Our goal is to provide you and your clients with high quality, easily accessible, advanced surgical services at our convenient central Melbourne location. Please feel free to call our surgical service for information or advice on any of your patients requiring surgical care.
Dr. Chris Preston BVSc (hons), MACVSc, FACVSc, DACVS. has advanced surgical training (University of Melbourne, University of California) in many areas of veterinary medicine.
- Orthopaedic surgery (bone & joint procedures)
- Soft-tissue surgery (abdomen, chest, head/neck)
- Reconstructive surgery (wounds, skin procedures)
- Neurology & neurosurgery (spinal procedures)
What sets our surgical referral service apart?
- Surgery is performed by an ACVS board-certified specialist.
- Post-operative patients are supervised by a vet overnight, monitoring for any complications or the need for additional pain medication.
- We strive to provide you and your clients with the most current options for surgical care using the latest techniques.
- We offer minimally invasive surgery (arthroscopy, intraoperative fluoroscopic-assisted closed fracture repair). As in the human field, use of new techniques and equipment allow faster recoveries with less discomfort.
- We take anaesthetic safety very seriously. Our typical patient is monitored by both our specialist, interns and an experienced veterinary nurse using pulse oximetry, lead II ECG, end-tidal carbon dioxide monitoring, body temperature monitoring, and blood pressure monitoring. Many surgical patients are maintained on a mechanical ventilator throughout their procedure to optimize respiratory function. We routinely provide operative and postoperative forced warm air to maintain core body temperature.
- We make patient comfort a top priority. Each patient receives an individualized pain-management plan.
There is always a risk with any surgical procedure. One of the risks is that there will be an anaesthetic complication and something will go wrong .
Modern techniques allow us better control of pain, use of lower general anaesthesia doses and superior patient monitoring. All of the patients at the Pet Emergency & Specialist Centre receive sedation prior to anaesthesia which achieves a calming effect to reduce anxiety. Often we will give the first needle with the pet owner present so that you can sit with you pet for a while before they are admitted to hospital.
All patients receive gaseous anaesthesia delivered in 100% oxygen.
We have state-of-the-at monitors which allows us to look at trends in physiological variables such as:
- Heart rate
- Respiratory rate
- Oxygen delivery to the tissue (pulse oximetry)
- Expired carbon dioxide levels (capnography)
- Electrocardiogram (lead II ECG)
- Blood pressure (oscillometric manometry)
In most cases we combine a local nerve block with systemic administration of pain relief drugs. This is called multimodal analgesia and is modern and effective. Epidural (spinal) injections can be given and provide powerful pain relief for procedures on the hindlimbs (lasting 18-24 hrs).
We also use forced warm air systems to blow hot air onto the patient’s body both during and after surgery to maintain core body temperature. This prevents shivering upon recovery. Patients are more comfortable and recover faster.
The most common cause of lameness (mobility problem) in dogs involves the knee joint. Dogs knee are very similar to human knees and so we as veterinarians have learned a lot about how to diagnose and effectively treat this joint by working closely with human orthopaedic surgeons. The basis of diagnosis involves a thorough physical examination by an experienced veterinarian.
In dogs, the kneecap is called the patella and this can become loose and cause locking of the knee and pain. We call this condition medial patellar luxation (MPL). The problem typically affects both knees and starts early in life. There are four grades ranging from mild to severe. Your local veterinarian should be able to tell you what grade MPL your pup has. Corrective surgery involves realigning the muscle-tendon (quadriceps) mechanism with the central axis of the limb (bone axis). There is an art in consistently achieving success with this surgery. Specialist vets have extensive experience and higher success rates. You should ask your local vet how confident they are with the surgery.
Many larger dogs tear their anterior cruciate ligament (ACL) and develop a loose painful knee. If the problem is not addressed early, a cartilage inside the knee called the meniscus, may also tear causing more pain. 30% of dogs will tear the other ACL within two years of tearing the first one. Arthritis develops within the knee joint if surgery is not performed. Early surgery by an experienced veterinarian offers the best chance of your dog returning to normal levels of activity.
Dr. Chris Preston is regarded as a pioneer of knee surgery for dogs in Australia. He introduced tibial plateau leveling osteotomy (TPLO), knee arthroscopy and knee replacement to this country. TPLO offers a clinical success rate of 95% at Pet Emergency & Specialist Centre. Arthroscopy involves use of small rigid telescopes to look inside a joint without the pain of open knee surgery. It is particularly relevant in dogs as they can be discharged the same day and there is no wound to lick at. Total joint replacement involves removal of worn out bearing surfaces and replacement with a metal-on-plastic artificial joint which removes the source of pain. Please call us for a free DVD on anterior cruciate ligament disease in dogs which we can mail to you.
