What’s
Hiding in
your Pet?
by Erin Quigley, DVM
Potentially harmful parasites! A parasite is an
organism that lives on (external) or in (internal)
an organism of another species (such as dog, cat or
human), known as the host. The parasites live and
reproduce by feeding on the host directly or by taking
in a portion of the host’s nutrients.
This month we will be talking about internal parasites
that affect your dogs and cats and potentially you and
your family.
Internal parasites
Last month we talked about a common internal
parasite that lives in heart, lungs and blood vessels of
dogs and cats called Heartworms. This month we will
be talking about another common classification of
internal parasites called intestinal parasites. Intestinal
parasites can live anywhere in the body but tend to
populate in the gastro- intestinal tract. The two main
categories of intestinal parasites are Helminths (aka.
worms) and Protozoa (single cell organisms). Let’s start
with worms…
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MetroPet Magazine | St. Louis - May 2014
Roundworms
Roundworms are among the most common intestinal
parasites of dogs and cats. These worms are large as
adults (3-18 cm in length) and when passed they
resemble spaghetti noodles.
Transmission — Dogs and cats of any age may get
roundworms but they are most vulnerable when they
are young. In fact 90% of puppies fewer than three
months of age can be infected. That’s because these
worms are often passed from a mother to her puppies
before birth through the placenta and shortly after
birth through her milk. All ages can become infected
by ingestion of fecal material of an infected animal.
This can happen easily by a dog stepping in soil
contaminated by an infected animal for example at a
park, or even in your yard if a stray animal or wildlife
has passed through. When your dog licks its paws, it
becomes infected.
Symptoms — In puppies or kittens common
symptoms include failure to gain weight, poor hair
coat, and pot-bellied appearance. In heavier infections
the young puppy or kitten may expel worms in
their vomit. Adult dogs and cats may show signs of
diarrhea, blood in stool, weight loss or vomiting.
** V
ery commonly a dog or cat may act completely
normal yet still be shedding the worm eggs
in the stool, without any visual evidence,
contaminating the environment (your home and
yard).
Prevalence — How common are Roundworms. As
stated above, roundworms are extremely common in
puppies. Every puppy should be tested, ideally before
coming home to your family and your other pets.
In adult dogs according to the Companion Animal
Parasite Council, the current statistic for Missouri
matches the National prevalence of 1 out of 45 dogs
tested are positive for round worms. This includes
dogs both on and off preventative.
Diagnosis — It is true that a diagnosis can be made
by seeing adult worms in the stool, but this is a rare
occurrence. The majority of the time our pets are
shedding microscopic eggs without our knowledge
or any evidence so a diagnosis needs to be made
by fecal flotation. This is the definitive diagnostic
test that uses special solutions, centrifugation and
microscopic exam to detect the parasite in your dog
or cat.
Take Away Point: You cannot look at your dog
or cats stool and know if he or she has intestinal
parasites! Most of the time worms are diagnosed in
dogs and cats with normal appearing fecal matter.
This is why your veterinarian recommends yearly
fecal examination.
Zoonotic — Yes, roundworms can be transmitted
to people, most vulnerable are children. How?
The most common way is through fecal-oral
transmission. Dogs and cats contaminate homes
and yards with infective eggs and larvae passed
in their stool. These eggs and larvae are resilient
and can survive in parks, playgrounds and yards,
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even inside homes. People get infected through direct
contact with infected feces. This can happen if a dog has
recently licked their contaminated paws and then pass
that material by licking a child’s face. Most commonly
transmission occurs when children play in contaminated
soil or sand boxes when hands or contaminated
objects go in the mouth. Immune
compromised adults also are also at
an increased risk.
When infection occurs in people
the ingested eggs hatch into larvae,
these larvae travel through the
liver, lungs and other organs. In
most cases, these “wandering
worms” cause no symptoms or
apparent damage. However, in
some cases they may produce a
condition known as visceral larva
migrans. The larvae migrate and
cause damage to tissue, affect the
nerves or even lodge in the eye, and
potentially cause blindness.
Prevention — So, what can we do to protect our pets
and family? Here is a list of things we can all do to
prevent the spread of worms.
