GASTROINTESTINAL PARASITISM –
WHAT CAN WE DO ABOUT IT?
Gastrointestinal parasitism is a major cause of diarrhea, poor growth rates, and a failure to thrive in older kids or adult goats.
Sub-clinical levels may cause significant losses in production (weight gain, milk production) without showing the above clinical signs
Goats become infected with gastrointestinal parasites by grazing infected pastures. Eggs are passed in the manure from infected goats and sheep onto pasture. The eggs hatch into larvae, migrate onto blades of grass, and are consumed by grazing animals.
Adult goats are just as susceptible to infection as are kids. Older animals do not develop immunity.
Control measures by which we may decrease the level of infection:
To avoid high levels of infection:
1) Provide large enough pasture areas that goats are allowed to follow their preferred browsing habits, without close cropping of grass. As the stocking number of goats increases, the greater the likelihood that the pasture will be overgrazed.
2) Rotate grazing of pastures. Goats can share pastures with horses and cattle, but not sheep, as sheep are plagued by the same gastrointestinal parasites as goats.
.
Limit infection by grazing management:
1) Maintain safe pastures (pasture not grazed in the second half of the previous year or pastures ungrazed until mid summer when over-wintered larvae have died off)
2) Kid indoors, early in the spring, to prevent contamination of pastures by the perparturient egg rise. The hormonal influence associated with approaching parturition brings about the maturation of hypobiotic larvae, (ingested larvae that encyst in the wall of the abomasum) leading to an increase in egg output into the feces. This results in greater pasture contamination.
Institute a Strategic Parasite Control Program:
1) Deworm adults at spring turnout.
2) Deworm at 3 week intervals for 4 treatments. After this time period, the eggs that survived winter on the pasture have either:
(a) Hatched into larvae and been consumed by the goat during grazing and destroyed by timed interval deworming treatment
(b) Hatched into larvae and have not been consumed from blades of
grass. These larvae have a finite energy supply and will die after a
period of time if not ingested.
(c) Egg did not hatch and is desiccated by summer heat and lack of
moisture and is no longer viable
3) A safe pasture with low levels of parasite eggs has now been created through strategic parasite control.
GOAT AND SHEEP GASTROINTESTINAL PARASITES HAVE SHOWN RESISTANCE TO ALL THREE MAJOR GROUPS OF DEWORMERS.
Group I: Benzimidazoles
Albendazole-”Valbazen”
Fenbendazole- “Panacur”f’SafeGuard”
Oxfendazole-”Synanthic”
Group II: Colinergic Agonists
Levainisol —<< Tramisol>>
Morantel-”Ruinental”
Pyrantel- < Strongid>>
Group III : Avermectins
Ivomectin — < Ivomec>>
Eprinomectin-<< Eprinex>>
Moxidectin-<< Quest,>> ~ Cydectin>>
Doramectin_ >>Dectomax>>
PITFALLS IN YOUR BEST LAID PLANS FOR DEWORMING PROTOCOLS
1. Estimation of body weight in goats is very imprecise and many goats are under dosed. Under dosing increases the rate of selection for wormer resistance by exposing parasites to sublethal concentrations of dewormer. Weigh goats whenever possible (while at shows) or use weight tapes.
2. Using a wormer that is ineffective due to resistance of the parasite.
HOW TO DETERMINE WHTCH GROUPS OF WORMERS ARE EFFECTIVE IN YOUR HERD:
1) Have your veterinarian perform a McMasters egg count (a specific type of laboratory test) on samples of manure from several of your animals prior to using a deworming preparation.
2) Deworm animals
3) Repeat McMasters egg counts 10-14 days after the deworming and look for a 90% reduction in the number of eggs.(Second count must be done within that 2 week period after worming so newly ingested eggs from pasture will not have time to develop and shed eggs.) (We charge $10 for a McMasters test) A wormer that is found to be effective can now be used with confidence.
Dewormers for goats
Avermectins: Withhold times
Ivermectin “Ivomec” Drench 3m1126#BW P0 lid meat 40d milk
“Ivomec << 1% injectable 1 mlIlOO # BW SQ
Doramectin “ Dectomax” 0.3mg/kg SQ 56 d meat 40d milk
Eprinomectin “Eprinex” 1m1120#BW P0 Od meat 0 days milk
Moxidectin “Quest”; “Cydectin” 0.5mg/kg P0 0 days meat ? milk
Benzimidazoles
Albendazole “Valbazen” 10mg/kg P0 27d meat Sd milk
Fenbendazole “Panacur”/”Safeguard” 4.6m1/l00#BW P0 14d meat 4d milk
APPROVED
Oxfendazole “Synanthic” 10mg/kg P0 14d meat 5d milk
Cholinergic Agonist:
Levamisol “Levasole > / << Tramisol>> 8mg/kg P0 lOd meat 4d milk
Morantel “Rumatel” 10mg/kg P0 30d meat 0 days milk
APPROVED
Facts to Remember
1) The estimation of weight in goats is very imprecise. Use some method other than the “eyeball method.”
2) Determine which families of wormers are effective in your herd by doing pre and post worming fecal egg counts.
3) Rotate wormers on a yearly basis between dewormer groups that have been determined to be effective in your herd.
4) Use strategic deworming intervals to reduce pasture contamination.
COCCIDIA- PROTOZOAL PARASITE
This is the most important cause of diarrhea in kids greater than 3-4 weeks old.
The coccidia that infect cattle, domestic pets, and poultry do not cause problems in goats.
TRANSMISSION;
All goats are infected with coccidia. Adult goats have developed immunity, but still carry low levels of parasite in their GI tract, and therefore act as a source of infection to younger, non- immune animals.
Kids become infected by ingestion of feces-contaminated food, water, and bedding. It is probable that all kids are infected during the first few weeks of life. Management standards determine whether or not signs of clinical disease develop.
Oocysts(eggs) that are ingested, rapidly undergo maturation and multiply within the gut A single oocyst could result in one to two million oocysts being passed 3-4 weeks later.
Infection can occur indoors in intensive rearing situations or at pasture where grass is sufficiently short for ingestion of oocysts lying on the soil surface.
CLINICAL SIGNS:
Depression, anorexia (off feed), weight loss, diarrhea (possibly with blood), dehydration, anemia, death
DIAGNOSIS:
By clinical signs and microscopic fecal examination
CONTROL:
IMPROVED HYGIENE IS THE CORNERSTORNE OF COCCIDIA CONTROL
1) Avoid overcrowding
2) Provide clean, dry, well- bedded pen for each batch of kids
3) Do not mix kids of different age groups
4) Raise food and water containers above the floor and prevent kids from jumping
in feed pans to avoid fecal contamination.
Prevention: Withdrawl
Monensin -Rumensin approved 15-2Ograms/T of feed 0 d meat
Lasalocid - Bovatec extralabel 20-3Og/T ? d meat
Decoquinate- Deccox approved 0.5#IT 0 d meat
Amprolium - Corid extralabel 25-50mg/kg body wt. ? d meat
These compounds may be added to feed. (Amprolium may be in feed or water.)
TREATMENT:
1) Sulfa drugs “Albon” 25mg’# loading dose for 1~ day
12.5mgI# maintaince dose for next 4 days
May dose individually or add to water.
2) Amprolium “Corid” 20-50mg/kg for 5 days in water
**This was taken from a handout Dr. Rings from Ohio State University handed out during a seminar.