Anthelmintics

Effective deworming program- small ruminants Deworm ewes shortly before, or right at, lambing. –best opportunity to disrupt the parasites' cycle in flocks –ensures a low parasite burden when ewes are turned out on grass –late lambing ewes should be treated twice with an anthelmintic.

Effective deworming program- small ruminants Deworm on grass. –Larvae in the pasture can overwinter –Deworming sheep or cattle on pasture is done when moderate to high parasite burdens in the pasture are anticipated –Deworming is done about three weeks after turnout on grass. It can be continued at intervals, depending on parasite exposure and risk

Effective deworming program- small ruminants Reduce pasture contamination. –Reducing the numbers of larvae eaten is a primary goal of any control program –If possible, mechanically harvesting spring grass will eliminate a large percentage of infective larvae, which die as hay is cured. –Yearly rotation of pasture using other species, such as horses, helps break the parasitic cycle since there is little infective crossover of worm species. Haemonchus contortus is an exception if cattle and sheep are alternated;

Effective deworming program- small ruminants Treat and move. This approach involves movement sheep and pairs, following worming, to fresh pasture or pastures where risk of exposure is low. Fall deworming. –Animals that accumulated parasites during summer months can have their worm burdens markedly reduced. –spring and early summer preventive program is not used. –Diagnostic assistance such as fecal examination can be done to quantify the worm burden.

Strategic deworming Focus on the pasture –Wet grass –> 55 F –“While the grass is dry without dew or rain, the cattle do not get worms “ –When to deworm when larvae are developing in the spring or fall during inhibition of larvae in the summer before the larvae emerge in early fall Cattle

Endoparasites Helminths are divided into two major groups: Nematodes: cylindrical, nonsegmented worms commonly called roundworms Platyhelminthes: flattened worms that are subdivided into two groups: Cestodes (tapeworms) Trematodes (flukes) Anthelmintics Anthelmintics Antinematodals Anticestodals Antitrematodals

There are three families of drugs which are used to treat internal parasites in livestock: 1. Benzimidazoles - Fenbendazole, Albendazole, Oxybendazole, Thiabendazole 2. Nicotinics - Levamisole, Pyrantel, Moratel 3. Macrolytic Lactones - Ivermectin, Doramectin, Moxidectin

Benzimidazoles Work by interfering with energy metabolism of the worm Recognize by –azole ending in drug name Always read the label to determine which parasites a drug is effective against All can be administered orally, either as a paste, a granulated powder, or a solution. Side effects are rare with benzimidaloles, but may include vomiting, diarrhea, and lethargy.

The Benzimidazoles Safeguard®, Panacur®, Valbazen®, Synanthic®, also called "white dewormers" broad spectrum and safe to use: ostertagiosis They are effective against tapeworms Albendazole is effective against adult liver flukes, but should not be used in pregnant or lactating females.

Safeguard ® Panacur® liquid 10% FenbendazoleBZD cattle, non- lactating goats roundworms lungworms tapeworms 2.3 ml/100 lbs. by mouth cattle: 8 days slaughter 0 milk withdrawal goats: 6 days slaughter Safeguard ® Panacur® paste FenbendazoleBZD cattle horses roundworms lungworms tapeworms 2.3 mg/lb. by mouth cattle: 8 days slaughter Safeguard Pellets FenbendazoleBZD cattle swine roundworms lungworms tapeworms 1 lb./100 lbs. by mouth swine: 14 days slaughter Synanthic ® drench 9.06% OxfendazoleBZD beef cattle non-lactating dairy roundworms lungworms tapeworms 2.5 ml/110 lbs. by mouth cattle: 7 days slaughter Valbazan® drench 11.36% AlbendazoleBZD cattle sheep roundworms lungworms tapeworms adult liver fluke 3 ml/ 100 lbs. oral restricted during pregnancy sheep: 7 days slaughter

Nicotinics Levamisole (Tramisol®), also called a "clear dewormer“ broad spectrum and effective against arrested larvae narrower margin of safety, especially in the injectable form. Pyrantel (Strongid®) is only effective against adult worms. Moratel (Rumatel®) is an oral feed additive and is only effective against adult worms