• Take your puppy or kitten immediately into the
veterinarian when you adopt them so they can
be screened for parasites with a fecal exam and
dewormed before exposing your family or other pets.
• Have your adult dog and cat tested annually for
intestinal parasites by a fecal examination at your
veterinarian’s office. Place your pet on a monthly
parasite preventative. There are oral and topical
preventatives appropriate for dogs and cats that their
doctor can recommend. Give these preventatives to
indoor and outdoor animals all year round. Because
parasites live inside our pets and shed any time of year,
preventatives should not be viewed as seasonal. Indoor
animals, like our feline companions, are exposed by
tracking in parasite eggs on the bottom of feet by the
family or the family dog.
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•A
t home you can promptly remove animal feces from
the yard or litter box to prevent contamination and
spread between animals. Keep dogs on a leash or in
fenced yard and keep cats indoors.
•M
onitor children when they are playing outside in the
yard, playground and sandboxes. Cover sandboxes
to prevent contamination.
Children and adults should
wash hands frequently,
especially if at risk of feces
handling or exposure to feces.
For people with weakened
immune systems, be especially
careful of contact with animals
that can transmit these
infections.
Hookworms
Hookworms are short (6 to
12 mm), thick worms that are
whitish to reddish brown with
a hooked front end. They are
rarely seen as adults so diagnosis is necessary by fecal
flotation to find eggs.
Transmission — Puppies can contract worms from
crossing the mother’s placenta and through the mother’s
milk similar to Roundworms. Hookworms are not
transmitted to kittens in pregnancy. All ages of dogs
and cats can obtain hookworms from ingestion of
contaminated fecal material. Something unique about
Hookworms is they can penetrate through skin of a dog,
cat or person, from infected soil.
Symptoms — Infected puppies and kittens can be
anemic and show pale gum color, and fail to gain
weight. They can also have a dull hair coat and become
dehydrated or have dark, tarry, soft stools.
When people are infected they have red, itchy skin with
a worm like lesion under the skin.
Prevalence — Nationally one out of every 51 dogs
tested are positive for hookworms. Missouri has an
increased risk with one out of 35 tested dogs being
positive. This increased prevalence may have something
to do with the fact that we do not tend to see adults in
stool, where occasionally we will see adult roundworms.
This is why it is so important we test our dogs’ and cats’
stool annually.
Diagnosis — Diagnosis is made by fecal flotation test at
your veterinarian’s office.
Zoonotic ­— Yes, similar to roundworms people,
particularly children, are at risk by a fecal-oral route.
Contaminated soil, sandbox or stool that is on your
pet or in your home is transferred to your hands and
then to your mouth. Unique to hookworms and more
common transmission in people is penetration through
the skin. Commonly it occurs when not wearing socks or
shoes while gardening or playing in sandboxes that are
contaminated.
Prevention — The steps to preventing hookworm
infection are identical to roundworms with deworming
of puppies and kittens, monthly prevention and annual
fecal examinations. In addition to removing feces from
the yard to prevent ingestion it is also recommended to
wear shoes and gloves while gardening.
Whipworms
Whipworms are named for their characteristic whipshaped body and infect dogs, foxes and coyotes; cats are
not affected. Adult worms are 4.5- to 7.5-cm long and are
rarely seen in stool. Transmission is through ingestion
of contaminated soil, and not through maternal placenta
or milk. Symptoms include diarrhea with bright red
blood or mucus, staining to defecate, and weight loss.
Diagnosis is made by fecal flotation and treatment is an
oral deworming medication. The national prevalence for
whipworms is 1 out of 116 dogs tested. The prevalence in
Missouri is 1 out of 31 dogs tested. The good news about
Whipworms is that they are not zoonotic (contagious
to people). The bad news about Whipworms is they
are impossible to get rid of from your environment.
Whipworm eggs can persist in soil for several years,
surviving winter freezing and even burning of top soil.
So once your dog is infected and yard is contaminated
monthly preventative specific to prevent whipworms
must be given every 30 days all year round. Dogs that
visit dog parks or live in communities where land is
shared between several pets are at increased risk.
