# Ketamine: Veterinary Uses, Dosing, and Effects

Ketamine is a dissociative anesthetic that veterinarians use for sedation, anesthesia induction, and pain control across a wide range of species. It works primarily as an N-methyl-D-aspartate (NMDA) receptor antagonist, which means it blocks a specific receptor in the nervous system that is involved in pain transmission and the development of chronic pain. Unlike many anesthetics, ketamine provides analgesia and amnesia while preserving protective airway reflexes and supporting blood pressure. It does not provide muscle relaxation, and it raises heart rate, blood pressure, and intracranial pressure. This article covers the pharmacology, labeled and off-label veterinary uses, species-specific dosing from published formularies and clinical studies, constant rate infusion (CRI) protocols for pain management, side effects including emergence delirium, and the clinical reasoning behind combining ketamine with other drugs.

This article is educational and is not a substitute for veterinary diagnosis or treatment.

## At a Glance

| Feature | Detail |
|--|--|
| Active ingredient | Ketamine hydrochloride (racemic mixture or S(+) enantiomer) |
| Drug class | Dissociative anesthetic, NMDA receptor antagonist |
| Species | Dogs, cats, horses, rabbits, and other mammals. Not approved for food-producing animals in the US. |
| How it is given | Intravenous (IV), intramuscular (IM), or subcutaneous (SC) injection. Also as a constant rate infusion. |
| Onset | IV: seconds to minutes. IM: 3 to 10 minutes depending on species and dose. |
| Duration | Single bolus: roughly 10 to 30 minutes of anesthesia depending on dose and species. CRI: maintained as long as the infusion runs. |
| Analgesia | Yes, including at sub-anesthetic doses |
| Muscle relaxation | No |
| Prescription status | Prescription only. In the US, ketamine is a Schedule III controlled substance under the DEA. |
| Storage | Room temperature, protected from light. Do not freeze. |

## What Ketamine Is and How It Works

<figure class="article-figure">
  <img src="https://upload.wikimedia.org/wikipedia/commons/6/65/7EU7_NMDA-Rezeptor_Esketamin.png" alt="NMDA receptor subunits GluN1 and GluN2A with ketamine bound" loading="lazy" decoding="async" width="1000" height="1301" />
  <figcaption>Ketamine acts by blocking the NMDA receptor, shown here with its GluN1 and GluN2A subunits and bound ligand. Image: C22H31NO2, CC BY-SA 4.0, via <a href="https://commons.wikimedia.org/wiki/File:7EU7_NMDA-Rezeptor_Esketamin.png" rel="noopener noreferrer">Wikimedia Commons</a>.</figcaption>
</figure>

### The NMDA receptor and dissociative anesthesia

Ketamine produces a state called dissociative anesthesia. The term describes the clinical picture: the animal appears to be in a trance-like state, with the eyes open and sometimes nystagmus (rhythmic eye movements), but is unresponsive to painful stimuli. The animal is not truly unconscious in the way that an inhalant anesthetic produces unconsciousness. Instead, the brain's normal processing of sensory input is disrupted.

The primary mechanism is blockade of the NMDA receptor. The NMDA receptor is a type of glutamate receptor found throughout the brain and spinal cord. Glutamate is the main excitatory neurotransmitter in the central nervous system. When the NMDA receptor is over-activated, it contributes to central sensitization, a process where the nervous system becomes hypersensitive to pain. This is why NMDA antagonists like ketamine are useful not just for surgical anesthesia but also for managing chronic and neuropathic pain.

Ketamine is a non-competitive antagonist at the NMDA receptor. It binds to a site on the receptor channel and blocks the flow of ions through it. This reduces the excitatory signaling that would otherwise amplify pain signals. At higher doses, ketamine also interacts with opioid receptors, monoamine transporters, and other targets, which contributes to its analgesic and sympathomimetic effects.

### Why ketamine does not relax muscles

Ketamine does not act on the neuromuscular junction or produce skeletal muscle relaxation. In fact, muscle tone is often increased during ketamine anesthesia. This is a critical practical point. When ketamine is used alone for anesthesia, the veterinarian must either accept the increased muscle tone or add a muscle relaxant such as a benzodiazepine (diazepam or midazolam) or an alpha-2 agonist (dexmedetomidine or xylazine). The combination of ketamine with a benzodiazepine is common because the benzodiazepine provides muscle relaxation and reduces the risk of emergence delirium.

