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An Urban Experience
WSVA7-0298
DERMATOLOGY
SOTAL - RESPONSIBLE ANTIMICROBIAL USE IN TREATING PYODERMA
T. Nuttall1
1University of Edinburgh, Royal Dick School of Veterinary Studies, Roslin, United Kingdom
RESPONSIBLE ANTIMICROBIAL USE IN PYODERMA
Dr Tim Nuttall
Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Roslin, UK.
tim.nuttall@ed.ac.uk
Introduction
It’s also important to recognise the depth of the infection. Surface and superficial infections are characterised by erythema and pruritus; they do not invade the dermis and often respond to topical therapy. Deep infections show swelling, haemorrhage, draining tracts and pain; they invade the dermis and deeper tissues, and may require prolonged systemic treatment.
Cytology
Cytology is a simple way to confirm bacterial infection. Techniques include adhesive tape-strips, indirect and direct impression smears, and needle cores and fine needle aspirates. Modified Wright-Giemsa stains such as Rapi-Diff® or Diff-Quik® are quick and easy, and reliably identify inflammatory cells and microorganisms. All bacteria that take up these stains appear blue-purple whether they are Gram-positive or Gram-negative. Full identification requires further tests and culture.
Neutrophils predominate in most cases. Macrophages and multinucleate giant cells are seen in chronic and/or deep pyoderma, but large numbers (i.e. granulomas or pyo-granulomas) should alter you to the possibility of a mycobacterial or fungal infection. Lymphocytes, plasma cells and eosinophils are seen in most inflammatory reactions.
Bacterial overgrowth syndrome shows large
numbers of bacteria with few inflammatory cells. Intracytoplasmic bacteria are a definite indicator of infection, but extracellular bacteria may be contaminants. Staphylococci are large cocci that form pairs, fours
or bunched groups. Streptococci, micrococci
and enterococci are smaller and form chains or
irregular groups. Rod bacteria from the skin include Pseudomonas, Proteus and coliforms. Mycobacteria do not take up Wright-Giemsa stains, but pyogranulomatous inflammation with small rod-shaped vacuoles is suggestive.
Bacterial culture and antimicrobial sensitivity testing
Bacterial culture and antimicrobial sensitivity testing is not always necessary. Staphylococci have a relatively predictable pattern of antimicrobial sensitivity and empirical treatment is often successful.
  We must use antibiotics responsibly to preserve their efficacy and minimise the development and spread of resistance. The key steps in responsible antimicrobial use and stewardship are:
• Ensuring the diagnosis - antimicrobials should not be used speculatively
• Selecting an appropriate antibiotic
• Giving it at the correct dose and frequency to clinical cure
• Managing underlying conditions.
Clinical diagnosis of pyoderma
Pyodermas are classified according to their clinical appearance:
1. Seborrhoeic pyoderma (erythema, erosions, exudation without pustules and collarettes): bacterial overgrowth syndrome and intertrigo.
2. Papules, pustules, scaling, focal alopecia: impetigo, bacterial folliculitis and superficial spreading pyoderma.
3. Erosions and/or ulcers: pyotraumatic dermatitis, intertrigo, and mucocutaneous pyoderma.
4. Ulcers and draining sinus tracts: furunculosis (deep pyoderma) and feline chin acne.
5. Nodules and/or regional swelling: abscess, cellulitis and necrotizing fasciitis.
 42ND WORLD SMALL ANIMAL VETERINARY ASSOCIATION CONGRESS AND FECAVA 23RD EUROCONGRESS
  






























































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