Injecting an internal blister under the skin and deeper into the muscle or along various structures like tendons and ligaments have been well a plied
tradition throughout the racehorse business for years and years. Only in the last 20 or so years has this practice seemed on the verge of extinction. I always had very good luck injecting my sore racehorses with a 2%
iodine injectable for many years and until the advent of RVI injections (Rubeola Virus Immunomodulator) developed by the Eudaemonic Corporation, I would inject iodine by the case in my shedrow. The United States'
FDA took McKay's Maxlin Injection off of the tack shop shelves in the mid-1980s and as far as I know, it never returned. Shame! .
McKay's was produced to be used for strains & sprains of muscles, tendons, and ligaments in horses. It was
formulated with 2% iodine USP in an almond oil NF base or sometimes peanut oil in earlier versions. It was very
useful stuff and seemed to help in the healing of very hard to treat anatomical injuries often characterized by limited
blood circulation. McKay's was a must for rear-end lameness of all types and I would often use two 50cc bottles on a horse in one setting, injecting 2-3cc per site throughout the major gluteal muscles. This was some times knows as injecting the whirlbone. I have also used this injectable to treat bad stifles by injecting the three patellar
ligaments. I would put about 1-2cc on each side of each ligament.
I have seen a number of miracle recoveries using such a protocol. You would inject a horse and immediately
take him to the track for a work which would help distribute the injected solution. A good sign the next day would be how sore your horse was. The sorer he was, the better the results!
I know it says on the bottle's instructions to only inject under the skin, but one can and often do deep muscle
injections. Howeer, avoid hitting a vein or nerve. I have injected cases of this stuff over 15 years while I trained racehorses and this was how I did it:
1) Fill a bucket with very hot-to-the-touch water and place the vials of McKays you plan to inject in it to
allow the almond oil base to warm up, reducing oil viscosity. Much easier to inject warm oil that way. I also throw in a bottle of isopropyl alcohol to warm that up, too.
2) When you get ready to inject, I would advise injecting your horse before a morning work. After injection, take animal out and work normally.
3) Take the isopropyl alcohol and rub down all of the regions you plan to inject. I only inject 1-2cc per
site so one 50cc vial should give you about 25 separate injection sites if you are injecting the rear-end musculature. I give intramuscular injections from the bottle for the heavy rear-end muscles, not the
recommended Subq. You can also hit the tradtional accupuncture points of this region. I fill a 12cc syringe full of the warm fluid and take a 19 or 20 gauge needle in my right hand and pound my target site with my
bare hand (needle protected from insertion) a few times and then the third time down, I move the needle in
place and stick the horse rather than inserting the needle first time off the bat into a new site. This seems to
trick the horse in not knowing when an actual injection will occur. Once the needle is in the muscle (1-1.5"
deep), I take the filled syringe (usually being held in my mouth) and aspirate it slightly to see if blood is
drawn into the neck. If no signs of blood, I continue the injection of 1-2cc per site of the iodine solution. I
do this all along the injection pattern on the rear-end. I mostly use one bottle per side. You want to stay away from injecting to clsoe to the spinal cord on the top mid-line or other major nerves and veins.
5) With stifles, I usually place 1cc on each side of the ligaments, subcutaneously injected.
6) After, injection, I gave a very deep muscle massage to try to work the iodine/oil into the muscles. You
can use rubbing alcohol or a liniment of some type to facilitate this post-injection massage.
7) Once injected, take the animal out for a normal work. This tends to work the iodine into and around the muscle even more.
8) I have found that the sorer the animal is the next day the BETTER! Some of my most successful cases
were with horses that could hardly walk out of the stall the next morning as compared to those that walked out normally.
Internal blisters (2% iodine in almond oil) are rather hard to come by in these modern times. In the past, anyone
could buy McKay's over-the-counter at any tack shop. No more. About the only way you can procure some is via a vet's prescription to a specialized compounding pharmacy. In my book, A Racehorse Herbal
, I will show you how you can make your own with proper sterile technique and lab equipment.
Dr. Borthwick writes about using a similar injection for a bad stifle:
"First, I palpate the three patellar ligaments: the medial, the middle and the lateral patellar ligaments. I inject 5cc at the site
where these ligaments meet over the tibeal tuberosity. I then inject 5cc at each of the three sites where the ligaments originate
from the patella. The 15cc (from each of the three injections sites) over the patella are concentrated at the site of origin but
some is infiltrated over the surfaces of the patella. I then infiltrate 5cc at the site of the lateral femoro-tibial ligament over the
lateral femoral condyle. The remaining 20cc I use to infiltrate the muscle mass around the stifle. I use 4cc per site in five sites
starting a few inches above the point of the stifle and make an arc over the lateral side and above the stifle joint. I then take
another 50cc vial and repeat this procedure on the other leg. Following the injection, the horse should then be worked. This
would be a four or five mile jog for a standard-bred or even a training mile. A riding horse should be saddled and ridden for 25-30 minutes with intermittent walk and trot, depending on the horse's condition."