Raven's Left Hind Infection and Cellulitis

Thursday this week I went out to feed the horses in the afternoon and found Raven three legged lame with only barely toe-touching on her left hind in her paddock with Daisy.  She was so painful I immediately was concerned that she'd been kicked and something was broken.  

It was rapidly swelling, so I put a pressure bandage on it with no-bows and a standing wrap to try to control the swelling while I waited for the veterinarian to come out.  Thankfully Dr Erwin was able to come out as an emergency call to look at her for me.  He felt it looked more like a cellulitis than trauma, though it was hard to say.  There is a relatively new test that can be done in the field to look for infection and inflammation, called a Serum Amyloid A, or SAA.  A normal healthy horse will have a number of up to 20 mg/L but Raven's was 68.  Not outrageously high, but not normal either.  We decided to use that as a baseline number to see how this progressed.  

I put Raven in the stall in the barn where she could still see her friends but was isolated since she had a fever, and she was extremely lethargic, lame, and dull in affect with no appetite at all.  It was so bizarre to see my hot feisty mare acting like a sedated stock horse.  

This is the treatment sheet from the first two days.  I record vital signs because fever indicates infection (or possibly pain), elevated heart rate can indicate pain, as can increased respiratory rate.  Raven got SMZ tablets for antibiotic, sucralfate to coat her stomach prior to getting bute to try to prevent ulcers.  She is prone to them when stressed and NSAIDS are often a trigger for ulcers to form so I wanted to get ahead of it.  The dexamethasone was to decrease inflammation, omeprazole and outlast for ulcer prevention.  I also have been using the cold laser therapy on her.  The notes section is for any other details about what we did that day and how she was responding.

By the next day Raven's leg was much more swollen, and she was still extremely painful.  Dr. Erwin came out again and we radiographed her left hind to rule out any fractures, and thankfully there were none.  When we repeated the SAA test it was 888 mg/l which told us that it was likely an infection.  It wasn't responding to the SMZ antibiotics I was giving her, so we switched to injectable antibiotics.  One was a long acting drug that lasted for 4 days, so I'll give her that one Tuesday evening as her second dose.  The other was an IV medication that I've been giving her daily.  I was a technician at vet clinics for years before going to training horses full time, so thankfully this is not an issue to have the variety of medications administered differently, and to track all the progress with my treatment sheets.

By Halloween, Raven's leg was looking significantly better.  The swelling had gone down a lot, and she's putting weight on it normally.  Her vital signs are normal, and her feisty and hot attitude is back with a voracious appetite, so I know she's feeling better.  The photos show how much the swelling has gone down as well.  I did switch her to less bute and added in BL pellets (easier on her stomach and have herbal anti-inflamatories, but not as powerful as bute so I didn't start with this).  

I'm so grateful the medications are working, and that I have the laser to use.  It was a good purchase to have in Colorado because of all the PT and rehab I did with horses as referrals from veterinarians there, and it really has made a difference with Raven's leg.  Usually cellulitis like this lasts for weeks, and if it fills the horse's lower leg for an extended period of time a recurrence is likely months later.  To have the swelling go down this quickly with an infection/cellulitis case is unusual.  I do think the laser has affected how well this has progressed.

It is suspected that a recurrence of cellulitis happens because with that level of swelling for an extended period of time in the lower leg, the lymphatic system may be compromised.  If that's the case, the horse is less likely to be able to clear swelling and cellulitis in the future.  To try to head this off I've kept Raven's lower leg wrapped with a standing pressure wrap to prevent pooling of lymph in her lower leg and hopefully preserving the lymphatic system so it will work correctly in the future.  I have also wrapped her right hind at night since it was the main supporting leg.  Keeping it unwrapped during the day allows the skin to breathe and diminishes the likelihood of skin issues.

Hopefully her leg will continue to improve and she'll be back to full turnout and riding again soon.  There's no time constraints on this since we're not currently competing, but it's comforting to know that my friend will likely make a full recovery, and she's improving quickly due to the supportive therapy in addition to the main medications. I'm really grateful to Chatham Animal Clinic and Dr. Erwin for coming out on an emergency call and especially for the attention to detail and follow up.  I love this mare and am so glad she's recovering well from something that was initially very stressful!