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The PetStuff Online Newsletter
Volume 1 Issue 2  August 20, 1999

Sponsored by PetStuff Online Store

Produced by Dr Dan

Have Pet Questions? Visit Dr Dan's New Bulletin Board!
It Beams Out With Electronic Vitality and Pet Wellness Information!


Chat With Dr Dan

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Well, I've learned lots of things this past week. I "hope" to never reveal your names on the mailing again like last week.  We have new mailing software, but I don't have the kinks figured out yet. Please bear with me while I learn.  I know the "vet med" end of it, but I'm a horrible neophyte dealing with the capabilities of the Internet. Who knows, maybe in 6 months I'll be doing real time movies of surgeries! I also became aware that AOL and other ISP's won't allow graphics to come through.  Jerks!  With no graphics this newsletter is like black and white TV! So if they don't come through this week I will get the newsletter posted on my web site with a link to it.  Please let me know if you don't get the graphical version. 

I want to announce my new Bulletin Board.  It is hosted (eg for free) by my ISP and is soooo cool. I really like the new technology they used.  Please fill it up with your pet questions. I think you will love the way it works with search capabilities, etc.  Hope to talk with ya there soon.  Address is:

If you have friends that might like to receive the PetStuff Newsletter tell them to send me an email with "ADD" in the subject line or "heaven forbid" if you want to be removed just put "REMOVE" in the subject line.

As usual, I'm out of time and have to get this off, so away we go...   Promise it will keep getting better!   

"Roundworms and Their Public Health Significance"

This week we would like to discuss an extremely common intestinal parasite of dogs and cats and many other animals.    Almost all mammals can have some form of roundworms.  Typically, these are the "spaghetti-like worms" you can see in the vomitus and feces of puppies and kittens. Since they can cause serious problems in humans (usually children) I wanted to bring attention to the dangers they can present.

What are they?
Roundworms are big worms. Typically they are white, about the diameter of a spaghetti-strand and about 4 inches in length.  Often times kittens or puppies vomit one up or we are horrified when we see them in the feces.

How do our pets get roundworms?
Kittens or puppies may be born with roundworms! We know that Roundworm larva are tiny enough to migrate through the placental blood supply to the fetal liver or lungs. Soon after birth the juvenile roundworms begin migrating from the liver and lungs to the intestine where they grow to adults and begin laying eggs. Within three weeks after birth, puppies and kittens can begin shedding roundworm eggs into the environment. 

A second source of infection is through the mother's milk - Roundworm larva can gain entry into the mammary glands and then be passed to the puppies or kittens as they nurse.

A third possibility is if the young animal should eat an embryonated egg found in fecal contamination of food or water bowls, the nesting box or other environmental sources. The egg hatches within the intestine and a "Blood-Lung" migration begins as described below.

In the three cases above we are talking about a "Blood-Lung" migration. In other words, from wherever the roundworm larva gains entry into the pet's body the larva then migrate to the liver via the portal blood system (the portal blood system is the one draining from the stomach, intestines and leading to the liver) . The larva are then carried by the circulatory system to the lungs where they can pierce the walls of tiny lung blood vessels (capillaries) and gain entry into the airways (alveoli and bronchioles).  The cilia (little whiskers that move foreign objects) lining the airways then move the larva up the bronchi and windpipe until they are coughed up and swallowed. Once they are swallowed they have become large enough that they can continue their maturation to adult egg-laying roundworms in the small intestine.

Somatic cycle... A second type of roundworm life cycle occurs when dogs or cats develop "age resistance" at about 6 months of age or older.  Instead of the larval form reaching the lungs via the blood and going through the "coughing up, swallowing and growing to adult in the intestine" phase another phenomenon occurs.  The so-called "age resistance" alerts the dog or cats immune system to the possible presence of roundworm larva. When a larva enters the body, the immune system traps it in walled-off granuloma's that may appear in nearly any tissue.  I have personally seen them in liver tissue when doing post-morteum exams. Once trapped in granuloma's, the larva can live for years occasionally escaping to become re-trapped in other granuloma's.   During the last 1/3 of pregnancy this migration of these juvenile roundworms is greatly accelerated allowing them to find their way into the placenta and fetus or into the mammary glands to infect nursing puppies.   When the bitch cleans the puppies she also may swallow infective eggs.

Complicated isn't it?  Maybe a graphic will help...

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What are the signs of roundworm infestation?
Actually, adult roundworms do little damage.  They do not attach to the intestine wall and drain the pet's blood or nasty things like that. They just move around in the intestine and eat some of the nutrients intended for the pet or brouse on the mucous lining the intestine wall. Occasionally they will cause irritation inside the intestine & transient diarrhea or if they are in great enough numbers they can actually block the intestine and constipate the anim. If they find their way up into the stomach they can cause the pet to wretch and vomit the worm up. 

More important to the pet's health are the migrating juveniles.  As they pass thru the liver and lungs they can cause verminous pneumonia or hepatitis.  Signs of roundworm infestation include: dull hair coat, pot-bellied unthrify appearance, poor weight gain, vomiting, coughing, intermittant diarrhea or constipation.  Heavily infested puppies or kittens occasionally die of worm-related pneumonia.

