Trying to save a horses eye…

Inspecting the equine eye

Today’s Diary Entry is sponsored by Chart Stables

So this morning at around 6am I got a sms for emergency surgery in the equine clinic, as always there was no indication of just what the surgery was going to be. Jumping out of bed I did an hours reading before then heading down to clinic so that I could be in on the pre-op. Heading into stables i found our equine surgeon talking with our ophthalmologist so realized it was eye related. I then found the patient, a foal that had sustained trauma to its right eye hiding in a stable behind mom.

Now i am not sure if i have written about foals before so I will include a few notes here. When working with foals you tend to also have to deal with mom, this can make it interesting as sometimes mom is not so keen on you touching her baby. Also adding another horse into a procedure just automatically doubles the danger. However to get the foal to go somewhere normally if you take mom the foal will follow, downside here though is that if mum gets nervous or scared then the foal will as well.

Because of this it is sometimes chosen to also sedate mom. So after mom leading the foal onto the scales to get the weight, and then the preparation of drugs it was time for the surgery. Now mom led the foal into the operating theatre, and the foal was positioned so that she would be able to have a controlled fall on the operating table. She was then given anesthetic drugs and carefully positioned onto the surgery table. Careful attention was given to mom during this time to ensure that mom did not freak out when her foal fell onto the table. Mom was then moved back to the stables whilst surgical prep started.

The area around the eye was cleaned and shaved whilst the anesthetic team monitored the foal and the ophthalmologist scrubbed and then prepared her instrument tray for the surgery. Something really important is balanced anesthetic and in this case it was also decided to use local nerve blocks around the eye to reduce the amount of general anesthetic needed. At this point it was uncertain whether the surgery would be to repair the eyeball or to remove it. The first thing the ophthalmologist did was to clean and examine the eye, unfortunately in this case the damaged was too severe and so the decision was taken to remove the eye.

Now this is a relatively simple procedure with several different techniques possible to achieve the goal of removing the eye. In this case because of the trauma what is called a transconjunctival approach was selected. This is where the conjunctive tissue (this is the tissue inside the eyelids) that surrounds the eyeball is cut to release the eyeball from the socket before the nerve and blood vessels are then cut. On this occasion the vessels were not ligated but compression used to achieve hemostasis by filling the empty socket with gauze to apply pressure until the bleeding stopped. A surgical drain was then placed to allow any fluid to drain from the wound. The eyelids were then trimmed to remove the eyelashes before these were sutured shut.

The foal was then taken to recovery. Now this is also different as we do not leave a foal to recover alone but support the recovery with the foal being restrained on the ground until the drugs wear off. Once the foal is reasonably awake we then help the foal to stand and support them until they can stand alone. After this mom is then brought back to be with the foal as this helps reduces stress in the foal.

A vet students (non)summer (part 2) wound healing and foals…

Mom watching over my shoulder during treatment of the foal

Today’s Diary Entry is sponsored by Pet Hooligans

Well after writing part 1 I’ve taken a few days R&R before the start of next semester (which is next Monday!) as its supposed to be the most intense year in the entire course with at my count around 48 hours a week of classes and practical. Now if you’ve not read part 1 you can read it here, if you have then welcome to part 2.

During my time in equine clinics I also got to see some wound healing, now this is something that I have covered in theory through a online webinar however I’d no practical experience at this point in time. Now the body is really good at healing itself (though sometimes incorrectly) if given time, however the changes are so slight that if you see it every day then its difficult to see any progress. To combat this it’s very useful to take photo’s as you go along so that you can compare the difference to a fixed point in time which can sometimes be very dramatic.

Generally with wounds it’s important to consider whether there is any damage to underlying structures which can change the prognosis considerably, and to consider and mitigate the risk of infection. The first wounds I saw were to the back of the hoofs and pastern regions (feet) and one case in particular had concern whether there was involvement of the underlying structures (cartilage etc). These wounds looked very bad initially, however over the next few weeks with regular bandage changes, debridement and treatment these healed very nicely. The bandage used here was pretty complicated yet provided great support to the injury both underneath and around – those these horses were completely confined to stables to prevent further injury!

We then had a new patient arrive in which though I did realise it at the start was going become an amazing learning experience for me. This patient was a 3 week old foal that had got a leg caught (possibly in a barbed wire fence) causing severe injuries. Though primary closure (aka suturing) was attempted this failed due to the tension in the wound and so we moved on to supportive care for healing by second intention (nature). Whilst this in itself was new to me, it got worse with the patient going septic (systemic infection with very high temperature) and so it went from general care to intensive 24 hour care with me at times actually staying overnight. This meant that I had a big learning curve on the different medications that were being used (I will never give a medication to an animal without understand its effects and potential side-effects). This worked for a while however the condition was getting worse so we started to question things, I spent a morning with textbooks working out the actually nutritional requirements including fluid (in a foal this young its a shocking 15 litres a day!) and proposed that we change our treatment quite dramatically which after discussion was accepted. During my time at BSAVA Congress I’ve met some good exhibitors (and equally some bad ones) that have been willing to talk through equipment with me even though I was not planning to spend money with them. One of the things I had been taught was about the fluid pump – no one else around knew anything about this – so I decided to bring this into play meaning that instead of just 100-200ml/hour I could get a rate of 999ml/hour of fluid into the patient instead.

So with a great improvement in the first day with this new fluid protocol (and me actually breathing a sigh of relief that I had not killed the patient with it) we could focus on the other problems. During the time in the stable the patient had developed septic arthritis (inflammation of a joint), and joint lavage had been performed twice to try to clean the infection out. One of the PhD students had done some research so we spent some time reading up on different journal articles with one of the techniques that we both noticed being that of regional limb perfusion. Now basically the theory is that drugs have side effects and the antibiotic we were using was bad for the kidney yet to get the concentration in the joint area we needed a high dose through the body which was bad (medicine really is a balancing act). Now with the regional limb perfusion technique what we did was simply create our own local area by restricting blood flow to the leg, and then delivering the drug directly to the leg meaning that instead of affecting all the body the main concentration was in the area we wanted.

Obviously this had risks as cutting of blood to any area is dangerous, and extremely painful. We used regional nerve blocks along with careful timing for this procedure with the patient sedated and after this procedure the inflammation subsided greatly. During this time we were still treating the original wounds which were healing nicely and we were supporting with a wound medication specifically to reduce the granulation tissue and so promote the contraction of the wound edges. I guess that this case will really be remembered as it’s the first time I’ve worked with a foal, and the first time that a single patient has meant looking after two animals. It really was at times quite unsettling being “watched” by mom…

Mom watching over my shoulder during treatment of the foal
Mom watching over my shoulder during treatment of the foal