Blunt motor vehicle trauma is a common accident that results in both limb and pelvic fractures in both dogs and cats. It is always unexpected and stressful to find out your loved one has been involved in an accident and sustained a serious injury. Selected basic fractures in young pups and kittens can be effectively managed with splints and casts provided care is taken to prevent rub sores from developing and the vet is sure that the bone will heal. More complex fractures and those that occur in large and older dogs are best referred to a specialist surgeon for surgical repair. Specialists have expertise, more experience, better equipment and trained assistants. You are able to request referral to a specialist from your regular vet.
It is important to appreciate that each and every fracture is slightly different and that each patient is different in terms of their size, activity and their healing capacity. At Pet Emergency & Specialist Centre, we have suregons who have extensive clinical experience and can apply a range of different implant sstems to any selected case. This means we can provide an optimal surgical solution for your pet. Please call us if you would like to discuss costs of fracture rpeair or would like to find out what the success rates are for surgical repair.
This dog suffered blunt trauma and had an operation to fix a broken thigh bone (bone plate & screws) (please click on each picture to enlarge if you wish to see more detail)
Luxation or disloction of the hip joint is a common injury following blunt trauma such as a car accident. Typically dogs stand with the leg rotated and are not willing to weight bear at all. The 'ball' can displace in different directions and this can affect the surgery that needs to be done. The first step is to relocate the 'ball' back into the 'socket' manually. This requires anaesthesia. A special sling is carefully placed to keep the ball in the socket. Up to 50% of the time this is successful. If the hip develops recurrent luxation, open surgery is required to hold the ball in place - we call this open reduction. The most common technique uses an anchor inside the pelvis to hold strong suture material which passes through a bone tunnel in the ball (Toggle pin technique). The success rate is high (>80%) if pets are exercise restricted after surgery. The ball can alternatively be removed as a salvage procedure, although the function is not quite as good and the recovery process is longer too (excision arthroplasty / femoral head and neck excision). If you have a big dog and the hip has been dislocated for a longer time, a false joint can also be considered (total hip replacement).
Manipulation of a dislocated hip and placement of an Ehmer sling
Open surgical reduction using a metallic anchor (Toggle pin technique)
Step 1: Gait Analysis
Lameness is a common reason for owners to take their dog to the vet. It is always helpful for the vet to have a look at the limp outside with the dog relaxed and walking freely. The next step is to perform a detailed orthopaedic examination looking for pain, swelling and abnormal movement of joints. An experienced vet can often pin-point the problem and recommend x-rays that can help you get a diagnosis. This 8 month old Border Collie from Shepparton had a limp for 4 weeks and we diagnosed shoulder pain during our examination. A bone chip can be seen on the x-ray. This was removed arthroscopically.
Hip dysplasia is a common. heritable malformation of the 'ball-and-sockets' whereby the joints are too loose. Pups typically develop stiffness after exercise and reluctance to play when they are 6-12 months of age. Your family vet can check the hips at the time of vaccination and suggest x-rays to make the diagnosis.
Unfortunately, loose hips tend to deteriorate and develop arthritis. It is often simple to remember that 'tight hips are good hips'. Normally, all of the weight-bearing forces are transmitted across the joint evenly as the surface of the ball and the concavity of the socket match perfectly (both are the same diameter) and there is a large area that is in contact. Dysplastic pups have the ball sliding out of the socket which results in poor load distribution due to a much smaller surface area that is in contact. The cartilage can wear away leaving the underlying bone exposed. This leads to bone-on-bone contact and causes discomfort and inflammation.
Elbow dysplasia is a common developmental problem that affects purebred dogs such as Labradors, Golden Retrievers, Rottweilers, Newfoundlands and other popular large breeds. The term dysplasia means that the joint does not fit together perfectly and this causes a problem inside the joint leading to bone chips (fragmented coronoid process or FCP). These small loose bodies rub the cartilage off the bone surfaces which eventually leads to arthritis. Typically pups develop a minor limp which gets worse after rest and heavy exercise. We look for a ‘head bob’ where the head drops when the normal front leg is in contact with the ground and a head rise when the affected front leg is in contact with the ground. Unfortunately, many dogs have involvement of both legs.
Examination of the leg by an experienced vet should reveal some degree of swelling and discomfort when the affected elbow is manipulated. There is a high correlation between a positive response during the examination process and pathology inside. X-rays of the elbow can then be performed to assess bone structure and see if here is evidence of arthritis developing. We have a modern CT scanner to look at the small fragments that cannot be seen with conventional x-rays. We also have digital radiography to allow further magnification of the elbow structures.
