island rehabber
05-17-2013, 08:06 PM
http://www.thesquirrelboard.com/forums/images/icons/icon1.gif ABCESSES IN SQUIRRELS

This thread begins with an excellent post originally contributed by HRT4SQRLS, and is intended to gather as much current information on the diagnosis and treatment of abcesses in squirrels.

I had wanted to start a thread about treating abscesses but had neglected to do it. I thought a dialog about this subject would be useful to find out what antibiotics rehabbers have used in the past and the outcome. Since I have been a member here I have read many threads and have seen many bad outcomes but I wanted to hear about the successes. The person from the UK that IR mentioned that had successfully used Clindamycin further prompted my interest.
I started studying the subject.

For those that are interested, I'll throw out some ideas. Sorry, it might be lengthy and boring to some so you might want to skip this post. It has always been disappointing to me to see squirrels succumb to infections that have gone global. One that particularly broke my heart was Linda's Hammie. Any time a vet will try to help a wildlife baby, I am appreciative because MOST won't even try. When they do try, I would never be one that would criticize their treatment. With that said, I think we all realize that the most of the case studies for treatment of squirrels is HERE on The Squirrel Board. Because of this, TSB needs to 'data mine' the information here to come up with things that WORK and things that DO NOT WORK.

Quinolone drugs (including Baytril) are excellent drugs and they certainly have their place in the treatment of infections. From information here on TSB it is obvious that Baytril or Ciprofloxacin is extremely effective in treating pneumoniae and UTI's ... Not so much with abscesses. When treating an abscess without a culture, you must cover all the possibilities with broad spectrum antibiotics or stack drugs to get full coverage of most organism groups. Infections, like little Dales that have involvement of the head, neck or mouth must have coverage to include all of the 'usual flora' organisms of the upper respiratory tract. All mucous membranes are colonized with normal or 'good' bacteria. This would include the upper respiratory tract, the GI tract and the genital tracts. As long as these organisms stay where they are supposed to, everything is great. When they don't, due to trauma, immunosuppressive or whatever, then big problems develop like the head abscesses we have seen on TSB. As we have seen, they get BAD very fast and are very aggressive and often fatal. It seems most Squirrel vets love Baytril. The problem with Baytril is that mucous membranes are polymicrobial and include anaerobes. Baytril has no activity against anaerobes. Anaeobes are the bacteria that grow without oxygen. That is why they are often found in deep seated infections and deep wounds ... NO oxygen. They are very nasty infections and stink like anything ... even the organism growing in the lab stinks BAD. Anytime a wound smells really foul, I would assume that anaerobes are involved and treat accordingly.

OK, what are the best drugs for treating anaerobes? Clindamycin, metronidazole and to lesser degree Chloramphical. Chloramphenicol is a very broad spectrum antibiotic that includes coverage for anaerobes. I believe it is used in veterinary medicine but it is seldom used in the U.S. for people because of issues with bone marrow suppression and toxicity (aplastic anemia). It is frequently used in developing countries because it is readily available and it is cheap. It is very good for treating the masses because it is very effective but because of the number of attorneys here it is seldom used here. I spoke with an Infectious Disease Docter about it. She said it is commonly used in her country (South America) and is now being looked at again in this country because of the extreme resistance problem we have with bacteria. I believe I have read about rehabbers that have used Chloro. I would love to hear the results. Due to its broad spectrum, it is probably quite effective.

Metronidazole ... The reason I like Metro is because it has a long tract record of being safe for squirrels. It is one of the drugs of choice for anaerobes. This is only my opinion, but I believe that any head, neck or mouth infection should include Metro because it will kill anaerobes that are probably involved as ONE of the players in a polymicrobial infection.

Clindamycin ... I am aware that the WMB book says that it should not be used in squirrels. The poster from the UK indicated that it worked great, as it should because it also targets anaerobes and a host of other Gram Positive organisms that are common in the upper respiratory tract. I wondered why the WMB said NO. From all that I could find it seems the GI issues are the reason. Again, according to an ID doc, it seems Clindamycin got a 'bad rap' because of its association with C.difficile infections. Of course, it does have the potential to cause this problem but it has been determined to be NO more likely to cause C.diff infections than other antibiotics. I was told that Clindamycin is used for treating head/neck infections while Metronidazole is used for treating anaerobes associated with abdominal infections. The anaerobic flora of the mouth (many anaerobic Streptococcus) respond better to Clindamycin, while the anaerobes of the GI tract (mostly anaerobic Gram negative flora) respond better to Metronidazole. I found that all the toxicity studies for Clindamycin were done with rats given high doses for long periods of time. I guess that's the best we can come up with as far as safety because there aren't many studies that use squirrels ... THANKFULLY.

HSMC Kathleen
09-27-2013, 04:50 PM
I have a little one who got an abcess on his nose. The vet tech here at the Humane Society where I work lanced it and gave him Clindamycin. It worked like a charm! I couldn't believe how fast it healed.
Hope his helps.


03-18-2015, 05:48 PM
It has been over a year since this thread was updated so I thought it would be good to add some data/treatment successes that have occurred in the last year.

In the original post from 5/13 the subject of treating anaerobic infections was brought up. The two predominant drugs for treating anaerobic infections are Metronidazole and Clindamycin. At that time there were very few case studies with the use of Clindamycin in squirrels. Metronidazole has been used many times with squirrels so it's safety had already been established. It has been mainly used for its antiprotozoal activity against Giardia. It was also used for diarrhea that failed to respond to other treatments. It also has antibacterial properties and is used as an antibiotic predominantly against anaerobic bacteria.

