Dogs are much more likely to become infected with the intestinal parasite known as whipworms than cats are. Once an infection has occurred, symptoms range from none in very mild cases to bloody diarrhea, dehydration, and anemia in more aggressive cases. Fortunately, whipworms can be avoided with a monthly preventive, and they are treatable with deworming medication.
Whipworms are one of several internal parasites that commonly live in the large intestines of dogs — and only rarely in cats. This type of worm is named for the whip-like appearance of its body, which has a thicker head that tapers into a thinner tail.
Whipworms live in the dog’s large intestine, where they burrow their tails into the intestinal wall, leaving their mouths free to eat. Female whipworms produce eggs — as many as 2,000 or more a day! — which are passed in the dog’s feces. The eggs enter the soil, where they become infective in two to three weeks.
Dogs become infected by ingesting eggs from the environment, often during grooming. The eggs hatch in the small intestine, releasing larvae that eventually travel to the large intestine and become adults.
When the infection is limited to a small number of worms, dogs may show no signs whatsoever. Heavier infections may cause inflammation of the large intestine, resulting in diarrhea with mucus and fresh blood. Severe infections may cause bloody diarrhea, dehydration, weight loss, and anemia (low numbers of red blood cells). It’s important to note that people cannot get whipworm infections from their dogs.
A whipworm infection is almost always diagnosed by finding microscopic parasite eggs during a veterinary fecal examination. However, there are a number of reasons why parasite eggs may not be found on a fecal examination, even when the dog is infected with whipworms. First, female whipworms don’t lay eggs all the time, so multiple fecal exams may be required over several weeks before eggs are found. Second, from the time a dog ingests a parasite egg, it can take up to three months before the female whipworm lays eggs. As a result, dogs may show signs of infection long before eggs are released in the feces. Finally, even when eggs are in the feces, they may be difficult to find in the fecal exam.
Even if whipworm eggs aren’t found, veterinarians often treat for a whipworm infection anyway, if the dog shows signs of infection.
All breeds of dogs seem equally at risk.
Treating whipworm infections usually comes down to giving one of a number of drugs that kill the worms in the large intestine. It’s recommended that all dogs in a household are treated, even if they don’t all test positive for the presence of the parasite. At least two doses of drugs two to three weeks apart is a common protocol, but other approaches can be equally effective.
To prevent other dogs from being exposed to whipworm eggs if your dog is infected, you should make every effort to pick up and dispose of feces as soon as possible. However, whipworm eggs are very resistant to temperature extremes and radiation from sunlight, so they can contaminate the soil for months or even years. That’s why it’s a good idea for your dog to have periodic fecal exams and receive a monthly heartworm preventive that protects against whipworms.
Tapeworms are nasty parasites that set up shop in the intestinal tract. A dog or cat usually gets a tapeworm by accidentally eating a flea that carries the tapeworm larvae. Often, there are no symptoms per se, and an owner usually discovers that his or her pet has a tapeworm upon seeing a segment of the worm, which looks like a grain of rice, in the pet’s poop. Rarely does this common tapeworm make a pet sick, but it’s not a good idea to ignore it. Fortunately, ridding a pet of a tapeworms is easy; a dose of an anti-parasite medication usually does the trick.
Tapeworms are long, flat, parasitic worms that live in the intestines of dogs and cats. Several species of tapeworms can infect pets but by far the most common offender is the tapeworm known in scientific circles as Dipylidium caninum. Other tapeworms, such as those classified under the genus Taenia, can also affect pets.
Tapeworms have a head that attaches to the intestinal wall and a series of segments, called proglottids, that make up the worm’s body. An adult tapeworm can reach six inches or more in length and has the appearance of a white piece of tape or ribbon.
Tapeworms don’t cause clinical signs in many pets. Apart from the hygiene problem caused by a bunch of little rice-like tapeworm segments exiting your dog or cat’s backside, these parasites seem to do little harm.
Tapeworm segments detach from the end of the adult tapeworm and are shed in the pet’s feces. Each segment contains numerous tapeworm eggs. Once in the environment, the segments break open, releasing the eggs, which eventually develop into tapeworm larvae.