### Cardiovascular and intracranial effects

Ketamine stimulates the sympathetic nervous system. This leads to an increase in heart rate, blood pressure, and cardiac output. In healthy animals, this is often beneficial because it supports blood pressure during anesthesia. In animals with heart disease or those that are already tachycardic, this effect can be harmful.

Ketamine also increases intracranial pressure (ICP). This occurs because ketamine increases cerebral blood flow and cerebral metabolic rate. For this reason, ketamine is used with caution in animals with head trauma, brain tumors, or other conditions where elevated ICP is a concern. However, some veterinary anesthesiologists still use ketamine in these patients if the airway is controlled and ventilation is managed, because the cardiovascular support may outweigh the ICP risk. This is a clinical judgment call.

## Labeled Uses and Common Veterinary Applications

Ketamine is not approved by the FDA for use in dogs, cats, horses, or rabbits. It is used extra-label in [veterinary medicine](/blog/careers/veterinary-medicine-careers-from-clinical-practice-to-public-health), which is legal and common when no approved alternative exists for a given condition. The drug is approved for human use and for use in certain non-human primates. In veterinary practice, ketamine is used for:

- **Anesthesia induction**: Ketamine combined with a benzodiazepine or an alpha-2 agonist is a common induction protocol, especially in cats and in patients where cardiovascular support is needed.
- **Chemical restraint**: In combination with other drugs, ketamine provides immobilization for procedures like wound repair, radiography, or minor surgery.
- **Analgesia**: At sub-anesthetic doses, ketamine provides analgesia for acute and chronic pain. It is often used as part of a multimodal analgesic plan.
- **Constant rate infusion (CRI)**: Ketamine is infused continuously during and after surgery to provide steady analgesia and reduce the requirement for other anesthetics.
- **Total intravenous anesthesia (TIVA)**: Ketamine combined with propofol (ketofol) can maintain anesthesia without an inhalant.

### What ketamine does not cover

Ketamine alone does not provide muscle relaxation, does not reliably produce surgical anesthesia in all species at safe doses, and does not provide visceral analgesia as effectively as somatic analgesia. It should not be used as the sole anesthetic for major surgery. It also does not provide good postoperative analgesia when used as a single dose for a painful procedure. The analgesic effect of a single bolus wears off before the surgical pain resolves.

## Species Dosing

The following table summarizes doses from published veterinary studies and recognized formularies. These doses are for reference only. A veterinarian must determine the appropriate dose for each patient based on species, health status, concurrent drugs, and the procedure being performed.

| Species | Route | Dose | Context |
|--|--|--|--|
| Dog | IV bolus | 0.5 mg/kg | Low-dose analgesic bolus before CRI [1] |
| Dog | IV bolus | 1 mg/kg | Analgesic bolus before CRI in combination with lidocaine and fentanyl or dexmedetomidine [2][3] |
| Dog | IV CRI | 10 to 40 mcg/kg/min | Analgesic CRI. 20 mcg/kg/min studied for 12 hours [1]. 10 mcg/kg/min studied for nociceptive testing [4]. |
| Dog | IV CRI | 0.6 mg/kg/h | Analgesic CRI in combination with lidocaine and an opioid [5][6][3] |
| Dog | IV CRI | 1 mg/kg/h | Analgesic CRI in combination with magnesium sulfate [7] |
| Dog | IV bolus + CRI | 0.5 mg/kg bolus, then 30 mcg/kg/min | CRI during propofol anesthesia [8] |
| Cat | IM | 5 mg/kg | Induction in combination with medetomidine (20 mcg/kg) [9] |
| Cat | IM | 7 mg/kg | Anesthesia in combination with dexmedetomidine (10 mcg/kg) [10] |
| Cat | IV bolus | 2 mg/kg | Co-induction with propofol [11] |
| Cat | SC | 0.5 mg/kg | Sub-anesthetic analgesic dose for acute abdominal pain [12] |
| Horse | IV | 2.2 mg/kg | Anesthetic induction dose (standard equine formulary) |
| Rabbit | IM | 20 to 40 mg/kg | Anesthetic dose in combination with xylazine or midazolam (standard exotic formulary) |

The doses above are drawn from specific studies and standard formularies. The dog CRI doses in particular vary widely depending on whether ketamine is used alone or in combination with other analgesics. When ketamine is part of a multimodal protocol with lidocaine and an opioid, the ketamine dose is typically lower (0.6 mg/kg/h) than when it is used as the primary analgesic (1 mg/kg/h or higher).

