1.5 years post spay, infection at scar site.

My Labrador was spayed in October 2022 (age 1 yr.). She healed without complications and has been fine since. During a follow-up visit to her vet for something unrelated, her vet noted that there could be an issue with the spay scar site. She noted that there may be a suture that didn't dissolve. To me the site looked unremarkable from any other time I had looked at it post-healing. I kept an eye on it. A couple weeks later, she developed an ulceration at the scar site...less that a dime in diameter. Moderate amount of purulent drainage. Erythema. Obviously infected. I cleaned the wound with Chlorhexidine, applied Neo-Predef powder to the site and took her to the vet the following day. Her regular vet was not in, so my Lab was seen by a vet who was unfamiliar with her. I felt it was important to have her seen immediately, so anyway... The vet took a quick look and said she didn't see any suture material in the wound. The sutures would have dissolved 5-6 months post-op, so we were well past that. She noted that there was a "pocket" and indeed there was when I examined it at home. Very small, much smaller than a q-tip in diameter. The vet started her on Cefpoderm x 14 days and recommended I continue with cleaning and applying the Neo-Predef 3x/day. The vet asked if my Lab had allergy issues. I told her that there were issues when I first adopted her at 1-yr. of age, but changing her food took care of that. Her allergy symptoms consisted of itching, red paws and a couple patches of alopecia on her side. Allergies were not an issue at the time of her being spayed. In her notes the vet stated that there was a pustule with purulent drainage and that the cause of this issue could be a "possible allergy" issue. She told me that after 2 weeks if the wound had not shown positive signs of resolving, we may be looking at surgery to repair the site. She seemed to be in a hurry to move on, so that was the end of our visit. This entire problem came out of the blue. I should also note that there has been no injury to that scar site area...superficial or otherwise. I have been a RN for 25 years and I've treated a lot of complicated wounds on humans...fistulas, tunneling, negative pressure dressings, etc. I know how difficult it can be to resolve these issues. But I have never seen an uncomplicated surgical wound develop a problem after such a long period of time. I have seen some improvement in the wound. Minimal drainage and erythema after 3 days of antibiotics. I'm concerned about the "pocket", as we don't know it's depth or whether there is any tunneling involved. It does appear to be smaller...perhaps closing up some. I would be interested in thoughts from others who may have dealt with this issue. I'm scratching my head over a possible allergy connection. Thanks.

Hello - this sounds fascinating, but as you'll be only too aware, no-one wants their dog to be an 'interesting case.'  Which it is; it seems a very long time for a wound to re-open, so I wonder what has changed in that area.  Was there a known infection? - even a lot of 'abscesses' don't need antibiotics, but of course you've had a vet look which we can't do fron here.  It does sound like a very strange one; we would indeed generally advocate microscopy + / - culture / biopsy for further investigation.

Thanks for your reply, Liz. I agree that a culture would have been indicated. I have emailed the vet to ask why this was not suggested. I should have asked about this at the appointment, but I felt we were getting rushed thru and I just didn't ask. My fault. There was no known infection present at any point pre or post spay. I would have to look thru her records, but I assume she had a course of antibiotics post-op. No complications, no delays in healing. Nothing remarkable. As I noted previously, I am seeing some improvement. Minimal serosanguineous drainage and trace erythema. I will post again when I have anything further to add. Thanks again.  

That's a pleasure.  I message back slightly sheepishly to say what I didn't state (with you being a Vet Nurse and knowing this), but would normally have; that obviously your vet is in a much better place to comment on what they can see and to treat appropriately, than some vet on the internet who has never seen the case and doesn't know the specifics.  I'm sure you're aware that we don't constitute a second opinion.  My key questions might be something like:  1) Is there an infection and 2) Could there be  a tumour, mast cell tumour, foreign material or other unexpected process preventing healing?  I suppose if you were going to sample, there's an FNA vs biopsies conversaiton to be had;  if you were going to pull up a load of mast cells for example, the architecture of a biopsy may be more useful, but there's the cost / procedure / fact it's healing now, to balance.  Again, your vet will be in the best place to say.   Good luck and please let us know how this case pans out!

Thanks. I'm not Vet Nurse, I'm a Registered Nurse. I've treated humans for 30 yrs. I know just enough about veterinary medicine to be dangerous :) There is quite a bit of overlap in some areas though. And no worries, I wouldn't consider your thoughts here to be, in any way a 2nd opinion. We're just bouncing around some ideas here and I certainly appreciate your thoughts. Obviously my dog's vet is in the best position to determine what is going on. The wound seems to be pretty much unchanged from a couple days ago. I would hope that there isn't a cancer at play here...she's only 2 yrs. old, but anything's possible. The possibility of a foreign material has crossed my mind. We've all heard stories about sponges, etc. being left behind. I don't want to think about that! She has 8 days left of her 14-day run of antibiotic. My gut (and years of wound care experience) tells me that this is not going to resolve on it's own. We shall see. Thanks again, I appreciate your thoughts.

For reference, 2 images. It's smaller than my index fingernail. Old scar tissue. There is a hole, or pouch or whatever we want to call it. I have no idea how far it extends.

I'm back to update on this post. After 10 days of Cefpoderm, I wasn't seeing much improvement. Last Tuesday, she was seen by her regular vet. She removed a very small amount of material from the pouch area...not possible to identify what it was. Also removed a small amount of granulation tissue. The pouch was approximately 0.5 in in depth. We changed antibiotics: Clindamycin orally, and Spectramast LC, which I have been injecting into the pouch via syringe. Six days after initiating this regimen I have seen positive changes in the size of the wound and the depth of the pouch. The wound looks much less "angry". We visited her vet today and she was very pleased with the progress. I will continue the current treatments for 10 days and we will see where we are. Her vet has high confidence that this wound will resolve without the need for surgery. Spectramast LC is a cephalosporin typically used to treat mastitis in dairy cattle. I've never heard of it being used with canines, so I found this interesting. Her vet remarked that she had not seen this type of wound scenario, with it occuring a year and a half after an uncomplicated spay surgery and healing. The best explanation we could come up with was that a suture (or part of a suture became walled-off during the healing process, and didn't fully dissolve, creating an abscess that has been festering until it opened up. In any case, my sweet Lab looks to be on the road to recovery. I hope this info will be useful to others.