I can’t believe
how quickly the past few weeks (and the majority of the summer) have blown by
so quickly! I got a later start out here
than I would have liked because I was in Washington DC doing the Smith-Kilborne
project, which was also a great and insightful experience. The first few weeks out here have involved a
lot of ICU training as well as learning who the doctors, techs, and assistants are
(there are 21 veterinarians including interns as well as techs and assistants
for each), where everything is located, and learning the general routine here. The majority of the work that I have done so
far has been in the ICU, although my schedule is changing now to include days
of observing and assisting with surgery as well as working with veterinarians
here in the field. One thing that I love
is that every Monday morning, there is a staff meeting with case presentations
and discussions of relevant current topics.
The first few
weeks in the ICU had some slow days, so I was able to go watch procedures and
workups in the exam rooms in the main part of the clinic. I feel like such a nerd being so excited
about seeing diseases and conditions that we learned about in vet school, but I
have gotten to see some really interesting cases lately! My third day here, I came in partway through
a procedure where they were doing a local block on a horse’s croup/hip area and
oddly, started seeing bubbles coming out of the horse’s skin as the needle was
removed. As I heard the attending vets
discussing the information about the presentation and history of the horse,
such as that it had received an intramuscular injection in that location a few
days prior, I realized that this horse had clostridial myositis and they were
preparing to do surgical fenestrations in the skin at that location.
As a refresher
for what clostridial myositis is…clostridial bacteria (commonly Clostridium perfringens type A, which is
a Gram negative anaerobe) can either be inoculated or lie dormant in muscle
tissue as spores. They can convert to
their vegetative, or active, form if there is sufficient trauma or irritation
to their surrounding environment of skeletal muscle. When that happens, they often release gas in
the local tissues (so you may feel crepitus upon palpation) and can release
some potent exotoxins that can potentially cause a systemic toxemia in the
horse. Although cases of clostridial
myositis are frequently associated with intramuscular Banamine injections, they
can also be caused by other intramuscular injections or even simple tissue
trauma.
Fortunately,
clostridial myositis is relatively uncommon.
Surgical fenestrations are necessary to perform because the bacteria
must be exposed to oxygen in order to destroy them and combat the infection. Prior to making incisions, the attending vets
used ultrasonography to evaluate the extent of the infection so that they could
determine where the cuts would need to be placed. The underlying tissues were also debrided and
the horse was later put in the ICU to be monitored and recover with IV
potassium penicillin, supportive care, and daily wound cleaning and
debridement.
The following
day was another light day in the ICU so I came up to the clinic later in the
day to observe and help with more cases.
A horse came in that had a high fever and was acting “off.” He had been turned out with other horses, and
had been bitten on the shoulder about 5 days prior to coming into the
clinic. The majority of his right side
was uneven looking and he had ventral edema down his right side. Again, crepitus could be palpated dorsally on
this horse and after the shoulder wound was evaluated with cytology,
clostridial myositis was again diagnosed.
The infection was more extensive in this horse and spanned from his
shoulder to the end of his abdomen from about ¾ of the way up dorsally down to
his ventrum. Again, he was evaluated via
ultrasound and was treated with surgical fenestrations, lavage, potassium
penicillin, and also gentimicin because his white blood cell count was
lower. A major concern with treating
horses with clostridial myositis is the potential complication of laminitis as
a result of the systemic toxemia, so these horses were also placed in ice boots
and Easy Rides (as well as having received general supportive care) and
fortunately had no major complications.
I have also
gotten to help with lameness and prepurchase exams both at the clinic and on
farm calls and have had the opportunity to observe some interesting
surgeries. The most interesting one so
far has been a carpal arthroscopy, not because they are very uncommon, but
because it was the first time that I have been able to see an equine surgery
that wasn’t performed as a standing procedure.
The arthroscopy was successful, and a large osteochondral fragment was
removed from the horse’s carpus that had been lodged between the distal radius
and the radiocarpal bone. I learned how
to recognize fibrillated cartilage and full thickness erosions, and Dr. Devine
then finished the procedure by performing microfracture on the full thickness
erosions to help stimulate fibrocartilage growth.
There have also
been many, many colicky horses that have come in. Two horses were also treated that came in
with a rectal tear, but unfortunately both had to be euthanized despite great
effort to save them. That lead to a very
useful discussion during the staff meeting on diagnosing the presence and
extent of rectal tears and complications, a review of treatment methods, and
good practices to help reduce the risk of causing one.
Overall, my
first two weeks have been a blast and I am excited to continue learning from
everyone here! Everyone has been very
kind and helpful, and I feel like I’m finally starting to get the hang of
things around the clinic. There has also
been a fair bit of turnover lately because the old interns just finished up
their year here and the four new interns have recently arrived. Also, new externs arrive every two weeks, so
that has been a good chance to meet and mingle with other vet students from
other schools. I have learned a
tremendous amount in my first few weeks already and am looking forward to
continuing to learn and contribute here for the rest of the summer!
-Calli
