An 8 day artificial infection study describing the treatment of an App infection with Denagard water soluble (120ppm thf) was reported at IPVS 2004 by Taylor, D. J. [?]. At this dosage mortality was eliminated and App specific lung lesions were reduced. The growth rate and substantially increased water and feed intakes were additional benefits noted in the Denagard medicated group.
Recent in vivo investigations (as noted below) from Chile and Canada have confirmed the clinical value of Denagard to combat App infection.
An in vivo field investigation in Chile [?] has shown that use of Denagard in drinking water at 180ppm thf for 7 consecutive days in the post-weaning period combined with in-feed Denagard (100ppm thf)+chlortetracycline (400ppm) in 5 day “pulses” at:
75 - 80 days of life
90 - 95 days of life and
105 - 110 days of life
is highly effective in the control of App [serotypes (I and II) infection]. For further information on 'Pulsed dosing' click here.
A study to eradicate App (serotype 7) infection from a comingled, multi-site, multi-source SEW system was reported from Canada [?]. Piglets from 9 breeding herds were co-mingled into AI/AO nursery barns with weaning at 16 - 18 days of age. App was diagnosed at post-mortem on a SEW multi-site system with deaths on the third site. To identify the farms contributing App positive piglets nasal swabs and serum samples were taken. 4 out of 9 supplier farms were shown to be supplying App positive pigs and Haemophilus parasuis was shown to be a co-pathogen in piglets from all 9 farms.
Denagard medication was provided in water in the nursery 2 days post-placement at a level of 100mg tiamulin hydrogen fumarate/litre for 5 consecutive days. The clinical results were dramatic:
- Sneezing stopped abruptly in the nursery piglets
- 12 months after the Denagard medication started App was neither diagnosed nor isolated
- Haemophilus parasuis was also eliminated.
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