INTERNAL PARASITES

Mission Veterinary Clinic and Animal Emergency Hospital

Dogs and cats can become hosts to many intestinal parasites and a few general statements apply
to all parasitic infections:
1. All de-worming medicines are poisonous to some extent and should only be used as needed
and under proper conditions.
2. At this time there is no one de-wormer that can eliminate all species of parasites.
Consequently an accurate diagnosis is necessary to treat your pet properly.
3. Diagnosis is usually made from a fresh stool sample (passed less than 12 hours) or, in
the case of tapeworms, seeing the segments in the stool.
4. Most puppies and kittens are infected before birth and, for this reason, will need de-worming
starting at 6 weeks of age. If hookworms are suspected, stools should be checked starting as
early as 23 weeks.
5. Occasionally, for a heavy parasitic infection, 3 or even 4 treatments may be necessary to
eliminate the parasite.
The following is a brief description of the common intestinal parasites with their symptoms,
diagnosis, treatment, prevention, and
human transmission.
ROUNDWORMS
This is a common worm of puppies and kittens, but can be seen in
any age dog or cat. Diagnosis is made from a microscopic examination of the feces or
from a description of the worm if it is seen in the stool or vomitus. Treatment is an oral
medication given at 2week intervals. Symptoms will vary from none to marked
vomiting and diarrhea, and abdominal swelling. Transmission to adult dogs and cats
occurs by infected feces contaminating the yard. As a result, prevention is accomplished
by isolating your pet from infected feces of other animals. For dogs, the heartworm
preventives also prevent roundworm infection. Transmission to humans is rare; young
children can develop “visceral larval migrans” by eating dirt cont
aminated with feces.
HOOKWORMS
This is also a common worm of puppies and kittens but is seen with
equal frequency in adults. This parasite sucks your pet’s blood and can cause severe
anemia. Diagnosis is made from a microscopic examination of your pet’s stool.
Treatment is either an oral medication or an injection or both. This is repeated 2 weeks
later. Symptoms will vary from none to blood in the stool (dark tarcolored stool) with
diarrhea. Severe cases may need a transfusion and hospitalization. Transmission to
adults occurs by infected feces contaminating the grass or soil. Prevention, therefore,
requires that the pet be kept away from contaminated areas. Two types of heartworm
preventive can also prevent hookworm infections in dogs. Transmission to humans is uncommon and is usually shows up as skin lesions.
 
WHIPWORMS:
This worm affects dogs only. Diagnosis is also made from a
microscopic exam of the feces. Eggs from this parasite pass intermittently, however, so
it may be necessary to check multiple fecals before a diagnosis is made. Treatment is an
oral or injectable medication given at 3 week intervals for several treatments depending
on the severity of the infection. Symptoms vary from none to a severe watery diarrhea,
vomiting, and marked weight loss. Some dogs require hospitalization for treatment of
dehydration, malnutrition, and infection. There is no human transmission.
TAPEWORMS
 
This common worm affects both dogs and cats. Transmission occurs
when your dog or cat bites and “eats” a flea. The intermediate form of the tapeworm is
inside the flea’s body and it then attaches to the intestine and begins to grow “segments”.
In about 3 weeks, these segments begin to pass in the stool. They are approximately ¼ to
½ inch long, flat, and white. After a short time in the air, they dry up to resemble a small
yellow flat seed. Diagnosis is made from seeing these segments on the stool or on the
pet’s back end rather than a microscopic fecal exam. Treatment is either by oral tablets or by an injection. The tapeworm infection kills existing tapeworms but it does not
prevent future infection.The only prevention is strict flea control. There is no direct
transmission from dog or cat to a human.
GIARDIA
This parasite is not a worm. It is a very tiny singlecelled parasite that can
live in the intestines of dogs, cats, and man. It is seen most commonly in dogs coming
out of kenneltype situations (pet stores, shelters, dog pounds, etc.) but its incidence is
increasing. Symptoms include intermittent or continuous diarrhea, weight loss,
depression, and loss of appetite. Diagnosis is made from a very fresh fecal specimen that
must be collected at the clinic for optimum results. A surprising number of affected
animals are “occult”; that is, they are infected but are negative on these tests even with
multiple examinations. As a result, this parasite is often treated without a confirming
diagnosis. Treatment is an oral medication administered at home. Prevention involves
careful disposal of all fecal material and cleaning contaminated areas. Humans can
become infected with Giardia so special care must be taken to wash hands and utensils.
COCCIDIA
This is also a singlecelled parasite. It is seen primarily in puppies and
kittens, although debilitated adults can also be affected. Transmission occurs by eating
the ineffective stage of the parasite. It then reproduces in the intestinal tract causing no
symptoms in mild cases to bloody diarrhea in severely affected pets.
Diagnosis is made from a fresh stool sample. Treatment varies greatly. Animals showing no signs of
illness are often not treated because a mild case is often selflimiting. Pets with diarrhea
are treated at home with an oral medication. Severely affected pets may need
hospitalization. Prevention involves disposal of all stools and cleaning the pet’s living
area. Human transmission is uncommon but can occur.

For more information on PARASITES call Mission Veterinary Clinic and Animal Emergency Hospital in Granada Hills at 818-363-8143

 
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