Anesthesia Guidelines: Chinchilla

Find guidelines for chinchilla anesthesia, including recommended anesthetic drugs and procedures.

Research Animal Resources (RAR) veterinary staff designed these guidelines to be general recommendations, not an inclusive list of all possible drug combinations that can be used in chinchillas.

Consequently, they do not include reference to specific research-associated concerns. If you have questions about using anesthetics for your particular situation, please work with your area veterinarian to develop the most effective anesthetic plan.


General considerations

Acclimation

Do not use newly arrived animals for experimental procedures until 72 hours after entry into the facility. A one-week acclimation period is recommended. This stabilization period is not required for animals used acutely (anesthetized and euthanized at the end of the procedure), although it is recommended. This provision allows animals to acclimate to the facility and reduces the chance of stress-induced disease, including anesthetic death.

Fasting

Pre-anesthetic fasting is not usually necessary for chinchillas due to their inability to vomit. However, if fasting is employed to reduce the accumulation of food within the oral cavity, limit to no more than 2-3 hours due to the high metabolic rate of small rodents. Never restrict water.

Eye protection

Chinchilla eyes remain open under anesthesia. This can lead to corneal drying and trauma. Apply ophthalmic ointment (eg. Paralube® or Lacrilube®) to eyes during all anesthetic events and reapply liberally as necessary.

Heat support

Because most anesthetic drugs cause hypotension and hypothermia, provide supplemental heat to animals under anesthesia and during recovery. Use circulating water or air heating devices, NOT electric heating pads in order to reduce the risk of thermal injury.

Fluid support

Consider providing warm subcutaneous (SQ) or intraperitoneal (IP) fluids, particularly for prolonged anesthetic events or if the animal is ill, aged, or debilitated.

Recovery

Continue to monitor animals until they are fully recovered. Continue to provide supplemental heat during recovery. When the animal is ambulatory, return it to the home cage with immediate access to food and water.

Monitoring

Standard mammalian monitoring techniques apply to chinchillas. The goal of monitoring is to maintain cardiovascular homeostasis and core body temperature.

Understanding the basic physiologic effects of the anesthetics used is paramount to correctly interpreting monitoring parameters. View descriptions of anesthetic agents.

Parameters to monitor in anesthetized chinchillas include anesthetic depth, heart rate, respiratory rate, oxygen saturation, expired CO2 (EtCO2), temperature, and mucous membrane color.

Normal ranges

  • Temperature = 98.6 - 100.4°F
  • Heart rate (beats/minute) = 200 - 350
  • Respiratory rate (breaths/minute) = 45 - 80 resting
  • Oxygen saturation = >95%
  • EtCO2 = 35-45 mmHg
  • Mucous membranes = pink, not pale, white, gray, or blue

Due to the small size of chinchillas, arterial blood pressure readings are highly variable and inaccurate unless arterial catheterization and direct measurement is used. 


Anesthetic drugs and procedures

Injectable Anesthetics

Injectable Anesthetics

Combined ketamine/medetomidine is the preferred injectable anesthetic in chinchillas. Other commonly used injectable agents are listed below. 


Ketamine + Medetomidine

Dose: Ketamine: 5 mg/kg and Medetomidine: 0.06 mg/kg
Route: IM
Comments: Provides 30 min of surgical anesthesia. Reverse medetomidine with atipamezole.


Ketamine + Acepromazine

Dose: Ketamine: 40 mg/kg and Acepromazine: 0.5 mg/kg
Route: IM
Comments: Prolonged recovery.


Ketamine + Midazolam

Dose: Ketamine: 5 - 10 mg/kg and Midazolam: 0.5 – 1.0 mg/kg
Route: IM
Comments: Provides light anesthesia.


Ketamine + Xylazine

Dose: Ketamine : 40 mg/kg and Xylazine: 2 mg/kg
Route: IM
Comments: Prolonged recovery time (120 min) without reversal of xylazine.

Inhaled Anesthetics

Inhaled Anesthetics

Isoflurane is the preferred inhaled anesthetic. It has rapid and reliable onset and recovery.

Inhalation anesthesia should be delivered by induction chamber, face mask, or endotracheal intubation. Intubation of chinchillas is very difficult due to long narrow oral cavity and large tongue. Inhalation anesthesia is therefore best maintained via a face mask.

Inhaled anesthesia requires gas anesthesia machines with an oxygen source and a precision vaporizer. The vaporizer must be compatible with the specific inhaled anesthetic agent. When using inhalant anesthesia, use a fume hood or an anesthetic system equipped with a gas scavenging system to minimize occupational exposure to exiting gases. Due to the small respiratory capacity in chinchillas, use a non-rebreathing system.


Isoflurane

Dose: 3-5% for induction; 1-2% for maintenance
Route: Inhalation
Comments: Given to effect.

References for these guidelines are available by request.


References

  • Exotic Animal Formulary. Fifth Edition. 2018.
  • Fox, J.G., et al. Laboratory Animal Medicine. Third Edition. 2015. 
  • Saunders, R. and Harvey, L. 2012. Anaesthesia and analgesia in chinchillas. Companion Animal Practice 34: 34-43.