Nematodes in Horses: Case Study 1 ('04)

Old Bolton Horse Farm is located in southern Pennsylvania and has 40 or more horses on 120 acres. The farm is divided into 8 different pasture areas of about 15 acres each. The horses are treated for nematode parasites twice a year (in the summer and late fall). The drug used and the actual timing of the treatment varies, but the horses on each pasture are treated at the same time.

The dates of the last treatment and the drugs used are:

Field	Horses	Date Treated	Treament
#15	Mares with their foals (horses (all mares) # 1 to 5)	8/22/04	"Quest"
#19	Mares with their foals (horses (all mares) # 6 to 10)	8/22/04	"Quest"
#17	Yearling fillies (horses #11 to 15)	6/28/04	"Equimax"
#16	2 year old fillies (horses #16 to 20)	6/9/04	"Equimax"
#3	Mares (horses #21 to 25)	6/9/04 (3 horses) 7/26/04 (2 horses)	"Equimax"
#7	Mares (horses #26 to 30)	11/10/03	"Eqvalan"
#14	Gelding (horse #31)	8/23/04	"Quest"
#18	Mares (horses #32 to 35)	8/4/04	"Equimax"

Questions:

1. Are there any groups that are more heavily infected than the others? Yes or No.

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Yes

2. If you answered yes to Question 1: What factor(s) do you believe contributed to differences seen?

    If you answered no to Question 1: What factor(s) do you believe contributed to the lack of difference?

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Age and time since last dosing.

3. List the ingredient that kills nematodes in each of the following drugs:

"Quest"

"Equimax"

"Eqvalan"

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4. List 4 genera of nemtodes found in horses that produce strongyle-type eggs.

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1. Strongylus
2. Trichostrongylus
3. Cyathostoma (and/or Cylicocyclus, Cylicodontophorus, Cylicostephanus, Gyalocephalus)
4. Triodontophorus

 

5. For each genus that you listed in Question 4 give the predilection site of the adult worms.

Click here for the answer:

1. Large intestine
2. Stomach
3. Large intestine
4. Large intestine