The most common tapeworm found in dogs and cats is associated with fleas. Developing flea larvae in the environment eat the tapeworm larvae, and pets become infected when they ingest an infected flea during grooming.
Human infections are rare and usually occur when people inadvertently consume an infected flea. Most cases involve children, and tapeworm segments may be found around the anus or in bowel movements.
Pets can become infected with tapeworms of the genus Taenia when they hunt and eat prey (such as a bird, rodent, or reptile) that has eaten the tapeworm larvae.
Dogs and cats generally don’t become sick from a tapeworm infection. Only very rarely has a large infestation been reported to cause weight loss or an intestinal blockage.
An owner may become aware that his or her pet has tapeworms by finding tapeworm segments stuck to the fur around the pet’s anus, in the pet’s bedding, or in the pet’s feces. When fresh, these segments are white or cream colored, can move, and look like grains of rice. As they dry, they look more like sesame seeds. Less commonly, pets may experience irritation or itchiness around the anus from passing the tapeworm segments.
Tapeworm eggs may be difficult to detect on a routine veterinary fecal exam. In most cases, the eggs are contained within the tapeworm segments, and unless the segments have broken open, they may not appear on a fecal exam. Infections are usually diagnosed by finding tapeworm segments around the pet’s anus or in the pet’s feces.
There is no breed predisposition for this extremely common condition.
Several medications are effective at eliminating tapeworm infections. At the same time, it is important to treat and control any flea infestation on the pet or in the environment. As long as the pet is exposed to fleas, he or she is likely to become reinfected with tapeworms.
Adopting an effective flea prevention strategy is an important way to help prevent your pet from becoming infected. Owners should also discourage pets from hunting and eating prey by keeping cats indoors and dogs on a leash when outside.
Dogs and cats, both young and old, are at risk for these nasty parasites, and because they are transmitted through fecal-contaminated soil, people, especially children, can become infected, as well. Symptoms in pets include coughing, digestive upset, a dull coat, and failure to gain or keep on weight. Younger pets and children can become seriously ill from a roundworm infection. Fortunately, roundworms can be avoided with a monthly preventive, and they are easily treated with deworming medication.
Roundworms are extremely common parasites that spend their adult lives in the intestines of puppies, kittens, dogs, and cats. There are several species of roundworms. Some can grow to about 7 inches in length and cause severe illness, especially in younger pets.
Mother dogs can pass roundworms to developing puppies in the uterus or through milk when the puppies are nursing. Kittens do not become infected in utero, but they can become infected when nursing.
Adult roundworms live in the intestines, where they reproduce and lay eggs. An infected dog or cat sheds roundworm eggs into the environment when it passes feces. Once the eggs are in soil, the worms develop to the infective stage within the egg. Other pets can become infected by eating the eggs from contaminated soil, which often happens when pets groom themselves, sniff or lick the ground, or eat grass and other things outside. Alternatively, pets can be infected when they eat infected prey, such as birds and rodents.
Once roundworm eggs are eaten, they hatch in the digestive tract. In most cases, the worms then migrate through the liver and lungs. Once in the lungs, the pet coughs up the young worms and swallows them. They eventually make their way to the small intestine where they mature into adults and reproduce.
Roundworms are considered zoonotic parasites, meaning that they can be transmitted from animals to humans. Children are most at risk for infection. They usually become infected from eating fecal-contaminated soil, which is often found at playgrounds, backyards, and beaches frequented by pets.
In humans, roundworms are a significant cause of several types of larva migrans, an illness caused by migration of young worms through body organs such as the liver, lungs, and nervous system. Young worms may also travel to the eye, where they can cause blindness. This ophthalmic condition is called ocular larva migrans and occurs in the United States but is far more prevalent in developing countries.
If there are children in the household, pet owners should have their pets tested (at least annually) and treated for roundworm infection if they’re found to harbor them. Keeping pets on a monthly heartworm preventive that also controls roundworms is strongly advised. Children should wash their hands after handling pets or going to a playground, beach, or backyard. Keeping sandboxes covered when not in use is helpful in discouraging neighborhood cats from using them as litterboxes.
