Understanding Anesthesia
What every Pet Owner Should Know
Anesthesia always carries some risk, though it’s usually very small—never zero. While most pets handle it well (serious reactions are rare, ~1 in 100,000), each pet’s needs are unique. We prioritize safety at every step, ensuring you’re informed and confident in their care. Let’s discuss how anesthesia works, what to expect, and how we keep your pet safe
Whether your pet is a six-month-old puppy coming in for a neuter or a sixteen-year-old kitty needing a dental procedure, anesthesia always carries some level of risk. That risk is unique to each pet, regardless of their age, and often very small—but never zero. While it’s important not to fear anesthesia, it is equally important to respect it. Anesthesia can mean the difference between a longer, healthier life and untreated pain or disease. That’s why we take every precaution to make it as safe as possible. For most pets, the risk of a serious adverse reaction to anesthesia is very low, approximately 1 in 100,000. Still, every pet is unique, and each procedure requires careful consideration of the risks and benefits.
We believe informed decisions are the best decisions. So let’s talk about anesthesia, what it is, what to expect, and how we keep your pet safe, so you can feel confident and empowered when it comes to their care
What Do Anesthetic Complications Look Like?
Anesthetic complications can range from very mild to severe. Most pets recover smoothly, but it’s important to understand that even rare risks deserve thoughtful discussion. This is a general overview—not an exhaustive list—but it can help you feel more informed and prepared.
Mild Complications: These are usually temporary and resolve with little to no treatment:
1. Slower than expected recovery, but your pet is up and acting normal within a few hours
2. Mild fever in cats after opioid pain relief—typically resolves on its own
3. Brief drops in blood pressure during surgery that are corrected quickly
4. Benign heart rhythm changes that don’t affect blood pressure and respond easily to medication
5. Rash or Irritation at the IV catheter site.
Moderate Complications: These may require further monitoring, testing, or hospitalization:
1. Regurgitation during anesthesia—can lead to aspiration pneumonia or esophageal damage (especially in flat-faced breeds like bulldogs);
2. Persistent low blood pressure or arrhythmias that don’t respond well to treatment
3. Prolonged recovery that includes signs like seizures or heart failure, or altered mental status.
Severe Complications: These are rare but potentially life-threatening:
1. Cardiac arrest (heart stops beating)
2. Severe aspiration pneumonia or esophageal stricture from regurgitation during surgery
3. Respiratory Arrest—highest risk in brachycephalic breeds e.g. bulldogs
What Factors can Affect Anesthetic Safety
Age
Let’s clear something up: age is not a disease! Just because your pet is a senior doesn’t mean they can’t safely undergo anesthesia. That said, older pets are more likely to have underlying health conditions, so we may recommend more thorough pre-anesthetic screening (like blood work,cardiac ultrasound) to ensure they’re good candidates.
Very young pets, especially those under 6 months of age or weighing less than 1 kg, also require special attention. Their small size and developing metabolism mean they can respond differently to anesthesia and medications and may need a modified approach.
Breed
Some breeds are known to carry higher anesthetic risks due to unique health predispositions: some of the more common examples include:
🔹 Dobermans may have clotting issues that make bleeding more likely.
🔹 Brachycephalic breeds (think Bulldogs, Boxers, and Boston Terriers) are at higher risk of breathing issues and regurgitation during or after surgery.
🔹 Certain cat breeds, like Ragdolls and Maine Coons, are more prone to heart disease that may not show up on a physical exam alone—sometimes only advanced testing can detect it.
Pre-Existing Conditions
Health problems like heart disease, seizures, kidney disease, or liver dysfunction can affect how your pet handles anesthesia. Most pets with these conditions can still undergo surgery safely, but they often require:
🔹 Additional testing (e.g., chest X-rays, probnp, cardiac ultrasound)
🔹 Tailored anesthesia protocols
🔹 Modified medication and fluid planning
Medical History
Never underestimate the value of a good history and physical exam! If your pet had a slow recovery from a previous procedure, tell us. If a past vet noted something unusual, we want to hear about it. Even small details can help us choose the safest medications and dosages for your pet.
