Table 1.
First‐line antimicrobial options for bacterial respiratory infections in the dog and cat
| Infection Type | First‐Line Drug Options |
|---|---|
| Acute bacterial upper respiratory infection (URI) in cats | Doxycyclinea or amoxicillin per os (PO) |
| Chronic bacterial URI in cats | Doxycycline or amoxicillin POBase the choice on C&Sb if available |
| Canine infectious respiratory disease complex (bacterial component) | Doxycyclinea or amoxicillin–clavulanate PO |
| Bacterial bronchitis (dogs or cats) | Doxycyclinea POBase changes if needed on clinical responses and C&S if available |
| Pneumonia in animals with extensive contact with other animals that have no systemic manifestations of disease (ie, fever, lethargy, dehydration) | Doxycyclinea POBase changes if needed on clinical responses and C&S if available |
| Pneumonia with or without clinical evidence of sepsisc | Parenteral administration of a fluoroquinoloned and a penicillin or clindamycine initiallyBase oral drug choices to follow on clinical responses and C&S results if available |
| Pyothorax (dogs or cats)b | Parenteral administration of a fluoroquinoloned and a penicillin or clindamycine initially combined with therapeutic lavage initiallyBase oral drug choices to follow on clinical responses and C&S results if available |
Minocycline has been substituted in some situations when doxycycline is unavailable or of greater expense. See Table 2 for dose recommendations.
Culture and antimicrobial susceptibility testing = C&S.
For animals with clinical findings of life‐threatening disease, the consensus of the Working Group was to administer dual agent treatment parenterally with the potential for de‐escalation of treatment and switch to oral drugs based on clinical responses and culture and antimicrobial susceptibility testing. See Table 2 for dose differences by route and the text for further recommendations for oral or parenteral administration.
Enrofloxacin is often chosen as there is a veterinary product for parenteral administration and the drug has a wide spectrum against Gram‐negative organisms and Mycoplasma spp. There are other drugs with a wide spectrum against Gram‐negative bacteria that can be substituted based on antimicrobial susceptibility testing or clinician preference. See Table 2 for a discussion of how to administer enrofloxacin and for other drug choices. Enrofloxacin should be administered at ≤5 mg/kg/24 h in cats to lessen risk of retinal degeneration. One reviewer noted that IV ciprofloxacin could also be used; however, the other reviewers (94%) believed that enrofloxacin should be used as labeled for veterinary use.
When enrofloxacin or other drugs with Gram‐negative activity are administered parenterally to animals with life‐threatening disease, concurrent administration of other parenteral drugs with activity against anaerobes and Gram‐positive bacteria is recommended. Common choices include ampicillin or clindamycin. Which of these drugs to choose will depend on the most likely infectious agent suspected and historical antimicrobial resistance in the geographical region. For example, Enterococcus spp. and Streptococcus spp. are more likely to be susceptible to a penicillin, and Toxoplasma gondii and Neospora caninum are more likely to be susceptible to clindamycin. Cephalosporins are generally not recommended for the treatment of anaerobic infections because of unpredictable activity and lack of evidence for their efficacy. Please see the text for further discussion of other potential drug choices or combinations.