention.

47 percent of anesthesia-related deaths in dogs occurred after the procedure, during recovery (Brodbelt et al. 2008). In the worldwide study from 2024, it was 81 percent (Redondo et al. 2024). The current AAHA anesthesia guidelines explicitly point out that most of these deaths occur within the first three hours after anesthesia ends (AAHA 2020).

Why then, of all times? Because several things come together in this phase that were under control during the procedure. Monitoring often ends with the last skin suture, even though the dog is still deeply under the influence of the drugs. The endotracheal tube that secured the airway is removed – but the swallowing reflex may not be back yet. Body temperature has dropped, and hypothermia slows the breakdown of the anesthetic drugs even further. Pain sets in as the intraoperative analgesia wears off. And the dog may be lying unobserved in a kennel.

That is exactly why the AAHA guidelines describe anesthesia as a continuum across four phases – preparation, induction, maintenance, recovery – rather than as the period during which the dog is unconscious. The guidelines frame it as a door-to-door process: anesthesia starts at home and only ends once the dog is back home, stable and free of pain.

For you, this is the most practically valuable question of all before a procedure: "How will my dog be monitored during recovery, and by whom?" A good answer describes a named person who keeps an eye on the dog, active warming and a pain management plan. An evasive answer is a warning sign.

3. Sedation is not a "mini anesthesia"

A widespread misunderstanding: for X-rays, nail trims or ultrasound, the dog is "only sedated," and that is supposedly something fundamentally different.

Medically, the line is blurry. Sedatives also depress circulation and breathing, and the CEPSAF study explicitly included sedated dogs. The difference lies in depth, not in the kind of risk.

In practice, this means that a pre-anesthetic exam, an informed-consent conversation and monitoring belong to sedation, too. And the seemingly more harmless procedure deserves the same questions as major surgery.

4. What happens before anesthesia

It starts with the pre-anesthetic exam: listening to the heart and lungs, checking the mucous membranes, temperature and weight, recording all pre-existing conditions and – important and often forgotten – all medications and supplements your dog receives. Some are continued before anesthesia, some are paused. The clinic decides that, but only if it knows about them.

These findings lead to classification into a risk class, which in veterinary medicine usually follows the ASA scale from 1 (healthy) to 5 (life-threateningly ill). This classification is not a formality: it is precisely the measure by which risk differed clearly in the CEPSAF study and in both newer studies, and it guides the choice of drugs, the level of monitoring and the staffing. What it is not: a prediction for the individual dog. It assigns the dog to a group, and as section 15 shows, two veterinarians will not necessarily do that the same way.

On pre-anesthetic bloodwork, which is the subject of much debate: it is neither a ritual nor a sales pitch; its purpose is to assess the organ function that determines how the anesthetic drugs are metabolized – above all the liver and kidneys. In young, clinically healthy dogs, the added benefit is limited; in older dogs or dogs with pre-existing conditions, it makes sense. As a guideline, the AAHA guidelines state that normal results in a clinically healthy patient can be used for roughly three to six months. So feel free to ask why a test is being done – a good clinic can explain its reasons.

5. Fasting: the old rule is outdated

"No food or water from the night before" – most people know this instruction, and in this form it is no longer up to date.

The reason for fasting is real: a full stomach raises the risk that food will get into the airways while the protective reflexes are switched off. This kind of aspiration pneumonia is a serious complication.

First, a note on the scope of this section: the following information refers to healthy patients under routine conditions. With pre-existing conditions, emergencies and certain procedures – for example on the gastrointestinal tract – your clinic may have good reasons to deviate. What counts is always the instruction for your dog, not the general rule.

Fasting for too long has drawbacks as well, though – low blood sugar in small breeds and puppies, nausea, and, paradoxically, a stomach that has been empty for a very long time can promote reflux of stomach acid. The AAHA therefore revised its recommendations in 2020 and advises shorter fasting times than used to be common. On water, the guidelines are especially clear: for healthy patients, they call for no withholding at all, but free access. The widespread practice of also taking away the water bowl from the night before has no basis in them.

For food, the times depend on age, size, pre-existing conditions and the procedure, and some groups differ considerably. For puppies under eight weeks and dogs under two kilograms, the guidelines call for withholding food for no longer than one to two hours – for them, low blood sugar is the greater risk. In dogs prone to regurgitation, a small meal of ten to twenty-five percent of the normal amount four to six hours before induction may even make sense. And diabetic dogs typically get half a meal and an adjusted insulin dose and are scheduled as the first case of the day.

