Vaccine Reaction Case Study

By: Brittany Aanerud, CVT

Presenting Complaint and History
“Goldie” was referred in by a veterinarian from southern Minnesota very late on the night of May 25th, 2011 night. Goldie was given a vaccine in the left hip (superficial gluteal). Eventually Goldie was reluctant to lift her left rear leg during the forward phase of a stride but she was bearing full weight on it. She appeared to be swollen from the injection site down to the hock and the gluteal muscles were hard on palpation. Her initial heart rate was 60 bpm, respiration was 24 rpm, and temperature was 100.9°F. Goldie’s mucous membranes were bright pink with a capillary refill time of 3-4 seconds. Around 2 p.m. (approximately 12 hrs after being admitted) her temperature had risen to 103.5°F.

Diagnostic Workup
As soon as Goldie was admitted to the clinic, blood was drawn to run a CBC, Chemistry profile, and Electrolytes. She also had her left rear leg ultra sounded to find what was causing her so many issues. The results were unbelievable; Goldie had formed pockets of gas that were increasing in size. Even after the pockets were dealt with, Goldie was regularly ultra sounded in order to catch any newly formed gas pockets.

Diagnosis and Discussion of Disease Condition
A swab was taken in one of Goldie’s gas pockets and it was sent to be identified. The results came back as Clostridial Myositis.

Clostridial Myositis is considered a ‘gangrene’ condition. The bacteria thrive in environments without oxygen; they eat away at tissue and produce gas through their life processes. All of this gas accumulates and forms pockets that get larger and larger. If this condition is not caught right away, the bacteria move throughout the body causing large areas of necrotic tissue and gas pockets from head to toe. Horses generally have approximately a 24% chance of surviving such a bacterial attack.

Dr. Borkoski was the treating veterinarian on this case. She informed me that many horses normally do have some form of Clostridium bacteria in their tissues/body and that they can become overwhelmingly populated due to a small lesion or injection. With horses it is very important to give vaccines/injections in the correct areas. With Goldie’s injection being in the superficial gluteal muscle where there is so much tissue, the bacteria thrived and there was nowhere for us to drain her wounds easily, which caused serious tissue irritation.

Treatment Regime
The initial treatment plan was to supply IV fluids, IV antibiotics, probiotics, topical DMSO, and ultrasound on a regular basis. Here is a more detailed list of what was done. Goldie was started on a long list of medications for all of her physical issues. Here is a list of her course of treatments and why they were done.

  • Antibiotics targeted at both anaerobic (organisms that do not require oxygen) and aerobic (require oxygen) bacterial infection.
  • Anti-inflammatory
  • Pain relievers, such as Lidocaine
  • Feet were iced to help with her fever and she was checked with the ultrasound several times to catch any new pockets forming.
  • Elevate (Vitamin E) given as an antioxidant
  • Walked and lounged, keeping her muscles moving to promote healing and push the puss up out of her wounds.

Goldie was slowly weaned off her medications as needed and able. Her last ultrasound was on May 31st and showed no new pockets forming. She was able to go home, 17 days after being admitted, with basic exercise and cleaning instructions.

Prognosis and Outcome
Goldie’s prognosis was initially guarded due to the fact that it was unknown the extent of the gas pockets. However, her prognosis was quickly changed to good as the pockets were only found in the left rear area. In most cases, the gas pockets formed by this type of anaerobic bacteria are not caught soon enough and the pockets are found throughout the body resulting in a terrible death. However, in her case, they were found very early and were dealt with in a speedy manner.

Although, Goldie left before she was completely healed, she is doing great and her owners send pictures to Dr. Borkoski regularly to show her progress of healing. She was a very lucky, special case, and it was amazing to see. Goldie’s case is a great example why vaccinations need to be taken seriously.

Healing Timeline in Pictures
Day 2: May 26th Fresh incisions with Penrose drains inserted and little drainage


Day 7: May 31st Incisions are very sore and there is a lot of drainage

4 5

Day 10: June 3rd Smaller incisions are healing slightly; skin is about to slough


Day 13: June 6th Wounds are being kept open for draining & skin has sloughed

7 8

Day 15: June 8th Drainage is starting to diminish and wounds are closing up

9 10

Day 17: June 10th Large wound is draining; healing is happening inside to out

11 12

Binns, Sarah (DVM), and Jennifer Davis (DVM). “Musculoskeletal: clostridial myositis.” vetstream: definitive veterinary intelligence. Vetstream, Ltd, 2010. Web. 30 Jun 2011. <;.
Borkoski, Ingrid. Personal Interview by Brittany Aanerud. 22 Jun 2011.