### Dog dosing details

In dogs, ketamine is often used as part of a combination CRI. A common protocol is a loading dose of 1 mg/kg IV followed by a CRI of 0.6 mg/kg/h, combined with lidocaine at 3 mg/kg/h and either fentanyl or sufentanil [5][3]. This combination is used for painful surgeries like total ear canal ablation and mastectomy. The ketamine component contributes to the analgesic effect and reduces the amount of inhalant anesthetic required.

A lower dose protocol uses a 0.5 mg/kg IV bolus followed by a CRI of 20 mcg/kg/min (which equals 1.2 mg/kg/h) [1]. At this dose, heart rate increased over the first four hours of infusion, and mean arterial pressure increased at the 40 mcg/kg/min dose. Behavioral changes such as stereotypical head movements and twitches occurred within four hours at the higher dose.

A study of low-dose ketamine CRI (0.5 mg/kg bolus, then 10 mcg/kg/min) in conscious dogs found that ketamine reduced temporal summation of repeated nociceptive stimuli but did not affect the threshold for a single stimulus [4]. The authors concluded that low-dose ketamine CRI cannot be recommended as a sole analgesic in dogs. This is an important limitation: ketamine works best as part of a multimodal plan.

### Cat dosing details

In cats, ketamine is frequently combined with an alpha-2 agonist for IM anesthesia. A study of 573 cats in a spay-neuter program used medetomidine (20 mcg/kg) and ketamine (5 mg/kg) IM for induction, with maintenance via intermittent IV boluses of ketamine (2.5 mg/kg) and diazepam (0.125 mg/kg) [9]. This protocol provided effective anesthesia for spay and neuter procedures.

Another study used ketamine (7 mg/kg) combined with dexmedetomidine (10 mcg/kg) IM for orchiectomy in cats [10]. Heart rate was lower during anesthesia compared with baseline, and hypertension was observed intraoperatively in all groups. The quality of recovery was low in all groups, but no side effects were reported.

For analgesia in cats, a case report described three subcutaneous doses of ketamine (0.5 mg/kg each) in combination with an ultrasound-guided transversus abdominis plane (TAP) block for acute abdominal pain from pancreatitis [12]. This protocol improved the response to medical treatment and shortened hospitalization. The authors noted that ketamine, which is mostly indicated for somatic or chronic pain, can be considered as an alternative for visceral pain in cats that are unresponsive to opioid-based protocols.

### Horse and rabbit dosing

Horse doses are from standard equine formularies. Ketamine is commonly used at 2.2 mg/kg IV for induction of anesthesia in horses, often in combination with a benzodiazepine or an alpha-2 agonist. The cardiovascular stimulation from ketamine is beneficial in horses, which can become hypotensive during induction.

Rabbit doses are from standard exotic animal formularies. Ketamine is used at 20 to 40 mg/kg IM in combination with xylazine or midazolam. Rabbits are prone to stress and respiratory compromise during handling, so IM injection of a ketamine combination is a common approach for induction. The high dose reflects the lower sensitivity of rabbits to ketamine compared with dogs and cats.

## Constant Rate Infusion Protocols for Pain Management

A constant rate infusion (CRI) is a method of delivering a drug continuously at a steady rate, usually via a syringe pump or infusion pump. The goal is to maintain a stable plasma concentration of the drug, which provides consistent analgesia without the peaks and troughs of repeated bolus dosing. Ketamine is well suited to CRI because its analgesic effects are dose-dependent and it has a relatively short half-life.

### Why use a ketamine CRI?

Ketamine CRI is used for two main purposes. First, it provides intraoperative analgesia, which reduces the amount of inhalant anesthetic needed and improves cardiovascular stability. Second, it provides postoperative analgesia, which reduces the need for rescue opioids and improves patient comfort. The opioid-sparing effect of ketamine is well documented. In one study of dogs undergoing spinal surgery, the addition of a medetomidine CRI to a ketamine-based protocol significantly reduced fentanyl requirements [13]. The median fentanyl dose was 0 mcg/kg/h in the medetomidine group compared with 3 mcg/kg/h in the saline group.