For you, this simply means: follow the timing your clinic gives you and don't invent your own. If you get a blanket twelve-hour instruction, you are welcome to ask about it – but a well-founded deviation from the general recommendation is not a mistake; it is the normal case for a dog who doesn't fall into the "healthy and uncomplicated" category.

👉 Why aspiration is so dangerous: dog coughing – recognizing the causes and responding correctly

6. How the day goes

Hardly anyone knows what happens between drop-off and pick-up – and that uncertainty is part of what makes people anxious. Here is the usual sequence.

Drop-off in the morning. Scheduled procedures are almost always in the morning, and there is a reason for that: it leaves the whole day for the recovery period under observation. A dog who has surgery at 4 p.m. wakes up just as the staff are leaving.

The wait. It is normal for your dog not to be taken in right away. Emergencies take priority, and the order also depends on pre-existing conditions – diabetic dogs, for example, are deliberately scheduled early. Expect that there may be hours between drop-off and the procedure.

The call afterward. At most clinics, you will get a call as soon as the procedure is over. Ask at drop-off when and at which number – and whether you need to be reachable in case a decision comes up during the procedure. That does happen: a tooth that turns out to need extracting after all, a finding that makes it sensible to extend the procedure.

Pick-up. It is deliberately not scheduled right after the dog wakes up. A dog who is just coming around is better off at the clinic than in the car – that is not a stalling tactic, but exactly the phase from section 2.

The discharge conversation. This is the moment when most information gets lost, because you are distracted and want to see your dog. So make sure you are given in writing: which medications to give and when, when water and food are allowed again, when the incision will be checked, which signs mean you should go back to the clinic, and which number to call at night.

A photo of the notes on your phone is worth more than trusting your own memory. By evening, almost no one remembers all five points.

7. What happens during anesthesia

The usual process follows a fixed pattern. First comes the premedication: a combination of sedatives and pain medication that relaxes the dog and reduces the amount of anesthetic needed. Then an IV catheter is placed – it is the life insurance of the procedure, because it guarantees immediate access for drugs in an emergency.

After induction, the dog is usually intubated: a tube in the windpipe secures the airway, allows ventilation and protects against aspiration. Anesthesia is usually maintained with an inhaled anesthetic gas, or alternatively intravenously.

During the procedure, the dog is monitored: heart rate and ECG, breathing, oxygen saturation, blood pressure, carbon dioxide in the exhaled air and body temperature. On top of that, IV fluids usually run to support circulation, and the dog is actively warmed – hypothermia is one of the most common and most underestimated complications of anesthesia.

The decisive factor, though, is not the device but the person in front of it. A monitor that nobody watches continuously is just decoration.

7.1 What monitoring measures and why

"The dog will be monitored" is an empty statement as long as it isn't clear what is being measured. So here are the usual parameters and what each one tells you.

Oxygen saturation shows how well the blood is loaded with oxygen. It is the most obvious value and at the same time a late one: it only drops once quite a few things have already gone wrong.

Carbon dioxide in the exhaled air is the more informative value. It shows in real time whether the dog is breathing, or being ventilated, adequately – and it shows this earlier than saturation does. A device that measures it is one of the clearest differences between basic and good monitoring.

Blood pressure. A drop under anesthesia is common and crucial for blood flow to the organs – above all the kidneys. It is one of the reasons IV fluids run during the procedure.

Body temperature. Under anesthesia, a dog loses heat because its own temperature regulation is impaired and the abdomen may be open. Hypothermia slows the breakdown of the anesthetic drugs and thus prolongs exactly the phase that section 2 identifies as the most dangerous. Active warming is therefore not a matter of comfort.

Heart rate and ECG show arrhythmias that can occur under anesthesia.

What matters most, though, is not the device but who is looking at it. All of these values only signal deviations to someone who sees them and can interpret them. That is exactly why the question in section 13 is about the person, not the equipment.

8. Pain management is part of anesthesia, not an extra

A point that was misunderstood for a long time: anesthesia and pain control are not the same thing. An unconscious dog does not consciously perceive pain – but its nervous system still processes the stimulus. Without targeted pain management, that processing stays active, and the dog may wake up in pain that is already established.

