The irrepressible nature of cats!

National Geographic Program

Airing this weekend, National Geographic's program on unlikely animal bonds.

An Interview with Dr. Frank

Dr. Paul Frank is a Board Certified Veterinary Radiologist, and has been with TVEC since September 2008. Recently we sat down for a conversation with Dr. Frank.

So, tell us, what exactly is a Veterinary Radiologist?

Well, the easiest answer is that I do the same job as a human Radiologist, I just work with different species. The long answer is that a Radiologist helps other veterinarians determine which imaging studies are most appropriate for their patients, helps acquire the images (in some cases), and interprets the images for the other veterinarians. We work with x-rays (radiology), ultrasound, MRI, CT (‘CAT scan’), and nuclear medicine as ways to image the patient. Each modality has its own pros and cons, and radiologists are trained to use them on all different types of species. The American College of Veterinary Radiology (ACVR) has a good website that explains this in more detail. Currently at TVEC, radiology and ultrasound are available in house, and MRI is available off-site.

Wow! I didn’t even know that there was such a thing as “specialists” in veterinary medicine, not to mention Veterinary Radiologists.

Yep, we exist! In reality there are only about 300 Board Certified Veterinary Radiologists in the ACVR (and not all of those are in this country). But there are also Internists, Surgeons, Dermatologists, Ophthalmologists, Oncologists, and on and on. If a medical procedure/test/therapy can be done for people, chances are it can be done for animals. And since many people these days are asking for the same quality of care for their pets as they get for themselves, it only makes sense that there are Veterinary Specialists to help provide that level of care.

When my pet gets x-rays made at my local veterinarian’s office, do they get interpreted by a Radiologist?

Probably not. Considering there are about 52,000 veterinarians who do some form of small animal practice in the USA, and only about 300 radiologists, it’s not really feasible for a Radiologist to review every case. And, General Practitioners are trained in proper ways of obtaining and interpreting x-rays, so it may not even be necessary in many cases. But for those cases that are challenging, or need a second opinion, a radiologist can be consulted. Just ask your veterinarian to submit the images to TVEC and they’ll usually get an answer the day the images arrive, with a written report to follow the next business day. Some veterinarians chose to submit all cases to a Radiologist, similar to the situation in human medicine, because they want the best possible care for their patients. And with the recent growth of the digital imaging in veterinary medicine, many vets can send their digital images to me via the internet (teleradiology), and get an answer sometimes in minutes!

What’s the most interesting species you’ve worked on in the past?

Probably the beluga whales. An aquarium asked me to help them get radiographs (x-rays) of their whales. It was quite an experience. My part was extremely limited, but watching the staff expertly pull-off this complicated procedure (they did much more than just get x-rays) was amazing. Of course, I had never seen any other beluga whale radiographs, so it was hard to really know what was ‘normal,’ but I think we helped the patient a great deal in any case. I’ve also worked with just about everything else imaginable. Birds, huge snakes, fish, lizards, ferrets, rats, all types of barnyard creatures. But my real passion is dogs and cats, and I’m fortunate to be able to really concentrate all of my energies on those two species here at TVEC.

Any interesting cases recently?

Really, people get into radiology for a variety of reasons, but one of the common things is that we like helping other veterinarians. It’s really rewarding to be able to help them make the pets feel better. So the recent case that sticks out in my mind isn’t really all that ‘amazing’ or ‘gee-whiz’, but it’s interesting to me. It was an 11-month-old Golden Retriever who was limping. The local veterinarian didn’t see anything on the x-rays and asked me for a second opinion. I was able to help them find that the pet had panosteitis, a relatively harmless and self-limiting, but painful, condition. As far as the ‘gee-whiz’ factor, it always comes down to ‘animals eat the craziest things.’ It's always fun to try and figure out how much the coinage in a stomach is worth, and I remember one cat that had a big stomach full of the owner’s hair bands. What are they thinking!?

Above, the original image showing a coin in the stomach.

Above, the same image, manipulated to show the details. It's a dime!

Kitty with a stomach full of hair ties/bands.

Thanks Dr. Frank!

Photo courtesy of Lisa Pepin

Photo courtesy of Lisa Pepin

Photo courtesy of Lisa Pepin

Did you know?