### Common CRI combinations

Ketamine is rarely used alone as a CRI. The most common combinations are:

- **Ketamine-lidocaine-opioid**: This is the most widely used CRI combination in dogs. A typical protocol is ketamine 0.6 mg/kg/h, lidocaine 3 mg/kg/h, and either fentanyl 5.4 mcg/kg/h or sufentanil 0.72 mcg/kg/h [5]. A loading dose is given before the CRI starts. This combination is used for painful surgeries like total ear canal ablation, mastectomy, and orthopedic procedures.
- **Ketamine-lidocaine-dexmedetomidine**: This combination adds dexmedetomidine (1 mcg/kg loading dose, then 1 mcg/kg/h) to the ketamine-lidocaine mix [2]. Dexmedetomidine provides sedation and analgesia, which can reduce the need for opioids. In one study, dogs receiving dexmedetomidine-lidocaine-ketamine required less ephedrine for hypotension than dogs receiving fentanyl-lidocaine-ketamine [2].
- **Ketamine-magnesium sulfate**: Magnesium sulfate is an NMDA antagonist like ketamine. A study in dogs undergoing tibial plateau leveling osteotomy used ketamine (0.5 mg/kg bolus, then 1 mg/kg/h) with or without magnesium sulfate (50 mg/kg over 15 minutes, then 15 mg/kg/h) [7]. The combination was evaluated for synergistic analgesic effects.
- **Ketamine-fentanyl**: This combination is used for analgesia in dogs undergoing mastectomy. A typical protocol is ketamine 0.5 mg/kg bolus then 20 mcg/kg/min, with fentanyl 20 mcg/kg bolus then 5 mcg/kg/h intraoperatively and 2 mcg/kg/h postoperatively [14].

### Practical considerations for CRI

When setting up a ketamine CRI, the veterinarian must calculate the dose rate carefully. A study of an iatrogenic ketamine overdose in a dog illustrates the risk. A 3.7 kg dog was inadvertently placed on a ketamine CRI at 67.6 mg/kg/h instead of the intended 0.2 mg/kg/h [15]. The dog received 270 mg/kg of ketamine over four hours and developed tachycardia, hyperthermia, anisocoria, and hypoglycemia. The dog recovered over 18 hours with supportive care. This case highlights the importance of double-checking dose calculations and pump settings.

The CRI should be discontinued gradually rather than abruptly. Abrupt discontinuation of a ketamine CRI can lead to a return of pain and possibly to emergence delirium. Some protocols taper the CRI over 15 to 30 minutes before stopping.

## Side Effects and What to Do About Them

### Emergence delirium

Emergence delirium is the most well-known side effect of ketamine. It is characterized by excitement, muscle tremors, vocalization, and sometimes hallucinatory behavior as the animal recovers from anesthesia. The exact cause is not fully understood, but it is related to the sudden return of sensory processing after NMDA receptor blockade.

Emergence delirium is reduced by benzodiazepines. Diazepam or midazolam given at the end of the procedure or during recovery can smooth the transition. The combination of ketamine with a benzodiazepine for induction also reduces the risk because the benzodiazepine provides muscle relaxation and sedation that counteracts the excitatory effects of ketamine.

In cats, recovery quality after ketamine-dexmedetomidine anesthesia was described as low in one study, but no side effects were reported [10]. The low recovery quality scores may reflect the dissociative nature of ketamine recovery rather than a true adverse event.

### Cardiovascular effects

Ketamine increases heart rate and blood pressure. In healthy animals, this is usually well tolerated. In animals with pre-existing tachycardia, hypertension, or cardiac disease, ketamine can worsen the condition. A study of ketamine CRI in healthy conscious dogs found that heart rate increased over the first four hours, significantly at one hour in the 20 mcg/kg/min group and at four hours in the 40 mcg/kg/min group [1]. Mean arterial pressure was significantly increased at two hours in the 40 mcg/kg/min group compared with the 20 mcg/kg/min group.

A study of ketamine CRI during propofol anesthesia in dogs found that cardiac index, stroke index, and peripheral vascular resistance index were not significantly different between the ketamine group and the control group [8]. Left ventricular systolic and diastolic function were also not significantly different. This suggests that ketamine does not impair cardiac function when used at the studied dose (0.5 mg/kg bolus, then 30 mcg/kg/min) in healthy dogs under propofol anesthesia.

### Intracranial pressure

Ketamine increases intracranial pressure. This is a concern in animals with head trauma, brain tumors, or other conditions that increase ICP. The mechanism involves increased cerebral blood flow and cerebral metabolic rate. In animals with compromised intracranial compliance, even a small increase in ICP can be dangerous. Ketamine should be used with caution in these patients, and only if the airway is secured and ventilation is controlled.

