Dermatis Recurrentes En Perros

MANAGEMENT OF RECURRENT SKIN INFECTIONS
Rosanna Marsella, DVM, DACVD
College of Veterinary Medicine
University of Florida, Gainesville, FL, USA
Recurrent skin infections have always been a source of frustration in general
practice but now, besides the normal frustration, we are also experiencing a
steep increase of antibiotic resistance which is adding challenge to the
management of thesecases. The resistance could be due to a variety of reasons
including widespread and not always appropriately done antibiotic use. For this
reason, is very important to use antibiotics well, using the right dose, for the right
amount of time, at the right dosing interval. Shorter courses of antibiotics
combined with suboptimal doses allow bacteria to build resistance.
Some antibiotics are alsomore prone to induce resistance and others and in
some cases they can induce resistance to antibiotics that had never been used
before. For this reason it important to consider topical therapy as much as
possible as use systemic antibiotics when really necessary. It is important to
control inflammation in the skin to minimize the conditions that could lead to the
development of a bacterialinfection. As a general rule, superficial pyoderma
should be treated for a minimum of 3 weeks or at least 7-10 days past
resolution of all clinical signs. A narrow spectrum antibiotic should be
preferred over a broad spectrum. Good choices for Staphylococcus would be first
generation cephalosporines, clindamycin, lincomycin. Other good choices would
be amoxicillin clavulanic acid keeping inmind that the dose used for skin
infection is higher than the standard dose (22mg/kg BID vs the commonly used
14mg/kg BID). Third generation cephalosporines are not better than first
generation to kill staphylococcus but can increase the risk for resistance due to
the broader spectrum of action.
Fluoroquinolones should not be used as first line of defense and only used when
really necessaryand indicated by bacterial culture. It is important to remember
that this category of drugs is concentration dependent and not time dependent.
Thus it is best to give one higher daily dose rather than two smaller daily doses in
the attempt to go above the mutation prevention concentration to minimize the
likelihood of antibiotic resistance. For deep infections, the average case would
require6-8 weeks of systemic antibiotic. Treatment should be continued for at
least 4 weeks past the resolution of all clinical signs.
When faced with patients that appear to constantly need antibiotics the first thing
to establish is whether this is a recurrent infection, a persistent infection maybe
because it is a resistant infection. Did the patient ever clear? Do we know this
through a recheck orby owner report? If the patient cleared, how long did it take
to relapse? One rule that I use is the 2 week rule. If it takes less than 2 weeks to
relapse I consider the relapse as a continuation of the previous infection. In most
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Proceedings of the Latin American Veterinary Conference, Lima, Peru - 2012
cases,this is due to insufficient length of the antibiotic course. If it takes more
than 2 weeks, then it could be a new bout if infection. Then the appropriate
question is: why is this happening? Clearly the patient has an underlying cause
that either has not been diagnosed or properly addressed.
Due to the increase of antibiotic resistance we now recommend to culture all
dogs with a chronicantibiotic history even if the infection is just a superficial
infection. In the past we would have assumed that the selection of a
cephalosporin would have been sufficient. Now we need a culture to help us
select the proper antibiotic. Out of necessity, we are also prescribing more
antibiotics like chloramphenicol, which had not been used for a long time. Due to
the infrequent use in the past,...