Porcine Proliferative Enteropathy (PPE, ileitis), caused by the intracellular bacterium Lawsonia intracellularis is a common and widespread infection on pig farms. It is considered the most important enteric infection in grower-finisher pigs with prevalence all around the world.
Chronic PPE infections result in damage to the intestine. This leads to compromised absorption of nutrients which affects growth and feed efficiency, causing diarrhea (Figure 1) and reducing uniformity (Figure 2). The acute form of ileitis infection (Porcine Heamorrhagic Enteropathy (PHE)) affects older pigs (4-12 months of age), causing high mortality and sudden death.
Ileitis - a disease consuming your profits
Sensitivity pattern of L. intracellularis strains isolated worldwide
- very high tylosin concentrations in the ileum / colon
- enterocyte penetration and accumulation
Only limited data on the in vitro sensitivity of L. intracellularis strains are available. This is due to the difficulty in isolating and maintaining L. intracellularis from fecal and intestinal samples, and the need to use complicated cell structure systems to evaluate antimicrobial activity in vitro. In vitro susceptibility of L. intracellularis strains from the USA, Denmark, UK, Brazil, Thailand, and Korea against tylosin are shown in Figure 3.
The intracellular minimum inhibitory concentration (MIC) data are related to the effective therapeutic concentrations achieved in the ileal content after in-feed administration at a recommended treatment dose of 5 mg tylosin/kg body weight (BW; 16 µg/ml) and at a double dose of 10 mg tylosin/kg BW (31.4 µg/ml). The black arrows in Figure 3 show the tylosin concentration in the ileum at the two different doses. The L. intracellularis strains demonstrate a high degree of intracellular susceptibility to tylosin.
Ileitis challenge study and Pharmasin® / Tylovet® treatment effect
In an ileitis challenge study, the effect of Pharmasin® / Tylovet® in-feed medication was tested in one treatment protocol (group 2: 100 ppm: treatment started 7 days after challenge) and compared to a non-medicated control group (group 1; Table 1).
None of the pigs in the treatment group showed any gross or histopathological signs of ileitis infection. In the ileitis infected, untreated group, macroscopic (62.5%) and microscopic (87.5%) lesions were found in the ileum, causing detrimental effects on average daily gain (ADG) and feed conversion ratio (FCR).
Pharmasin® / Tylovet® the first-choice solution against ileitis infections
The concentration of tylosin found in the ileum achieved at a dose of 5 mg/kg BW exceeded the tylosin MIC values for the pathogen L. intracellularis. Results of various challenge and field studies verify the clinical effectiveness of Pharmasin® / Tylovet® medication against ileitis.
Pharmasin® / Tylovet® is the first-choice solution for grower-finisher ileitis treatment and control.
References are available on request.