Lawhorn, Bruce

English

Texas A&M University

L-2423
Texas Agricultural Extension Service
Internal Parasite Control
in Farrowing Operations
Bruce Lawhorn
Extension Veterinarian
The Texas A&M University System
Internal parasites are a common problem in swine
operations. The degree of economic damage they
cause depends on the management practices used
(deworming, nutrition, sanitation), the design of the
facility and the reinfection rate.
There are many internal parasites of swine.
Roundworms, whipworms, nodular worms and
lungworms are examples. Economic damage is best
exemplified by the common swine roundworm. Pigs
may eat the microscopic roundworm eggs when their
environment is contaminated with manure. Larvae
from these eggs migrate through the liver and lungs to
the small intestine. They cause coughing, pneumonia,
liver abscesses and reduced growth rate. In the small
intestine larvae mature to egg-laying adults in about 60
days. These adult worms seed the environment with
eggs that are extremely resistant and long-lived and
may infect or reinfect all exposed pigs.
Roundworms are commonly diagnosed by micro-
scopic examination of swine manure samples using the
flotation technique. Since the animal may be infected
with migrating larvae which have not yet become egg-
laying adults in the intestines, this test is less than 100
percent accurate. Knowledge of liver scars in animals
marketed from a herd may indicate whether or not a
worm problem exists in breeding animals purchased
from that herd.
Many producers prefer to routinely deworm new
breeding animals during an isolation period. Depend-
ing on the dewormer used, only the adult worms or
recently hatched larvae in the intestine may be killed,
while migrating larvae will persist. SafeGuard® (fen-
bendazole) added to feed is a recently approved broad
spectrum dewormer that kills adult worms in the intes-
tines and lungs as well as migrating larvae. It is highly
effective against whipworms. Ivomec® (ivermectin), at
Icc per 75 pounds of body weight injected sub-
cutaneously or under the skin, is an even newer broad
*Atgard®, an organophosphate dewormer, should
not be used within 3 weeks of other organophosphates
(i.e., Tiguvon®, lice pour-on, Prolate@).
spectrum dewormer. However, it has limited effective-
ness against whipworms. Atgard®* (dichlorvos),
Tramisol® (levamisole) and Banmith® (pyrantel
tartrate) are added to feed and mainly kill adult worms
in the intestines. Levamisole is used also in water and
Atgard® cannot be fed in pelleted feed. Pyrantel
tartrate can be used at a low level in the feed for 30
days or more to kill roundworm larvae as they emerge
from eggs in the intestines. Dichlorvos is highly effec-
tive against whipworms. Levamisole has limited effec-
tiveness against whipworms.
No matter what precautions are taken with newly
purchased breeding animals or those selected from the
herd, if the environment is contaminated with eggs all
pigs will soon be infected. For this reason a swine
producer should have an ongoing program for control-
ling internal parasites within his herd. The key to
control lies with the breeding herd. An initial control
program should include the following steps:
1. Deworm the entire breeding herd with Safe-
Guard®, Atgard®, Tramisol®, Ivomec® or Banmith®
three times at 21-day intervals. Different products may
be used at each deworming.
2. After step 1 has been completed, routinely
deworm sows about 2 weeks before farrowing to min-
imize transmission of worms from sows to pigs.
3. Wash sows before farrowing and put them into a
clean, disinfected farrowing area.
4. Routinely deworm all sows at weaning.
5. Deworm boars at least every 3 to 6 months.
6. Deworm pigs at 8 to 10 weeks of age in two
applications 3 to 4 weeks apart. Use SafeGuard®,
Atgard®, Ivomec®or Tramisol®. An optional pro-
gram, if roundworms are a~articular problem, is to
deworm pigs with Banmith beginning at 4 weeks of
age and continuing for 30 days.
7. Monitor the effectiveness of the program by con-
ducting routine fecal examinations and checking for
liver scars when market pigs are slaughtered. Animals
that die on the farm also should be checked for liver
scars.
Texas Agricultural Extension Setvice • The Texas A&M University System • Zerle L. Carpenter, Director • College Station, Texas
8. Deworm all incoming breeding animals while
they are kept in an isolation area. The need for this step
is determined by the source of the breeding stock
and/or fecal sample examination.
After internal parasite problems are reduced, steps
2, 5 and 6 may be sufficient for control. It may even be
possible to eliminate step 6 once the breeding herd is
free of parasites, provided animals are not exposed to
worm eggs in their environm~nt.
/
Educational programs conducted by the Texas Agricultural Extension Service seNe people of all ages regardless of socioeconomic level, race,
color, sex, religion, handicap or national origin.
Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended, and
June 30 1914, in cooperation with the United States Department of Agriculture. Zerle L. Carpenter, Director, Texas Agricultural Extension
Service, The Texas A&M University System.
4M- 7-90, New AS 7


Internal Parasite Control in Farrowing Operations.

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Internal Parasite Control in Farrowing Operations.

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