Dustin - Abscess on rear leg

[olorin19]

I am starting a new thread, but the original is titled "Abscess on rear leg".

Recap and update:

Dustin is an adult male, two years old as early August (came into my care 9/15/2014 at 5-6 weeks). Successfully released spring 2015, has lived in my back yard ever since, and while otherwise a wild squirrel, has remained friendly with me, sleeping in nest box during cold/wet weather.

Injured leg first observed 6/24 so bite wound likely at least a few days prior, as it looked nasty by then.
Bite to ankle joint on left rear leg.
Managed to contain him in nest box a few days later.
Surgery to lance/drain abscess on 6/29 and first Convenia injection.
Abscess drained and Convenia injections again on 7/11 and 7/27, started also on Enrofloxacin on 7/27.
Limited improvement from all of this, i.e. joint still large and inflamed, and little or no use of leg in motion, limited use when not moving (resting on it somewhat, scratching behind ear). But where the is life, there is hope.
Started soaking leg in epsom salts on 7/15 with some okay results.
Contacted TSB and started on Clavamox, with ten days twice daily from 8/3 p.m. to 8/13 a.m.
Also started Derma Gel on 8/4, twice daily on area.
Great improvements observed:
Dustin is making extensive use of the left rear leg when running and climbing. By no means 100%, but far more than previously.
He is definitely pushing off with it when running and using it when climbing upwards.
The joint itself (finally) startied to reduce in size. By the end of Clavamox, only slightly larger than the other leg, but nothing like it has been over the previous six weeks.
I have not yet observed Dustin to use the left leg to dangle or descend, at least nothing like he does easily with the uninjured right leg.

Today 8/18, it appears that the joint is getting larger again. I am going to get a good look at it either later this evening or first thing in the morning.

Based on previous expert replies, it would appear that Clindamycin is the possible next step.

Question: If the leg is indeed swelling again, is that enough to where we need to start Clindamycin ASAP? I want to do whatever is best for Dustin. The Clavamox was tough on his gut, and it took 4-5 days on a good probiotic to get his poop to look almost normal again.

Any suggestions? Or anything particular as far as appearance of the joint?

It feels like there may be a scab again, in which case it is likely draining. I have never really seen pus or much obvious discharge, as Dustin licks at the area quite thoroughly. A few days ago, it did not seem like there was a scab. (It is not easy for me to see. The scab is medial, and holding Dustin in a position where I can see is hard solo, and having anyone else present makes him harder to hold, whereas he more or less relaxes with me, at least by comparison.)

[HRT4SQRLS]

I was afraid of that. Because the infection goes back to June and the infection involves a joint, there is the possibility of a bone infection. Clindamycin would be my next choice because of it's excellent bone penetration.

Most bone infections involve Gram positive organisms like Staphylococcus. My only concern is the trend of Staphylococcus developing resistance to Clindamycin. I read an article recently stating around 80% of Staphylococcus were sensitive to Clindamycin. I noted a trend where I work, only 60% are sensitive to Clindamycin. That's concerning.

Even with that in mind, I would still try it. Bone infection are VERY difficult to cure. If they become chronic, they can't be cured at all. A prolonged bone infection causes fibrosis of the tissue (scarring) and antibiotic penetration is reduced.

[olorin19]

I was afraid of that. Because the infection goes back to June and the infection involves a joint, there is the possibility of a bone infection. Clindamycin would be my next choice because of it's excellent bone penetration.

Most bone infections involve Gram positive organisms like Staphylococcus. My only concern is the trend of Staphylococcus developing resistance to Clindamycin. I read an article recently stating around 80% of Staphylococcus were sensitive to Clindamycin. I noted a trend where I work, only 60% are sensitive to Clindamycin. That's concerning.

Even with that in mind, I would still try it. Bone infection are VERY difficult to cure. If they become chronic, they can't be cured at all. A prolonged bone infection causes fibrosis of the tissue (scarring) and antibiotic penetration is reduced.

Thanks as always, HRT4SQRLS

I will contact the vet and get Clindamycin.

[olorin19]

I spoke with the receptionist (vet not in yet) and she mentioned Clindamycin is available either orally or by injection.

Which is preferable? Or should I ask for both?

Thanks!