From this follows the principle that underpins modern anesthesia: pain medication is given before the painful stimulus, not after. Pain that never develops in the first place is much easier to control than pain that has already set in. That is why the premedication usually already includes a pain medication.

The usual approach is multimodal: several drugs that act at different points, plus, depending on the procedure, a local anesthetic block of the surgical area. This also reduces the amount of anesthetic gas needed – and with it the strain on the circulation. So good pain management can make anesthesia not only more bearable, but also safer.

The transition to home is what matters in practice. The effect of the clinic's medication wears off at some point, often in the evening or during the night. So ask specifically which pain medication your dog received, how long it lasts and what you will give at home. "He probably won't need anything else" is not a sufficient answer after a procedure that involved tissue injury.

8.1 How to recognize a pain management plan

Because "he'll get pain medication" is just as empty as "he'll be monitored," here are the features of a well-thought-out approach.

It starts before the incision. Pain medication works better when it is given before the stimulus occurs – pain that has already set in is harder to dampen than pain that has been prevented. That is why the premedication from section 7 already includes a pain medication.

It combines several points of action. Different drugs act at different sites. In combination, the same effect can be achieved with lower individual doses – with fewer side effects.

It extends beyond the appointment. A procedure doesn't only hurt on the day of surgery. A plan that ends at pick-up is not a plan.

It allows for adjustment. How much pain a dog shows varies from dog to dog. Good clinics tell you how to recognize that the dose isn't enough – and what to do then.

That last point is where things fall apart at home. In dogs, pain rarely shows as whimpering; it shows as restlessness, panting, withdrawal, a changed posture or a dog who doesn't want to lie down. If you wait for your dog to "tell" you that it hurts, you will often wait in vain.

9. Why heart findings under anesthesia can be misleading

A point that can lead to misdiagnoses in practice: many anesthetic drugs and sedatives reduce the heart's contractility. If a poor echocardiography value shows up during sedation, it does not necessarily mean the heart muscle is diseased.

This has been documented, for example, for alpha-2 agonists such as dexmedetomidine: in a study of healthy dogs, fractional shortening – a measure of pumping strength – fell from around 41 to about 24 percent (Wang et al. 2016), below the usual normal range, without any heart disease being present.

The rule, therefore, is this: a heart finding that only shows up under sedation or anesthesia is read in light of the drugs used and, if there is a suspicion, confirmed in the awake dog through a targeted examination. Otherwise, a measurement artifact can turn into lifelong medication.

👉 More on this mistake: dilated cardiomyopathy (DCM) in dogs

10. Risk groups that need special planning

Short-nosed (brachycephalic) breeds such as Pugs, French Bulldogs or Boxers already have narrowed airways when awake. For them, recovery is especially critical, because the tube secures the airway and the narrowing returns once it is removed. They are therefore typically left intubated longer and monitored more closely.

Dogs with heart disease need drug choices adapted to their condition and close blood pressure monitoring. A known heart condition is not an exclusion criterion – but it is a reason to assess it properly beforehand.

Dogs with the MDR1 defect, mainly herding breeds, lack a functioning transport protein that moves certain drugs out of the brain; some sedatives and anesthetic drugs act more strongly and for longer in these dogs and are dosed lower accordingly. In dogs from the affected herding breeds, the MDR1 status therefore belongs on the table before any anesthesia – provided it is known or can be tested beforehand. This does not mean a test for every dog.

Very small dogs and puppies lose heat faster and are more prone to low blood sugar. Overweight dogs are harder to dose and breathe less well under anesthesia.

👉 Why the genetic test matters here: the MDR1 defect in dogs – ABCB1, P-glycoprotein and drug sensitivity

10.1 Why short-nosed dogs need their own plan

This group deserves more than two sentences, because for them the critical phase is precisely the one that is the most dangerous anyway.

The mechanism is simple: as long as the tube is in place, the airway is secured – a short-nosed dog sometimes breathes better under anesthesia than when awake. That is exactly why things can tip when the tube is pulled: the narrowing returns abruptly, in a dog whose protective reflexes are not yet fully back.

What good planning does with this: leaving the tube in longer, until the dog actively rejects it rather than merely swallowing; letting the dog wake up lying on its belly or chest rather than on its side; positioning the head and neck extended; and monitoring beyond the usual time. Some clinics keep a plan ready for these dogs to secure the airway again.