Any time a wound or abscess has involvement with a mucous membrane and/or a very foul odor, treatment should include coverage for anaerobes. Originally, metronidazole was used successfully for this purpose.

Due to the limited data on the use and safety of Clindamycin in squirrels, it was not widely used. Another factor was the statement in the Wild Mammal Baby book, "Caution: Do not use with lagomorphs, ruminants (deer) or rodents including beaver, porcupine and woodchuck." :) I don't think anyone wanted to be the first to recommend it. I noticed a few cases where Clindamycin had been used successfully in squirrels ... a poster from the UK, the poster in this thread and a few others. Since those original reports, Clindamycin has been successfully used to treat squirrels on TSB so it's safety has been established. I might add that I'm not aware of any serious GI issues with it either. It was tolerated well.

Now that both of these drugs have been established as safe and effective in treating anaerobic infections I wanted to add to this thread the reason why one would be chosen over the other. Clindamycin has a spectrum of activity with a shift towards Gram Positive organisms like Streptococcus and Staphylococcus and of course anaerobes. Metronidazole has a spectrum of activity with a shift toward Gram negative organisms like those of the GI tract. Organisms that colonize the mucous membranes of the upper respiratory tract are predominantly Gram positive organisms including Strep and anaerobic/microaerophilic Strep. Because of this, Clindamycin would be the better choice for treating anaerobic infections involving the head, neck and mouth. If you get a tooth abscess, Clindamycin would probably be the drug prescribed. On the other hand, Methronidazole would be used on an abdominal abscess or penetrating wound of the abdomen for coverage of the anaerobes. Keep in mind that, both of these sources are polymicrobial (many mixed types of bacteria) so often more than one drug would be prescribed to achieve coverage of a wide spectrum of organisms.

Skin is colonized with mostly Gram positive organisms like Staph and Strep. When treating a wound on the body (not associated with a membrane) like an arm, leg, back, etc. you need to include treatment for 'skin type' organisms. Yes, Staph. aureus lives on our skin. While Clindamycin can be used to treat a wound, it's spectrum of activity is too narrow for empiric therapy (treating without a culture). It has no activity against gram negative organisms. This is why Clavamox is such a good drug for treating wounds. It has activity against Gram negative and Gram positive organisms. When there is suspected joint or bone infection, Clindamycin is an excellent drug due to its ability to penetrate bone. It doesn't matter how good the drug is if it can't get to the site of the infection.

Ciprofloxacin is a first generation fluoroquinolone. When it was first introduced in the 80's it had good coverage of both Gram negative and positive organisms. Due to the development of resistance, Ciprofloxacin is now used for Gram negative organisms. It is not used for Staph, Strep (both Gram positive) or anaerobes. Some of the newer fluoroquinolone drugs have broad spectrum of activity but Cipro ... not so much. Because it has limited coverage for Gram positive organisms it would not be a good choice for treating wounds.

It is in logical to conclude that anaerobic organisms would be associated with deeper infections because of the exclusion of oxygen in these wounds or abscesses. This is true but just because an infection is deep or has a closed abscess it does NOT have to be an anaerobic infection. Staphylococcus aureus is a prime example. It is definitely an aerobic organism and it is probable the most common organism associated with closed abscesses and wound infections in general. It will grow without oxygen in a closed abscess. MANY aerobic organisms can grow without oxygen. They switch metabolic pathways from an oxidative metabolism to a fermentative type metabolism and grow very nicely without oxygen. The opposite is not true of obligate anaerobes. They will not grow in the presence of oxygen and would seldom be involved in superficial wounds.

SMZ-TMP (Septra, Bactrim, etc) can be used for wounds but it's activity is very slow. It is also associated with more side effects than other antibiotics. A very positive note regarding this drug is that there is very little resistance to it even though the sulfa drugs are some of the oldest known antibiotics. Because of this lack of resistance, it is an old drug that has found a new niche as the drug of choice for treating uncomplicated MRSA infections.

I think it's important to note that some abscesses can be managed by draining and flushing alone. Also important to note is that antibiotics alone will not eliminate an infection involving a large abscess. Draining the abscess is necessary for the antibiotic to penetrate to the site of the infection.

03-18-2015, 06:12 PM
Thank-you so much for taking the time to give this explanation! It is clear and very easy to understand. Exactly what simpletons such as myself need!:thumbsup

island rehabber
03-18-2015, 06:35 PM
I've printed this out and placed a copy in my WMB book. Patti, thank you SO much for explaining this!

08-27-2019, 11:43 AM
We released a squirrel about 6 weeks ago. He still comes back to visit almost daily.
When he came yesterday, he had two sores. One is on his arm, one is on his chest. Today, the one on his chest is swollen, but it was hard to get a picture.

Would you consider this an absess? Could it be an ant bite? Could this be the result of a fight with another squirrel?

How would you treat it?

08-27-2019, 12:03 PM
If it is swelling up, mostly it is an abscess. You would treat it with antibiotics. Why donít you bring him back in and treat it, then send him back out. If you can hold his arms like that, you can get him in. It might be a nice break for him.

08-27-2019, 12:30 PM
What a cutie. Do you see any lumps anywhere on him that have a hole in the middle? Bot fly larvae can look a lot like an abscess and once they leave, the site looks a lot like an abscess that has burst and drained.