Puppies and kittens are usually the most severely affected and often look potbellied. Other signs include:
Veterinarians can diagnose a roundworm infection by finding microscopic roundworm eggs on a fecal exam. Unfortunately, some owners discover that their pets are infected when live roundworms are expelled in vomit or feces.
All breeds of dogs and cats are equally susceptible.
Veterinarians routinely treat young pets with an anti-parasite medication several times, interrupting the worm’s life cycle via parasiticide treatment every few weeks until pets can be placed on a monthly heartworm preventive that also controls roundworms and other intestinal parasites.
Roundworm infections are very common in puppies and kittens, but eggs aren’t always apparent in fecal material from infected pets. Your veterinarian may therefore recommend deworming puppies or kittens even if a fecal test does not confirm a roundworm infection. Many antiparasite medications kill only adult worms in the intestines, not the migrating younger worms or eggs. Therefore, if a pet is infected with roundworms, a veterinarian may recommend two to three rounds of treatment to clear the infection. Generally, fecal samples are rechecked after treatment to make sure the infection has been resolved.
Because roundworm eggs can remain infective in the environment for months to years, pet feces should be removed and disposed of immediately.
When walking your dog, keep him or her on a leash to help reduce exposure to areas that may have been contaminated by other dogs or cats. This will also minimize the chance of your dog eating infected rodents and birds.
If possible, cats should be kept indoors to prevent them from hunting infected prey. However, even indoor animals can catch infected mice. Sharing litterboxes and outdoor bathroom areas can spread roundworms among pets, so new pets should be tested for roundworms and other internal parasites before being introduced to your household.
Always consult a veterinarian about the best ways to protect a pet — and its human family — against intestinal parasites. A monthly heartworm preventive that includes medication for roundworms is a good start for year-round protection from these parasites. Since it’s easy to forget a monthly treatment and no parasiticide is 100 percent effective, periodic fecal exams are still recommended to ensure that a pet remains parasite free.
It’s unpleasant to think about hookworms. The name conjures up an awful vision, but it’s even more unpleasant for your pet to have them. Dogs and cats, both young and old, are at risk for the nasty parasites. And because the eggs can be transmitted through pets’ feces, people can also become infected. Symptoms in pets can include anemia, black diarrhea, coughing, a dull coat, and failure to gain weight. Fortunately, anti-parasite drugs can be used to treat an infection, and monthly preventive medicine can protect your pet from hookworms.
Hookworms are internal parasites that generally live in the small intestines of puppies, kittens, dogs, and cats. These worms attach to the intestinal tissue and suck blood and other nutrients from their hosts. Infected mother dogs can transmit hookworm larvae to their puppies during nursing. These larvae migrate through the puppy’s body to the lungs, where they are coughed up and swallowed, finally arriving in the small intestine.
Infected dogs and cats also release hookworm eggs into the environment through their feces. In the environment, hookworm larvae develop into the infective stage and hatch from the eggs so that when pets lie down in contaminated environments they pick up hookworm larvae in their coats and become infected during grooming. Eating stool outright can also lead to infection.
Hookworm larvae in the environment can also penetrate the pet’s skin (dog or cat) and travel through the body, eventually arriving at the small intestine. Dogs and cats can also become infected with hookworms by eating infected animals, such as rodents, or insects, like cockroaches.
Hookworm infections are considered zoonotic, meaning that they can be transmitted from animals to humans. Typically, people are infected when hookworm larvae from the environment penetrate the skin. The larvae then migrate under the skin, resulting in a condition called cutaneous larva migrans. People with this condition may experience itchy skin lesions with a snakelike pattern.
Occasionally, ingested larvae will migrate to the intestine, causing abdominal pain. However, hookworms do not mature to adults in humans, so these infections usually resolve on their own.
