This page contains a Flash digital edition of a book.
“Strongyle infestations are the number one intestinal parasite threat to horses. T ough there are more than 40 diff erent species, they can be divided into two groups—small strongyles and large strongyles—each group infl icting a diff erent type of damage. Fecal egg counts cannot diff erentiate between small and large strongyle eggs because their appearance is the same. But other research, based on identifying the larvae that hatches from eggs, determined that over 95% of strongyle eggs were from small strongyles.”


once thought to be the medication that would end parasite infestations.


STRONGYLES—VARIETY IS LIFE Strongyle infestations are the number one intestinal parasite


threat to horses. T ough there are more than 40 diff erent species, they can be divided into two groups—small strongyles and large strongyles—each group infl icting a diff erent type of damage. Fecal egg counts cannot diff erentiate between small and large strongyle eggs because their appearance is the same. But other research, based on identifying the larvae that hatches from eggs, determined that over 95% of strongyle eggs were from small strongyles.


SMALL STRONGYLES Adult worms of small strongyles—also known as cyathostominae,


cyathostomes and cyathostomins—are less than 2.5 inches in length. T e larvae do not migrate to other tissues in the body. T ey are the


most common worms found in horses. Aſt er performing more than 20,000 fecal egg counts, Horsemen’s Laboratory records indicate that of the 30% that were positive, 95% were identifi ed as strongyles.


LARGE STRONGYLES Large strongyle adults are more than 2.5 inches in length. T e larvae


penetrate the wall of the intestine and invade the lining of the arteries that provide blood supply to the gut. T ey also migrate to other organs and tissues of the body. T ey are the most destructive because large strongyle larvae that are eaten by the horse migrate through several organs. However, today their appearance is relatively rare since iver- mectin was approved as a deworming medication. Prior to ivermectin, other deworming medications could not be absorbed from the intestine in a high enough concentration to aff ect the larvae.


continued next page


Two bad actors: T e large white worm is an ascarid (roundworm); females can lay up to a million eggs per day and survive for years on pastures and in stables.


Foals are particularly susceptible to roundworms, developing immunity around 18 months. T e red parasites are bot-fl y larvae. Bot fl ies lay their eggs on the legs and face of the horse where they are ingested. When the larvae at ach to the stomach wall, they can cause infl ammation and ulceration. Large numbers can obstruct the exit from the stomach, causing colic, stomach perforation and fatal peritonitis.


WWW.TRAILBLAZERMAGAZINE.US • June 2012 | 37


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100