Imidazothiazoles Work by stimulating the nematode’s cholinergic nervous system, leading to paralysis of the parasite (therefore, not ovicidal) Effective against ascarids, strongyles, whipworms, and hookworms Was used as a microfilaricide in the past levamisole (Levasol®) An example is levamisole (Levasol®) Expels most nematodes in 24 hours (some may be passed alive) Expels most nematodes in 24 hours (some may be passed alive) Available in oral forms such as pellets, powder, suspensions, and pastes Available in oral forms such as pellets, powder, suspensions, and pastes Also has anti-inflammatory and immunostimulant properties Also has anti-inflammatory and immunostimulant properties May cause toxicity in host animal due to cholinergic effects May cause toxicity in host animal due to cholinergic effects

Prohibit Drench Powder Levamisole Hydrochloride TETR cattle sheep roundworms intestinal worms lungworms Depends on dilution cattle: 2 days sheep: 3 days Tramisol/L evasole® drench LevamisoleIMID sheep cattle roundworms intestinal worms lungworms 1 oz./100 lbs. 1 ml/50 lbs. by mouth sheep: 3 days slaughter Tramisol/L evasole® injectable for cattle 13.65% LevamisoleIMIDbeef cattle roundworms lungworms 2 ml/100 lbs. Sub-Q cattle: 7 days Tramisol/L evasole® boluses/ob lets LevamisoleIMIDsheep roundworms lungworms 1 bolus/50 lbs. by mouth sheep: 3 days slaughter

Macrolytic The Macrolytic lactones or "avermectins" (Ivomec®, Dectomax®, Quest®, Cydectin®) newest family of drugs broad spectrum and have a wide margin of safety They are also effective against external (biting) parasites, including nose bots Moxidectin is a persistent-activity dewormer that continues to kill worms after it is administered. Drench for SHEEP!

Trade NameDrug Ingredient Drug Family *!Approved Species Specificity NOT complete- most common ONLY Labeled Dosage for approved species *Goat Dosage is Higher Withdrawal time for approved species Cydectin® 0.5% pour-on for cattle MoxidectinML beef cattle non-lactating dairy cattle roundworms lungworms external parasites 5 ml/110 lbs. topical cattle: 0 days slaughter Cydectin® 1% injectable MoxidectinMLbeef cattle roundworms lungworms external parasites 1 ml/110 lbs. cattle: 21 days slaughter Cydectin® oral drench for sheep 0.1% MoxidectinML sheep Not for lactating dairy sheep roundworms lungworms external parasites 1 ml/11 lbs. by mouth or 1 ml/5 kg sheep: 7 days slaughter Dectomax® injectable 1% DoramectinML beef cattle swine roundworms lungworms external parasites 1 ml/110 lbs. (cattle) 1 ml/110 lbs (swine) Sub Q or IM cattle: 35 days slaughter swine: 24 days slaughter Dectomax® pour-on for cattle 0.5% DoramectinMLcattle roundworms lungworms external parasites 5 ml/110 lbs. topical cattle: 45 days slaughter Ivomec® Eprinex pour-on EprinomectinMLcattle roundworms lungworms external parasites 5 ml/110 lbs. topical cattle: 0 days slaughter Ivomec® pour- on for cattle IvermectinMLbeef cattle roundworms lungworms external parasites 1 ml/22 lbs. topical cattle: 48 days slaughter

Ivomec Plus Injection Clorsulon Ivermectin MLbeef cattle roundworms lungworms external parasites Adult liver flukes 1 ml/110 lbs. SQ cattle: 49 days slaughter Ivomec® injectable 1% IvermectinML beef cattle swine roundworms lungworms external parasites 1 ml/110 lbs cattle. 1 ml/75 lbs. swine Sub-Q cattle: 35 days slaughter swine: 18 days slaughter Ivomec® sheep drench 0.08% Primectin ™ Drench IvermectinMLsheep roundworms lungworms external parasites 3 ml/26 lbs. by mouth sheep: 11 days slaughter Quest® 2% equine oral gel MoxidectinML horses ponies roundworms lungworms external parasites 0.4 mg/2.2 lbs. not for horses intended for food Zimecterin -EZ® paste 1.87% IvermectinML horses ponies roundworms lungworms external parasites 1 tube/1250 lbs. oral not for horses intended for food

Economics - Sheep

References heltable.htmlhttp:// heltable.html _4110/2009_lectures/33_parasites_cattle_ sheep/HTML/Class_Notes.htmhttp:// _4110/2009_lectures/33_parasites_cattle_ sheep/HTML/Class_Notes.htm /04/when-is-right-time-to-deworm- cattle.htmlhttp://extensionvetmed.blogspot.com/2009 /04/when-is-right-time-to-deworm- cattle.html site.cfm?ID=188