September 28, 2009 is World Rabies Day.

"The mission of World Rabies Day is to raise awareness about the impact of human and animal rabies, how easy it is to prevent it, and how to eliminate the main global sources."

Source

A chance to see...

Triangle Veterinary Emergency Clinic recently agreed to help out UNC photojournalism student Lisa Pepin with her class project and allowed her to shoot "24 hours in the life of a clinic".

We'll be posting some of Lisa's work over the next few days, giving you a glimpse of what goes on behind the scenes at TVEC.

Our thanks to Lisa Pepin for sharing her work with us. Good job, Lisa!

Cruciate ligaments: an interview with Dr. Mike Grafinger

Today we present an interview with Mike Grafinger, DVM. Dr. Grafinger ('Graf') is a Diplomate of the American College of Veterinary Surgery and one of the owners of TVEC.

We know that people get injuries to their cruciate ligaments (like athletes who damage their ACL), but we were surprised to learn that dogs suffer the same problems. What are the cruciate ligaments?

Cruciate means "crossed" or "X" in Latin. There are two cruciate ligaments that form an “X-shape” within the stifle (AKA, knee) joint. There main function is to stabilize the knee joint. The caudal cruciate ligament prevents the tibia from caudal instability (tibia moving independently towards the tail), and the cranial cruciate ligament prevents independent movement of the tibia in the cranial direction (towards the head). The cranial cruciate is more commonly injured.

Why is the stifle so likely to be injured?

The knee joint is one of the weakest joints in both dogs and humans because it is composed of multiple ligaments which stabilize it. The elbow and hip joints have interlocking bones and ligaments which make these joints more stable. The femur sits on top of the tibial plateau, while the cruciate ligaments keep it there. Some dogs have a steep tibial plateau (e.g. Rottweilers, Labradors, etc) which can predispose the cranial cruciate ligament to injury. Think of the tibial plateau as a table top and the femur as a ball sitting on top of it. An excessive slope can result in the ball sliding off or down the table which places strain on the supporting cranial cruciate ligament. Eventually the ligament can rupture which results in acute lameness. Other causes of cranial cruciate ligament injury include: excessive internal rotation of the lower leg and hyperextension of the knee joint.

How is cruciate rupture diagnosed?

The most reliable means of diagnosing the injury is to move the femur and tibia in a “front to back” direction to demonstrate the instability. This movement is called the “drawer sign”. Imagine dresser drawers (stifle joint) and pulling one drawer (tibia) partially out. This is analogous to the tibia moving forward independently of the femur secondary to cruciate injury. Also, the tibial compression test is used to determine if the upper tibia will move forward (tibial thrust) when the hock or ankle is flexed. Tibial thrust causes pain when elicited. A positive drawer sign and tibial thrust can only occur once the the cranial cruciate ligament has been ruptured.

Will my dog require sedation for an orthopedic exam or for other diagnostics?

Most often cranial cruciate rupture can be diagnosed while the dog is awake. However if the dog is experiencing severe pain, has very strong muscles, or is uncooperative, he or she may require sedation in to order examine the joint thoroughly. Usually about half of the patients require sedation. Therefore, withhold food from your pet the morning of the appointment.

Your pet will also have specific radiographs taken of the stifle joint and associated upper/lower leg bones. These radiographs will be used to evaluate if there is osteoarthritis in the joint, if there is another unexpected problem in the joint or bones and for potential surgical planning.

How is cranial cruciate ligament injury treated?

Most dogs are very painful and reluctant to use the affected limb, and most dogs require surgical stabilization. Triangle Veterinary Emergency Clinic stabilizes these joints using two different techniques. Extracapsular stabilization is used to stabilize knees in small to medium or less active dogs. A heavy nylon suture anchors the lower femur to the upper tibia simulating the cranial cruciate ligament and alleviating the cranial drawer sign. This technique is performed outside of the joint compartment or capsule (e.g. extracapsular).

A tibial plateau leveling osteotomy (TPLO) neutralizes tibial thrust in larger, active dogs with cranial cruciate ligament injury. This technique involves cutting the bone associated with the tibial plateau and leveling the table so the ball will not slide off the back. Then a plate and screws are used to fix the tibial plateau osteotomy in a flat tabletop position.

