Wet and Warm Weather May Lead to Worm Problems in Sheep, Goats

Combining wet weather and warm days usually mean an increase in internal parasites or worms in sheep and goats.

According to Dr. Jodie Pennington, small ruminant educator with Lincoln University Extension, worms are the primary internal parasite of small ruminants and are the biggest problems in meat and dairy goats.

“They are also a problem with sheep, although not of the same degree as with goats,” said Pennington.

The only way to control worms is for goat and sheep producers to have a deworming and sanitation program in place and then adhere to it.

“Worms not only kill both young and old goats, they contribute to poor growth rates, an unthrifty appearance, coughing, diarrhea, and, in severe cases, bottle jaw,” said Pennington.

To minimize contamination of uninfected goats, maintain a dry, clean environment with a sound manure management plan. Depending on location and density of animals in the field, deworming may have to be repeated at different times during the year.

There are different types of deworming programs that can be effective for goats. One of the most effective includes monitoring the level of parasite eggs in the feces (fecal egg counts).

“You or your veterinarian may conduct FECs either on a routine schedule or when an animal is suspected of having worms and then deworm animals that have high FECs,” said Pennington.

Fecal egg counts can be used not only to monitor the level of infestation of internal parasites in goats but also to determine the effectiveness of the dewormers used to treat the goats.

“Many producers now use a dewormer until it is no longer effective before switching to another dewormer. This technique is believed to save effective products of unrelated compounds for future use in the parasite control program,” said Pennington.

All dewormers can be effective, but presently two of the most effective dewormers include moxidectin and levamisole (which recently came back on the market as a sheep drench).

General control recommendations for internal parasites include manure management by frequent removal of manure, rotation of pastures, decreased stocking rates and taller pastures for goats which will minimize exposure to larva of internal parasites.

Pennington says it is also a good idea to feed and water goats in troughs or racks that are above the ground to prevent manure contamination. A concrete pad around the base of the trough can prevent goats from getting close enough to get manure in the water.

“Goats should be dewormed as often as needed to control worms, as indicated by FECs. However, the need for deworming varies greatly among herds, depending on sanitation, forage management, and observation skills of the caretaker,” said Pennington.
(by David Burton, MU Communications Specialist)