Effects of Atropine Injections

[tinab158]

When I picked my female Lab up from being spayed, she had a large, soft bump under her skin behind her right shoulder.  It was approximately 3.5" in diameter and raise approximately 2"...in fact; it looked as though a baseball had been sliced in half and placed under her skin.  It wasn't warm or red.  

I asked one of the vets on staff what it was (he had not treated my dog and I couldn't speak with the one who did), he replied that he had never seen such a thing.  A vet tech who was nearby state that is where they injected my dog with Atropine.  

It was then explained that Atropine was used to reduce salivation during surgery.  The vet advised me to contact them if it had not gone down within a few days.  Within 24 hours it resembled a hockey puck...definitely round but flat, not rounded and raised and still pliable...it was approximately 1/2" to 1" in height.  By the third day it resembled a perfectly round piece of cardboard under her skin...barely raised, but definitely still there and still soft.

I took my dog to another vet approximately 2 weeks later because the cardboard-like disc was still present and now it was hard.  I was prescribed salve in an attempt to keep it pliable and antibiotics...over the next few weeks the skin, hair and a good chuck of flesh slowly unattached itself from my dog.  We were left with a deep "hole" in her flesh for weeks.  We applied antibiotics and kept it clean.  She recovered beautifully,  although she has a hairless scar approximately 3" in length.

In speaking with my new vet, she stated she had never seen anything like it.  Without having seen it, have you heard of a reaction such as this?  Or a reaction such as this with the use of another drug (as in, maybe they injected her with something other than Atropine).

Any information is appreciated.  

[Cliff Redford, DVM]

I too have never seen something like this with atropine but a few times have seen similar lesions due to other injections. I expect that atropine was in fact used and this is either a lesion due to an infection that occurred under the skin from the injection, or knowing how atropine works it is an unusual reaction. On top of drying the mouth, atropine also strengthens the heart, which is the main reason it is used during anesthetics. This effect also effects the blood supply and I am wondering if your dog had a strange reaction to the atropine and it damaged the blood supply to the area which caused the sloughing of the skin. The good news is that the 3 inch scar will shrink over the next 6 months and likely will be about one tenth of that size and hardly noticeable.

[tinab158]

Thank you for your explanation, Dr. Redford.  

In your opinion, would the infection occur immediately?  As the baseball-sized and shaped dome was present when I picked her up from the spaying.  Or is this something that would have occured over the next few weeks?   Either way, you have never heard of such an immediate reaction at the injection site of Atropine?

My dog was spayed in September '09 and we were still working with the open wound in November and December. (it took several weeks for the hard disc-like area to actually start to release from the body.)  In fact, by that time...the damaged area was almost 5" in diameter and perfectly round.  Slowly the hair/skin/flesh lifted from the outer edges working towards the center of the wound, leaving a crater-like area.  I wish I could attach pictures to show exactly how it lifted from her body.

Today, two years and 10 months later, she sports the 3"x1" oval scar.  I would agree with you...over a period of about six months the scar was about 1/10th of it original size.  Luckily, my dog is not vain and the scar doesn't bother her.  :)

PS  The reason I'm asking this question some 3 years after surgery, is I  was never really satisfied with the explanatioin given by that clinic.  Something didn't sit right with me, but it was what it was and my dog was fine after a few months (and a few hundred dollars later).  A couple weeks ago, my Lab started having behaving sluggish and downright icky.  A trip to our new vet detected a mass in her belly.  X-rays, bloodwork, an ultrasound, a CT scan and aspirates later...it was reveled there was an infection in the mass.  The mass was removed 4 days ago.  What was it you ask?  The vet who performed the spaying proceedure left 2 and a half 3"x3" gauze pads inside her belly!  The body walled off the foreign material and it grew to a size larger than a tennis ball!  Ya, I'm not happy with that.