MRI frequently asked questions

What is the MRI procedure?

The initials MRI stand for magnetic resonance imaging. During the procedure, a strong magnet exerts a unique effect on the limb placed within the magnetic field. This magnetic effect on the tissues is measured and computed into images that allow excellent visualization of tissue abnormalities in both bone and soft tissues.

Why is an MRI necessary?

This special imaging technique allows us to evaluate the structural relationship between soft tissues and bone in the same image. Radiographs typically evaluate only bone, while diagnostic ultrasound looks primarily at soft tissues such as tendons and ligaments. MRI gives exceptional detail of both types of tissue simultaneously. MRI is a focal imaging modality. It is used to zoom in on one particular area of the body rather than image a large region. Additionally, MRI provides the ability to look at structural anatomy in areas that previously have been inaccessible with other imaging techniques. MRI has given us a completely new window into the structures of the foot, improving our diagnostic and treatment capabilities.

Is MRI painful?

Because MRI is a noninvasive diagnostic technique, it is not painful. The horse is given only a light sedative to minimize motion during the procedure and to ensure safety for the horse and technician. Neither the horse nor people feel any sensation when near the magnet.

How is the procedure performed?

On arrival the MRI technician will examine the horse. A catheter is then placed in the jugular vein for use during sedation. The front or hind shoes must be removed depending on whether a front or hind limb is being imaged. The metal in the shoes will degrade the quality of the image if in close proximity to the magnet. The horse is positioned so the area of interest is within the center of the horseshoe shaped magnet. A series of exams called sequences are produced, which form pictures of the anatomy of the limb. A repetitive clicking sound is heard while the sequences are being produced.

How long does it take to perform an MRI?

Appointments are scheduled Monday through Friday at either 9:00 a.m. or 1:00 p.m.
Approximately four hours should be allocated to image one area of the body. This allows time for preparation of the horse and feet as well as acquiring the images. The horse should arrive at least one hour prior to the appointment time the day of the procedure and may leave the same day unless scheduled for other procedures.

What should I bring to my appointment?

Please bring your horse's medical history, radiographs, and reports from previous exams. The radiologists may wish to review these documents before interpretation of the MRI images. We want to provide you with the most comprehensive evaluation possible so the more historical information you can provide, the better. We work very closely with your regular veterinarian to make sure an accurate diagnosis is reached. You should also be prepared to provide leg bandages, blankets, and instructions for feeding your horse should an overnight stay becomes necessary. On occasion, further diagnostics are warranted so your horse might have to stay overnight in order to allow time for additional procedures.

How do I find out the results of the MRI?

Please allow up to three working days for the radiologists to review your horse's medical history and to interpret the MRI images. Your veterinarian will receive a written report of the interpretation as well as a copy of the exam. Our clinic veterinarian will discuss the case with your regular veterinarian who can then provide you with the necessary follow-up treatment and long term recommendations.

Nuclear Scintigraphy frequently asked questions

What is Nuclear Scintigraphy?

Nuclear scintigraphy is a very sensitive diagnostic procedure that helps pinpoint areas of bone remodeling and inflammation. Nuclear scintigraphy is a broad, regional imaging tool and gives the veterinarian general information about where the problem is located.

How is the procedure performed?

The procedure involves the injection of a safe and short acting (24 hr) radioactive material, technetium99, which is temporarily selectively taken up by bone that is actively remodeling. On arrival, the imaging technician will examine your horse.A catheter is placed in the jugular vein for sedation and technetium administration.

Your horse is positioned in front of a large gamma camera and the soft tissue (pool phase) images are collected immediately following injection of the technetium. The radioactive technetium is a low energy beta emitter so the gamma camera reads the energy and then the computer translates the information into a picture. Following the pool phase, the horse is returned to its stall for two hours to allow time for the isotope to be taken up by the skeletal system. Following the two-hour break, the bone phase images are collected.

How long does the procedure take?

The procedure typically takes five hours (including the two-hour up-take time). The horse should arrive no less than one-hour prior to the procedure time and must stay over-night.

Can I visit my horse during the over-night stay?

