Intestinal Problems
In Cats and Dogs
Caused By Parasitic Intestinal Worms
The picture above is to drive home that tapeworms, round worms, and hook worms can cause serious diseases in people as well as pets. 

You can minimize the threat to your pets as well as your family by controlling the problem in your pets with a regular, periodic deworming program to include once a year fecal tests for your pets.

On This Page:

A review of the products we use to control:

   Tape worms

   Round Worms

   Hook Worms

   Whip Worms

   Tape Worms


More Information About Intestinal Diseases On Other Pages:

Intestinal Problems in Cats and Dogs; Introductory Page


Giardia and Cryptosporidia

Diarrhea Page

Parvo Page

Constipation Page

Food Related GI Problems

Here's a list of the main points I want to get across:

Puppies and kittens are typically born with lots of round worms ... a percentage of which become encysted larvae that will wait for some immune weakness in that puppy or kitten months or years later.  One reason that pets need periodic deworming with an effective product

Any pets that walk anywhere outside your house or kennel are constantly exposed to microscopic, infective worm eggs and larvae.  Another reason that pets need periodic deworming with an effective product.

Round and Hook worms can sometimes cause serious diseases in humans.  Another reason that pets need periodic deworming

Tapeworms can also cause serious problems in humans but periodic deworming for tape worms is usually not necessary.  However, if you notice rice sized worms on your pet's stool ... or dried up segments stuck to the hairs near your pet's anus that look a little like sesame seeds ... then ask your vet for the appropriate treatment and get more aggressive about flea control

There are many deworming products being sold that no longer work well.  The worms have become resistant.  So spend the extra few dollars and get your deworming products from your vet.  He or she will be selling and using the most effective dewormers for your area.

Even the deworming products that vets use and dispense won't always kill 100% of your pet's worm load nor prevent repeat infestations, so in addition to deworming your pet ... do periodic fecal tests on your outdoor pet's stool.

Parasitic worms take advantage of pets that are pregnant or who have weakened immune systems from fleas, stress, poor nutrition, or disease.  They prey on the weak, the very young, the very old, and those in filthy conditions.

Keep your pet's stool cleaned up in your yard and kennels and keep your pet happy, well fed, free of fleas and heartworms, and healthy.

On Other Pages:

Diseases people get from from worms from their pets

Coccidia; a protozoan parasite causing diarrhea and other problems in puppies and kittens

Giardia; an amoebic parasite causing diarrhea, nausea, and other problems in pets

Cryptosporidia; another parasite that causes diarrhea in pets and humans

Heartworms; a parasite spread by mosquitos that causes severe heart, vascular, and respiratory disease in dogs, cats, and maybe humans.

Ringworm; a fungal disease of the skin that is contagious between dogs, cats, and humans ... but not caused by a worm.

All the important stuff I know about fleas


Zoonotic Diseases; the disease people get from pets


All pets are in danger of worms. 

Even indoor cats occasionally get exposed to worms 

Outdoor pets are exposed to lots of worm eggs and worm larvae.

Puppies, kittens, young pets, pregnant pets, are especially vulnerable to intestinal parasites.

Also vulnerable are any pets with weaken immune systems from old age, disease, poor nutrition, and stress.

Major types of intestinal worms that cause problems in pets:

Several types of Cestodes or tapeworms are spread by fleas and are resistant to most types of regular deworming products.  Tapeworms are big enough to see (about the size of a piece of rice), but if your pet has tapeworms, you will see them on the stool only ocassionally.

Several types of Nematodes; Round worms, Hook worms, and Whip worms:

Roundworms are easy to see ... about half the size of piece of spaghetti.  Roundworms are very common in puppies and kittens and the adult stages of the worm are susceptible to most deworming medicines.  However, roundworm larvae are very resistant to deworming medicine and that's one reason why periodic deworming is needed through out life.

