Sunday, March 27, 2011

My Thoughts from 'Along The Way'

I hope you enjoyed reviewing the assorted collection of images that I have acquired over the past several weeks. As promised, here are some of my thoughts about them.

What's wrong with this picuture? This is way too much ice for the end of March!

I realize the picture quality is not very good on these next two images. I'm not a very good photographer(if you have seen the pictures I take Coggins testing, you already know that). If you look very carefully at the pupils (the black circles in the center of the eye) you would see that this horse looks like he has two pupils in each eye. This is the result of an underdeveloped iris. The condition is called an iris coloboma. It is not really a disease process, but rather a congenital malformation. It occurs with much greater frequency in eyes that have very little pigment (i.e. blue eyes). It is not a painful condition for the horse, but sometimes they have a little diffiulty controlling the amount of light that enters the eye, since the iris cannot function normally. There is no treatment for this condition.

Somewhere down this trail you can't go any futher, but it's a long way away...miles and miles.

Complaint: "I took my horse out for the first ride of the year, and he acted terrible. He kept tossing his head and wouldn't do anything I wanted, so I just decided to put him away. Any ideas?"
If you look carefully at this picture, you will see that the bit has been put on this bridle backwards. The shank portion of the bit is attached to tthe headstall and the reigns are attached to where the headstall is supposed to go. The chin strap is installed as a nose band.

I realize it might be a little difficult to get your orientation with this next picture. Let me explain. This is a view of the inside of a horses mouth (speculum in place holding the mouth open). You are seeing the set of teeth on the upper left side of the horse. This is very old horse. The first tooth, toward the front, is pretty much worn down to nothing. There is just a little stump of it remaining. The next tooth back is still present. The third tooth back is extremely loose and desperately wants to fall out. The forth tooth back is missing, thus just some gum there. The last tooth back, that you can see, is worn down to the gum and does not have any enamel left.

This is what the third tooth back looked like after I 'helped' it fall out. As you can see, there is virtually no living tissue left associated with this tooth. It was just a source of irritation and infection to the horse.

It's definitely not hot, it's not a tin roof, but it is a cat.

This is an 'under the tail' view of a horse with fairly extensive melanomas. In horses these tumors are usually benign (not cancerous) but they can become fairly extensive, as in this case. This is almost exclusively a grey horse disease. There are a number of different options for dealing with these. Again, this is a topic worthy of its own blog posting at some future date...stay tuned.

This is a lateral (side view) x-ray of a horses foot. This horse has, and has had laminitis. The dense white line on the front of the hoof is barium past. We put that on the hoof before we take the x-ray so that we can clearly see where the hoof wall is on the radiograph. Some people use a nail or wire for this purpose, but I firmly believe that barium paste is a far superior hoof wall marker. The nice thing about barium is that it conforms perfectly to the hoof wall, so you can see dishes or changes in countour that would be missed with a rigid wire. Note is this projection the amount of coronary band swelling. You can see it where the barium bulges out at the very top of the hoof (i.e. the coronary band). The front side of the bone inside the hoof (coffin bone)should be parallel to the hoof wall (or barium paste). As you can see in this image they are not. The coffin bone has shifted within the hoof capusule due to a break down of the attachment of the bone to the hoof wall. The bone has shifted as a result of all of the other forces acting upon it. Under normal situations, the laminae work to oppose the force of the deep digital flexor tendon. In horses with laminitis the laminae 'loose their grip,' so the pull of the deep digital flexor tendon 'wins.' This is perhaps an over simplification of the process, but it is in essence what happens.

This is one view from a venogram on a horse that had a very mild case of laminitis. Venograms are definitely a topic worthy of their own posting at some future time. They are an excellent way to visualize the integrity of the live tissues in the horses hoof and to assess how they are being influenced by load and pressure. A diagnosis of laminitis would have been very difficult to make in this horse without a venogram. But because it was identified early, before any rotation or displacement occured, we were able to intervene to take some of the load off of the laminae while they healed. The idea here is to keep the horse from developing any displacement of the coffin bone, rather than come back in a month and see the rotation after it has taken place and at that time say 'yup, he had laminitis.' Early intevention is crucial to sucessful treatment of this disease.

Here is another case of laminitis. The shoes placed on this horse are designed to significantly decrease the pressure tthat the deep digital flexor tendon exerts on the coffin bone and thus greatly reduce the chance for further rotation. They are also ridiculously effective at promoting sole growth. One of the caveats to using these shoes is that it is absolutely imperative that they be applied correctly. Without good radiographs it is not possible to know if they are being used properly or not. This set of radiographs demostrates that quite well. It is very important that the bottom of the coffin bone not be more than 5 degree off of parallel with the bottom of this shoe. The bottom of the coffin bone of most horses is 3 to 5 degrees off of parallel with the ground surface. When horses rotate, the angle the bone makes with the ground surface increases. In horses with a significant amount of coffin bone rotation it can be a challenge to get the alignement just right.

This radiograph is the same hoof after the shoe has been properly aligned to the coffin bone. As you can see in this x-ray the bottom of the coffin bone is now just about parallel with the hoof contact side of the shoe.

As I mentioned previously, this is embryo is 7 days old (the egg was fertilized 7 days ago). I am still awed by the fact that this microscopic structure is a horse. It may not look like one right now, but in 11 months it will running around a pasture.

1 comment:

  1. Hey Deron- Thank you for your very interesting and fun blog! I have gone back to it a couple of times to read it again! Your blogs are awesome...and I appreciate all the time and effort that you put into them. Keep them coming!!!

    Thanks again!