microscopic look at hookworm

Parasites are not only a health problem for our pets,
but our families as well.

A parasite is an organism that lives on or inside another organism (the host) and causes harm to the host.
Parasites generally enter the body through the mouth or skin.  Parasites that enter through the mouth are swallowed and can remian in the intestine or burrow through the intestinal wall and invade other organs.  Parasites that enter through the skin bore directly through the skin or are introduced through the bites of infected insects (the vector).  Some parasites enter through the soles of the feet when a person walks barefoot, or through the skin when a person swims or bathes in water where the parasites are present.

There are many types of parasites, internal and external, that our animals can transmit to us.  The monthly worming medications such as Interceptor,  Sentinel and Heartgard control many of the problems we see, but there are many other microscopic parasites that require a more specialized medication, and early detection is important.  This is easily remedied.

We recommend a routing stool screening once a year.  This can be performed at any time, during one of your twice-yearly visits (we can have the results in about 25 minutes) or you can place a fresh stool sample in a jar and bring it by at your convenience for our technicians to do a thorough lab analysis. 

We will pull your pets file and chart any updates, take care of charges, and get a phone number to call you so we can promptly report the lab results to you.  If medication is needed to clear up any problems found, it will be ready for you to pick up at your earliest convenience.

below-microscopic look at Giardia &
diagram of how toxoplasmosis is spread

Toxoplasmosis

WHAT IS TOXOPLASMOSIS?
Toxoplasmosis is the disease syndrome caused by a protozoan organism called Toxoplasma gondii. It affects most animals (most notably sheep, cats, and humans), but even insects, fish, and earthworms may be carriers. Because of the risk to an unborn child, many medical doctors go so far as to recommend that pregnant women do not keep cats as pets.

WHAT IS THE RISK TO AN UNBORN CHILD?
A human with an acute Toxoplasma infection experiences varying degrees of illness: fever, swollen lymph nodes, muscle stiffness, joint pain, swollen liver, and spleen (manifested as a sore upper abdomen). These symptoms may be so mild as to go unnoticed. Illness lasts 1 to 12 weeks and is often dismissed as a bad cold or mononucleosis.

However, if the person infected is a pregnant woman, the Toxoplasma organism may cross the placenta. The amount of damage done depends on the stage of pregnancy at the time of infection. Infection in early pregnancy may result in miscarriage or stillbirth. Infection in early pregnancy may result in a child with varying degrees of blindness (due to inflamed retina) and/or various severe neurological conditions including hydrocephalus, microcephaly, and retardation. Sometimes problems are not evident at birth and show up late in life.  Fortunately, only 30% to 40% of infections in pregnant women result in damage to the fetus.

The problems described above occur only when someone is infected with Toxoplasma for the first time; that is, a person who has already had the infection is not likely to get sick again nor is she likely to transmit the organism to an unborn child. (It is estimated that one third of the U.S. population has already had toxoplasmosis.) In general, people who do experience more than one acute episode are severely immunosuppressed (as from AIDS or cancer therapy.)

HOW DO PEOPLE GET THIS DISEASE?
There are two basic forms of toxoplasma organism: the oocyst, which is shed in the cat feces, and the Toxoplasma tissue stages, which live in the flesh of such food animals as hogs and lambs. A person who inadvertently eats either of these forms of Toxoplasma is liable to become infected.

IF MY CAT HAS TOXOPLASMA, WON'T HE BE OBVIOUSLY SICK?
Not necessarily. The form of infection which is contagious to humans is the intestinal form in which the cat sheds oocysts in its feces. The cat may or may not show diarrhea.

Cats may experience an acute illness similar to that which humans experience, however, in adults cats, symptoms are usually mild and go unnoticed. This form of infection is not contagious to humans, though a pregnant cat could transmit the disease to her kittens.

HOW IS MY CAT A RISK TO ME?
The cat has probably been over-emphasized as a carrier of toxoplasma; most human infections result from eating tissue stages of Toxoplasma in undercooked meat.