What is the treatment?
It is easy to get rid of roundworms in the intestine.  Just give any oral wormer effective against roundworms.    My favorite is any brand with pyrantel pamoate as the active ingredient.   This is generally well tolerated by the pet, safe and effective, but...    Once again the "migrating juvenile worms are the problem". Nothing at all will kill the juvenile worms trapped in granuloma's.  It is best to worm breeding female dogs and cats before breeding and again 3, 6 and 9 weeks after welping.   Juveniles migrating through the liver and lungs also will not be killed by conventional wormers.  This is why we like to worm puppies and kittens twice three weeks apart and then check a fecal specimen three weeks later. This allows all migrating juveniles to reach the intestine where they are easily killed.

So what's the big deal with public health significance?
Here is where it gets a bit frightening! Roundworm larva have actually blinded young children and caused countless other problems.  The humans most affected are children from early neonatal age to four or five years of age, however any age can be affected. Why is this?  The secret lies in hand-to-mouth ingestion of roundworm eggs.  Lets say the cat uses the sandbox for a litter area.  Kids playing in the sand very easily can pick up eggs on their hands and where do their hands go?  Right in the mouth without being washed.

Once the embryonated roundworm egg reaches the intestine of the human it hatches and the larva penetrates the intestine wall.  From there it gains entry into the blood stream and may end up just about anywhere in the body including vital organs such as the eye, brain, liver, kidneys, heart wall, lungs, etc.  Since humans are an unnatural host for the roundworm larva, their body reacts and walls off the larva in little granuloma's (similar to what occurs in adult dogs and cats).  These granuloma's may cause sudden dysfunction of any of these organs resulting in illness.

The most often diagnosed illness is loss of sight in one eye. The roundworm larva is trapped in the optic disk behind the retina of the eye and a granuloma forms.  These granuloma's have been mistaken for retinoblastoma's (cancer of the retina) and the eye was mistakenly removed. I believe the reason the problem is so often diagnosed in the eye is because we know it is happening.  We experience loss of vision; the eye is removed and the larva is discovered.

Remember what I said above? When roundworm larva are encased in granuloma's they are impossible to kill with any anti-parasitic drugs and they are also impossible to detect.  How many cases of persons seizuring with no apparent cause could be related to roundworm larva?  It is impossible to know because the granuloma's are impossible to detect. We can't remove the brain and search for the larva microscopically.

I hope I didn't scare you by making you aware of this problem.  The problem is rare, but it "can" happen at any time.  This is an important reason for people to always wash their hands before eating or putting a finger in the mouth. Who knows, it could save your eye!

Be Safe - Be Sure - Have Your Vet Check Your Pet for Intestinal Worms Twice a Year!

Next Week

I would like to continue on with the subject of the worms of dogs and cats and how they can affect humans.    Here is the schedule.

August 27th - Hookworms and Why Dogs Are Kept off Beaches
September 3rd - Whipworms and the Neighbors Dog
September 10th - Those Disgusting Tapeworms

A Little Pet Humor in Closing

Cat Rules

The Vacuum Cleaner
This appalling Beast is known by many names, Cat Eater being the most prevelant. Normally pliable, agreeable humans will turn into raging monsters while under It's influence, running around the house sucking up all the carefully shed Cat hair and terrorizing the feline residents with evil glee. Nothing can stop It until the influence is over and the foul device is put back in It's closet. All you can do is run and hide when you hear the engine roar to life and hope that It doesn't find you. On some occasions, however, the humans are forced to open the vacuum cleaner and remove a swollen dusty bag from within. This is It's stomach, and must be destroyed if you get can get the chance. Do not worry if a human yells at you, for the yell is really that of the Beast in pain. Some Cat circles are of the belief that the weekly ritual is actually a struggle for control, as the Beast attempts to free itself from the human's grasp so it can rampage at will. The back and forth motions of the machine are supposedly indicators of this battle of wills. Regardless of the interpretation, Cats should definitely keep a low profile until the Beast is returned to its lair and the human returns to normal for the week.

Bad Dog

A list of phrases dog owners should get their naughty pets to write on the Blackboard 100 times...
I will not lift my leg to the [xxxx]:
Anything growing in the vegetable garden; house corner; new boyfriend; mailman; wood stove; subordinate pack members; Grandma's plush chair; the conformation judge; good-looking neighbor man that Mommy is trying to impress; Daddy in the lawn chair; the next-door neighbors lawn; anything that is both vertical and indoors; living room corner; in Mommy's closet; under Daddy's desk chair; on the Meditation Mat; on the one couch I'm allowed on; on the rug in the back bathroom where I thought no one would ever check; on Daddy's briefcase; on the human's toilet; on my Mommy's foot as she stands there talking to the neighbor; my side-kicks food bowl; my brothers Fuzzy Toy.


Images used in this publication taken from Hill's Atlas of Clinical Anatomy, Published by Veterinary Medicine Publishing Company, Inc.   A publication used by veterinarians to teach their clients about their dogs and cats in sickness and health.

Have A Good Week

Later,  Dr Dan