[HRT4SQRLS]

Oral

[olorin19]

Have bottle of CLINDROPS containing 20 mL
Equivalent to 25 mg per mL Clindamycin
Recommended oral dose is 0.3 mL by mouth once daily
Dustin is approx 1.25 lbs (two year old male, not especially large)

Dosage okay?

And two more questions:

How long on the Clindamycin?
Any point in resuming Clavamox (taken 8/3 - 8/13) concurrently, or has that done whatever it was capable of doing already?

Thanks!

[HRT4SQRLS]

Have bottle of CLINDROPS containing 20 mL
Equivalent to 25 mg per mL Clindamycin
Recommended oral dose is 0.3 mL by mouth once daily
Dustin is approx 1.25 lbs (two year old male, not especially large)

Dosage okay?

And two more questions:

How long on the Clindamycin?
Any point in resuming Clavamox (taken 8/3 - 8/13) concurrently, or has that done whatever it was capable of doing already?

Thanks!
Question for you Olorin19. How difficult is it going to be to dose Dustin? I'll warn you now that Clindamycin tastes nasty so it is unlikely that he will take it willingly. The reason I ask is because of the once daily recommendation. Cindamycin has a fairly short half-life. Because of this (in humans) it is usually dosed 3-4 times a day. I realize that's not possible for squirrels. I would rather see you dose twice per day so the drug level won't drop so low between doses. I think it would give better results.

Typically we have dosed at 10mg/kg for each dose which is a total of 20mg/kg/day when a bone infection is suspected. Your vet is dosing at approximately 13mg/kg/day. The WMB doses at 10-20mg/kg/day. You can stick with the vets dose but personally I would split that amount (0.15ml) and give it twice a day.

I wouldn't give the Clavamox unless you see a failure to respond with the Clindamycin. I would give the Clindamycin for 10 days to start and then evaluate but if infection is in the bone, treatment will take much longer.

[olorin19]

Question for you Olorin19. How difficult is it going to be to dose Dustin? I'll warn you now that Clindamycin tastes nasty so it is unlikely that he will take it willingly. The reason I ask is because of the once daily recommendation. Cindamycin has a fairly short half-life. Because of this (in humans) it is usually dosed 3-4 times a day. I realize that's not possible for squirrels. I would rather see you dose twice per day so the drug level won't drop so low between doses. I think it would give better results.

Typically we have dosed at 10mg/kg for each dose which is a total of 20mg/kg/day when a bone infection is suspected. Your vet is dosing at approximately 13mg/kg/day. The WMB doses at 10-20mg/kg/day. You can stick with the vets dose but personally I would split that amount (0.15ml) and give it twice a day.

I wouldn't give the Clavamox unless you see a failure to respond with the Clindamycin. I would give the Clindamycin for 10 days to start and then evaluate but if infection is in the bone, treatment will take much longer.

I can certainly dose twice daily - that is what I was doing with the Clavamox. Dustin is indoors for now, and I am letting him out (of the cage) to run around before and after work. Dosing him just means that i need to hold him and give him his meds. He does not enjoy this, but it works well enough.

Should I go higher than the 0.15 mL twice daily? From what you write above, it sounds like around between 0.23 mL twice daily would be better. I have 20 mL total, so at that dose there is enough for over 40 days if needed.

We never managed to weigh Dustin. But if Wikipedia's 400g to 600g range is right for an adult eastern grey, I would guess about 500 g. Dustin was a runt who caught up with help from Dad, but he is certainly no more than average size now.

[HRT4SQRLS]

Assuming 500g, at the higher dosing (10mg/kg/dose) the dose would be 0.20ml, so yes, you could go slightly higher than the 0.15 ml.

[olorin19]

Tomorrow (8/29) will complete ten days of Clindamycin 0.20 ml twice daily.

There does not seem to be any swelling in the joint, and Dustin does not seem to be favoring the leg with the remaining exception that he does not dangle from it. Palpating the joint, it does feel a bit different than the other. Perhaps structural damage from the bite, or perhaps from the infection?

So my plan is to complete the ten days, then take a couple days to give him probiotics, then move him to his outdoor cage later in the week when the weather is a bit cooler and less humid. (Dustin will have been indoors for seven weeks at that point.) The outdoor cage is heavy gauge 1" x 2" mesh, and prior to injury, he was able to fly around effortlessly in all directions. So, this will give me a chance to observe his degree of mobility in a more vertical environment, and of course to look for any signs of the infection returning.