Hookworm infections are most severe in young puppies and kittens. Given a large enough worm burden, pets can die from hookworms. Signs of a hookworm infection include:
Diagnosing a hookworm infection is usually achieved by identifying hookworm eggs during a fecal examination. Unfortunately, hookworm adults don’t shed eggs all the time, so it can be difficult to identify the infection in some cases. That’s why routine deworming and several fecal examinations are always recommended in puppies, kittens, and pets with signs listed above.
Dogs or cats of any breed can become infected with hookworms.
Puppies and kittens are routinely treated every few weeks with an anti-parasite medication that eliminates hookworms and other internal parasites for at least two sequential treatments or until they are old enough to be placed on a monthly preventive medication.
Because hookworms can cause anemia (decreased red blood cells), pets with severe infections may require fluids, iron supplements, and even blood transfusions.
Several anti-parasite medications can be used to treat hookworm infections in dogs and cats.
All pets should be on a monthly parasite preventive regimen.
To prevent human infection, pet owners should remove and dispose of feces from the yard and sandboxes as soon as possible. Gloves and shoes should be worn at all times while gardening.
Imagine little bugs munching away and crawling around inside of your ears. The noise alone would be enough to drive you mad. It’s not likely to happen to you, but your pet can get ear mites, which are tiny parasites that set up house in the ear canal. Cats are more likely than dogs to suffer from the nasty bugs, but both can get them. Signs of infestation include scratching at the ears, dark debris in the ears, shaking the head, and red and inflamed ears. Ear mites can also cause a secondary ear infection to take hold. But hear this: Ear mites are easy to treat with medication.
Cats and dogs can both harbor ear mites, but the problem is more common in cats. Ear mites are small parasites that live primarily in the ears. Ear mites sustain themselves by eating skin cells, blood, and earwax. They deposit their waste (a dark, crusty debris) in the ear of the host animal. They also mate and produce eggs in the ear of the host. The mite’s entire life cycle is only about three weeks, and the mite spends its whole life on the animal. Ear mites are contagious between cats and dogs and to some other animals (for example, ferrets), but they are not considered contagious to humans.
The most common signs of ear mite infestation include:
Ear mites are microscopic. Examining ear debris under a microscope is the easiest method of diagnosis.
Secondary infection of the ears may also be identified through microscopic evaluation of the ear debris.
There is no known breed predisposition when it comes to this parasite.
Fortunately, ear mite infestations are highly treatable. If ear mites have caused a secondary ear infection it should be treated while the ear mite infestation is being treated.
Your veterinarian can prescribe medicated ear drops to kill ear mites. Because ear mites are contagious to other pets, all animals in the household should be treated.
Some spot-on flea and tick preventives are effective against ear mites in cats and dogs. Using these products monthly will control ear mite infestations in animals exposed to them.
Keeping cats and dogs indoors so they are not interacting with community animals carrying these mites is another approach to prevention.
That mosquito buzzing in your ear at night can drive you a little bit mad. But it can have far more serious consequences for your dog. Mosquitoes can carry heartworm larvae, and a bite from an infected insect could mean heartworm disease — and permanent damage to the heart, lungs, and blood vessels — for your dog down the line. A dog might not show any signs of infection, or he or she might cough, be lethargic, or lose weight inexplicably. Treatment usually involves a series of injections. The good news is that by following a heartworm prevention medicine regimen, it can be completely prevented.
Heartworm disease is a serious and potentially fatal condition that affects dogs, cats, and up to 30 other species of animals. It is caused by parasitic worms (heartworms) living in the major blood vessels of the lungs and, occasionally, in the heart. These worms are transmitted (as microscopic larvae) through the bite of an infected mosquito. The scientific name for the heartworm parasite is Dirofilaria immitis.
Heartworms are spread through the bite of a mosquito, and dogs increase the risk of infection for other dogs, cats and other animals. When a mosquito bites an infected dog it draws blood that contains immature heartworms (called microfilariae [pronounced micro-fill-air-ee-ay]). These microfilariae mature inside the mosquito to become infective larvae. When the mosquito eventually bites another dog or a cat, the larvae enter the new host. In dogs, these larvae often mature to become adult heartworms, which produce more microfilariae and continue the heartworm’s life cycle.
