Intestinal coccidiosis is caused by infection with
any one of the coccidia species: Isospora,
Besnoitia, Hammondia, Sarcocystis,
Toxoplasma, or Cryptosporidium.  Infection
with Isospora is most common in dogs.  
Infection occurs when infective eggs are
ingested from a contaminated environment, or
an infected transport host is ingested.  Rodents
and other small prey can carry coccidia,
making ingestion of their tissues and feces
infective.  Infection with coccidia can also occur
when uncooked meat from infected herbivores
such as cows or sheep is ingested.  After
ingestion of ocysts, the incubation period is
usually 6 to 10 days.
Most vets will be quick to tell you that it is from
unsanitary conditions, but that is not always the
case.  The presence of coccidia in the feces of
dogs is fairly common.  Up to 72% of dogs may
have some level of infection with coccidia.  
Multiple dog kennels are most prone to
infection.  The major sign of coccidiosis is
diarrhea which is soft or watery, and may
contain mucus, blood, and shreds of intestinal
epithelium.  Vomiting, dehydration, loss of
appetite, weight loss, and decreased activity
level are other signs associated with coccidia.  
Diarrhea is typically most severe in puppies
under 4 months of age.  Adult dogs may harbor
coccidia with few clinical signs, but serve as a
source of infection to puppies.  Diagnosis is
made by microscopically identifying oocysts in
feces.
Strict sanitation is important for prevention of
infection.  All cages and kennel runs should be
cleaned with steam or a strong sodium
hydroxide solution to kill oocysts.  Prompt
removal of feces helps reduce exposure to
infective feces. Elimination of rodents and
rodent feces will reduce coccidia in the
environment.  Any meat that is fed should be
thoroughly cooked.  Older dogs that may be
asymptomatic carriers should be kept separate
from young puppies.
Puppies showing clinical signs of coccidiosis
should be treated orally with sulfadimethoxine
(Albon or Bactrovet) at 25 to 30 mg/lb body
weight per day for 10 days.  Amprolium (Corid)
is not approved for use in dogs, but has been
used effectively in kennel operations.  
One-quarter teaspoon of 20% powder per four
puppies is mixed with the puppy food for 10
days, or 1.5 to 2 tablespoons of 9.6%
amprolium solution can be mixed with one
gallon of free-choice water.  With severe cases
of coccidiosis, secondary intestinal bacterial
infections are common, and treatment may
need to be prolonged.
Coccidiosis