Yes, you may visit your horse. However, for your safety, you will not be allowed into the stall until at least 24 hrs has passed since your horse's injection.

What should I bring to my appointment?

Please bring your horse's medical history, radiographs, and reports from previous exams.You should also be prepared to provide leg bandages, blankets and feeding instructions.


What can I expect at my horses dental appointment?

Your horse's dental appointment may take up to 60 minutes depending on what we find during the oral exam.
 The first part of the procedure is to perform a complete oral exam. We use a dental head lamp, mouth speculum, mirror and various probes to perform a thorough inspection of the mouth of your horse.

Sedation, a complete oral exam can only be performed using sedation to relax the horse, and the use of a mouth speculum to have an unobstructed view of the dental arcades. Sedation is also given to help ensure the safety of both the horse and those involved in the dental procedure. The amount and type of sedation given is based on consideration of your horse's weight, age, breed, health and disposition. Care is always taken to administer the least amount of sedation necessary to perform the treatment.

The dental treatment plan for each horse is based upon the findings during the oral exam and consideration is always given to your horse's health, age, competitive discipline and dental history. 

Certain dental imbalances cannot be fully corrected at one appointment, and a return visit usually in six months time, may be necessary.

There is the occasional horse, especially older horses and those with pre-existing dental pathology, that may experience slow eating for a day or two post-procedure. If deemed necessary your horse may be given an anti-inflammatory (Banamine or Bute) at the completion of the procedure. Based on the exam findings, other recommendations may be discussed with you by the veterinarian in charge of the case. 

Your horse should be rested for the remainder of the day after the appointment, yet may return to regular work the following day. 

You will receive a dental chart documenting the exam findings, procedure details, as well as our follow up recommendations, including when your next dental appointment is due. This chart is sent to you and also placed in your horse's permanent medical history records. We may also take photos to document your horse's exam. 

A staff veterinarian will contact you regarding the need for any non routine follow up care.

What facilities/equipment are needed to perform dentistry in the field?

 A quiet, shaded area with a strong overhead beam/pole to suspend the dental halter is a necessary work space. If an overhead beam/pole is not available, please let us know and we can bring a portable headstand that can be used in place of the dental halter 

Electricity supply within 100 feet of the work space (we use a variety of instruments for dental maintenance that require electricity) 

Water supply

It is very helpful if you provide us before the appointment any history of dental issues, mouth or bridle problems you may be experiencing, or abnormalities you may notice in your horse's eating behavior 

Please let us know of any health problems, allergies, or behavioral issues your horse may have



Dr. Natasha Werpy, DVM, ACVR is available for imaging consultation and is able to perform advanced ultrasound examinations at the SDEG clinic. Dr. Norm Rantanen, DVM, ACR is also available for imaging consultation on a more limited basis.

Equine Orthopedic Services

Orthopedic Evaluation

The lameness examination involves a combination of historical information from the client, visual examination of the horse in motion, musculoskeletal palpation and manipulation, and variably using diagnostic blocking and advanced imaging to determine the source of pain or decreased performance. If a problem is diagnosed, SDEG can provide numerous therapeutic treatments and will design a lay-up and rehabilitation program specific to the horse's injury.

Pre-Purchase Examination

Comprehensive examination prior to purchasing or leasing a horse is essential for identifying underlying health conditions that may exist in the horse you are thinking about buying or leasing. The pre-purchase exam is tailored to the clients needs and can include advanced imaging, baseline blood work and drug screening, and consultation with our boarded specialists, if requested.

Orthopedic Surgery

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Orthopedic Hospitalization and Layup

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Shockwave Therapy

Shockwave therapy is a therapy commonly used for treating lameness as a result of osteoarthritis in horses, although it does not alter the course of the disease. Shock wave therapy has also been shown to aid in expiditing the healing process with soft tissue injury such as tendonitis, suspensory strain, and lumbar myositis.

