Docstoc

Parasites

Document Sample
Parasites Powered By Docstoc
					Parasites
Why are parasites an issue?
• Low growth
• Decreased production
• Goats highly susceptible- browsing vs. grazing
What are some signs of parasite
         infestation?
                Some Signs
• Anemia – specific to parasites that consume
  blood
• Weight loss
• Weakness
• Rough coat
• Diarrhea- sometimes bloody stool
• High FEC
• Bottle Jaw
What are some parasites we are
      concerned about?
     (candy for answers)
       Some Parasites of Note
• Haemonchus Contortus- (barber pole worm)
  rising problem in New England, major problem
  in southern US
• Ostertagia
• Trichostrongylus
• Nematodirus
• Cooperia
Prevention…
             Some methods:
• Rotational grazing
• Keeping older stock and younger stock in
  separate pastures, rotate younger stock ahead
  of older stock
• Off the ground feeders, not near bedding area
• Get/keep resistant goats (the dream)
What are the tests we use to detect
            parasites?
                     Tests
• Body Condition Score (BCS) – weight loss/gain
• FAMACHA – looking at the color of mucuos
  membranes under the eye to detect anemia
• Fecal Egg Count (FEC)- counting parasitic egg
  levels
• Packed Cell Volume (PCV)- looking at the
  percentage hematocrit to detect anemia
• Larval test- using a fecal sample to raise and
  identify specific parasites infecting herd
                      BCS
• Assess potential weight loss
• If food availability has remained constant, one
  cause may be parasite infection
• Scale of 1-5, 1 = thin 5= obese
• Subjective
                FAMACHA
• Developed in South Africa
• Quick assessment for anemia
• Anemia the major symptom of H. contortus
  infection, a major parasite problem in warmer
  climates (like South Africa).
• Subjective
                         FEC
•   May be done with centrifuge or fecal float
•   Measures the number of eggs per set amt feces
•   Can be done as group or individual sample
•   Egg morphology can detect different subsets of
    parasite infection to target problem
•   Relevant number of eggs depends on the method used
•   i.e. EPG (Eggs per Gram) measured using McMaster’s
    method
•   http://www.fao.org/wairdocs/ILRI/x5492E/x5492e05.h
    tm website with good descriptions of varied methods
•   We use fecal flotation
                    PCV
• Small blood sample centrifuged
• Hematocrit portion used to determine RBC
  count which in turn indicates anemia
• Standard in goats: 22-38
                Larval Test
• Used in parasitology labs
• Requires more equipment and a period of
  about two weeks
• Challenging:
Okay, we know we have a parasite
problem (UMass definitely does)

       What do we do now…
               Chemical Dewormers
• Administered orally, topically, sub-Q, IM
• Technically a poison
• Resistance – kills less than 90% of intestinal parasites
• Cost
• How often and how much:
   -goats typically take a higher dosage (150% of sheep dose according to
  sheep & goat medicine)
   -goats generally off label
   -traditional method taught here: before kidding, every time put on new
  pasture
   - also in use: winter deworming and post-kidding deworming, weather-
  dependent deworming ( 10-14 days after rain), or based on signs
• Dose based on heaviest animal in herd
• Selectively deworm
               Sub-Groups
• Benzimidazoles- aldendazole (Valbazen),
  fenbendazole (Safeguard)
• Levamisole
• Macrocylic lactones- ivermectin, moxidectin
    Some types of Chemical Dewormers
             you could see…
•   Albendazole
•   Fenbendazole
•   Ivermectin
•   Levamisole
•   Moxidectin
       Alternative Dewormers
• COWP – Copper Oxide Wire Particles
• Garlic Juice
• DE- Diatomaceous Earth
    The Final Alternative Dewormer:
                 Culling
• Take problem animals out of herd
• How do the problem animals effect the rest of
  the herd?
• Why doesn’t this always work in our herd?
                   Sources
• Sheep and Goat Medicine by David Pugh
• “War of the Worms” presentation by
Anne Zajac (parasitologist at Virginia Tech)
• Goat Medicine by Dr. Mary Smith

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:10
posted:12/25/2011
language:English
pages:23