Selection of antibiotics for meticillin‐resistant Staphylococcus pseudintermedius: time to revisit some old drugs?

The aim of this review is to consider systemic therapy options for meticillin-resistant Staphylococcus pseudintermedius (MRSP). Infections caused by MRSP in small animals--particularly dogs--have been frustrating veterinarians in recent years. After a susceptibility test is performed, veterinarians are left to select from drugs that have not been frequently encountered on a susceptibility report. Some of these are old drugs that have not been used regularly by veterinary dermatologists. As MRSP is, by definition, resistant to all β-lactam antibiotics, including cephalosporins, penicillins and amoxicillin-clavulanate combinations, the β-lactam drugs are not an option for systemic treatment. As most MRSPs are multidrug resistant, familiar drugs, such as trimethoprim-sulfonamides, fluoroquinolones, macrolides and lincosamides (clindamycin), are also not usually an option for treatment. Therefore, veterinarians are left with drugs such as rifampicin, chloramphenicol, tetracyclines, aminoglycosides and vancomycin to choose from on the basis of an in vitro susceptibility test. Some of these drugs were originally approved over 50 years ago and may not be familiar to some veterinarians. Each of these drugs possesses unique properties and has particular advantages and disadvantages. Veterinarians should be particularly aware of the adverse effects, limitations and precautions when using these drugs. New drugs also have been developed for meticillin-resistant Staphylococcus aureus in humans. These include linezolid, ceftaroline, daptomycin and tigecycline. Although these drugs are very infrequently--if ever--considered for veterinary use, the properties of these drugs should also be known to veterinary dermatologists.     

Evidence-Based Treatment for Laminitis-What Works?

Acute or recurrent laminitis often results in marked structural or mechanical disruption of the hoof with rotation or sinkage of the coffin bone within the hoof capsule in affected horses or those predisposed to developing this complex and devastating disease. A complete knowledge and understanding of laminitis and its complex pathophysiologic cascade remains elusive despite the substantial time and effort that many scientists and clinicians have dedicated over the last few decades. As a result, preventive and therapeutic management strategies remain empirical and anecdotal, with little emphasis on evidence-based medicine. Evidence-based medicine involves integrating individual clinical expertise with external clinical evidence from systematic research to make the best possible decisions regarding patient management. Numerous and overlapping theories have been postulated for the pathophysiology of laminitis. Although beyond the scope of this discussion, the current most commonly discussed theories include vascular or ischemic, inflammatory, metabolic, enzymatic, and biomechanical. In reality, many of these pathways or others yet to be identified are likely involved in the complex cascade of acute laminitis. Substantial focused and relevant research is needed to advance our knowledge and understanding of this complex disease and to develop more effective preventive and therapeutic strategies based on sound scientific and clinical evidence.