Heartworm disease can cause a variety of medical problems affecting the lungs, heart, liver, and/or kidneys. Severe complications can lead to death. Although a safe and effective treatment is available, it can be a costly and complicated process depending on how long the dog has been infected and how severe the infection is.
Despite the fact that heartworm disease is virtually 100 percent preventable, many dogs are diagnosed with it each year. The American Heartworm Society (AHS) estimates that one million dogs in the United States have heartworm disease today, and that this number may be rising.
Some dogs may show no signs of infection. However, depending on the number of worms and the duration of infection, dogs may begin to show the following clinical signs:
Apart from clinical signs, heartworm disease can be diagnosed using laboratory tests that check the dog’s blood for evidence of infection. Additional testing, including a CBC (complete blood cell count), blood chemistry panel, and urinalysis may be recommended for a heartworm positive pet to help assess the severity of the disease. Sometimes evidence of heartworms can be seen on ultrasound images or radiographs (X-rays) of the heart and lungs.
Dogs of any breed can become infected with heartworms.
If infection is detected early enough, heartworm disease can be treated before permanent damage to the heart, lungs, and/or blood vessels occurs. However, if the infection has been present for a long time or consists of a large number of worms, the risk of complications increases. In these cases, treatment can be more expensive and complicated and dogs may take many months to recover from the infection.
Standard treatment of heartworm disease in dogs involves administering a series of injections with a medication that kills the heartworms. Surgical removal of the worms may be recommended in some cases.
Unfortunately, untreated heartworm disease can be fatal.
Safe, easy-to-give, effective medications are available to prevent heartworm disease. Most heartworm preventive medications are administered as monthly oral or topical (spot-on) medications. There is also a product that can be administered as an injection every six months by your veterinarian. Whichever method of heartworm prevention is chosen, prevention is convenient and inexpensive compared to the dangers of the disease for dogs.
The microscopic organism called coccidia lives in the intestines of a dog or cat and causes a disease referred to as coccidiosis. Signs include diarrhea, vomiting, loss of appetite, and lethargy. Puppies and kittens can become dehydrated and even die from an infection, though some pets never show any signs at all. A pet can pick up the infection from the soil, an infected animal’s feces or by eating an infected rodent. Fortunately, there are medications to treat coccidiosis in both dogs and cats.
Coccidiosis is a common parasitic intestinal condition caused by a microscopic, single-celled organism known commonly as coccidia. Though there are several types of coccidia, dogs with this condition are usually infected with Isospora canis, while cats are infected with Isospora felis.
Infected dogs and cats shed cysts containing the parasite in their stool. These cysts can survive in the environment for as long as a year. Other pets can become infected by swallowing the cysts from a contaminated environment, usually during grooming. Dogs and cats can also contract the parasite by eating an infected rodent.
Once inside the pet’s digestive tract, the cysts break open and the parasite enters an intestinal cell, where it reproduces. The cell eventually ruptures, releasing the parasites and damaging the intestinal lining.
The coccidia species that infect dogs don’t infect cats, and vice versa. However, the cysts in the feces from one dog can infect another dog, and the cysts in the feces from one cat may be infective to another cat. It’s very unlikely that a human will become infected with the species of coccidia that affect dogs and cats.
A high incidence of coccidiosis is seen in kenneled dogs, especially when they are housed under intensive conditions for a long time. Puppy mills and other busy breeding kennels are most often plagued by coccidiosis, so buyers are cautioned to investigate these facilities for signs of diarrhea.
Signs of coccidiosis include watery diarrhea that will often be tinged with blood or mucus. Pets with this condition may also experience vomiting, a loss of appetite and lethargy. Puppies and kittens can be severely affected, exhibiting dehydration, weight loss, and, in some cases, even death.
Older pets usually have milder signs. Some pets can show no signs at all while still shedding the parasite cysts in their feces.