Usually a cat will only shed oocysts after the first infection of Toxoplasma; a cat that has already had a toxoplasma infection usually will not re-shed the oocysts unless its immune system has been compromised (as through the feline leukemia virus infection or drugs.) Cats shedding oocysts generally do so for 5 to 14 days.

Oocysts require 24 to 48 hours to sporulate; that is, grow into a form which is dangerous to people. For this reason, the cat's litter box should be changed daily or twice daily. Dangerous oocysts when gardening. Note that freezing weather will not reliably kill dangerous oocysts in soil nor will freezing meat kill the dangerous tissue forms.

Your cat may be tested to see if he/she has already had toxoplasmosis; a cat that has already been infected is unlikely to shed dangerous oocysts in the future.

HOW CAN I AVOID INFECTION?

1. Probably the most important thing is to be careful when cooking raw meat, especially lamb and pork. DO NOT EAT MEAT OR TASTE MEAT BEFORE IT IS FINISHED COOKING.
2. Wash your hands after handling your cat and his/her litter box. 
3. Do not allow your cat to eat raw meat. Feed only commercial cat food and do not allow your cat outside to hunt. 
4. Change the litter box daily or twice daily. It is best of course, if someone else changes the box while you are pregnant.
5. Do not dump the litter box into the backyard. Always wear rubber gloves when gardening. 
6. Do not allow the cats access to barns where food animals are kept. This is how food animals get infected.
7. Do not drink raw milk, especially goat's milk

Although it is possible to get toxoplasmosis from cats, no correlation has been found between cat ownership and toxoplasma infection. There is, however, a very strong association between Toxoplasma infection and working with raw meat as in a slaughterhouse or as a butcher. Be careful handling raw meat.

FOR MORE TOXOPLASMOSIS INFORMATION:

http://web.vet.cornell.edu/public/fhc/toxoplas.htm

Sarcoptic Mange

(ALSO CALLED SCABIES)

THE ORGANISM AND HOW IT LIVES

Sarcoptic mange is the name for the skin disease caused by infection with the Sarcoptes scabei mite. Mites are not insects; instead they are more closely related to spiders. They are microscopic and cannot be seen with the naked eye.

Adult Sarcoptes scabei mites live 3 to 4 weeks in the host’s skin. After mating, the female burrows into the skin depositing 3 to 4 eggs in the tunnel behind her. The eggs hatch in 3 to 10 days producing a larva which, in turn, moves about on the skin surface eventually molting into a nymphal stage and finally into an adult. The adults move on the surface of the skin where they mate and the cycle begins again with the female burrowing and laying eggs.

Sarcoptes Scabei: Female sarcoptes mite burrowing in the skin and leaving a trail of eggs behind her. Her presence generates an inflamatory response in the skin similar to an allergic response.

APPEARANCE OF THE DISEASE
The motion of the mite in and on the skin is extremely itchy. Further, the presence of mites and their eggs generates a massive allergic response in the skin which is even more itchy.

Mites prefer hairless skin thus leaving the ear flaps, elbows and abdomen at highest risk for the red, scaley itchy skin that characterizes sarcoptic mange. It should be noted that this pattern of itching is similar to that found with airborne allergies(atopy) as well as with food allergies.

Dog with dematitis problem typical of sacrcoptic mange. Note: Many dogs do not develop the classical ear margin crusts until later in the disease.

As the infection progresses, eventually most of the dog's body will be involved. Classically, though, the picture begins on the ears (especially the ear margins), the elbows, and abdomen.

The term scabies refers to mite infestations by either Sarcoptes scabei or other mite species closely related to Sarcoptes scabei. While Sarcoptes scabei can infect humans and cats, it tends not to persist on these hosts. When people (including some veterinarians) refer to sarcoptic mange or scabies in the cat, they are usually referring to infection by Notoedres cati, a mite closely related to Sarcoptes scabei. In these feline cases, it would be more correct to refer to notoedric mange, though the treatment for both mites is the same. Notoedric mange, in cats, generally produces facial itching and scabbing.

