Anesthesia in Exotic Animals

As an exotic animal veterinarian, I’m often confronted with the belief that anesthesia for exotic pets is highly risky. It’s a belief founded in reality, but it’s not an assured death sentence for the animal, especially if the medical team approaches the case with consideration.

Perianesthetic Mortality 

Death during or shortly after anesthesia is termed “perianesthetic mortality”. A handful of studies have looked at perianesthetic mortality in exotic animals – small mammals (Sources 1 & 2), snakes (Source 3), and birds (Sources 4 & 5). Some of the repeated findings across these studies include the following: 

• Perianesthetic mortality is higher in exotic pets than in dogs and cats
• Healthy pets may have lower risk of perianesthetic mortality than sick pets 

To put some raw numbers on the risk of perianesthetic mortality: 

• Rabbits
  • Healthy: about 1.5% – 4% 
  • Sick: about 7.5%
• Guinea Pigs
  • Healthy & sick combined risk: 3.8% 
• Birds (Various Species)
  • Healthy & sick combined risk: about 3.5% 
• Snakes
  • Healthy & sick combined risk: 2.8% 

For comparison, the perianesthetic mortality risk for dogs (healthy and sick combined) was recently estimated in one publication at 0.69% (Source 6). So, while the risk for exotic pets may not seem astronomically high, it is higher than for dogs. 

Minimizing the Risks 

So how do we minimize the risk to our patients? I’m rather proud of the high standards that AERC’s Anesthesia and Avian & Exotic Medicine Departments have set for our exotic patients. Some of the foundational practices are as follows: 

1. Formulate a thorough plan for before, during, and after anesthesia.   

Communication is an essential part of a well-functioning team. Before each pet’s procedure, our Anesthesia team and our Avian & Exotic Medicine team have a group discussion of the pet’s medical history, reason for anesthesia, proposed anesthetic drug protocols, instrumentation needs, and any anticipated complications. We make sure that our equipment is all set up and ready to go before we start, and emergency drug doses are calculated and drawn up.  

Anesthetized and intubated bearded dragon; an intraosseous catheter has been placed in the left tibia.

2. Intubate and mechanically ventilate as many patients as possible. 

Intubation is the placement of a tube into the trachea (windpipe). Doing so allows us to breathe for the pet which is a big help since anesthetic drugs often suppress the animal’s breathing – which can lead to reduced oxygen delivery to the body and increases the risk of perianesthetic mortality. Our team is skilled at intubating everything from macaws to budgies, leopard geckos to pythons, rabbits to guinea pigs. Once the pet is intubated, we connect them to a ventilator specially designed for smaller animals. We then monitor numerous parameters to ensure that they remain stable throughout the procedure. 

Anesthetized and intubated guinea pig; an intravenous catheter has been placed in the left cephalic vein.

3. Place IV catheters and make use of constant rate infusions.   

A constant rate infusion (CRI) is a constant flow of anesthetic drug into the patient’s IV line – it allows for lower overall doses, and the ability to change the rate of infusion to increase or decrease the effects. Using multiple CRIs not only gives us intricate control over pets’ anesthetic depth, but also the ability to increase pain control when needed.  

Of course, using CRIs requires placing IV catheters, so we do so in nearly every animal we anesthetize. We often place more than one IV catheter so we can use more CRIs! If the patient is too small or too sick for an IV catheter, we can place a catheter into a long bone (called an intraosseous or IO catheter), which functions in the same way, allowing us to give CRIs and fluids directly into the circulatory system. 

While exotic pet anesthesia IS riskier than it is for dogs, it may be less risky than you think. And know that our team is making every effort minimize the risk for your pet!  

If you have questions or concerns about your pet’s procedure and anesthesia plan, always consult with your pet’s veterinary team. 

Learn more about our Avian & Exotic Medicine Service here. 

Sources: 

1. Brodbelt DC, Blissitt KJ, Hammond RA, Neath PJ, Young LE, Pfeiffer DU, et al. The risk of death: the confidential enquiry into perioperative small animal fatalities. Vet Anaesth Analg. 2008;35:365-373. doi:10.1111/j.1467-2995.2008.00397.x
2. Lee HW, Machin H, Adami C. Peri-anaesthetic mortality and nonfatal gastrointestinal complications in pet rabbits: a retrospective study on 210 cases. Vet Anaesth Analg. 2018;45:520-528. doi:10.1016/j.vaa.2018.01.010
3. Morrison HL, Rasys AM, Quandt JE, Divers SJ. Retrospective assessment of general anesthesia-related challenges, morbidity, and death in snakes: 139 cases (2000-2022). J Am Vet Med Assoc. 2023;261(4). doi:10.2460/javma.22.10.0477
4. Seamon AB, Hofmeister EH, Divers SJ. Outcome following inhalation anesthesia in birds at a veterinary referral hospital: 352 cases (2004-2014). J Am Vet Med Assoc. 2017:251(7):814-817. doi:10.2460/javma.251.7.814
5. Dobbs P, Moittié S, Liptovszky M. Avian anaesthesia related mortality and the associated risk factors in a UK zoological collection. Vet Anaesth Analg. 2021:48:922-929. doi:10.1016/j.vaa.2021.04.012
6. Redondo JI, Otero PE, Martínez-Taboada F, Doménech L, Hernández-Magaña EZ, Viscasillas J. Anaesthetic mortality in dogs: a worldwide analysis and risk assessment. Vet Rec. 2023;e3604. doi:10.1002/vetr.3604