Isospora suis Infection in Nursing Pigs

1. Isospora suis Infection in Nursing Pigs Peter Moisan North Carolina Department of Agriculture Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

2. Case History • Herd of several hundred sows. • Farrow-to-finish operation. • Diarrhea in preweaned piglets for many months. • Various diagnoses in the past. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

3. Case History (cont.) • The current outbreak involved 10-15-day-old piglets. • Morbidity 50% and mortality 10-20%. • Territoriality did not change (pigs were not very weakened by diarrhea). • Survivors were stunted and underweight. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

4. Gross Lesion • Regionally extensive necrotizing enteritis. • Often with pseudomembrane. • Pasty tan (butterscotch pudding-like) feces. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

5. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

6. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

7. Microscopic Lesion • Acute, severe, necrotizing, regionally extensive enteritis with villous attenuation, regeneration, and intracytoplasmic coccidia. • All coccidian life stages were represented. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

8. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

9. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

10. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

11. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

12. Life Cycle of Isospora suis • Oocysts are shed in the feces and sporulate in a few days. • Sporulated oocysts are ingested. • Oocysts excyst and release sporozoites that infect the small intestinal enterocytes. • Merozoites are produced by endodyogeny of the sporozoites and produce several generations that infect additional enterocytes. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

13. Life Cycle (cont.) • Merozoites go through merogony to form gamonts. • Microgametocytes and macrogametocytes fuse by gametogeny to form new non-sporulated oocysts. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

14. Significance of Piglet Coccidiosis • This is a syndrome that occurs “between other scours syndromes”. • Pigs are too young for some scours agents and too old for others. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

15. Significance (cont.) • Pigs develop coccidiosis at 10-14 days of age. • If younger, we are more likely looking at: • Clostridium difficile. • Clostridium perfringens Type A or Type C. • Colibacillosis. • TGE. • Rotavirus. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

16. Significance (cont.) • Pigs develop coccidiosis at 10-14 days of age. • If older (post-weaning), we are more likely looking at: • Salmonella. • Brachyspira. • Lawsonia. • Rotavirus. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

17. Significant Diagnostic Tips • Pasty stools. • Age between other major diarrhea syndromes. • Villous attenuation. • In severely affected villi, the coccidia are hard to locate. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

18. Significant Diagnostic Tips (cont.) • When very few coccidia are present, we need to consider other causes of villous atrophy, such as TGE, rotavirus, and Clostridium perfringens Type A or Type C. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

19. Acknowledgements • Histology Technician Mary Horne and the Histology Staff at Rollins Laboratory. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only