What kind of treatments/prevention measures are available for parasites (deer...
According to information in the article from Mississippi State in the following website: http://msucares.com/livestock/smallruminant/meatgoatmemo_jun08.pdf
The meningeal worm or deer brain worm causes partial paralysis in goats, sheep and llamas that are exposed to the parasite by deer. The parasite occurs in deer and does not cause clinical symptoms as it does in goats. The larvae are passed in deer feces and are ingested by a variety of snails and slugs where they develop into infective larvae over a 3-4 week period. The snails or slugs are consumed by grazing goats. Inside the goat, the larvae penetrate the intestine and migrate to the spinal cord through the abdominal cavity over a 10 day period. The larva gets lost in migrating from the spinal cord to the brain because the goat anatomy is different from the deer. They end up destroying brain tissue causing differing degrees of paralysis. Symptoms of the brain worm include paralysis of one or more limbs, excessive tail twitching, circling, abnormal head position, blindness, inability to get up, toe dragging, being in a dog-sitting position or difficulty or exaggerated movement of limbs when walking. The disease usually occurs in the fall and winter.
There is no treatment for the brain worm that is very effective. Sometimes it is treated with high doses of various dewormers (fenbendazole and ivomec) and steriods, but treatment is often not effective. Since the parasite is carried by deer and uses a snails or slugs as the infective intermediate host, prevention consists of discouraging deer from using the pasture and making the environment unfavorable for snails and slugs. As goats clear the cover from an area, deer will visit that area less frequently. Guard dogs may chase deer away from pastures. A number of snails may serve as intermediate host and some may be so small (1/4") as to be overlooked. Snails prefer water, and so swampy areas are good habitat for snails. Therefore, fencing goats out of areas that often have water can help on prevention. Slugs and some snails prefer organic matter, leaf piles and compost. These areas may be cleaned up if the area is not extensive. Guinea hens and Muscovy ducks are reputed to be effective at controlling snails and slugs and may aid in prevention of the deerworm. Some producers deworm goats every 30 days from 30 days after the grazing season until a hard freeze to prevent the deerworm. Ivomec and fenbendazole (Safeguard, Panacur) are the most common dewormers used for this purpose. This will likely create dewormer resistance, but for many people, these dewormers do not work for roundworms. One producer used a low dose of Rumatel fed every day in a minimal amount of corn and appeared to be effective.