Roundworms in Cats
Deworming the queen before or
during pregnancy does not prevent all
ascarid infestation of kittens after birth, but it will decrease the frequency
and severity. Medications do not eliminate encysted larvae.
The second most common feline ascarid is Toxascaris leonina. This ascarid is
not passed via the milk into nursing kittens but can be acquired by ingesting
the eggs or by eating infected rodents.
Ascarids usually do not produce a heavy infestation in adult cats, but may
do so among cats who do a lot of hunting. In kittens, a heavy infestation can
result in severe illness or even death. Such kittens appear thin and have a
pot-bellied look. They sometimes cough or vomit, have diarrhea, are anemic, and may develop pneumonia as the worms migrate from the blood
vessels to the air sacs of the lungs. Worms may be found in the vomitus or the
stool. Typically, they look like white earthworms or strands of spaghetti that
are alive and moving.
Treatment: Pyrantel pamoate is a safe, effective choice and can be used in
nursing kittens. Kittens should be dewormed by 3 weeks of age to prevent
contamination of their quarters by ascarid eggs. A second course should be
given two to three weeks later to kill any adult worms that were in the larval
stage at the first deworming. Subsequent courses are indicated if eggs or worms
are found in the stool. Many veterinarians suggest deworming kittens monthly
until 6 months of age.
Pyrantel pamoate dewormers can be obtained from your veterinarian. You do
not have to fast your cat before using this medication. Be sure to follow the
directions of the manufacturer about dosage. Milbemycin, ivermectin, and
selamectin are also very effective dewormers, but they are generally used in
older kittens and adult cats.
Public health considerations: Ascarids can cause a disease in humans called
visceral larva migrans. This is considered to be a serious public health
problem and is one of the top zoonotic diseases. Most cases are caused by the
canine ascarid, Toxocara canis, but Toxocara cati also can produce this
disease. Some cases are reported each year, usually from areas with a mild
climate. Children are most frequently affected, and often have a history of
eating dirt. Outdoor sandboxes should be covered when not in use to prevent
cats from using them as litter boxes, and gloves should be worn when