Arthroscopy allows immediate and unparalleled visualization of the internal condition of a joint using a small diameter rigid telescope (2.7mm). The operator learns how to move the telescope around to improve the field of view and see structures more clearly. Bone chips can be removed delicate hand instruments. Surgeons an grade the degree of pathology inside a joint and determine the best course of action from there on. Many younger dogs (6-18 months old) improve after arthroscopic ‘cleanups’ where abrasive fragments are removed prior to the development of advanced arthritis. Typically we record the arthroscopic procedure of your pet on a CD and mail this to your vet so that they have an opportunity to see the problem first hand. This is of benefit to you as your vet is more likely to stay actively involved in the treatment of the arthritis process.
Sliding Humeral Osteotomy
A new and exciting surgical option for elbows that have either not responded to arthroscopy alone or have medial compartment disease (full-thickness loss of cartilage), is a procedure called a sliding humeral osteotomy (SHO). This treatment was developed from the University of California and has been tested in Europe in many clinically affected cases. We make a transverse cut in the shaft of the humerus (upper arm bone), slide the top section of bone towards the healthy side of the underlying joint, and then stabilize the bone using a custom, stair-step plate and screws on the inside of the leg. The bone will heal back to normal strength in 8 weeks. This style of surgery transfers the major compressive forces across the joint away from the diseased side onto the more healthy side. It is a solution that saves the joint offers a low risk option in dogs with moderate arthritis.
Total Elbow Replacement
Elbow replacement surgery involves replacement of worn out parts with a metal-on-plastic false hinge. The implants are stable and only offer bending and motion in one plane. Dogs with severe arthritis and daily disability are candidates for this surgery. Cemented and cementless systems are available so that we can match the implant characteristics to the patient’s bone quality. Owners need to be aware that the recovery is prolonged and requires consistent attention and dedication over a period of several weeks. Excellent results can be achieved with marked improvements in limb use and overall mobility.
Spinal cord disease can cause leg weakness and back or neck pain. There are numerous possible causes such as disc prolapse (bulging disc), trauma (accident), neoplasia (cancer) and inflammation (swelling). Fortunately the most common cause is intervertebral disc disease which can, in most cases, be fixed with surgery.
How would you know if your pet develops a spinal cord problem? Your pet will develop a combination of muscular weakness and ataxia (incoordination) resulting in stumbling and dragging of the feet. If this deteriorates, your pet may not have sufficient strength to stand and walk without your help. You may also notice hunching and alterations in the way they posture (stand) which can be a sign of pain. Other pets will start yelping and whinning if in pain. Look at the nails - sometimes the central toes have worn toe-nails.
The first step in investigating for a suspected spinal cord problem is to have an experienced vet perform a thorough neurological examination. This involves a systemical assessment of each limb, testing reflexes and looking for clues as to the style of spinal cord disease that may be affecting the patient. Further imaging tests which can be helpful include: plain survey spinal radiographs, contrast myelography (dye study), CT & MRI scanning. We can also analyze the cerebrospinal fluid (fluid that bathes the spinal cord).
Position for neck x-ray
Spinal fluid collection
CT - disc herniation
MRI - disc bulge
Neurosurgery (spinal surgery) should only be performed by a registered specialist in small animal surgery. This type of operation needs to be done well to provide the best chance of recovery. The spinal cord is very unforgiving and mistakes during surgery may result in a poor outcome. Dr. Chris Preston received extensive neurosurgical training at one of the world's premier University departments - the University of California, Davis. He has extensive experience in all dteremining if surgery is appropriate for your pet. Excellent results can be achieved in most dogs provided all steps are followed and postoperative care is provided.
What do we do when performing spinal surgery ? If there is a broken neck or back, we can align the bone and stabilize it with implants and the bone will heal. If there is a disc herniation (prolapse) we drill an access hole in the bone (laminectomy) and decompressive (relieve the pressure) on the spinal cord. Sometimes the spine is unstable so we can place implants after decompression to reduce motion. If we are dealing with spinal cord cancer, the treatments are limited to reducing the tumor mass; rarely do we achieve a cure.
The recovery process after major spinal surgery can be prolonged. Clients can experience an emotional roller-coaster as there may be good days followed by bad days. The rehabilitation process begins after surgery with passive limb exercises performed by our veterinary and nursing staff. We offer underwater treadmill hydrotherapy to aid in faster recovery as the bouyancy of water helps reduce the weight passing through the legs. This is available for in-patients but can also be arranged for out-patients too.