### Behavioral changes

At higher doses or with prolonged infusion, ketamine can cause behavioral changes such as stereotypical head movements, twitches, and nystagmus. In the study of ketamine CRI in conscious dogs, these changes occurred within four hours in the 40 mcg/kg/min group [1]. They were not observed at the 20 mcg/kg/min dose. These effects are usually transient and resolve when the infusion is stopped.

### Respiratory effects

Ketamine generally preserves respiratory function, but it can cause respiratory depression at high doses or when combined with other respiratory depressants. In the cat spay-neuter study, transient apnea was the most common complication, but it resolved spontaneously [9]. Oxygen saturation was lower in cats that did not receive gabapentin premedication, with more cats showing SpO2 below 90 percent in females. This highlights the importance of monitoring oxygen saturation during ketamine anesthesia.

### Hypoglycemia

Hypoglycemia was reported in the dog that received a massive ketamine overdose [15]. The mechanism is not clear, but it may be related to the stress response or to altered glucose metabolism. Blood glucose should be monitored in animals receiving high doses of ketamine or prolonged CRIs.

## Which Animals Should Not Receive Ketamine

Ketamine should be avoided or used with extreme caution in:

- **Animals with elevated intracranial pressure**: Ketamine increases ICP, which can worsen brain injury.
- **Animals with severe cardiac disease**: The sympathomimetic effects of ketamine can increase myocardial oxygen demand and worsen arrhythmias.
- **Animals with hypertension**: Ketamine can further increase blood pressure.
- **Animals with hepatic disease**: Ketamine is metabolized by the liver. Hepatic impairment can prolong the duration of action.
- **Animals with a known hypersensitivity to ketamine**: Although rare, allergic reactions can occur.
- **Food-producing animals in the US**: Ketamine is not approved for use in food-producing animals, and residues may persist in tissues.

The narrative review of tiletamine-zolazepam, a related dissociative anesthetic, notes that its use is contraindicated in cats with cardiorespiratory, hepatic, or renal disease [16]. The same caution applies to ketamine, given the shared mechanism of NMDA receptor antagonism and the reliance on hepatic metabolism.

## Drug Interactions

Ketamine interacts with several other drugs commonly used in veterinary anesthesia:

- **Benzodiazepines (diazepam, midazolam)**: These drugs are synergistic with ketamine. They provide muscle relaxation and reduce the risk of emergence delirium. They also allow a lower dose of ketamine to be used.
- **Alpha-2 agonists (dexmedetomidine, medetomidine, xylazine)**: These drugs are synergistic with ketamine and are commonly combined for IM anesthesia. They provide sedation, analgesia, and muscle relaxation. The combination can cause bradycardia and hypertension.
- **Opioids (fentanyl, morphine, hydromorphone)**: Opioids are synergistic with ketamine for analgesia. The combination is commonly used in CRIs. Opioids can cause respiratory depression, which may be additive with ketamine at high doses.
- **Propofol**: Ketamine and propofol are combined for total intravenous anesthesia (ketofol). The combination provides stable cardiovascular function and profound antinociception [17]. A study in dogs found that ketofol CRI produced a significant decrease in the Patient State Index and a shift to low beta waves on EEG, indicating a deep level of anesthesia [17].
- **Inhalant anesthetics (isoflurane, sevoflurane)**: Ketamine reduces the minimum alveolar concentration (MAC) of inhalant anesthetics. A study in dogs found that ketamine at a loading dose of 3 mg/kg and a CRI of 50 or 100 mcg/kg/min reduced the MAC of sevoflurane [18]. This means that less inhalant is needed when ketamine is used, which reduces the cardiovascular and respiratory depression associated with inhalants.
- **Magnesium sulfate**: Magnesium is also an NMDA antagonist. The combination of magnesium and ketamine may have synergistic analgesic effects [7].
- **Lidocaine**: Lidocaine is often combined with ketamine in CRIs. The combination provides both local anesthetic and NMDA antagonist effects. Lidocaine can cause cardiac toxicity at high doses, so the dose must be calculated carefully.

