Be prepared for parasite problem when sheep and goats graze on pastures

Sheep and goats are more susceptible to internal parasites than other livestock, due to their grazing behavior and poor immunity.

Internal parasites are a health problem affecting small ruminants. The parasite that causes the most problems to small ruminants is Haemonchus Contortis, better known as the “barber pole” worm. The barber pole worm is a blood-sucking parasite that pierces the lining of the abomasum, causing blood plasma and protein loss to the host. The symptom most commonly associated with barber pole infection is anemia, characterized by pale mucous membranes, especially in the lower eye lid; and “bottle jaw,” an accumulation of fluid under the jaw.

The use of clean or safe pastures will help to control parasite problems. A clean or safe pasture is one in which sheep or goats have not grazed for 6 to 12 months. A pasture grazed by cattle and/or horses is also considered safe, since sheep/goats and cattle/horses do not share the same parasites. Pastures that have been renovated or rotated with row crops are clean, as are pastures in which a hay or silage crop has been removed.

In the past, producers relied heavily on anti-parasitic drugs, called “anthelmintics” to control internal parasites in their goat herds. Unfortunately, parasites have become increasingly resistant to many of the anthelmintics. In addition, few anthelmintics are FDA-approved for use in goats.  As a result, producers can no longer rely on anthelmintics alone to control parasites in their herds. A more integrated approach will be necessary. You can slow the development of resistance on your farm by not introducing anthelmintics resistance to your farm. New arrivals should be isolated and dewormed with products from at least two families of drugs. Care should be taken not to under dose animals. Combinations of products may slow down resistance. A product should be used on a farm until it is no longer working.

Family

Drug Ingredient

Trade Name

Approved for Sheep

Approved for Goats

Benzimidazoles

fenbendazole

Panacur®

No

Yes

Safeguard®

No

Yes

albendazole

Valbazen®

Yes

No

oxfendazole

Synanthic®

No

No

Imidazothiazole

 levamisole

Prohibit®

Yes

No

Tramisol®

Yes

No

morantel tartrate

Rumatel®

No

Yes

Macrocyclic lactones

ivermectin

Ivomec®

Yes

No

moxidectin

Cydectin®

Yes

No

doramectin

Dectomax®

No

No

Amino acetronitrile derivatives

monepantel

Zolvix®

No

No

Consult with your veterinarian for off-label use concerning:  product choice, dosage, animal class, withholding time, mode of administration, use of drugs in combination

There are two tools that producers can use to more effectively control internal parasites: fecal egg counting and FAMACHA©. Fecal egg counts can be used to determine the level of pasture contamination and the need for anthelmintic treatment. FAMACHA© is a system whereby you examine the lower eyelid of the sheep and administer treatment only if signs of anemia are present.

For More information or information on upcoming programs contact Mike Metzger or Richard Ehrhardt

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