Equine Athlete: Week 2-4

Hi again! My summer with the Equine Athlete team has been AMESOME, I am so lucky! We have been travelling a lot, which is an exciting adventure. The only down fall is that I don’t get to see me dog every day. The last few weeks have been crazy, actually every week with them is crazy, that is why I love it! I experienced my first horse show on the other side of things, I use to work and show for an Arabian horse farm for eight years prior to this fellowship. It was an adjustment being on the other side, but I enjoyed it way more! It is so rewarding to be able to follow these horses success and knowing that you (Equine Athlete) were a huge part of that success.

One thing that really jumped out at me these last couple weeks was how common laminitis really is. I know it is mentioned all the time because it is such a serious and common disease but I guess I never realized HOW common it is. We have looked at about 7 different horses with signs of laminitis.

Put simply, laminitis is inflammation of the laminae inside the hoof wall, but there is much more to this. The coffin bone/third phalanx is connected to the hoof wall by the laminae which are folds making the bond between the hoof wall and the coffin bone very strong. If this attachment fails or there is inflammation of the laminae the horse will experience significant pain, due to the coffin bone pulling away from the hoof wall. If not managed properly the coffin bone can continue to rotate and penetrate through the sole.

The cause of laminitis can be complex, horses at high risk of laminitis are ones that have been introduced to lush grass or put on a high concentrate diet, horses with metabolic dysfunctions such as, Equine Metabolic Syndrome (EMS) or Pars Pituitary Intermedia Dysfunction (PPID) and lastly physical causes. Horses that are introduced to lush grass or concentrates can show signs of acute laminitis due to the high amount of sugars that trigger the release of inflammatory mediators from the hindgut resulting in inflammation. EMS is an endocrinopathy affecting horses and ponies. It is characterized by obesity, laminitis and insulin resistance. Obesity can cause high insulin concentrations which then causes vasoconstriction leading to a decreased blood flow to the hoof.  This can then compromising the structures of the hoof. Also the high concentration of insulin can act on the epidermal cells of the lamellar tissue by activating insulinlike growth factor (IGF) receptors. Activation causes the cells to grow and change, causing weakening of the bond between the hoof wall and the coffin bone. PPID is another metabolic factor that can cause laminitis, it is commonly known as Equine Cushing’s Disease. PPID is a dysfunction of the pituitary gland which then causes an increased release of cortisol from the adrenal gland. Increased cortisol can cause vasoconstriction as well, which will limit the circulation to the hoof. Furthermore increased cortisol can lead to insulin resistance causing more breakdown of the bond between the hoof wall and coffin bone like mentioned above with EMS. Physical forces can also cause laminitis, this is seen mostly when a horse is bearing weight on one limb to compensate for an injury on the other limb.

Managing this disease is possible but can be demanding. One of the most important aspects is to maintain an ideal body condition, overweight horses can cause more stress on the hoof as well as cause metabolic dysfunctions. Placing the horse on soft surfaces or in softrides is key to making them more comfortable. Other treatments include non-steroidal anti-inflammatory drugs (NSAIDS), a specific diet and proper shoeing. The diet should include a high forage, low concentrate and limited access to grazing on lush pastures. Lastly it is very important to take periodic radiographs in order to monitor the progression of changes within the hoof.

This is one of the laminitis cases I was able to learn from. This first image was taken 01/29/2018

when first signs of laminitis started to occur. You can appreciate the small separation between the hoof wall and the coffin bone (black space). Also you see the coronary band located near the coffin joint, this is normal. When comparing this image to the one below taken 05/14/2018, the coffin bone is more rotated and is now pushing through the sole. If you look at the coronary band in this image you can see that it is closer to the fetlock joint rather than the coffin joint. This goes to show that if this disease is not treated quickly and properly it can progress rather fast and become a more serious problem.

We are headed to more farms this week for prep work for the upcoming regionals. I will keep you updated on more cases that I find interesting. Stay tuned!

Have a good week,

Katelynn Cox