## How Ketamine Compares with Alternatives

Ketamine is one of several injectable anesthetics used in veterinary medicine. The main alternatives are:

- **Tiletamine-zolazepam**: This is a combination of a dissociative anesthetic (tiletamine) and a benzodiazepine (zolazepam). It is similar to ketamine in its mechanism but has a longer duration of action and is available as a premixed solution. A narrative review notes that tiletamine-zolazepam provides rapid onset of anesthesia, but recovery profiles vary significantly between species due to differing metabolic rates [16]. In cats, it is contraindicated in those with cardiorespiratory, hepatic, or renal disease. In dogs, it is indicated for short procedures or as an induction drug before inhalant maintenance. The review notes that clinical dosages are generally lower than manufacturer label recommendations, particularly for IV administration, which requires titration to clinical effect [16].
- **Propofol**: Propofol is an injectable anesthetic that provides smooth induction and rapid recovery. It does not provide analgesia. It can cause hypotension and respiratory depression. Ketamine is often combined with propofol to provide analgesia and cardiovascular support.
- **Alfaxalone**: Alfaxalone is a neurosteroid anesthetic that provides smooth induction and muscle relaxation. It does not provide analgesia. It can cause respiratory depression.
- **Etomidate**: Etomidate is an imidazole anesthetic that provides cardiovascular stability. It does not provide analgesia. It can cause adrenal suppression with prolonged use.

Ketamine is unique among these alternatives because it provides analgesia in addition to anesthesia. This makes it particularly useful for painful procedures and for patients where pain management is a priority.

## Questions to Ask a Veterinarian

If your pet is scheduled to receive ketamine, you may want to ask:

1. Why is ketamine being used instead of another anesthetic?
2. Will my pet receive ketamine alone or in combination with other drugs?
3. What monitoring will be used during anesthesia?
4. What are the risks of ketamine for my pet's specific health condition?
5. How will pain be managed after the procedure?
6. What should I expect during recovery?
7. Are there any signs of complications I should watch for at home?
8. Is there an alternative protocol if I am concerned about ketamine?

## Clinical Relevance, Limitations and Common Mistakes

Ketamine is a valuable drug in veterinary anesthesia and analgesia, but it has significant limitations. It does not provide muscle relaxation, it increases heart rate and blood pressure, and it increases intracranial pressure. It should not be used as a sole anesthetic for major surgery. It is most effective when used as part of a multimodal protocol that includes other analgesics and anesthetics.

A common mistake is to use ketamine as a sole analgesic for severe pain. A study of low-dose ketamine CRI in conscious dogs found that it reduced temporal summation of repeated nociceptive stimuli but did not affect the threshold for a single stimulus [4]. The authors concluded that low-dose ketamine CRI cannot be recommended as a sole analgesic in the dog. Ketamine works best when combined with opioids, local anesthetics, and other analgesics.

Another common mistake is to underestimate the risk of emergence delirium. Benzodiazepines should be available to smooth recovery, and the recovery area should be quiet and dimly lit to reduce stimulation.

A third mistake is to miscalculate the CRI dose. The case of the 338-fold overdose in a dog illustrates how a simple calculation error can lead to a life-threatening situation [15]. Dose calculations should be double-checked by a second person, and infusion pumps should be programmed carefully.

Finally, ketamine should not be used in animals with elevated intracranial pressure without careful consideration of the risks and benefits. The increase in ICP can be harmful in patients with head trauma or brain tumors.

Individual cases require veterinary judgment. The information in this article is a guide, not a protocol.

## Frequently Asked Questions

### What is ketamine used for in veterinary medicine?

Ketamine is used for anesthesia induction, chemical restraint, and pain management in dogs, cats, horses, rabbits, and other mammals. It is often combined with other drugs for surgical anesthesia and as a constant rate infusion for postoperative pain.

### How does ketamine work?

Ketamine blocks the NMDA receptor in the brain and spinal cord. This reduces pain transmission and prevents central sensitization, a process where the nervous system becomes hypersensitive to pain.

### Does ketamine provide muscle relaxation?

No. Ketamine does not provide muscle relaxation. It often increases muscle tone. Benzodiazepines or alpha-2 agonists are added to provide muscle relaxation.

### Can ketamine be used alone for surgery?

Ketamine is not recommended as a sole anesthetic for major surgery. It does not provide adequate muscle relaxation or visceral analgesia. It is most effective when combined with other drugs.

### What are the side effects of ketamine?

Common side effects include emergence delirium, increased heart rate, increased blood pressure, and increased intracranial pressure. Behavioral changes such as head movements and twitches can occur at higher doses.

### How is emergence delirium treated?

Emergence delirium is reduced by benzodiazepines such as diazepam or midazolam. A quiet, dimly lit recovery area also helps.

