The Porcine Respiratory Disease Complex (PRDC) is a term used to
describe several diseases that can affect pigs from birth through
finishing, with the primary impact usually seen around week 18 to
20. The disease complex includes two primary viruses – PRRS
(porcine reproductive and respiratory syndrome) virus and SIV
(swine influenza virus) as well as Mycoplasma hyopneumoniae bacteria.
Several secondary bacteria are also found in PRDC: Actinobacillus
pleuropneumoniae (APP), H.
parasuis, A. suis, Strep. suis and salmonella.
A key to PRDC is mycoplasmal pneumonia, also called enzootic pneumonia,
which is caused by Mycoplasma hyopneumoniae. The disease
is extremely common, especially in commingled groups of pigs.
Disease is spread
contact from sows to piglets, and then among piglets once they
are commingled. The disease has a slow onset with a long incubation,
so symptoms may not show up until pigs are 3 to 6 months of age.
Almost all mycoplasmal pneumonia infections are complicated
by secondary pneumonias, which can result in high death losses.
Severe disease is often due to a complex interaction between mycoplasma bacteria,
a poor environment (including changes in weather), and secondary
infections from other bacteria, viruses and parasites.
Rhinitis and pneumonia
Atrophic rhinitis (AR) is caused by Bordetella bronchiseptica.
These bacteria can act as the primary invader, or may set the animal
up for a secondary
infection with bacteria such as Pasteurella multocida. Nasal passages
damaged by AR are not able to do an effective job of filtering
the air the pig breathes, allowing more bacteria access to the
This, in turn, makes it more likely that the pig will develop
B. bronchiseptica also causes bronchopneumonia,
a more severe disease that can occur in piglets as young as 3
to 5 days.
Pasteurella multocida is another important cause of pneumonia.
It has two primary types – Type A and Type D. Type A is
a secondary invader that takes advantage of previous lung damage
and causes severe
pneumonia. Type D colonizes in the nasal passages and releases
a toxin that damages tissues. It can cause atrophic rhinitis in
Severe cases of pneumonia in growing pigs can be caused by Actinobacillus pleuropneumoniae (APP). Onset is sudden and can be very contagious
with high morbidity and mortality. Some pigs may be found dead without
having shown clinical signs, which include heavy respiratory distress.
Once established in a herd, the disease may be evident only as a
cause of reduced growth rate and persistent coughs.
Swine salmonellosis is the fourth most costly disease of swine,
with annual losses estimated at $20-100 million. It is a systemic
disease characterized by pneumonia, as well as liver abscesses
PRDC, mycoplasmal pneumonia:
chronic, non-productive cough and an unthrifty appearance; decreased
rate of gain and decreased feed
Rhinitis: Sneezing, snuffling, rubbing the nose,
black tear streaks from the eye and excessive nasal discharge.
Bronchopneumonia: Coughing and labored breathing.
APP: Open-mouth breathing with bloodstained frothy nasal and oral
discharge, and high fever, anorexia and reluctance to move.
Concentrate is a proven, broad-spectrum antibiotic effective
in treating swine pneumonia caused by Actinobacillus pleuropneumoniae (APP).
It also treats swine dysentery associated with Brachyspira
(Serpulina) hyodysenteriae. The water-soluble medication
can quickly and conveniently be administered with response usually
evident within 24 to 48 hours. It is readily absorbed from the
gut and can be found in the blood within 30 minutes after dosing.
Shield™ is a convenient 1-mL vaccine
that can be given to any pig 2 weeks of age or older. Revaccination
with a booster dose
in 2 weeks produces elevated and extended immunity to
help prevent the potentially devastating effects of mycoplasmal
PneumoSTAR® SIV is
the only vaccine that provides swine
influenza virus (SIV) protection
in just one dose. It has broad cross-reactivity among various SIV
strains, which means more effective immunity. It is labeled for
intramuscular administration, with a 1-mL dose at three weeks of
age or older.
Rhinicell® FD is
a single-dose, intranasal vaccine that can be given to piglets at
one day of age to prevent atrophic rhinitis caused by
B. bronchiseptica. It can also be given as
an intramuscular injection to gilts and sows prior
to farrowing. Also available is Rhinicell
+ E, the only intranasal erysipelas/Bordetella vaccine
approved for use in newborn piglets.
Shield™ TX4 provides
convenient four-way protection, helping prevent atrophic rhinitis
caused by B. bronchiseptica and P. multocida Types A and D, pneumonia caused by P.
A, and erysipelas. It includes a toxoid against the Type D toxin.
Salmo Shield Live offers one-dose
protection against both the septicemic and respiratory forms of
salmonellosis caused by Salmonella
It should be given to herds where salmonella has been a chronic,
ongoing problem or in commingling feeder operations where carrier
animals are common.
Caution: Do not feed Denagard
10 undiluted. Do not use in feeds for animals other than swine.
being treated with Denagard (tiamulin) should not have access to
feeds containing polyether ionophores (e.g., lasalocid, monensin,
narasin, salinomycin and semduramicin) as adverse reactions may
occur. See product label for directions for use and additional information.
Caution: Do not use Denagard
Liquid Concentrate undiluted. Contraindications: Swine being treated
with Denagard (tiamulin) should not have access to feeds containing
polyether ionophores (e.g., lasalocid, monensin, narasin, salinomycin
and semduramicin) as adverse reactions may occur. See product label
for directions for use and additional information.