Porcine Respiratory Disease
Porcine respiratory disease of mixed aetiology is highly prevalent in intensive pig farms and can cause high economic losses.
The most common pathogens are:
- Actinobacillus pleuropneumoniae (APP)
- Pasteurella multocida
- Mycoplasma hyopneumoniae
- Staph. aureus.
Sometimes infections can be reduced by good husbandry, but in most cases antibiotic treatment is required.
Baytril is highly effective against the organisms causing porcine respiratory disease.
APP infections cause high fever, severe respiratory distress and sometimes a blood-stained discharge from nose and mouth. The mortality in young pigs can reach up to 50%, and the survivors have persistent cough and reduced growth. The onset of an APP infection is very rapid, and intervention with an antibiotic is a must.
To determine the efficacy of Baytril against experimentally induced pleuropneumonia, four groups (A – D) each of five pigs (20 kg bw) were inoculated with an aerosol of APP.
Groups A, B and C were injected i.m. with Baytril 5% injectable solution. (group A 2.5 mg/kg bw, groups B and C 5 mg/kg bw), the first injection at 8 (groups A and B) or 12 (group C) hours post-inoculation.
A fifth group (E) was not infected and not treated and served as negative control.
All infected pigs developed the signs and symptoms of pleuropneumonia but symptoms were milder in the Baytril-treated groups. There were no deaths among the treated animals, whereas 60% of the untreated pigs died within 64 hours.
Daily average weight gain in the treated animals was minimally affected.
At sacrifice, the survivors of group D had developed lung abscesses and bronchiectasis, and APP was recovered from both animals.
Not one of the Baytril-treated animals had developed pleuropneumonial lesions and APP could not be recovered from these animals.
The efficacy of Baytril in naturally occurring respiratory infections (of bacterial and mycoplasmal origin) in pigs was tested in 117 pigs that showed symptoms of respiratory infection after transportation to the fattening unit, crowding and ration changes.
56 pigs were randomly assigned to group 1 (Baytril) and 56 to group 2 (Placebo). 5 pigs were used for necropsy to define the pathogens involved. Actinobacillus pleuropneumoniae, Streptococcus suis, Pasteurella multocida and Mycoplasma hyopneumoniae were found in the respiratory tract of pigs submitted for necropsy. Group 1 received Baytril 10% injectable solution at a dosage of 5 mg/kg bw for 5 consecutive days, group 2 received sterile saline as placebo.
Treatment success at day 7 post-treatment in the Baytril group and the placebo group was evaluated, as well as the continued treatment success on day 28.
The overall treatment success was 75% in the Baytril group and 5% in the placebo group.
This trial documented, among others things, the high efficacy of Baytril against mixed respiratory infections under field conditions.
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