Add to this the point from section 5: these dogs are more often prone to regurgitation, and for them an adjusted fasting time can make more sense than the longest possible one.

For you, this means: with a Pug, a French Bulldog or a Boxer, the recovery question from section 13 is not one of six but the decisive one. And the answer should mention short-nosed dogs explicitly, not stay general.

11. "My dog is too old for anesthesia"

You hear this a lot – and it rests on a reasoning error. Not because age is irrelevant: over the years, concurrent diseases become statistically more common, and in that sense the risk does rise with age. The error lies in treating age as the sole reason to rule out a procedure. What matters is not the number of years alone, but above all which diseases are actually present. A healthy twelve-year-old can be a better anesthesia patient than a six-year-old with heart disease.

This reasoning error is tricky because it does harm in both directions. It can lead to necessary procedures not being done – painful teeth that are not treated, a tumor that is not removed – and that can cost more quality of life than the anesthesia would have. The right question is never "Is he too old?" but: "What does the procedure achieve, what does it cost, and how can the risk be reduced?"

👉 What really changes with age: caring for a senior dog

12. Anesthesia-free dental cleaning: what's missing

Offers for dental cleaning without anesthesia sound tempting, especially to owners of older dogs. Medically, however, the procedure is something different from what the name suggests.

In an awake dog, tartar can only be removed above the gum line. The actual disease – inflammation and bone loss – takes place below it, in the periodontal pockets. That is exactly the area that can be neither cleaned nor assessed without anesthesia. Nor is it possible to take X-rays of the tooth roots, which are where a considerable share of findings show up in the first place.

The result is a set of teeth that looks clean while the actual disease process can carry on unchanged – and the check-up at the vet may be considered done. On top of that comes the stress of being restrained, which is considerable for many dogs.

If you are hesitating because of the anesthetic risk, you are better served by an honest conversation about risk and an adapted plan than by a procedure that covers the problem up cosmetically.

13. The questions that matter – and why good anesthesia costs money

13.1 Six questions before the appointment

The individual questions are scattered throughout this article. Here they are together, in order of importance.

Who monitors my dog during the procedure? This means a person whose job is the anesthesia – not someone who assists on the side.

Who monitors him during recovery, and for how long? Based on the data, this is the most important question of all, and it often goes unasked.

What does the pain management plan look like – during and afterward? A good answer names several drugs and a plan for home.

Will my dog be warmed, and with what? Hypothermia prolongs recovery and is one of the most common preventable complications.

What happens if a decision comes up during the procedure? And will I be reachable for it?

What fasting times apply specifically to my dog? If the answer is a blanket twelve-hour instruction, the follow-up question from section 5 is worth asking.

None of these questions is a sign of distrust. Clinics that work carefully are happy to answer them – they are questions about the very things they are proud of.

13.2 Why prices vary so much

If you compare quotes, you will find considerable differences for what seems to be the same procedure. That is rarely down to profit margin and mostly down to what is included.

Anesthesia performed to current standards includes: a thorough pre-anesthetic exam, bloodwork if indicated, an IV catheter, IV fluids during the procedure, intubation, monitoring equipment, active warming, several pain medications, one person who does nothing but monitor for the entire time – and the same attention during recovery.

Each of these items costs time, materials or staff, and each of them is a place where corners can be cut. A much cheaper quote is therefore not automatically dubious, but it is a reason to ask what exactly is included.

So the honest comparison is not "anesthesia versus anesthesia" but "which services versus which." And for a procedure whose risk depends substantially on monitoring and recovery, that is not a side issue.

14. What you can do at home

Beforehand: Write down all medications and supplements, including the seemingly harmless ones. Report any coughing, diarrhea or anything unusual over the past few days – an infection can be a reason to postpone the appointment. Stick exactly to the fasting times your clinic gives you. And ask the three questions that matter: Who monitors during the procedure, who monitors during recovery, and what does the pain management plan look like?

Afterward: Expect your dog to be wobbly, clingy or out of it for the rest of the day – that is normal. Keep him warm and in a quiet, non-slip area where he can't jump onto furniture or climb stairs. Offer water as soon as the clinic allows it. The first meal should come no earlier than when your dog is standing steadily and reliably holding up his head – usually a few hours after waking up, in small portions and always only after the clinic has given the go-ahead. Feeding too early, while the swallowing reflexes are still impaired, is exactly the mistake the fasting beforehand was meant to prevent.

