By Mitchell Nisley, Eric Burrough and Nicholas Gabler, Iowa State University

Coccidia are protozoan parasites that imbed and replicate inside intestinal tissue of suckling and nursery piglets. Ingested through fecal and environmental contamination, these parasites damage the piglet's absorptive cells which increases diarrhea incidence and leads to reduced performance and higher mortality rates. The prominent species of coccidia that affects young pigs is Cystoisospora suis.  

The best prevention and treatment strategy involves combining thorough crate cleaning and disinfection with medication. However, effective prophylactic medications are limited, with Ponazuril and its derivatives often considered. Ponazuril, administered as a single oral dose within the first week after birth, offers maximum efficacy against coccidiosis. However, in recent years, coccidiosis infections in young pigs have been on the rise due to availability and restrictions on medications, efficacy of disinfectants, and persistent labor shortages and high labor costs for deep cleaning.

Previous research from our laboratory demonstrated that both Amprol (amprolium) and Sul-Q-Nox (sulfaquinoxaline) can significantly reduce Cystoisospora suis fecal shedding in nursery pigs within just three days of water-based administration. Therefore, our goal has been to understand coccidiosis in young suckling pigs. It was hypothesized that combining these two treatments would effectively decrease coccidia infections, similar to Ponazuril, in suckling pigs within a naturally infected production environment.

Animals and methodology

A total of 75 litters at a commercial sow farm in central Iowa with a coccidiosis history were utilized. Balanced by parity, litters were randomly assigned to one of three treatments: 1) Negative control [Control]; 2) Positive control, 1 mL of 20 mg/ml Ponazuril suspension administered day 5 of age; and 3) Experimental treatment 1.5 ml of 9.6% Amprol + 1 ml of 31.92% Sul-Q-Nox solution [Amp + Sul-Q] administered at day 5 and 10 of age.

Pigs were weighed on day 5 of age and at weaning (day 15-18). Piglet diarrhea incidence and mortalities were monitored throughout the study. At weaning, one pig per litter was sacrificed for intestinal tissue and rectal contents to analyze coccidia oocysts burden. Rectal contents underwent sucrose float analysis and Cystoisospora suis polymerase chain reaction to assess oocyst incidence. Fixed small intestinal tissue sections was also examined by a veterinary pathologist who was blinded to treatment for the presence of intraepithelial coccidia.

Figure 1. Fecal float procedure.

Figure 2. Fecal float with shed oocyst present.

Findings

Over the suckling period, piglet weight gain and mortality did not statistically differ between treatments (P > 0.05). Minimal diarrhea episodes were observed at weaning in pigs treated with either Amp + Sul-Q or Ponazuril (P < 0.001). Cystoisospora suis oocyst presence was detected in fecal floats as early as day 5 of age. Over the treatment period, Amp + Sul-Q and Ponazuril treatment significantly decreased coccidia oocyst presence in rectal contents compared to the control, with both fecal float and PCR analyses confirming this reduction (both P < 0.05, respectively). Additionally, Amp + Sul-Q and Ponazuril proved effective at reducing coccidia oocyst presence in jejunal tissue (P < 0.05).

Conclusion

These findings collectively suggest that Ponazuril or a combined treatment of Amprol and Sul-Q-Nox can successfully reduce a natural coccidia burden in suckling pigs by lowering coccidia proliferation and oocyst shedding and minimizing the occurrence of diarrhea.