Deworming your Cat
Although some deworming medications are
effective against more than one species of worms, there is no medication
that is effective against them all. Accordingly, for a medication to be safe
and effective, a precise diagnosis is required. It is also important that the
medication be given precisely as directed. Natural side effects, such as diarrhea and vomiting, must be distinguished from toxic reactions.
All dewormers are poisons-ideally, they are more poisonous to the parasites
than they are to the hosts. For these reasons, it is advisable to deworm your
only under veterinary supervision.
A very large proportion of kittens are infested with ascarids. Other worms
may be present, too. It is advisable to have your veterinarian check your
kitten’s stool before treating her for ascarids. Otherwise, other worms and
internal parasites, such as coccidia, may go undetected.
Worm infestations are particularly harmful in kittens who are subjected to
overfeeding, chilling, close confinement, or a sudden change in diet. Stressful
conditions such as these should be corrected before administering a deworming
agent. Do not deworm a kitten with diarrhea or other signs of illness, unless
your veterinarian has determined that the illness is caused by an intestinal
Kittens with ascarids should be dewormed at 2 to 3 weeks of age and again at
5 to 6 weeks. If eggs or worms are still found in the stool, subsequent
treatment should be given. Due to public health considerations, many
veterinarians recommend deworming kittens with a safe dewormer every month
until 6 months of age.
Deworming Adult Cats
Most veterinarians recommend that adult cats be dewormed only when there is
specific evidence of an infestation. A microscopic stool examination is the
most effective way of making an exact diagnosis and choosing the best deworming
It is not advisable to deworm a cat who is suffering from some unexplained
illness that is assumed to be caused by worms. All dewormers are poison-meant
to poison the worm, but not the cat. Cats who are debilitated by another
disease may be too weak to resist the toxic effects of the deworming agent.
Cats of all ages, particularly those who hunt and roam freely, can be
subject to periodic heavy worm infestations. These cats should be checked once
or twice a year. If parasites are identified, they should be treated. It is
reasonable to deworm outdoor cats routinely for ascarids and tapeworms, even without a
positive stool sample. Many anthelmintics are safe for repeated use. Tapeworms
segments may be seen frequently, and when discovered, they should be treated.
Cats with tapeworms may need to be treated as often as four or five times a
A queen should have her stool checked before breeding. If parasites are
found, she should receive a thorough deworming. This will not protect her
kittens from all worm infestations, but it will decrease the frequency and
severity of any parasite infestation. It will also help to put her in the best
condition for a healthy pregnancy.