Your dog needs to go back to the vet if he keeps vomiting, if he still can't stand steadily after several hours, if he has trouble breathing, if the wound is bleeding, or if he seems to be suffering despite pain medication. In dogs, pain rarely shows as whimpering – more often as restlessness, panting, withdrawal or a changed posture.

👉 How to really recognize pain: recognizing pain in dogs

14.1 Preparing your dog – the part that falls within our field

Up to this point, this has been about medical planning. But there is a part that comes before the appointment and that no veterinarian can do for you: how your dog experiences the day.

This is not a side issue. A dog who lets himself be touched, held and examined often needs less restraint, sometimes less sedation, and may be calmer when waking up. A dog who is already thrown off balance on entering the clinic starts a procedure that strains the circulation anyway with his circulation already running high.

Practice handling, well in advance. Touching the paws, looking at the ears, looking into the mouth, touching the neck, letting himself be laid on his side. Each time briefly, voluntarily, and stopping before the dog pulls away.

Think about the IV catheter. For the catheter, a front leg is held and shaved. A dog who is familiar with having a front leg held experiences this moment completely differently.

Build up muzzle training early if a muzzle is likely to be needed. A muzzle that is put on for the first time at the clinic can become associated with exactly that situation – and that can have lasting effects.

Visits for no reason. Pop in briefly, treats, back out again. Many clinics explicitly support this. It can make a big difference, and it takes ten minutes.

The crate as a safe place. If your dog is used to a crate, you have a retreat for the rest period afterward that doesn't need to be explained first.

The catch is the timing: all of this works when it is built up before it is needed. A week before a scheduled surgery is often too late, and in an emergency it is too late anyway. That is why handling belongs in basic training and not in the preparation for an appointment.

👉 Desensitization and counterconditioning in dogs

15. Limits of the evidence

Many of the detailed numbers in this article – the breakdown by health status and the share of deaths after the procedure – come from the CEPSAF study, whose data were collected between 2002 and 2004 in the UK. Monitoring technology, drugs and training have evolved since then, and the authors themselves noted that small animal anesthesia was becoming increasingly safe. The newer studies from 2022 and 2024 do not simply show a decline, though: their figures range from 0.10 to 0.69 percent because they examine different populations and time windows and define an anesthesia-related death differently. None of these figures is therefore a fixed value for today's risk – and they come from countries and veterinary care systems that may differ from the one your dog is treated in.

The ASA risk classification is also a rough grid with considerable room for judgment: two veterinarians may classify the same dog differently.

And finally, averages say little about the individual dog. A risk of one in 600 or one in 150 is a statement about a large group, not a prediction for your dog – whose individual risk may be well below or above it.

For context on the sources as a whole: this article relies on three large studies, one guideline from a professional association and one experimental study on the effect of a sedative. These are very different types of sources. The large studies provide figures on frequency, the guideline consensus recommendations based on the literature, the experimental study a single measured finding. None of them replaces the others – and none says anything about the clinic where your dog is treated.

16. Conclusion

Anesthesia in dogs is safer than its reputation suggests – what matters is less the procedure itself than the patient's health status and the care that surrounds it. The greatest potential for improvement lies precisely where hardly anyone expects it: in the recovery period, when – depending on the study – about half or more of the deaths occur. If you can ask only one question before a procedure, don't ask about the anesthetic drug; ask who will be watching your dog as he wakes up. And age alone is never a reason to forgo a necessary procedure.

👉 What to look for when choosing: what makes a good veterinarian

If you take away a single question from this article, let it be this one: Who monitors my dog during recovery, and for how long? It targets the phase in which, depending on the study, about half or more of the deaths happen, it costs nothing, and the answer tells you more about a clinic than any list of equipment.

Key takeaways on anesthesia in dogs

The overall risk is low. In large studies, anesthetic- or sedation-related mortality was 0.10 percent within 48 hours in UK general practice (Shoop-Worrall et al., 2022), 0.17 percent in the older British CEPSAF analysis (Brodbelt et al., 2008) and 0.69 percent in a worldwide study (Redondo et al., 2024). Because populations, time windows and definitions differ, these figures are not directly comparable.

The risk is closely tied to the patient's condition, not just to the anesthesia. In the CEPSAF study, it rose to 1.33 percent in dogs with severe pre-existing disease; in healthy dogs, it was well below the overall figure.

