EXTERNAL & INTERNAL
PARASITES
External Parasites
External parasites that infest cats include a variety of small
to microscopic insects and arachnids that derive their nutrients
from the cat's blood, tissue fluids, or skin cells. Fleas,
ticks, lice, fly larvae and mites are external parasites that
can be a source of much irritation to a cat. External parasites
cause the most common skin disorders of cats and help transmit
other diseases (e.g., bubonic plague, hemobartonella, Lyme
disease, and perhaps cat-scratch disease). Common signs of
external parasitism include intense itching, red crusty lesions
or scaly skin. Your veterinarian can provide effective treatments
and control methods for most feline external parasites.
Fleas, the most common external parasite
of cats, are wingless, brownish insects that are powerful
jumpers. Although fleas are small, they are visible to the
naked eye. Adult fleas suck blood from the cat, so a heavy
infestation can cause anemia, especially in young kittens.
A condition called flea-bite hypersensitivity, the most common
allergic skin disease of cats, affects individuals that are
allergic to the flea's saliva.
There are many safe and
effective flea-control products currently available on the market,
but the most effective flea control strategies require simultaneous
treatment of both the cat and its environment. Make sure that
any insecticides used (e.g., sprays, dips, or powders) are safe
for use on cats, because many flea products formulated for dogs
can be very toxic to cats. Some insecticidal products cannot
be used on kittens less than two to three months of age. Also,
it's best not to use insecticides from the same class (e.g.
organophosphates) in different forms on the cat or in the environment
for fear of cumulative toxic effects.
Internal Parasites
Parasites that infect the intestinal tract of cats can be worm-like
organisms (e.g., roundworms, hookworms or tapeworms) or microscopic
organisms called protozoa (e.g., Isospora, Toxoplasma, Giardia)
Most intestinal parasites deprive the infected cat of important
nutrition, causing weakness and susceptibility to viral or bacterial
infections. Although initially infecting the intestinal tract,
Toxoplasma organisms usually cause disease in other parts of
the body. Therefore, keeping your cat free of parasites is important
for its long-term health.
Intestinal parasites
can usually be diagnosed when your veterinarian analyzes a fecal
sample. Occasionally, an owner may see an intestinal parasite
in vomit or in feces that resembles a white, threadlike worm,
or the parasite may resemble a rice grain near the cat's tail.
If your cat is infected, proper medication should be obtained
from your veterinarian. A fecal sample should be checked after
treatment to ensure that the parasites have been eliminated.
Because some intestinal parasites can also cause disease in
human beings, have your cat checked at least annually for intestinal
parasites.
Heartworm disease is
often thought of as a problem in dogs only, but the internal
parasite, Dirofilaria immitis, can infect cats as well. If you
reside in an area where dogs are infected, cats living in the
area are at risk of infection too. Dirofilaria immitis is carried
by mosquitoes, so both indoor and outdoor cats are at risk.
Although infection can be serious or even deadly, it is easily
avoided by monthly administration of preventative medication.
