Introduction: Swine parasitosis

The breeds used in pork production currently have a high genetic potential, so the profitability of farms today is mainly due to the removal of constraints to optimize this innate potential.

The parasites are a limiting factor of great importance, making a priority to detect the main pathologies, remove and prevent their appearance in the farms.

The variety of parasites that can affect pigs is very wide, and their frequency and importance depends on several factors.

En este artículo se tratan los aspectos generales, epidemiológicos y económicos de la coccidiosis neonatal porcina, una de las enfermedades parasitarias de mayor impacto en la producción porcina intensiva.

This article refers to the general factors, epidemiological and economic aspects of neonatal swine coccidiosis one of the parasitic diseases of major impact in intensive pig production.

Neonatal swine coccidiosis

Coccidiosis is a disease caused by intracellular protozoan parasites that colonize the digestive system.

The genres of coccidiosis that affect pork are Eimeria and Isospora. Specifically, Isospora suis is the causative agent of neonatal coccidiosis, the main enteric disease in piglets caused by protozoa.

There are other species of coccidiosis able to infect pigs, as I. suis, I. and I. almataensis neyrai, but has not been shown that may be causing the disease.

1. History

Although Isospora suis infection was identified as the cause of enteritis in 1934, it was not associated with a problem of great importance in breeding pigs to mid 70s.

With the increase of intensive farming, coccidiosis has been added importance because of continuous farming systems and other innovations facilitate the realization of the full cycle of the parasite. Therefore, coccidiosis can be considered a re-emergent disease that has become a common cause of neonatal diarrhea in modern farms.

1. Epidemiology

Isospora suis is one of the most prevalent enteric parasites in swine production worldwide. Despite its worldwide distribution, its prevalence is usually higher in countries where pigs are raised intensively. For example, in Europe, the average prevalence of Isospora suis in farms is between 45 and 85% and more than 30% of pigs are infected. In the US and Canada, between 15 and 20% of cases of diarrhea in piglets diagnosed in laboratories.

Tabla 1. Prevalence of Isospora suis in pigs in accordance with the system of production in different countries.*Int = Intensive, Var = varios

Coccidiosis by I. suis usually affects pigs between the second and third week of life, and is less frequent and severe in older weanling piglets.

Once infected piglets, begins to increase the number of oocysts that pollute the environment and as a result, it is easier to consume lot of oocysts, requirement necessary to cause clinical disease.

1. Impact in the farms

The high number of mortality caused by neonatal makes coccidiosis significant economic losses. Mortality is not usually a problem (it is below 20% even in the most severe outbreaks), except in cases where secondary bacterial infections occur.

Colonization of the intestinal mucosa of the jejunum and ileum by parasites injure digestive epithelium, causing villous atrophy and crypt hyperplasia. These lesions prevail for about nine days and are the source of nutrient malabsorption and clinical signs observed in litters: yellowish diarrhea, dehydration in piglets and unevenness of the litter.

Weight gain is severely diminished and piglets result in reduced conversion rate and growth retardation not only during the days when symptoms appear, but more prolonged period due to the regeneration of the absorption capacity of the intestine with the infection. This represents a worsening of farm production parameters for a long time. This represents a worsening of farm production parameters for a long time.

Moreover, secondary enteric processes have an additional treatments cost until weaning (up to 88% more spending on antibiotics).