Patients who are managed conservatively usually develop osteoarthritis, persistent pain, decreased range of joint motion and are likely to develop meniscal injury if surgery is not performed. The purpose of surgery is to stabilize the joint, alleviate discomfort and to the slow the progression of impending osteoarthritis.

I have heard of torn cartilage. Does this also occur in dogs?

There are two cartilaginous discs called menisci which lie between femur and tibial surfaces. These structures function as shock-absorbers or cushions between these bones. Occasionally the meniscus can damaged because it becomes entrapped between the unstable surfaces of the bone. Entrapment may cause a tear or crushing injury. Injury to the meniscus can be extremely painful. These structures are examined at the time of surgery and are partially or completely excised depending on the extent of damage.

My dog is overweight. Does that relate to injury?

Obesity or excessive weight gain can be a strong contributing factor in cruciate rupture, as well as, exacerbating pre-existing osteoarthritis. The ligament may become weakened because of the excessive force and tension generated with each step. Obesity will also increase your pet’s period of convalescence post-operatively. It will make your pet’s other knee more susceptible to a cruciate injury post-operatively; especially if there is pre-existing osteoarthritis. In fact, dogs with osteoarthritis in the opposite stifle have 50-60% chance of rupturing the cruciate some time in their life. Excessive weight increases this percentage. Therefore, it is strongly recommended to decrease your pet’s caloric consumption prior to surgery and during his/her period of convalescence.

Weight loss can be achieved with prescription diets which are lower in calories and higher in fiber. Also consider feeding your pet multiple smaller portioned meals throughout the day or feeding less during periods of decreased activity (e.g. feed less at night before your pet goes to bed).

What is involved with surgical stabilization for cruciate injury?

As in human medicine, general anesthesia is used to make sure the animal is unconscious for muscle relaxation and pain control. This will involve using a pre-anesthetic analgesic (alleviates discomfort), a brief intravenous anesthetic in order to place an endotracheal tube followed by gas anesthesia for the remainder of preoperative preparation and surgery.

The entire leg is shaved up to the middle of the back. The shaved area is disinfected with surgical scrub and alcohol in preparation for a sterile operating field. Once sterile, the surgeon will perform the operation. Preoperative preparation can take approximately 20 to 30 minutes to perform.

Once in the operating room, the operation takes about 1 ½ hour to 2 hours plus to perform, depending on whether there is concurrent meniscal injury. The animal will have an IV catheter placed and be on IV fluids throughout the surgery and after surgery. He or she will also receive post operative analgesics to maintain pain control. A bandage will be placed over the limb to help reduce swelling and provide comfort. The bandage usually remains in place for about 2-3 days.

What are the risks and complications of cranial cruciate stablization?

During surgery patients are placed on a blood pressure monitor, respiratory ventilator , and a multi-parameter monitoring device to measure respirations, ventilation and heart beat to name a few. The nurse anesthetist is responsible for closely monitoring the patient, managing anesthesia and communicating any concerns to the surgeon. There are risks associated with anesthesia and we do see anticipated side effects to organs including the brain, kidneys, liver, heart and lungs. Occasionally side effects can be life-threatening in critical patients however generally the risk of anesthesia is less than 1 %.

Complications for extracapsular cranial cruciate stabilization include: deep infection of the nylon leader line, crimps or bone, implant failure, fracture of the tibial crest, meniscal injury and/or a superficial infection The most common complication is a superficial infection of the incision line and meniscal injury. Approximately 10-15% of cases will have secondary meniscal injury at some point in their life, which requires surgical intervention.

The complication rate for a TPLO is less than 10%. Complications include: superficial infection, deep infection of bone and implant, patellar tendonitis, tibial tubercle fracture, tibial fracture, implant failure, nonunion of the bone (bone not healing) and/or meniscal injury/impingement. The most common complications are patellar tendonitis and a superficial infection. Both of these can be managed conservatively with medical therapy. Fractures and implant failures are usually attributed to too much activity during his or her convalescent period. Meniscal injury has to be addressed surgically.

Thanks, Dr. Grafinger.

For more information, call TVEC to schedule a consultation with Dr. Grafinger.