A diagnosis of coccidiosis is made by identifying parasite cysts on a fecal exam. Any new pet being introduced into the home should have a fecal sample tested as soon as possible to diagnose coccidiosis or other intestinal parasite infections. Because some pets never show any signs, fecal tests during annual physical examinations are considered standard practice for all pets.
All breeds of dogs and cats are considered equally susceptible.
Several oral medications may be used to treat coccidiosis. Most pets will require daily treatment for 5 to 10 days, but some pets will have to be retreated if the infection isn’t resolved after the first or even second go-round. In multi-dog or multi-cat households, it’s a good idea to treat the other dogs and cats, respectively, to prevent reinfection from other pets that may carry the parasite but show no signs.
Pets (particularly puppies and kittens) with severe dehydration may need fluid therapy and hospitalization.
Since the cysts are often difficult to find on a fecal exam, veterinarians will sometimes treat pets if there’s a high suspicion of coccidiosis, even if no cysts are found in their stool.
Preventing pets from being infected by coccidia cysts in the environment, washing his or her bedding and cleaning any kennel/heavily populated areas with an ammonia product should be a basic practice, especially if multiple dogs/cats share the area. Picking up and disposing of feces as soon as possible, and keeping pets from hunting rodents, if possible, are also considered fundamental preventive measures.
Fleas are everywhere. Even the cleanest, most pampered pets can get fleas and once inside your home, fleas can spread rapidly. Depending on where you live, the risk of flea infestation diminishes somewhat in colder months because freezing temperatures kill off many outdoor pests, but infestation remains a year-round concern as there are many warm places where fleas can thrive. The good news is that there are effective products to help prevent your pet from becoming infested.
These small, wingless insects are common pests of wildlife such as Possums and rabbits. As wild critters crawl around your yard, they deposit flea eggs that grow into adult fleas seeking a home. Wandering pets offer the new crop of fleas a safe haven, a source of food (blood), and a good place to raise a family. In addition to these sources, pets can pick up fleas from other infested dogs or cats.
The scratching caused by fleas can lead to skin damage and secondary infection. Fleas can also pass on diseases such as tapeworm, cat scratch disease, and blood parasites. Getting rid of fleas from your pet and your home can be a major chore in some cases, so it is best to focus on preventing them.
Adult fleas usually spend their entire lives on a host animal, where they feed, mate, and produce eggs. Once laid, flea eggs drop to the ground, hatch, and develop into larvae that feed on organic material. The bedding of infested pets is often loaded with eggs and larvae that are too small to be noticed. After a while, these larvae spin a cocoon and develop into pupae and then into adult fleas that hatch out and seek another pet (or the same one) on which to live.
In the winter, freezing temperatures can kill off eggs and larvae in the environment, but not those living in sheltered havens such as nests, burrows, and your living room. It’s easy to see how even a single pair of fleas can lead to a massive household infestation over a period of weeks to months.
Fleas are very small and difficult to find because they hide within the thick hair coats of dogs and cats. Adults look like small reddish-brown sesame seeds. They can occasionally be seen scurrying in the hair coat, especially around the neck and ears, along the rump and tail head, and in the underbelly and groin areas (where thinner hair can make them easier to see). But often, the only sign of a flea problem is your pet’s scratching and biting, which can produce raw areas of skin infection.
In many instances, pets can become allergic to fleas, so that even a single bite sets off intense itching and red, sore, infected “hotspots.”
Sometimes, you may also see “flea dirt,” which is dried-up flea excrement. If you brush this gritty material out of the hair coat onto a white sheet of paper or paper towel, you’ll notice individual, reddish brown crusts that look like tiny commas. If you add a drop of water, you’ll see a brown ring around the “dirt” as the digested blood leaches out into the paper. If an area is heavily infested, you may even see bites on people, usually around the ankles, from newly emerged adult fleas seeking their first blood meal.
Many products are available to kill fleas and prevent their reproduction. These products are generally safe and effective, and many last for a month or longer after a single application. Most monthly preventives are topical products that are applied to the skin between the shoulder blades or along the backline of dogs and cats, but some products come in pill or collar form. Your vet can help you decide which one is most appropriate for you and your pet.