There are many reasons for your vet to recommend abdominal surgery and sometimes we need to explore the belly on an emergency basis due to pain, a mass or accumulation of blood. Abdominal ultrasound is available and can help clarify if there is a lump, fluid retention or internal bleeding.
A linear incision is made in the skin and underlying tissues to allow us to open the abdominal cavity and expose the internal organs. The surgeon can then move and examine the liver, stomach, intestines, spleen, kidneys and bladder. Once a problem is found we can then correct it at the same time. The wound is closed by stitching (suturing) the two sides together again. Most cats and dogs recover quickly after this procedure. An epidural injection is given to all patient at the Pet Emergency & Specialist Centre having this procedure.
Laparoscopy involves use of rigid telescopes to explore the belly without opening it. The instruments are placed through small cuts (portals) and the inside of the abdomen is carefully inflated using gas. This allows a quick appreciation of each organ so that we can tell the pet owner if invasive surgery will help or not. Laparoscopy is available at the Pet Emergency & Specialist Centre.
Unfortunately cancer is common in pets and can present in many ways. Some cancers develop throughout the body and require chemotherapy. Fortunately, many cancers can be treated with surgery saving your pets life. Radiation therapy is an excellent way to treat cancer too, but at this time has limited availability in Australia.
Many patients that develop cancer seem OK on the outside. The cancer is often slow-growing and minimally painful. The exception to this is bone cancer which grows fast and causes severe lameness.
The earlier a diagnosis is made the earlier we can start treatment and the better the chances of disease control are.
There are often different treatment options that are available for any particular case. The skill as a vet is to be aware of what can be done and choose the best treatment option in each case.
Many clients are initially hesitant to have their pet undergo extensive surgery when they are not sure if the pet will live past one year. This is a personal choice and we can help you decide by giving you science and support during this difficult time. Often people return and praise us by saying that they were happy to have made the decision to proceed with treatment.
Cancer pain can be effectively managed in most cats and dogs using modern oral medications such as non-steroidal anti-inflammatories and opioids.
Various skin flap and free grafting techniques can be used in the dog and cat to close wounds which are unamenable to simple apposition. Simple closure techniques, including undermining and tension -relieving patterns, should be considered first before more involved techniques are employed. Complex wounds involving large tissue defects and distal limb locations can be managed effectively in many cases with subdermal plexus or pedicle flaps and axial pattern flaps.
A pedicle graft, or skin flap, is a portion of skin and subcutaneous tissue with an intact vascular attachment that is transferred from one body area to another. Properly developed flaps survive because of their intact circulation. Flaps are versatile and have the following uses: covering defects with poor vascularity, improving regional circulation to an area, providing a full-thickness skin surface over areas where padding and durability are essential, giving immediate protection to nerves, vessels, tendons and other structures susceptible to exposure and injury and providing a skin surface with hair growth characteristics comparable to that of the donor area.
Pedicle grafts that incorporate a direct cutaneous artery and vein are termed axial pattern flaps. These flaps have an excellent blood supply and enable to surgeon to create large flaps of considerable dimension. A knowledge of regional anatomy is required to consistently incorporate the desired vasculature when creating the flap. Flaps can be transposed and rotated up to 180° into the recipient wound. For each of the described axial pattern flaps in common use, the donor defect is able to be closed primarily with minimal tension and loss of function. The two most versatile axial pattern flaps are the thoracodorsal and the epigastric flaps which can be used to reconstruct wounds of the trunk and proximal limb wiht their pedicle located at the caudal shoulder depression and inguinal area respectively. Compound or composite flaps are axial pattern flaps that involve two or more tissue types and can be use to provide more bulk than simple cutaneous flaps. Latissimus dorsi myocutaneous flaps have been used to close full-thickness chest wall defects and cover deep olecranon decubital ulcers.
Reconstructive microsurgery refers to the use of an operating microscope and microvascular technique in facilitating reconstruction of difficult wounds. The premise of reconstructive microsurgery involves harvesting autogenous tissue from a body part distant to the wound, transferring that tissue into the wound bed for reconstruction, and reestablishing the transferred tissue's blood supply by microvascular anastomosis of vessels feeding the flap to vessels adjacent to the wound bed. Tissue transferred in this manner are most commonly termed "free flaps". The long-term patency rate of microsurgically anastomosed vessels in dogs is approximately 95% using well established techniques and appropriate instruementation. The major application in small animal surgery is to reconstruct difficult foot and paw wounds where skin flaps are unable to reach distally and for filling tissue defects on the face after ablative cancer surgery.