DIAGNOSIS
When an animal with sarcoptic mange scratches itself, it breaks open the tunnels that the mites have burrowed into and the mites are killed (though the itch persists due to toxins in the skin). The result is that the mites can be very difficult to confirm by skin scraping tests. (Probably mites are confirmed in 50% or fewer of sarcoptic mange cases.)

Since negative test results do not rule out mite infection, a "maybe mange" test is frequently performed. This consists simply of treating for sarcoptic mange and observing for resolution of the signs within 2 to 4 weeks.

Of course, if mite presence is confirmed by skin scraping, then one knows immediately the cause of the itching and need not be concerned about allergy possibilities or other diseases and the condition can be addressed with confidence.

BIOPSY - Mange mites are rarely seen on a skin biopsy sample, though, if the sample is read out by a pathologist who specializes in skin, the type of inflammation seen in the sample can be highly suggestive of sarcoptic mange. This is an example of a skin disease where it makes a difference whether the pathologist reading the sample specializes in reading skin samples.

TREATMENT

While sarcoptic mange is difficult to diagnose definitively, it is fairly easy to treat and a number of choices are available.

DIPPING - Anti-bacterial or anti-itch shampoos preceed one of several anti-mite dips. Paramite dip (an organophosphate), Mitaban dip (Amitraz), and Lime-Sulfur dips given weekly are usually effective. Disease typically resolves within one month. Dips are often used in combination with one of the other treatments listed below.

IVERMECTIN- This is one of the most effective treatments against Sarcoptes scabei yet is is off-label as far as the FDA is concerned. There are several protocols due to the very long activity of this drug in the body. Typically an injection is given either weekly or every two weeks in 1-4 doses. In most cases this treatment is safe and effective but some individuals have a mutation which makes ivermectin very toxic at the doses used  to kill mites. These individuals are usually of the Collie family: Collies, Shetland Sheepdogs, and Australian Shepherds are classically affected. There is now a test that can determine if any dog has the mutation that makes Ivermectin use dangerous.

SELAMECTIN (REVOLUTION®) - Selamectin is an ivermectin derivative recently marketed for the control of fleas, roundworms, hookworms, ticks, ear mites and sarcoptic mange mites. Normal monthly use of this product should prevent a sarcoptic mange problem but to clear an actual infection studies show an extra dose is usually needed after 2 weeks for reliable results. This product is probably the best choice for Collie or Australian shepherd breeds.
See information from the manufacturer on Revolution.

ALL DOGS IN A HOUSEHOLD WHERE
SARCOPTIC MANGE HAS BEEN DIAGNOSED
SHOULD BE TREATED.

MILBEMYCIN OXIME (INTERCEPTOR® OR SENTINEL®) - Milbemycin Oxime is approved for heartworm prevention as a monthly oral treatment. Happily, it also has activity against sarcoptic mange and several protocols of varying success have been recommended by different dermatologists. This is another medication that one might find recommended.

For more information from the manufacturer, visit their page for Interceptor:
http://www.petwellness.com/dog_inter_home.aspor their page for Sentinel:
http://www.petwellness.com/dog_sent_home.asp

HOW THE INFECTION IS SPREAD
Sarcoptic mange mites are usually spread by direct contact from host to host. While mites can live off of a host for days to weeks depending on their life stage, they are only infective for 36 hours, which means that environmental decontamination is generally not necessary.

IF A SARCOPTIC MANGE ANIMAL IS IN THE HOME, IT IS A GOOD IDEA TO WASH ANY BEDDING IN THE WASHING MACHINE (OR REPLACE WITH NEW BEDDING), AND WASH ANY COLLARS OR HARNESSES.

