Page 1392 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

The foal 1367

VetBooks.ir useful in pleural effusions, pleuritis, haemothorax, • Trimethoprim sulpha: 15–30 mg/kg p/o q12 h.
• Ceftiofur: 5–10 mg/kg i/m or i/v q12 h.
bronchopneumonia, pulmonary abscesses and rib
fractures (Fig. 14.32). Endoscopy of the respiratory
tract is possible with care. Endoscopes should be less • Cefquinome: 1 mg/kg i/m or i/v q12 h.
• Oxytetracycline: 5–10 mg/kg i/v q12 h.
than 9 mm in diameter. Arterial blood gas analysis • Doxycycline: 10 mg/kg p/o q12 h.
may be appropriate in the management of severely
affected individuals. Trimethoprim sulpha (30 mg/kg p/o q12 h) is the
Full post-mortem examination and cultures only antibiotic considered to be effective against
should be carried out on any foal that dies, in case it Pneumocystis jirovecii. It is important that the foal is
is the sentinel for an outbreak of infectious disease. treated for an adequate length of time, until clini-
cal signs and clinical pathology have completely
Management resolved. When treatment continues over several
Antibiotics weeks the dose should be increased with increasing
Given that many of these cases have a primary or body weight of the foal.
secondary bacterial component, the use of antibi-
otics is essential. Broad-spectrum antimicrobial Increasing clearance of secretions
treatment is typically started prior to tracheal wash The use of bronchodilators may be helpful in some
results becoming available or when tracheal aspirates foals.
have not been performed.
The use of erythromycin in cases of R. equi infec- Environmental management
tion has been superseded by more effective newer- When there is significant respiratory compromise
generation options such as clarithromycin and the following management aids may help:
azithromycin. When specifically treating R. equi,
current recommendations remain to use the mac- • Avoid excessive handling/stress.
rolides alongside rifampicin. Studies have shown • Provide a cool, airy environment.
the clarithromycin/rifampicin combination to be • Reduce levels of dust and respiratory irritants.
the most effective. Azithromycin can be useful for • Avoid hyperthermia (a risk in high
foals that are difficult to treat and benefit from a environmental temperatures for some foals
prolonged inter-dosing interval. The risk of hyper- receiving macrolide antibiotics).
thermia associated with macrolide administration • Avoid transport unless essential.
was most commonly encountered with erythromy-
cin use, but is also reported with both clarithromy- Respiratory support
cin and azithromycin, and therefore care should be Severely compromised foals may benefit from
taken. From weanling age onwards, consideration humidified intranasal oxygen therapy.
should be given to the risk of precipitating colitis.
Macrolide- and rifampin-resistant (less commonly Anti-inflammatory drugs
encountered) isolates of R. equi will require the use Phenylbutazone or flunixin meglumine may be used
of different antimicrobials. Dose rates for the antibi- judiciously at low doses in severe cases. They should
otics mentioned above are: be used for short periods of time. The use of paren-
teral or nebulised corticosteroids may be beneficial
• Clarithromycin: 7.5 mg/kg p/o q12 h. for cases of interstitial pneumonia.
• Azithromycin: 10 mg/kg p/o q24 h.
• Rifampicin (should never be used alone): Prognosis
5–10 mg/kg p/o q12 h. The prognosis for treating cases of uncomplicated
bacterial (including R. equi) bronchopneumonia
With other causes of bacterial pneumonia, clar- is good. Most survivors are able to race as well as
ithromycin can be used alone. In addition, the fol- age-matched peers. The prognosis for most cases of
lowing antimicrobials may be used: atypical interstitial pneumonia is guarded.