The most critical stretch is recovery. In the CEPSAF study, 47 percent of the deaths occurred afterward (Brodbelt et al., 2008), in the worldwide study 81 percent (Redondo et al., 2024); most recovery deaths occur within the first three hours after anesthesia ends (AAHA, 2020). The most important question before a procedure is therefore about exactly this phase.

Sedation is not a different risk, but the same one at a lesser depth. Sedated dogs were explicitly included in the analysis.

The old fasting rule is outdated. For healthy patients, the guidelines call for no routine withholding of water; very small and very young dogs should not go without food for longer than one to two hours.

Heart findings from anesthesia need to be confirmed in the awake dog. Under dexmedetomidine, fractional shortening in healthy dogs fell from around 41 to about 24 percent (Wang et al., 2016) – without any heart disease being present.

Age is not a reason on its own to rule out anesthesia. Concurrent diseases become more common over the years, and they count for the risk – not the number of years alone. A healthy twelve-year-old can be a better anesthesia patient than a six-year-old with heart disease – and procedures that are skipped often cost more quality of life than the anesthesia would have.

Anesthesia-free dental cleaning misses what matters. Below the gum line, an awake dog's teeth can be neither cleaned nor assessed, and dental X-rays are not possible – the teeth look clean while the disease process continues.

The figures are not a time trend. The detailed CEPSAF data date from 2002 to 2004; the newer studies from 2022 and 2024 examine different populations with different definitions, so their figures cannot simply be compared with the older ones.

References

• Brodbelt, D. C., Blissitt, K. J., Hammond, R. A., Neath, P. J., Young, L. E., Pfeiffer, D. U. & Wood, J. L. N. (2008): The risk of death: the Confidential Enquiry into Perioperative Small Animal Fatalities (CEPSAF). Veterinary Anaesthesia and Analgesia 35(5): 365–373. https://doi.org/10.1111/j.1467-2995.2008.00397.x (98,036 dogs; overall risk 0.17% or 1 in 601 within 48 hours; in dogs with severe pre-existing disease 1.33% or 1 in 75; 47% of deaths in the postoperative period)
• Grubb, T. et al. (2020): 2020 AAHA Anesthesia and Monitoring Guidelines for Dogs and Cats. American Animal Hospital Association. https://www.aaha.org/resources/2020-aaha-anesthesia-and-monitoring-guidelines-for-dogs-and-cats/ (anesthesia as a continuum across four phases; most anesthesia-related deaths within the first three hours of recovery; revised fasting times; three to six months as a guide for normal prior results in a clinically healthy patient)
• Redondo, J. I., Otero, P. E., Martínez-Taboada, F., Doménech, L., Hernández-Magaña, E. Z. & Viscasillas, J. (2024): Anaesthetic mortality in dogs: A worldwide analysis and risk assessment. Veterinary Record: e3604. https://doi.org/10.1002/vetr.3604 (55,022 dogs from 405 veterinary centers in eight countries; anesthesia-related mortality 0.69% from premedication to 48 hours after extubation; 81% of deaths in the postoperative period; higher risk with higher ASA class, older age, obesity and emergency procedures)
• Shoop-Worrall, S. J. W., O'Neill, D. G., Viscasillas, J. & Brodbelt, D. C. (2022): Mortality related to general anaesthesia and sedation in dogs under UK primary veterinary care. Veterinary Anaesthesia and Analgesia 49(5): 433–442. https://doi.org/10.1016/j.vaa.2022.03.006 (VetCompass records from over 300 UK practices, 157,318 dogs, 2010–2013; anesthesia- or sedation-related death 0.10% within 48 hours and 0.14% within two weeks; 0.009% in neutering procedures; higher risk with ASA III–V, age over nine years and urgent procedures)
• Wang, H.-C., Hung, C.-T., Lee, W.-M., Chang, K.-M. & Chen, K.-S. (2016): Effects of intravenous dexmedetomidine on cardiac characteristics measured using radiography and echocardiography in six healthy dogs. Veterinary Radiology & Ultrasound 57(1): 8–15. https://doi.org/10.1111/vru.12305 (fractional shortening in healthy dogs fell from around 41% to about 24% – evidence of the effect of sedation on echocardiographic values)

Frequently asked questions about anesthesia in dogs

What owners ask most often before a procedure