6.1 What types of treatment are available for Ileitis?

Proliferative enteropathy or Ileitis is a bacterial disease, caused by the Gram-negative intracellular bacterium, Lawsonia intracellularis. It is therefore possible to use certain antibiotic agents that target these types of organisms by a specific antibacterial effect. It is always important to use the correct agents at the recommended dose otherwise efficacy will not be optimal, whatever drug is used.

In acute proliferative enteropathy situations, with high morbidity (many cases in the group) and high mortality, the use of injectable formulations of effective antibiotic agents are usually recommended for the most “at-risk” pigs. This is usually followed by use of water-soluble formulations of effective antibiotic agents to deliver a high dosage in an effective manner in the correct water supply. Pigs will generally consume water when they are sick, even though their appetite for food may be diminished. Water delivery of medications allows a safe and quick way to deliver a reasonably accurate dosage to a large group of pigs. It also has the advantage that the feed supply does not necessarily have to be altered for the medications. The use of in-feed premix formulations is also a realistic option for the management of clinical situations of Ileitis, both for the acute and the common chronic form. Several scientific studies have confirmed the good effect of tiamulin, tylosin and lincomycin premix formulations for control and prevention of Ileitis on many farms across Europe. In Denmark, Tiamulin is the first choice for Ileitis prevention. In most cases, these studies were conducted on growing pigs with the chronic form of the disease. These on-farm investigations of attempted therapy and control programs using oral antibiotics have properly included control groups, multiple comparative farm site study sets and direct diagnostic confir­mations of the disease

It is important to realise that a comparison of the different methods of delivering drugs to animals shows that injections will give the most accurate dose per animal, but are the most difficult to administer. Soluble formula­tions may also used but require a high dose per animal and specific delivery mechanisms. In-feed formulations are the easiest to use, but may not deliver a full or an accurate dose to all animals in a group. The correct dose for each drug for each method of delivery must be carefully checked before it is used. Water and feed medication are handicapt by various fac­tors including variability in consumption due to age and health status. It is important to realise that drugs given as a parts per million dosage in water or in feed will have different levels in the body of each pig it is given to, because the body weight and health of each pig will vary as they grow. It is therefore best to express dosage of drugs on a mg of drug per kg of bodyweight dosage.

As well as these important issues, a decision to use antibiotic treatments also include factors such as the quality of the product, its cost, tech­nical support team of the company involved, withdrawal times and other regulatory issues.