Theraputic Ultrasound

Therapeutic ultrasound machines work by converting electrical current into high frequency acoustic energy waves. Ultrasound waves typically can travel one to five centimeters into the body’s soft tissues. The deep penetrating waves allow heat to travel further into the patient’s tissue. This allows small vibrations of cells to change the tissues permeability, and diffusion rates. This often results in a decrease in inflammation and bruising, leading to a more comfortable recovery with decreased healing time. Therapeutic Ultrasound is an effective treatment for both chronic and acute injuries. At San Dieguito Equine we have five therapeutic ultrasound machines that are available for weekly or monthly rental.

IRAP Joint Therapy

The use of IRAP is an effective intra-articular treatment for joint disease. The IRAP system has been designed to stimulate the horse's own white blood cells to produce anti-inflammatory mediators and enzymes that can reduce the inflammation present as a result of degenerative joint disease. Initially, the patient's blood sample is collected and brought back to our clinic for processing, typically taking 24 hours. After processing, the IRAP is ready to be used, however additional treatment doses may be stored at our clinic for up to one year. When injected into a joint, the protein rich serum stimulates a regenerative response from cartilage cells, through a process of cell division and increased cell recruitment. This is actually what sets IRAP apart from other intra-articular treatments for joint disease. The fact that IRAP stimulates cartilage cells means that it has a disease-modifying component as well as an anti-inflammatory component. The serum also contains cytokines that act to reduce inflammation within the joint. In addition, there are other anti-inflammatory proteins produced during the incubation process that work synergistically with the cytokines to further reduce the inflammation within the diseased joint. The injection process is typically done under sedation at the patient's field location.

Platelet Rich Plasma (PRP)

PRP is a treatment used for tendon and ligament injuries.The collection and preparation of platelet rich plasma is simple, non-invasive and takes only about 30 minutes. Blood is collected from the horse's jugular vein and then spun down in a centrifuge; this allows the blood serum to be separated from the rest of the red blood cells. The process of spinning the serum is then repeated to leave only the platelets concentrated at the bottom of the sample. The excess serum is removed and the platelets are re-suspended to be injected under ultrasound guidance into the injury site. This process is performed at our clinic and the horse is sedated for the duration of this treatment.

Bone Marrow Derived Stem Cell Therapy

Stem cell therapy is most commonly used for tendon and ligament injuries. Stem cells have the potential for mass replication due to being non-specific to a local area in the body. This feature allows stem cells to differentiate into different types of cells in response to their local environment, i.e. where they are injected into. The process of harvesting stem cells includes sedating the patient and collecting bone marrow from the sternum. The bone marrow and nutrient rich serum that is collected and then sent to the laboratory for isolation and culture. The laboratory process of culturing stem cells results in a significant increase in the number of stem cells in a concentrated preparation. Culturing of stem cells typically takes about 7-10 business days after which the stem cells and nutrient rich serum can be injected back into the patient at the injury site. Typically, the injection is done under ultrasound guidance to assure the most accurate delivery of the stem cells to the injury site.

Advanced Diagnostic Imaging

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) uses strong magnetic fields and radiofrequency pulses to produce images with superior bone and soft tissue detail. Our low field system allows us to acquire images of the distal limb in the standing, sedated horse. We do not have to put the horse under general anesthesia. We gather images in multiple planes allowing the radiologist to precisely locate the cause of the problem. Depending on the temperament of the horse, the exam usually takes about 3 hours.

MRI is an exciting technology as it allows us to diagnose lameness causing injuries that show few or no abnormalities with other imaging techniques like radiographs or ultrasound. For more information about what to expect if your horse has an MRI at our clinic, please see the frequently asked questions page.

Nuclear Scintigraphy

Nuclear scintigraphy, commonly called a bone scan, is a diagnostic procedure used in lameness cases. It involves i.v. administration of a radiopharmaceutical to the horse. The horse is then returned to its stall. While in the stall the radiopharmaceutical accumulates in areas where bony remodeling is actively occurring. We then gather information using our gamma camera and can recognize areas of injury where there is more "uptake” of radiopharmaceutical than normal. This type of imaging is especially useful in diagnosing injuries that are difficult or impossible to visualize with radiographs or when the horse has a multi-limb lameness. The imaging process takes approximately 3 hours to complete and an overnight stay is required to ensure adequate elimination of the isotope from the horse’s system. For more information about what to expect if your horse has a bone scan at our clinic, please see the frequently asked questions page

Digital Radiography

Digital radiography allows for detailed diagnostic studies of bone pathology with consistent image quality. Images can be seen immediately as there is no film that needs to be developed. SDEG utilizes the Eklin portable DR system at the clinic and in the field. Preliminary review of the images can happen in the field. However, final interpretation is made on our high quality monitor at the clinic. At your request, we can save all radiographs on a CD for your records.