### Can ketamine be given at home?

No. Ketamine is a controlled substance and must be administered by a veterinarian. It is given by injection in a clinical setting.

### Is ketamine safe for all species?

Ketamine is used in many species, but it is not safe for all. It should be avoided in animals with elevated intracranial pressure, severe cardiac disease, or hepatic disease. Food-producing animals should not receive ketamine in the US.

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1. [Effects of ketamine constant rate infusions on cardiac biomarkers and cardiac function in dogs.](https://pubmed.ncbi.nlm.nih.gov/29534859/)
2. [Influence of intravenous fentanyl or dexmedetomidine infusions, combined with lidocaine and ketamine, on cardiovascular response, sevoflurane requirement and postoperative pain in dogs anesthetized for unilateral mastectomy.](https://pubmed.ncbi.nlm.nih.gov/38744657/)
3. [Influence of Constant Rate Infusions of Fentanyl Alone or in Combination With Lidocaine and Ketamine on the Response to Surgery and Postoperative Pain in Isoflurane Anesthetized Dogs Undergoing Unilateral Mastectomy: A Randomized Clinical Trial.](https://pubmed.ncbi.nlm.nih.gov/36587868/)
4. [Plasma levels of a low-dose constant-rate-infusion of ketamine and its effect on single and repeated nociceptive stimuli in conscious dogs.](https://pubmed.ncbi.nlm.nih.gov/18706837/)
5. [Effects of fentanyl-lidocaine-ketamine versus sufentanil-lidocaine-ketamine on the isoflurane requirements in dogs undergoing total ear canal ablation and lateral bulla osteotomy.](https://pubmed.ncbi.nlm.nih.gov/32792272/)
6. [Comparison of the effects of morphine-lidocaine-ketamine and fentanyl-lidocaine-ketamine combinations administered as constant rate infusions on postprocedure rectal temperature in dogs.](https://pubmed.ncbi.nlm.nih.gov/31887085/)
7. [Effects of a synergic interaction between magnesium sulphate and ketamine on the perioperative nociception in dogs undergoing tibial plateau leveling osteotomy: a pilot study.](https://pubmed.ncbi.nlm.nih.gov/39539316/)
8. [Effect of a constant rate infusion of ketamine on left ventricular systolic and diastolic function in dogs anesthetized with propofol.](https://pubmed.ncbi.nlm.nih.gov/39617176/)
9. [Retrospective evaluation of preanesthetic oral gabapentin in cats receiving total injectable anesthesia in a high-quality, high-volume spay-neuter setting.](https://pubmed.ncbi.nlm.nih.gov/40187297/)
10. [Ketamine-dexmedetomidine combined with local anesthesia, with or without different doses of atipamezole in the postoperative period, for orchiectomy in cats.](https://pubmed.ncbi.nlm.nih.gov/36459451/)
11. [Effects of using a propofol priming and coinduction with ketamine or S(+) Ketamine on the dose of induction and duration of propofol in cats.](https://pubmed.ncbi.nlm.nih.gov/42035835/)
12. [Sub-anesthetic doses of ketamine associated with TAP block in a cat with acute abdominal pain.](https://pubmed.ncbi.nlm.nih.gov/42155922/)
13. [Opioid-sparing effect of a medetomidine constant rate infusion during thoraco-lumbar hemilaminectomy in dogs administered a ketamine infusion.](https://pubmed.ncbi.nlm.nih.gov/31791743/)
14. [Plasma concentration, cardiorespiratory and analgesic effects of ketamine-fentanyl infusion in dogs submitted to mastectomy.](https://pubmed.ncbi.nlm.nih.gov/35701767/)
15. [Treatment and outcome following substantial ketamine overdose in a dog.](https://pubmed.ncbi.nlm.nih.gov/36874544/)
16. [A narrative review of the clinical applications of tiletamine-zolazepam in canine and feline anesthesia.](https://pubmed.ncbi.nlm.nih.gov/42382112/)
17. [Ketamine-Propofol Coadministration for Induction and Infusion Maintenance in Anesthetized Dogs: Effects on Electroencephalography and Antinociception.](https://pubmed.ncbi.nlm.nih.gov/37958146/)
18. [Effects of intravenous lidocaine, ketamine, and the combination on the minimum alveolar concentration of sevoflurane in dogs.](https://pubmed.ncbi.nlm.nih.gov/18363578/)