Dog MRI: Everything You Need to Know

We’ve all heard of X-rays, and most people will also have heard of a CT scan. But what about MRI? MRIs in humans are pretty common, and they’re becoming more common for our pets. In fact, a dog MRI can be really useful in diagnosing certain neurological problems. 

If your dog needs an MRI, you’ll want to know what to expect, the cost, and the risks associated with it. In this article, we’ll cover all of this and more.

What Is an MRI? 

MRI stands for Magnetic Resonance Imaging. It uses large magnets to create an image of body tissues, by measuring how quickly protons in the body react to the magnet. It is non-invasive, non-harmful, and the most advanced type of imaging we use for dogs and other pets.

While useful for many conditions, MRIs are the diagnostic tool of choice for brain and spinal cord problems. In these conditions, CT scans and X-rays are of limited assistance. X-rays show bones really well, because they absorb lots of radiation, but this means they can’t show an image of what’s inside a bone like the skull. CT scans are similar, as they’re produced by taking lots of X-rays in a circle. 

That’s where MRI comes in – the bone doesn’t block the MRI in the same way. MRIs can also ‘see’ smaller issues – down to 1-2 mm in size – which would be missed with a CT scan. This makes MRIs great for dogs with neurological problems or some cancers where small but significant problems may not otherwise be caught.

Why Do Dogs Need MRIs?

MRIs can theoretically be used to diagnose most problems with a physical cause. However, because the machines are expensive to run, most veterinarians don’t have access to one. That’s why they will try to utilize X-ray or ultrasound for anything they can. 

This means MRIs for dogs are typically reserved for uncovering things that X-rays and ultrasounds can’t – such as the cause of neurological abnormalities like wobbliness, seizures, paralysis, or back pain. 

MRIs usually diagnose:

• Brain problems, such as:
  • Strokes
  • Hydrocephalus
  • Tumors
• Spinal problems, such as:
  • Disc disease
  • Spinal fractures
  • Narrowing of the spinal canal

MRIs may also be employed to diagnose complex joint conditions or abdominal conditions if X-rays or CT scans are not available. Because MRIs can image smaller problems than even CT scans can, they may be used for diagnosing some types of diffuse cancers where small changes can still be significant.

Types of Dog MRIs

MRIs in dogs are usually of the “normal” type. They look at a part of the body and produce an image of it, just like an X-ray would.

You may also come across the term ‘functional’ MRI, or “fMRI.” This is a type of MRI that looks at the brain and watches areas “light up” when they’re in use. It is used with humans to visualize why a patient has speech loss and memory issues, and to help plan brain surgery. 

fMRIs are not generally utilized with dogs. This is because dogs generally need an anesthetic for an MRI, which prevents their brain from functioning correctly. However, there are several studies where dogs have been trained to lie still for the fMRI, allowing research into things like whether an fMRI can predict a good service dog. fMRIs are helpful for research purposes but are unlikely to be recommended for pet dogs.                                                                                                                                                                                                                                                                                                                                        

MRI for Dogs: Risks to Consider

The main risk for a dog MRI is that in order for pups to stay still for it, they need a general anesthetic. MRIs can take an hour or more, depending on what is being imaged, and it’s essential that the animal doesn’t move during this time. 

While all anesthetics carry a risk, your dog’s condition may mean they are more at risk than normal. Your veterinarian will explain all the risks as they apply to your pet, and what they will do to minimize those risks – like running blood tests to check organ function before the anesthetic. 

As MRIs are produced by a giant magnet, some dogs will also be at risk if they have metal in their body. While this is more common in humans, some dogs will have a pacemaker or bone implants that may mean it’s not safe for them to get an MRI. Please make sure your veterinarian knows about any previous surgeries, as this may change whether an MRI is suitable for your dog.

What to Expect During a Dog MRI

If your dog needs an MRI, be prepared to travel to a large hospital and have a long wait while they’re imaged. Your veterinarian will talk about your dog’s individual risks with you before the study – you should be honest about any previous issues or surgeries to ensure your dog is as safe as possible for the procedure. 

When your dog goes for his MRI, they’ll first be assessed by a veterinarian to make sure that the anesthetic will be safe. The veterinarian will give a sedation, followed by the anesthetic. Your dog will have a cannula placed in their leg to enable venous access, and will usually be attached to a fluid bag (drip) to keep them hydrated and their blood pressure normal. 

Once they are fully asleep and stable, your dog will be taken to the MRI suite. They will be put onto a special table that slides into the center of the machine, and will be positioned so the area of interest is central in the machine. They may have a contrast agent injected into their vein – this allows certain areas to ‘light up’ and become more visible on the MRI.

Unfortunately, you can’t stay with your pet while they have an MRI. In fact, nobody will be in the room with your pet unless necessary – usually, all anesthetic controls and monitors, and the computer itself, are outside the room. But don’t worry, your dog’s anesthetist will be able to monitor them using readouts of heart rate, blood pressure, and temperature. 

Rest assured that your dog will be well taken care of and will not know that you aren’t there. Depending on your veterinarian, they may allow you to be with your dog as they come back around from their anesthetic, usually an hour or so later. 

Dog MRI Cost: Understanding the Financials

There’s no doubt that MRIs for dogs are costly. These machines are expensive to buy, expensive to house (they take up a lot of room), and expensive to run. They also require staff with advanced qualifications and extra training, which adds to the cost. Once the anesthetic, blood tests, consultations, and image interpretation are factored in, you’re looking at a pretty hefty price tag. 

So how much is a dog MRI? In the end, dog owners are looking in the region of $2,000 to $5000, depending on their location, their pet, what is being imaged, and what has already been done by their primary care practitioner. 

Pet insurance will normally take care of the cost of an MRI if it’s for a condition they’re covering, but the high cost can sometimes cause pet owners to use up the rest of their insurance money. In this case, credit cards, crowdfunding, and payment programs can all help. If you can’t afford it, you should talk to your veterinarian. They may be able to come up with a less expensive alternative or refer you to a charity clinic that offers a low cost MRI for dogs.