How do we Minimize these Risks?
Pre-screening and planning, careful intraoperative monitoring and team based approach with care givers in the postoperative period to catch any potential complications as quickly as possible.
Before Surgery
Pre-surgical physical examination:
A doctor will evaluate your pet prior to any anesthesia by performing a full physical exam and cardiac auscultation to help reveal possible health conditions that can affect their anesthesia.
Pre-operative blood work:
This is to evaluate your pet’s kidney and liver function as well as hydration status. Bloodwork appointments are done with a Registered Veterinary Technician (RVT) at least 2 – 3 weeks in advance of the surgical date. Once we’ve received the results a team member will be in touch to let you know if it is safe for your pet to proceed with surgery.
Additional Screening: For pets with additional health considerations or other risk factors that may influence anesthesia safety, further screening may be recommended.
Chest radiographs: May be recommended for higher-risk pets (older or brachycephalic). X-rays assess heart and lung health, which are key for anesthesia safety, and help detect issues like heart enlargement or lung congestion. If abnormalities are found, anesthesia can be modified, and extra monitoring may be provided.
Cardiac ultrasound or proBNP blood test: May be recommended for cardiac patients or high-risk breeds. An ultrasound provides detailed images of the heart’s structure and function, while proBNP detects elevated levels of a biomarker linked to heart stress. An ECG measures heart electrical activity to detect irregular rhythms that may not show in a physical exam. Since certain heart issues increase anesthetic risk, identifying them beforehand helps your vet tailor the safest plan.
Perioperative medications in brachycephalic patients:
For our brachycephalic patients we often recommend a regime of medications for a few days before and after surgery to help prevent regurgitation and its associated complications. Please ask us if you think this would be right for your pet.
Fasting prior to anesthesia:
This means nothing to eat after 9 pm (including treats) and no breakfast the morning of the procedure. Your pet can have access to water no later than 6 am the morning of the procedure.
During Surgery
Continous Monitoring with a Registered Veterinary Technician (Veterinary Nurse):
During your pets anesthesia a trained veterinary nurse will continuously monitor your pet’s heart rate, blood pressure, respiratory rate, ECG, CO2 levels and oxygen levels to ensure they remain stable before, during and after their procedure.
IV catheter and fluids:
IV access is important for emergency drug administration. IV fluids also help maintain blood pressure and help replace lost fluids. It also speeds up the recovery process by diluting anesthetic agents and enhances the metabolism and elimination throughout their liver and kidneys.
Pain management:
To ensure patient comfort during and after the procedure and into the recovery period once the pet is discharged home.
Team-Based Care
At YSAH, anesthesia and surgery are never a solo effort—it’s a team approach. And you, the pet parent, are a vital part of that team. Close observation at home can make all the difference when it comes to identifying and addressing complications early. After surgery, please keep a close eye on your pet and let us know right away if you notice:
🔹 Slower than expected recovery (still groggy, unsteady, or disoriented hours later)
🔹 A lack of appetite
🔹 Coughing, noisy breathing, or shortness of breath
🔹 Difficulty swallowing or signs of discomfort in the throat
Prompt communication with our team allows us to act quickly if concerns arise, ensuring the best possible outcome for your pet.
While anesthesia carries inherent risks, modern veterinary medicine has made it safer than ever—especially when paired with thorough pre-screening and expert monitoring. At YSAH, we treat every pet as an individual, tailoring protocols to their unique needs. Whether your furry friend is a playful puppy or a wise senior, our team approach ensures they receive the gold standard in care. If you have concerns about an upcoming procedure, we’re here to discuss them—because your peace of mind matters as much as your pet’s well-being.
– The Yonge Sheppard Animal Hospital Team 🐾