Page 43 - WSAVA2017
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Specimens for culture should be taken from pustules. If pustules are not found specimens may be taken from pus beneath crusts, and from papules or epidermal collarettes.
Contact with owners should be maintained to promote effective compliance and to determine if and when failure to respond to treatment, or recurrence, occurs.
Topical antimicrobials (ointments, gels and creams) should be considered, which can be applied to localised lesions 2 to 3 times daily. Such products may contain antibiotics (e.g., mupirocin), silver sulfadiazine, benzoyl peroxide and hydroxyl acids. More extensive areas
of infection can be treated with shampoos, lotions, sprays and rinses. These contain antiseptics such as chlorhexidine, benzoyl peroxide, ethyl lactate, povidone iodine, triclosan and hydroxyl acids; they are commonly used 2 to 3 times weekly and until 7 days after lesions resolve, with contact times of 10 minutes before rinsing or conditioners. They can then be used for prophylaxis on a weekly or less frequent basis depending on response.
Empirical systemic drug therapy choices can be made in non-recurrent cases and when there has been no history of antimicrobial drug exposure. Otherwise, drug selection should be based on C&S tests. First-tier empirical drugs include clindamycin, first generation cephalosporins, potentiated sulphonamides, and lincomycin. When first-tier drugs are not appropriate and topical therapy cannot be used, second tier drugs may be chosen; these include fluoroquinolones, doxycycline, chloramphenicol and rifampin. Most of the Working Group members felt that third generations cephaloporins should be second tier drugs, but the evidence to support their placement in this category was lacking, and so they were listed as first or second tier drugs.
Systemic antimicrobial drugs given at subtherapeutic doses or as pulse therapy have been used to prevent or delay recurrence but such protocols are likely to promote the development of antimicrobial resistance and are discouraged.
Acute Upper Respiratory Tract Disease (URTD)
Consider an observation period of up to 10 days without antimicrobial treatment for cats and dogs with acute URTD. Antimicrobial therapy should be considered if
a mucopurulent nasal discharge is accompanied by fever, lethargy or anorexia. In the latter case, appropriate empiric therapy would be doxycycline (first choice) followed by amoxicillin. The duration should be 7-10 days.
Avoid performing C&S on nasal discharge from cats with acute URTD.
An Urban Experience
If empiric antimicrobial therapy is ineffective, a diagnostic work-up is indicated.
Chronic Upper Respiratory Tract Disease in Cats
A diagnostic work-up is recommended. If treatable causes of nasal discharge are not identified, then nasal lavage or brushings could be submitted for C&S testing, and a nasal biopsy could be submitted for histopathology. Treatment should be based on these results.
Should nasal discharge recur, the previously effective antimicrobial drug should be used for a minimum of 48 hours; if this is ineffective, then switch to a different class should be considered, provided a diagnostic work-up to rule out other causes of nasal discharge (tumors, fungal infection, foreign bodies etc) has been performed.
Bacterial Bronchitis in Dogs and Cats
Airway lavage with cytologic examination and C&S testing is indicated if bacterial bronchitis is suspected.
While awaiting results of the above tests, empiric treatment is recommended with doxycycline for 7 to 10 days. If this results in clinical improvement, treatment should be continued for 1 week past resolution of clinical signs.
Antimicrobial therapy for pneumonia should be initiated as soon as possible and within 1-2 hours if signs of sepsis exist.
Antimicrobial therapy should be parenteral while patients with pneumonia are hospitalized.
If there is no evidence of systemic sepsis, parenteral administration of a beta-lactam is recommended for empiric therapy; if signs of sepsis are present, then
a combination of a fluoroquinolone and ampicillin or clindamycin is recommended pending the results of C&S if possible. Animals should be re-evaluated for possible discontinuation of antimicrobials no later than 10 to 14 days after starting treatment.
Pyothorax should be treated with IV fluids and drainage of pus after placement of chest tubes. Surgical debridement may be required.
Empiric antimicrobial therapy pending the results of C&S should be with a parenteral combination of a fluoroquinolone and a penicillin or clindamycin.
It has been recommended that treatment continue for at least 3 weeks and ideally 4-6 weeks, but the optimum duration is unknown. Animals should be re-evaluated 10 to 14 days after starting treatment.

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