Does this seem like a good approach?

[HRT4SQRLS]

Tomorrow (8/29) will complete ten days of Clindamycin 0.20 ml twice daily.

There does not seem to be any swelling in the joint, and Dustin does not seem to be favoring the leg with the remaining exception that he does not dangle from it. Palpating the joint, it does feel a bit different than the other. Perhaps structural damage from the bite, or perhaps from the infection?

So my plan is to complete the ten days, then take a couple days to give him probiotics, then move him to his outdoor cage later in the week when the weather is a bit cooler and less humid. (Dustin will have been indoors for seven weeks at that point.) The outdoor cage is heavy gauge 1" x 2" mesh, and prior to injury, he was able to fly around effortlessly in all directions. So, this will give me a chance to observe his degree of mobility in a more vertical environment, and of course to look for any signs of the infection returning.

Does this seem like a good approach?

It does sound reasonable. There is definitely the possibility of permanent damage to the joint from the initial injury and/or the infection. He will adapt to it. My only concern is smoldering infection in the bone. You'll know for sure when you discontinue the AB. If there is lingering deep seeded infection it will flair back up. At that point, the only option will be 4-6 weeks of AB. If things remain stable.. no redness, no limping... you should be good to go. Let's hope for the best.

[olorin19]

Dustin finished ten days on Clindamycin on 8/29
After two days on probiotics, Dustin moved to outdoor cage evening of 8/31
As of tonight 9/3, it will have been five days off the antibiotics
His mobility seems fine. While not using the left rear leg to dangle, he certainly uses it to climb up the cage walls (1" x 2" heavy gauge wire), run around, etc.
I see no sign of decline in his mobility over the past five days. Dustin remains quite active, glad to be back outside, and eager to be released.

While I will need to get him out to really have a proper look, the ankle joint does not seem at all red or obviously swollen.
It might be slightly larger than when he stopped the antibiotics, although the best way to tell will be palpation.
Since the injury is more obvious medially, it has never been easy for me to hold him in a position that also allowed me to see it.
But I palpated it thoroughly twice daily for over a month when giving antibiotics, epsom salt soaks, etc., so I have a good sense of size, texture, etc.
It does look like there is still a scab.

My question is basically this: Is the absence of obvious red inflammation and significant swelling after say a week off antibiotics sufficient to release him? Or should there be no swelling, no scab, etc.?

While I am cautiously optimistic, I would rather be safe than sorry as far as releasing him. This time of year, he may not sleep in his nest box once released, so it might not be all that quick to bring him back inside if the infection flairs back up after release. When I first saw the injury in late June, I had to wait four days before a thunderstorm made him use the nest box in order to corral him.

[HRT4SQRLS]

Olorin19, it does sound like things are heading in the right direction.
I agree with your assessment. It would a real shame to have fought this battle since June and for lack of an additional week or so, the battle might need to be started over again. I would observe for the obvious signs of returned infection. I would like to see the scab gone before he's released to ensure there is nothing under it that could spark a 'wildfire' if you know what I mean.

Any obvious 'new' swelling of the ankle will be problematic but I doubt you will ever get back to a completely normal size and feel of a normal ankle so I wouldn't necessarily use that as a release criteria.

I'm guessing that your friend is pretty happy to be in the release cage after all this time. As long as he is OK there and not pacing and thrashing about with potential to re-injure the leg I would hold him a bit longer and wait for the scab to come off. I think you should be able to tell a lot from the fresh tissue under it when it becomes visible.

Also, he might be more streetwise now. He might not be so easy to catch the next time. :rotfl

[olorin19]

Dustin had diarrhea - watery w/ mucus - which I had not seen before. His gut seemed good when he went out Wednesday. So I brought him back in today for more probiotics, and managed to get a photo of the leg with the help of my son.

The red area that is lower and to the left has been an active spot all along. The other one (according to my son) was not there when photos were taken a month ago.

Does this look like there is still infection, or is this more superficial?

277597

[olorin19]

277630277631277632

Here are photos from today. The area where the scabs were seems smooth, and there is no obvious sign of inflammation or swelling.

Because his gut is still a bit off, and because the highs will be in the low 90s and high 80s this week, I am going to bring him back inside in the morning before work, then when I get home give him more probiotics and derma gel then back outside overnight.

Any comments on how the leg looks are much appreciated in advance - thanks!