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.

• 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;

• 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

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

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.

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

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.

Trade NameDrug

IngredientDrug

Family*!Approved

Species

SpecificityNOT 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

Moxidectin MLbeef cattle

non-lactating dairy cattle

roundworms lungworms

external parasites

5 ml/110 lbs.topical

cattle:  0 days slaughter

Cydectin® 1% injectable Moxidectin ML beef cattle

roundworms lungworms

external parasites1 ml/110 lbs.

cattle: 21 days slaughter

Cydectin® oral drench for sheep 0.1%

Moxidectin MLsheep

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%

Doramectin MLbeef cattle

swine

roundworms lungworms

external parasites

1 ml/110 lbs. (cattle)

1 ml/110 lbs (swine)

Sub Q or IM

cattle:  35 days slaughterswine: 24 days slaughter

Dectomax® pour-on for cattle 0.5%

Doramectin ML cattleroundworms lungworms

external parasites

5 ml/110 lbs.topical

cattle:  45 days slaughter

Ivomec® Eprinex pour-on

Eprinomectin ML cattleroundworms lungworms

external parasites

5 ml/110 lbs. topical

cattle:  0 days slaughter

Ivomec® pour-on for cattle

Ivermectin ML beef cattle roundworms lungworms

external parasites

1 ml/22 lbs.topical

cattle: 48 days slaughter

Ivomec Plus Injection

ClorsulonIvermectin

ML beef cattle

roundworms lungworms

external parasitesAdult liver flukes

1 ml/110 lbs.SQ

cattle: 49 days slaughter

Ivomec® injectable 1%

Ivermectin MLbeef cattle

swine

roundworms lungworms

external parasites

1 ml/110 lbs cattle. 1 ml/75 lbs. swine

Sub-Q

cattle:  35 days slaughterswine: 18 days slaughter

Ivomec® sheep drench 0.08%Primectin™ Drench

Ivermectin ML sheeproundworms lungworms

external parasites

3 ml/26 lbs.by mouth

sheep: 11 days slaughter

Rumatel® Medicated Premix

Morantel Tartrate

TETRcattle goats

mature roundworms

1/10 lb./100 lbs.cattle: 14 days goats:  30 days

Prohibit Drench Powder

Levamisole Hydrochloride

TETRcattlesheep

roundworms intestinal worms

lungworms

Depends on dilution

cattle: 2 dayssheep: 3 days

Quest® 2% equine oral gel

Moxidectin MLhorsesponies

roundworms lungworms

external parasites0.4 mg/2.2 lbs.

not for horses intended for food

Safeguard® Panacur® liquid 10%

Fenbendazole BZDcattle, non-

lactating goats

roundworms lungworms tapeworms

2.3 ml/100 lbs.by mouth

cattle:  8 days slaughter0 milk withdrawalgoats: 6 days slaughter

Safeguard® Panacur® paste

Fenbendazole BZDcattle horses

roundworms lungworms tapeworms

2.3 mg/lb.by mouth

cattle:  8 days slaughter

Tramisol/Levasole® injectable for cattle 13.65%

Levamisole IMID beef cattle roundworms lungworms

2 ml/100 lbs. Sub-Q

cattle: 7 days

Tramisol/Levasole® boluses/oblets

Levamisole IMID sheeproundworms lungworms

1 bolus/50 lbs.by mouth

sheep:  3 days slaughter

Valbazan® drench 11.36%

Albendazole BZDcattle sheep

roundworms lungworms tapeworms

adult liver fluke

3 ml/ 100 lbs. oral

restricted during pregnancy

sheep: 7 days slaughter

Zimecterin-EZ® paste 1.87%

Ivermectin MLhorsesponies

roundworms lungworms

external parasites

1 tube/1250 lbs.oral

not for horses intended for food

Safeguard Pellets

Fenbendazole BZDcattleswine

roundworms lungworms tapeworms

1 lb./100 lbs.by mouth

swine: 14 days slaughter

Strongid® T paste

Pytrantel Pamoate

TETRhorsesponies

mature roundworms

2.27 mg/lb.by mouth

not for horses intended for food

Synanthic® drench 9.06%

Oxfendazole BZDbeef cattle

non-lactating dairy

roundworms lungworms tapeworms

2.5 ml/110 lbs.by mouth

cattle:  7 days slaughter

Tramisol/Levasole® drench

Levamisole IMIDsheep cattle

roundworms intestinal worms

lungworms

1 oz./100 lbs. 1 ml/50 lbs.by mouth

sheep: 3 days slaughter

References

• http://www.sheepandgoat.com/articles/antheltable.html

• http://www.uwyo.edu/vetsci/Courses/PATB_4110/2009_lectures/33_parasites_cattle_sheep/HTML/Class_Notes.htm

• http://extensionvetmed.blogspot.com/2009/04/when-is-right-time-to-deworm-cattle.html