Tapeworms
Tapeworms have a flattened, ribbon-like appearance
and are often seen in motile segments that resemble
white rice directly in stool, near the anus of an infected
dog or cat, or in the environment. Transmission is
through ingestion of fleas or animals that carry fleas such
as rodents and rabbits. Often our pets carry tapeworms
for months at a time without any symptoms. Tapeworms
may absorb nutrients in the intestinal tract, but rarely
cause disease. If signs are present it is commonly itching
or dragging their hind ends. Unique to tapeworms is that
diagnosis is typically by observation of the segments on
the animal or in the environment; these parasite eggs
are rarely detected on fecal examination. Treatment of
this parasite is by oral medication and prevention is by a
high quality monthly flea preventative. As far as risk of
infection to people, it is through contact with the fleas on
your pet and in your home or by accidental ingestion of
fleas. Most people infected do not show symptoms, but
diarrhea, abdominal pain and anal itching are possible.
Protozoa
Giardia - is a microscopic two-celled organism with
flagella (whip like tails) that lives and reproduces in the
small intestines of infected humans or other animals.
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Individuals become infected through ingesting or
coming into contact with contaminated food, soil, or
water. The Giardia parasite originates from contaminated
items and surfaces that have been tainted by the feces of
an infected carrier. Commonly dogs ingest this parasite
by drinking water from creeks, rivers and rain puddles.
The symptoms of Giardia, which may begin to appear
2 days after infection, include violent diarrhea, excess
gas, stomach or abdominal cramps, upset stomach, and
nausea. Resulting dehydration and nutritional loss may
need immediate treatment. Diagnosis can be made at
your veterinarian, and treatment includes specific course
of antibiotics and anti-parasitic drugs with supportive
care, such as fluid therapy.
Coccidia — is a single-celled organism that infects
the intestinal tract of dogs and cats, particularly kittens
and puppies in shelter environments. Infection causes
diarrhea with weight loss, dehydration, and (rarely)
hemorrhage. Severely affected animals may present with
anorexia, vomiting, and depression. Death is a potential
outcome. Dogs and cats may shed coccidia in feces but
remain asymptomatic. Many times an asymptomatic or
mild infection may become significant during times of
stress such as changing environments to a new home.
Published surveys indicate that coccidia are present in
from 3% to 38% of dogs, and 3% to 36% of cats in North
America. Diagnosis is made strictly by centrifugation
fecal exam. Treatment is a sulfa-type drug for duration
of 7-20 days. Prevention is soley based on environmental
control, and disinfectants of surfaces and treating
exposed animals. Unfortunately in some environments
there is much resistance in coccidiosis infection, despite
medicating and disinfecting. Because humans are not
susceptible to the species of coccidia that infects dogs
and cats, canine or feline coccidia are not considered
zoonotic agents.
Summary
Whether its worms or protozoa, microscopic organisms
may be shedding off your family pet at any time without
any evidence. Speak with your veterinarian today so she
can help you protect your pet and your family from all
of these harmful parasites with one simple yearly test, as
well as provide a preventative fit for your dog or cat and
lifestyle needs.
Erin Quigley, DVM,
Member of AVMA,
MVMA, grew up in
Florissant, MO, and
received a Bachelor’s
degree in Biology
at Missouri State
University. After
college I worked
as a receptionist
at Rock Road Animal Hospital, a
zookeeper at the St. Louis Zoo and a
veterinary assistant at Howdershell
Animal Hospital until attending
Veterinary School at University of
Missouri-Columbia. I graduated with
my Doctorate of Veterinary Medicine
and have lived in O’Fallon, Missouri
since I graduated. I have worked as a
veterinarian in Troy, Wentzville, and
Florissant, MO, until purchasing Animal
Medical Center of Wentzville in 2010.
I married in 2011 and live with my
husband Ryan and boxer dog Finnegan
in Lake St. Louis/O’Fallon. When
my husband and I have free time from
the clinic we enjoy spending time with
our dog, family and friends. Our hobbies
include attending Cardinal baseball and
Mizzou football games. We also enjoy the
outdoors biking, boating and horseback
riding.