Hookworms and whipworms are microscopic but are deadly if ignored ... they bore holes into the intestines and suck blood.  Sucking blood is bad enough, but they also lead to inflammation of the bowel walls leading not only to infection but to absorption of fecal matter into the blood stream.
To make matters worse, both hook and whip worms are often resistant to deworming  medications and can be difficult to control.

Hook worms affect dogs, cats, and humans.

Whip worms are mainly a canine problem.

Here's a review of the more common deworming products used in the United States:


Cestex:  very effective.  100% kill of adult tapeworms with 1 dose, but treatment should be repeated in 3 weeks to kill the remaining non adult stages.

Praziquantel: Available now as a generic and like Cestex 100% effective for adult tapeworms with 1 dose , but treatment should be repeated in 3 weeks to kill the remaining non-adult stages.

Profender:  A new medication (2007) for cats.  Profender is applied to the back of the neck and kills 100% of round worms, hook worms, and tapeworms with 1 dose.  Repeat treatment is usually not needed.

Note: Tapeworms have to spend part of their life cycle in either a flea or a rodent.  So make sure you also deal with your flea problem.  If your dog or cats likes to catch and kill mice or rats you might want to check their stool periodically for tape worms.

Tapeworms are resistant to nematode deworming products.  Only the 3 products listed above do a good job at killing tapeworms.

Products used to control round and hook worms in cats and round, hook, and whip worms in dogs

Profender for Cats:  this new product kills all the worms that affect cats with a single dose.  Including tapeworms.  This product is described above in the tapeworm section

Revolution for Cats:  Revolution is an all purpose parasite control medication for cats that does a good job of controlling fleas, round worms, hook worms, heartworms, ear mites, and sarcoptic mange mites.  I love this product for cats but it's fairly expensive if you don't need heartworm or flea control.

Revolution for Dogs:  I like Revolution and use it on my own dogs for flea control and to prevent heartworms.  But it's not a very effective deworming product in dogs.

Advantage Multi:  This new (2007) multi purpose parasite control product is good for flea control, prevents heartworm, and is an excellent killer of round, hook, and whip worms.  Available for both cats and dogs

Sentinel:  A once a month pill that prevents flea eggs from hatching, prevents heartworms, and is very effective at killing round, hook, and whip worms. 

Note; all of the above products are described in more detail on our pages about flea control

Panacur or fenbendazole: Much less expensive than the multi purpose products reviewed above, Panacur doesn't control fleas or heartworms. 

But if dosed several days in a row, and then repeated in 3 weeks, it's very effective against round, hook, and whip worms.  Safe for kittens and puppies.

Piperzine:  Still sold in pet stores and on the internet.  Only somewhat effective for round worms and not at all effective for hook or whip worms.  Usually makes your pet vomit and feel lousy.  NOT RECOMMENDED

Low dose pyrantel/Nemex:  Sold in pet stores and over the internet.  Pyrantel is the active ingredient in many different brands of dewormers including the once a month heartworm preventive HeartGuard Plus and the generic copies of HeartGuard Plus.

Pyrantel is very safe and very effective for round worms.  And somewhat effective against hook worms.

But intestinal worms ... at least in the South East United States ... have become resistant to low dose pyrantel.  To overcome this problem, we either use higher off label doses, or repeat doses more often, or both.

That's why giving heartworm preventive with pyrantel added works pretty well at controlling round and hook worms ... because we're giving it monthly.

High Dose Pyrantel:  Pyrantel comes in a much more concentrated form for horses.  It's inexpensive and works much better than the pyrantel products labeled for dogs and cats.  But it's off label and some vets won't risk a law suit in the rare event that a pet has a bad reaction to treatment.

Most vets use pyrantel for puppies and kittens because it's so safe and effective on round worms which are so common in puppies and kittens.

But because even the off label strengths of pyrantel aren't effective against whip worms or hook worms that have become resistant, most vets use other worm products and periodic stool testing in their recommended deworming programs.

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