A dog MRI scan itself typically takes 45 minutes to 2 hours, depending on the body part being examined and whether contrast dye is needed. But the total time your dog spends at the veterinary facility is longer, usually 6 to 8 hours, because the procedure requires general anesthesia with its own preparation and recovery phases.
How Long the Scan Takes
The actual imaging portion of a dog’s MRI varies by what’s being scanned. Spinal MRI studies typically run 45 to 75 minutes, depending on the spinal region and whether contrast-enhanced images are needed. Brain scans fall in a similar range. Joint or soft tissue imaging can be shorter if the area of interest is smaller and fewer image sequences are required.
Most veterinary specialty clinics estimate 1.5 to 2 hours for a standard MRI exam. That accounts for positioning, running multiple imaging sequences, and any contrast-enhanced images. Each individual sequence takes roughly 2 to 5 minutes, and a full study requires many sequences captured from different angles and with different settings to give the radiologist a complete picture.
What Adds Time to the Procedure
Several factors can push a scan toward the longer end of that range or beyond it.
- Contrast dye: Many MRI studies include a stage where a contrast agent is injected into the vein, followed by a waiting period of about 10 minutes before additional images are captured. This adds both the wait and a second round of imaging sequences.
- Multiple body regions: If your dog needs both a brain and spinal MRI, or imaging of more than one joint, each region adds its own full set of sequences.
- Patient size: Larger dogs require more “bed positions” to cover the area of interest, and each position needs its own set of sequences.
- Motion artifacts: MRI is extremely sensitive to movement. Even small motions from breathing can degrade image quality, sometimes requiring sequences to be repeated or gated to the dog’s respiratory cycle.
Why General Anesthesia Is Required
Dogs can’t hold still for 45 minutes to 2 hours inside a loud, enclosed machine, so general anesthesia is standard for veterinary MRI. Even mild sedation isn’t enough because the slightest movement creates blurry, unusable images. The machine produces loud knocking and buzzing sounds that would cause any awake dog to shift or startle.
A study comparing common anesthetic agents in dogs undergoing MRI found that total anesthesia time averaged around 105 to 120 minutes. That includes the time under anesthesia before, during, and immediately after scanning.
Recovery and Total Time at the Clinic
After the scan, the anesthetic gas is turned off and your dog begins waking up. How quickly this happens depends on the specific anesthetic used and your individual dog. Research on dogs recovering from MRI anesthesia found that most dogs could lift their heads within 5 to 11 minutes after the anesthetic was stopped. Standing took a bit longer, and some dogs were groggy for a while after that.
Even after a dog is on its feet, veterinary staff monitor for any delayed anesthetic effects, nausea, or unsteadiness before sending the dog home. This monitoring period is a significant part of the day. Most veterinary specialty clinics ask you to plan on leaving your dog for 6 to 8 hours total, from drop-off to discharge. A typical schedule looks something like this: you drop your dog off in the morning, the team runs pre-anesthetic bloodwork and places an IV catheter, the scan happens mid-morning or early afternoon, and your dog recovers through the afternoon before you pick them up.
What to Expect When You Pick Up Your Dog
Most dogs are walking and alert by discharge time, but mild grogginess for the rest of the evening is normal. Your dog may be less interested in food, slightly wobbly, or sleepier than usual. These effects are from the anesthesia, not the MRI itself, which is painless and uses no radiation. By the following morning, the vast majority of dogs are back to their normal behavior.
Your veterinarian or the specialty clinic will typically have preliminary MRI results the same day or within 24 hours. In some cases, images are sent to a board-certified veterinary radiologist for a formal reading, which can take an additional day or two.