Heartworm infection in a dog heart

Heartworm Statistics:

1    Number of heartworms needed to kill an infected cat

5    Number of years a heartworm can live inside a dog

6    Age at which pets can begin taking heartworm preventives (in weeks)

14   Potential length of a female heartworm (in inches)

50   U.S. states in which heartworm disease has been reported

100 Percentage of heartworm cases that are preventable

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1. Adult flea
Adult fleas (1.5 - 6 mm) can remain attached to their host thanks to extensions (setae) en hooks. Before sucking blood (about 150x its own body weight), the flea pierces the skin of its host with its mouth and injects saliva that contains an anti-blood-clotting agent. The saliva may cause of an allergic skin reaction. After the first blood uptake, fleas undergo a metabolic change and need regularly new blood meals to survive (they become an obligate parasite). After mating females can lay up to 40 eggs a day.

2. Eggs
The eggs (about 0.5 mm) develop best in a warm and humid environment. The eggs, which are smooth and can easily fall on the floor, hatch between 1 and 10 days of being deposited on the host.

3. Larvae
The larvae that emerge from the eggs mind light and extreme temperatures. Dark, sheltered dust nests like carpets, rugs and splits in wooden parket are ideal habitats for larvae. They feed on organic debris (e.g. crumbles and skin scales) or also on feces from adult fleas. The larvae go through three stages of instars.

4. The pupae stage
The adult larvae (about 5 mm in length) envelop themself with a sticky cocoon and turn into pupae. The pupay may may remain dormant for monthes inside the protective cocoon.

5. Young flea
The young flea (in this view dissected out of the cocoon) often stay inside the cocoon until they percept a favorable trigger, like a raise in temperature or carbon dioxide level of the surroundings, vibrations or changes in light pattern. Then, they crawl out of the cocoon within a couple of seconds and use their powerful posterior legs to jump on their host.

    Parasites are animals that live off of other animals. In the case of fleas, ticks, or other external parasites, it’s pretty easy to tell when your pet is being a “host” to these nasty critters. But that’s not always true; your pet may be eaten alive and you might have no idea.

     One example is heartworm.  This doesn’t sound good, and it’s not. This is an extremely common parasite spread by mosquitoes to your dog or cat. Since mosquitoes can enter homes, even completely indoor pets can be at risk.  Heartworm can kill dogs. In cats, the only symptom may be sudden death. That’s the bad news. The good news is that heartworm is completely preventable. So, you’d think this disease would be virtually non-existent. But much to our surprise, in 2001, almost a quarter of a million dogs were reported as heartworm positive by veterinarians. In the vast majority of these dogs, they were positive because their owners were simply not treating them with any of the readily available, inexpensive preventive products.

     These positive dogs can be treated for their heartworm infection. However, treatment of existing heartworm infection in dogs can be risky and it’s expensive. In cats, there is no treatment.

     Prevention is as easy as giving a monthly chewable to your pet. The monthly preventatives really do work.

     Heartworm isn’t the only nasty parasitic bug. Intestinal worms like roundworms and hookworms are common, especially in puppies. One “sniff of the ground” in an area where other dogs have been can allow the microscopic eggs or larvae to enter.

     Dogs with worms might not have symptoms, or they may show signs like diarrhea or weight loss. Your veterinarian can do a fecal test to check for the presence of parasites.   Both roundworm and hookworm can be transmitted to people.  Roundworm is particularly dangerous, sometimes causing blindness – and it most often happens to children because they’re the ones playing in the mud or sand and then not washing hands.  As many as 10,000 cases of roundworm are reported to the CDC in the United States each year. However, not all cases are reported, so no one knows how often it actually occurs.

     The Companion Animal Parasite Council now recommends year-round protection from intestinal parasites as well as heartworms. Talk to your veterinarian about products that protect against all of these parasites.

Some flea facts:

• Fleas are insects - they have six legs,  three body parts.

• A single flea can lay up to 50 eggs daily and 2,000 eggs in a lifetime.

• A flea can suck more blood daily than a vampire bat.

• There are 2,000 flea species; Ctenocephalides felis - the cat flea typically

infests cats and dogs.

•  Fleas can jump in excess of a foot, that’s a person jumping about a half a block.

• The rat flea helped spread the bubonic plague.

PET THOUGHTS

“It is a sobering thought that cats and dogs are more loyal, trustworthy and reliable than human beings,” Desmond Morris.