Monthly treatments have largely replaced sprays, powders, dips, and flea collars that were mainstays of years past. If desired, some insecticidal sprays and shampoos can be safely applied in combination with monthly treatments. Ask your veterinarian to be sure these pesticides are safe when used in conjunction with monthly topical or oral medications. Always make sure to read labels carefully and heed all directions and warnings! And never use a canine flea product on a cat!
Judicious, consistent use of the most effective treatments will eventually eliminate flea infestations over time. To speed up the process, you can also use indoor and outdoor insecticides to kill off fleas around the home. Similarly, thorough washing of pet bedding and vacuuming carpets and upholstery will help remove many immature flea stages before they can turn into adults that jump onto your pet.
Most pets have no side effects when flea treatments are used correctly. If you’re worried about using man-made chemicals, ask your vet about “natural” flea control. But be warned, some so-called natural products are much less effective and can in some cases be more toxic than their man-made counterparts.
Giardiasis is caused by a parasite that takes hold in the intestinal tract and causes diarrhea, vomiting, weight loss, and tiredness. It’s passed to the environment through infected feces, and both dogs and cats can get it. If a pet has been infected with the giardiasis-causing organism, a vet can give him or her medicines to treat the problem, but it’s a stubborn bug and it may take more than one treatment to eliminate.
Giardiasis is a diarrheal disease that can affect many species: dogs, cats, and even humans. It’s caused by Giardia, a single-celled parasite that attacks the gastrointestinal tract of infected animals.
Among experts, there is some question about the number of Giardia subtypes that can cause disease in animals and the potential of these subtypes to also infect humans. Though humans are susceptible to infection with Giardia, infection by the same subtypes prevalent in animals is thought to be exceedingly rare but remains a point of controversy and investigation.
Giardia is found worldwide and in every region of the United States. According to the Companion Animal Parasite Council, approximately 16 percent of symptomatic dogs and approximately 10 percent of symptomatic cats have been found to be infected with Giardia.
The parasite lives in the intestines of infected animals and humans, and infected individuals pass the parasite in their feces, in the form of cysts, into the environment. These cysts can remain infective for months, especially when conditions are cool and humid. The infection is transmitted when a host ingests water from a contaminated pond, lake, or stream or ingests contaminated food or soil. Outbreaks of giardiasis are more common when animals are housed in crowded conditions, such as in kennels or shelters.
Clinical signs of giardiasis typically develop within five to 16 days after exposure to Giardia. In many cases, infected pets show no or slight signs of disease. Signs can include:
Because these signs can also be caused by many other diseases and health concerns, a complete physical examination and basic diagnostic testing of the stool and blood are recommended.
Several types of fecal tests can be used to diagnose giardiasis. In some cases, tests may need to be repeated more than once to obtain a definitive result.
In most cases, the disease course is mild. Some animals — particularly puppies, kittens, or animals with underlying health conditions — may have more severe diarrhea and vomiting and may require supportive therapy with fluids and anti-nausea medications. Dehydration can be a serious concern in these cases.
No breed predilection for giardiasis has been established in cats or dogs.
There are medications for treating giardiasis, but the infection can be difficult to cure, so multiple courses of treatment may be necessary. Pets should be bathed frequently throughout treatment to remove infective cysts from the coat.
Because pets that have been treated have no immunity against future infection, these pets can easily be reinfected. Therefore, living areas should be disinfected; ammonia, dilute bleach solution, or steam cleaning can be effective.
If there are other pets in the household, medications may be administered to them as a preventive measure — and because identifying the infection can be frustrating it’s reasonable to assume other pets in the household have been exposed to the same Giardia sources and are likely to be infected. Contaminated soil can remain infective for months under certain conditions, so walking treated dogs in a different area may reduce the risk of reinfection.
Giardia is common in the environment. Outdoor dogs and cats, working or hunting dogs, and pets that swim or have contact with potentially fecal-contaminated water can be at risk for exposure.
