Equine Athlete: Week 9-12

Hello again, sorry I have been away, I forgot my computer while I was on the road the last 3 weeks! These last few weeks have been so crazy!!! Youth Nationals was full of excitement and limited sleep! Before we left for Youth Nationals we did a lot of prep work. During this time I learned a lot about osteochondrosis.  

Osteochondrosis in horses can lead to OCDs and subchondral cystic lesions. OCD stands for osteochondritis dissecans, a growth disturbance that happens in young horses when the cartilage fails to mature properly. The impaired development can lead to loose bone that can either remain partially attached or break off and irritate the joint. This can be caused by many reasons such as rapid growth, improper diet, genetics, hormonal imbalances, and/or trauma and exercise. It is seen more in certain breeds such as standardbreds and warmbloods but it can be seen in any breed. The most common joints that we see this defect in, are the hock, stifle and fetlock joint. OCDs are commonly seen bilaterally, therefore it is critical to examine both joints even if clinical signs are not present. Clinical signs usually include effusion of the joint and lameness but it is not uncommon to have no clinical signs at all. In order to diagnose OCDs, a physical examination, lameness examination and radiographs are performed. We took radiographs of a few horses that had effusive hocks just before nationals and found that they did in fact have OCDs present. Because  we didn’t have the time frame before nationals to get them removed we instead drained the joint and injected steroids to make the horse more comfortable. After they returned from nationals they are planning to get them removed surgically. Many times though, these bone chips do not cause the horse any problem and are left in and/or are never noticed. Although if they decide to surgically remove them, after surgery they are to be put on stall rest for a couple weeks and managed with anti-inflammatory drugs. After two weeks exercise can be introduce gradually and after six weeks they generally are able to return to normal exercise. On the other hand, osteochondrosis also causes subchondral cystic lesions, that are just as serious or sometimes more serious than an OCD. They are similar is the sense that they have the same clinical signs, diagnosis and treatment. These cysts, unlike an OCD are usually unilateral rather than bilateral. It is important to recognize the OCD or the cyst at the earliest stage possible so that it can be treated appropriately so that there is not future problems.

Below are some radiographs that illustrate what an OCD looks like:

 

Also during prep work for Youth Nationals I was able to watch two endoscopic examinations, which I have never seen on a live horse before. The owners of the first horse complained that when he was asked to put his head in a specific position he was making abnormal noises and it seemed that he wasn’t able to breathe properly. With that, we examined his larynx and found that he had a partial left laryngeal hemiplegia, meaning that his left arytenoid wasn’t functioning properly. It wasn’t totally collapsed but it did not open all the way. This type of defect can have the potential to progress and totally collapsed or it could stay the same. There are two different treatment options in this case, a prosthetic laryngoplasty also known as a tie back surgery or a ventriculectomy. The tie back surgery could only be done if the arytenoid was to totally collapse. This procedure ties back the paralyzed arytenoid and permanently holds the cartilage in an open position. Differently, a ventriculectomy removes the ventricle and the vocal cord that is located under the arytenoid which widens the airway and reduces the respiratory noise.

The second endoscopic examination we performed was to recheck a horse that had severe gastric ulcers. The recheck found that the horse had a dramatic improvement due to proper management with a tube of gastrogard daily. A horses stomach is divided into two different sections the squamous or non-glandular portion and the glandular portion. The division between the two is called the margo pilactus, this is where the stomach is most affected by gastric ulcers. The non-glandular portion is another aspect that is commonly affected by gastric ulcers as well because it lacks mucous secretion which protects the epithelium.

A little more about Youth Nationals.. it was a fun and exciting few weeks! I loved being part of the success! Watching the horses that we treated go national champion was so rewarding. My job these last couple weeks was to be in charge of lasering and/or therapeutic ultrasounding horses that needed it before they showed. I did on average 12 horses a day, which was exciting to interact with the different farms and different horses. In the mean time I would help with anything else that was going on such as lameness exams, running fluids, pre-purchase exams, colics, and many other interesting cases.

There were a few horses that had torn their suspensory ligament, which was devastating for them and their rider. But it was an opportunity for me to learn more about ultrasonography and PRP treatment. Dr. Hill’s treatment approach for a torn tendon or ligament is injecting PRP in the damaged area. PRP stands for Platelet-Rich Plasma, which contains protein growth factors that are secreted by platelets to stimulate healing. These growth factors recruit cells to the area which help in the formation of new blood vessels and connective tissue. Without the PRP injected into this area it’s nearly impossible for a tendon or ligament to heal properly. The body does have the ability to produce some new connective tissue but it does not have the ability to organize the fibers in the correct manner. With that, the PRP is able to enhance the healing of the torn/damaged tendon or ligament. This Platelet-Rich Plasma is harvested from the patient’s blood and processed which is then re-injected into the damaged area. It is important that the animal is NOT given any anti-inflammatory drugs after the treatment because it could kill the PRP. Healing a tendon or ligament takes time, these areas have limited blood flow to help in the healing process, even after the PRP treatment. The horses is usually put on stall rest for four to six months, due to the high susceptibility to injury. Every horse is different so it is important to keep track of the healing process by performing ultrasound examinations every sixty days to see what the next step in the treatment plan may be. Aside for the treatment, these cases helped me to become more familiar with ultrasonography. I believe that it is a difficult concept to get down so the more I am introduced the better I became at recognizing different structures. I was able to ultrasound a few of the horses myself, which is harder than it looks and is a skill I need to continue to practice.

I have learned so much this summer and it has made me so excited and motivated to continue to my venture to become a DVM. I have one week left working with Equine Athlete, I am sad that it is coming to an end but so thankful for all the knowledge and friendships I have gained.