Ultrasound is a valuable imaging tool used to visualize soft tissue structures in the horse. Joint, tendon, and ligament injuries can be diagnosed and monitored using this modality. It also allows for evaluation of thoracic and abdominal organs for horses with suspected systemic illness. SDEG has portable ultrasound units in each ambulatory vehicle and a large hospital unit at the clinic.


Both portable and videoendoscopy are available at SDEG. Evaluation of the upper respiratory tract is possible out in the field. Our 3-meter endoscope allows examination of the stomach and aids in diagnosis of gastric ulceration and other disorders. The exam can be recorded and saved on a CD for you, if desired.


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Equine Wellness Management


Acupuncture involves the placement of thin, sterile, stainless steel needles at specific points on the body where nerve bundles penetrate fascia, in close proximity to major blood vessels that are surrounded by small nerve bundles, and where nerves enter or exit muscles. Insertion of acupuncture needles (dry needling) results in a local and systemic response by the nerves in the region. Local effects cause release of anti-inflammatory substances, improve circulation, and activate the immune system and tissue repair.

Acupuncture is performed by a veterinarian certified in veterinary acupuncture. Acupuncture is used to treat acute and chronic musculoskeletal injury, improve the general well being of athletic horses, and provide additional systemic support for horses suffering from a broad range of medical conditions, such as gastrointestinal, kidney, liver, or lung disease.

Dr. Maureen Kelleher of San Dieguito Equine Group is a Certified Veterinary Acupuncturist available for acupuncture appointments.


Animal chiropractic focuses on maintaining and restoring the health of your animal's nervous system through identifying vertebral subluxation complexes in the spinal column and extremities and performing the appropriate adjustments. Your horse will be examined in static and dynamic motion. Hands are used as the tool to assess the amount of motion/restriction in joints, spasm of muscles, flexibility, asymmetry, etc. 

When a joint is found to have decreased motion, a specific, low amplitude, high velocity thrust (ie: adjustment) is performed. This in return restores appropriate communication between nerves in the nervous system. Animal chiropractic may be used as an integrative treatment for many musculoskeletal conditions, such as back, sacroiliac and neck pain. Depending on your horse's history and examination, a period of rest may be recommended post treatment. A plan for future examinations will be discussed at the appointment if needed. Some equine athletes are maintained on a monthly schedule while others may be examined once to twice yearly. 

Dr. Rebecca James performs chiropractic at San Dieguito Equine Group. She completed training for Animal Chiropractic at Options for Animals and was certified in Animal Chiropractic by the International Veterinary Chiropractic Association (IVCA).


If you think your horse may have an eye issue, please call our office immediately.  With many eye issues, the sooner a proper diagnosis is made and treatment started, the better the chance of a successful outcome.  We are here 24/7/365 and consider all eye issues possible emergencies.  Eye Care for Animals is available for advanced ophthalmology cases and consultations can be scheduled at the San Dieguito Equine Group clinic in San Marcos, CA.

Advanced Performance Dentistry

Annual dental examinations and routine teeth floating are essential to early recognition and management of dental problems that can affect digestion, body weight, and performance. SDEG provides power dentistry based on individual horses' needs for preventative maintenance, to correct dental abnormalities and to maintain proper functioning. 

Wellness Ambulatory Services

General wellness management is essential to maintaining your horse’s health and performance. SDEG is committed to providing general services such as vaccines, deworming, nutritional consultation, annual examinations, insurance examinations, Coggins testing, and travel certification. We have a highly dedicated team who understands how to appropriately develop a wellness management plan for your horse, as every horse is different.