Preventive measures should include regular removal of feces from the yard or kennel. As much as possible (or reasonable, given the need for exercise and general quality of life), prevent pets from drinking from, or swimming in, lakes, streams, and ponds.
Most veterinarians recommend testing new puppies or kittens or adult pets for Giardia before they are introduced to your other pets.
Though it is considered controversial whether humans and pets can be infected by the same subtypes of Giardia, it is always a good idea for people to wash their hands after playing with pets or disposing of fecal material (infective or not).
Gastrointestinal (GI) parasites can make your dog or cat — and sometimes even you — sick, which is why it’s so important to prevent infestations, and, if they do occur, to treat your pet quickly. Here are some of the things you need to know to keep your pets safe.
Even the cleanest, best cared-for pets are susceptible to these bugs, which take up residence in the stomach or intestines. Some of these parasites can be spread from mother to puppy or kitten or by fleas or rodents or through the feces. Good hygiene, regular visits to the veterinarian, preventive medicines and deworming treatments can keep your pets free of these pesky intruders. Luckily, if your pet is infected, many effective treatment options are available. Your vet can guide you on what is the best strategy for your pets.
Some GI parasites are big enough that you can actually see them; others are invisible without a microscope. Regardless of their size, GI parasites can cause serious illness and even death in pets. Here, the most common GI parasites in pets:
Roundworms: Visible to the naked eye, roundworms resemble small pieces of spaghetti. In people, roundworms can lead to larva migrans, an illness caused by migration of young worms through the nervous system, liver, lungs, and other organs. They can even travel to the eye and cause blindness.
Hookworms: These worms attach to the intestinal wall and suck blood and other nutrients from their hosts, leading to severe blood loss and diarrhea in infected pets. And larvae found in the environment can penetrate the skin and cause illness in a new host. When humans are infected, the condition is called cutaneous larva migrans. The tell-tale symptom? Itchy skin lesions with a snakelike pattern.
Tapeworms: These are long, flat worms made up of numerous segments containing tapeworm eggs. For one species of tapeworm, the immature stage of the tapeworm lives inside of a flea. When your dog or cat grooms a flea off of its hair, it eats the flea—and the tapeworm, which then hatches inside your pet and continues its life cycle. You can become infected if you inadvertently eat tapeworm eggs or infected fleas.
Giardia: Giardia organisms are single-celled parasites that live in the intestines, and can be spread through fecal-contaminated water, food, or soil.
Whipworms: Whipworms live in the large intestines of dogs and shed eggs into the environment. When this occurs, the contamination can persist for years. Female whipworms can produce more than 2,000 eggs a day.
Coccidia: Coccidia are microscopic GI parasites. They can cause severe diarrhea in some infected pets.
Usually, GI parasites shed their eggs in the host’s feces. Once this occurs, other pets can be exposed through direct contact with the feces or contaminated soil, water, or plants. Some of these bugs can remain in the environment for months or years. Other parasites infect rodents and other small animals. When a dog or cat eats these animals, it becomes infected. Finally, some GI parasites can infect puppies and kittens when they nurse from their infected mothers, and puppies can sometimes become infected during fetal development.
Parasites are tricky, as often, dogs and cats don’t show any signs of illness. But if your pet has diarrhea, is vomiting or loses weight, he may have been infected. In this situation, a trip to your veterinarian is a good idea.
Fecal testing can detect GI parasites in most cases, but not always, which is why some veterinarians recommend deworming (administering medication to treat and control infections) even if the fecal test doesn’t confirm the existence of bugs. In fact, because puppies and kittens are commonly infected with GI parasites, many veterinarians routinely deworm them several times. Deworming medications are safe when used properly and come in a variety of formulations, including pills, chewable tablets, liquid medications and topical products that are applied to the skin between the shoulder blades. Your veterinarian can recommend the most appropriate deworming medications for your pet.
There is no single medication that can treat and prevent all GI parasites, but many monthly heartworm preventive medications also control some of these microscopic bugs. Your veterinarian can recommend several safe and effective medications.
To protect your pet and your family, take the following precautions: