Trichuriasis (Whipworm) in Dogs Both dogs and cats suffer from the whipworm (Trichuris trichiura) parasite. It is generally transmitted by ingesting infested matter, although whipworms can be contracted from other infected animals. Whipworm eggs can live in an environment anywhere from a few months to years, and can be present in soil, food, or water, as well as in feces or animal flesh. Additionally, whipworms infect dogs of any age.
Symptoms and Types A whipworm infection may present itself as a large bowel inflammation or bloody diarrhea, or it may be asymptomatic. Other symptoms commonly associated with a whipworm infection include dehydration,anemia, and weight loss. It is worth noting that symptoms may begin prior to any visual evidence of whipworm eggs.
Causes Dogs contract whipworms by ingesting infested or contaminated matter (e.g., food, water, flesh).
Diagnosis The veterinarian will confirm the diagnosis by conducting the fecal flotation procedure on a stool sample. If parasitic eggs or whipworms are present, they will float to the surface of the glass slide.
Ancylostomiasis ( Hookworm) in Dogs Hookworms can be fatal, especially in puppies. As such, pet owners need to be vigilant for signs of hookworms in their dogs. These blood-sucking parasites can invade, inhabit, and live in the dog's small intestines. In their fourth-stage larvae, the hookworms can cause anemia and inflammation in the dog's small intestine. Active worms leave bite sites and those sites continue to seep blood.
Symptoms A dog with the parasite looks unhealthy and has a poor appetite; the linings of its nostrils, lips, and ears will be pale. If hookworm larvae get into the lungs, the dog will cough, as well as present several other symptoms, including dark and tarry stool, diarrhea, and constipation. Death can come suddenly if the dog is not immediatelytreated.
Causes Puppies usually acquire this condition through milk from their mothers. These infestations are always caused by ingestion or by larval penetration of the skin, generally found in contaminated water or in a contaminated environment.
Diagnosis Hookworms cannot be seen with the naked eye and must be therefore be microscopically examined by your veterinarian through a stool specimen. This examination will also help the veterinarian determine what course of treatment to prescribe. If some of the puppies in a litter have died, hookworms should be suspected.
Cestodiasis ( Tapeworm ) in Dogs Cestodiasis is the medical term for tapeworm infestation. Tapeworms typically settle in the small intestine. The tapeworm species can include Taenia, Dipylidium Caninum, Echinococcus, and Mesocestoides. Treatment to destroy tapeworms is critical to avoid transmission to humans (typically children) and to avert damage to the dog's body. With prompt treatment, prognosis is positive.
Symptoms As the tapeworm grows, pieces of it break off into segments and pass into the dog's intestines. You may see dried, white to cream colored segments, or pieces, of tapeworm in the dog's feces or in the fur under the tail. Some tapeworm species break off into segments that are too small to see, while the segments of other tapeworm species will resemble sesame or cucumber seeds in size and appearance. Still other species of worm will pass into the feces and can be readily seen. Dogs may bite or lick the anus, or drag their hind quarters across the floor in response to the itching.
Causes Tapeworms are acquired by ingesting the immediate host containing larvae. Tapeworm eggs are frequently ingested through adult fleas. Other sources that are potential transmitters, and that a dog is likely to ingest, include rabbits, birds, and rodents. Scavenging may also lead to an infestation of tapeworms.
Diagnosis Tapeworms will be found in the anal sac or in the feces of the animal. A fecal, or stool, sample can be used to review for the presence of tapeworms. False negatives do occur, but most test results are conclusive.
Ascariasis (Roundworms ) in Dogs
Is a disease affecting dogs caused by the intestinal parasitic roundworm (or Ascaris lumbricoides). Roundworms are often quite large -- up to 10 to 12 centimeters in length -- and can be present in extremely high numbers within an infected animal. When they are found in a dog's body, it can lead to abdominal swelling (distension), colic, gastrointestinal issues and even intestinalrupture.
Symptoms The following signs or symptoms are common in dogs that have roundworms: Colic - Lethargy - Vomiting - Abdominal - swelling -Abnormal feces - Poor nursing (in females) - Anorexia -Coughing (caused when the roundworm larvae have migrated into the dog's lungs)
Causes Adult dogs can become infected through the ingestion of roundworm eggs, which are found in infected food, water, vomit, or feces. Pups can then contract the parasite during the pregnancy or by drinking the milk from an infected pregnant animal. And if one of the newborns in a litter is exposed to roundworms, the entire litter can contract the parasite.
Diagnosis Upon examination of the dog, a swollen abdominal region is commonly detected. There may also be signs of weakness and loss of appetite. A fecal swab will then be taken to detect the presence of roundworm eggs. Dead roundworms being passed out of the animal's body is another good indicator of the disease.
Dirofilariasis ( Heartworms ) in Dogs
Dogs suffering from heartworms are, in fact, infested by the organism Dirofilaria immitis, a parasitic nematode(roundworm) commonly referred to as the heartworm. The severity of this diseaseis directly dependent upon the number of worms present in the body, theduration of the infestation, and the response of the host (the infested dog is the host).
In regions where Dirofilaria immitis isendemic, dogs without proper heartworm protection are almost 100 percent likelyto suffer from heartworm infestation. The heartworm is mainly endemic ingeographic areas with tropical and subtropical climates, and is also commonlyfound along the Atlantic and Gulf Coasts, and the Ohio and Mississippi river basins. The presence of Dirofilaria immitis is not limited to these areas, however, it is found worldwide. Dogs have been diagnosed with heartworm disease in all 50 U.S. states.
Heartworm disease is preventable with the administration of a heartworm prophylaxis (preventative) medication, as recommended by a veterinarian. For those dogs that do contract heartworm disease, the prognosis is good for mild to moderate cases, and such conditions can be relatively uneventful. Dogs with more severe cases may suffer from lung complications resulting from extreme medication given to kill serious infestations.
Symptoms and Types Heartworm disease is defined in three classes, varying in severity. Dogs with Class I heartworm disease are often asymptomatic, meaning they exhibit no visible symptoms, or may only exhibit minimal signs such as an occasional cough. Class II patients usually exhibit coughing and unusual intolerance to exercise. The most severe cases, defined as Class III, may show symptoms of anemia, exercise intolerance, fainting spells, and -- in severely affected dogs, right-sided chronic heart failure.
A physical examination may reveal further symptoms, especially in Class III cases. These include high blood pressure (hypertension), labored breathing, and extremely rapid heartbeat (tachycardia).
Causes Heartworms are spread through mosquitos that carry the infective heartworm larvae. These larvae migrate from the bite wound through the dog’s body until they reach the heart and blood vessels of the lungs, a process that takes approximately six months. The larvae mature in the dog’s body -- an adult heartworm can grow to be about 12 inches long. These adults reproduce and release immature heartworms, known as microfilariae, directly into the dog’s blood. When a mosquito bites an already infected dog, it may take in these microfilariae with the dog’s blood, and then pass on the infective heartworm larvae (the microfilariae develop once inside the mosquito)to another dog, thereby continuing the parasite’s life cycle and spreading the disease to the next host.
Risk factors associated with heartworm disease include residence in endemic regions, such as tropical areas, outdoor habitation, and lack of the proper prophylaxis to prevent heartworm infestation.
Diagnosis If heartworm disease is suspected, an electrocardiograph (which monitors changes in the heart) may reveal heart rhythm disturbances and/or enlargement of the right ventricle of the heart (hypertrophy).
Additional tests may include a urine analysis, serologic tests that can identify the female heartworm antigen, and X-rays, which may reveal enlargement in key arteries associated with heartworm disease.
Treatment In initial treatment, most patients are hospitalized as they receive administration of an adulticide designed to kill the adult heartworms. The microfilariae in the body can be eliminated with a monthly prophylaxis, which can be administered at home. For more severe cases, such as dogs experiencing thromboembolic complications (in which a blood clot that has formed breaks loose and travels through the blood stream to clot another vessel), hospitalization may be necessary for a longer period of time.
In some cases, a surgical procedure may be necessary to remove adult worms from the right heart and pulmonary artery by way of the jugular vein. This procedure is recommended if the infestation consists of a high number of adult worms.
Living and Management Upon initial heartworm treatment, activity should be severely restricted for at least four to six weeks after administration of the adulticide. Severely affected dogs may need to be kept in a cage to limit activity. For dogs recovering from congestive heart failure, a moderately restrictive sodium diet is recommended.
An antigen test should be done four months after adulticide treatment to check for continued presence of the adult Dirofilaria immitis. If the test is positive, the adulticide treatment can be repeated, or a surgical procedure performed instead. Some dogs with persistent infestation may not require retreatment, depending on the patient’s age and severity of the disease. Older dogs, for example, may not be overly affected by mild recurrent worm infestations.
Prevention Routine heartworm prophylaxis (preventative) should be given to any at-risk dogs, for example those living in endemic regions, as directed by your veterinarian. This is essential to preventing heartworm infestation. There are a number of medical preventatives that are highly effective and commonly used. It is possible for infestation to occur if a prophylaxis is not regularly administered.
Coccidiosis in Dogs Coccidiosis is a parasitic type of infection, caused by the coccidian that most commonly causes watery, mucus-based diarrhea in dogs. If it is not treated, over time it can cause damage to the lining of the dog's intestinal tract. With treatment, the prognosis is good. Coccidia are parasites that are often misunderstood in dogs. After the first exposure, coccidia parasites are always present in the puppy’s intestines, and they’re just waiting to take advantage of any digestive upset. It is rarely the initial cause of the diarrhea, but once diarrhea starts, the coccidia will overgrow to large numbers to keep the diarrhea going.
Coccidia are a major issue for puppies under 8 weeks old.
Puppies are born with a sterile gut, and their mother seeds their gut with good bacteria during cleaning them and caring for them. However, puppies can also get coccidia from their moms, so the goal is to keep the puppy’s exposure to a minimum number. There are a variety of products you can use for both treatment and prevention, but prevention is most important for consistently healthy puppies. Symptoms and Types You may notice that the dog has watery, mucous-like diarrhea. As the condition progresses, bloody diarrhea and an inability to withhold it will begin to show. The dog may also be in a weakened state.
WHERE DO COCCIDIA COME FROM?
Oocysts (pronounced o'o-sists), like those shown above, are passed in stool. In the outside world, the oocysts begin to mature or sporulate. After they have adequately matured, they become infective to any host (dog or cat) that accidentally swallows them.
To be more precise, coccidia come from fecal-contaminated ground. They are swallowed when a pet grooms/licks the dirt off itself. In some cases, sporulated oocysts are swallowed by mice and the host is infected when it eats the mouse. Coccidia infection is especially common in young animals housed in groups (in shelters, rescue areas, kennels, etc.) This is a common parasite and is not necessarily a sign of poor husbandry.
WHAT HAPPENS INSIDE THE HOST? The sporulated oocyst breaks open and releases eight sporozoites. These sporozoites each finds an intestinal cell and begins to reproduce inside it. Ultimately, the cell is so full of what are at this stage called merozoites that it bursts, releasing the merozoites that seek out their own intestinal cells and the process begins again. It is important to note how thousands of intestinal cells can become infected and destroyed as a result of accidentally swallowing a single oocyst.
As the intestinal cells are destroyed in larger and larger numbers, intestinal function is disrupted and a bloody, watery diarrhea results. The fluid loss can be dangerously dehydrating to a young or small pet.
HOW ARE COCCIDIA DETECTED?
A routine fecal test is a good idea for any new puppy or kitten whether there are signs of diarrhea or not as youngsters are commonly parasitized. This sort of test is also a good idea for any patient with diarrhea and is recommended at least once a year for healthy dogs and cats as a screening test. The below photograph shows coccidia oocysts seen under the microscope in a fecal sample. Coccidia are microscopic and a test such as this is necessary to rule them in. It should be noted that small numbers of coccidia can be hard to detect so just because a fecal sample tests negative, this does not mean that the pet is not infected. Sometimes several fecal tests are performed, especially in a young pet with a refractory diarrhea; parasites may not be evident until later in the course of the condition.
HOW IS COCCIDIA TREATED? The most common medicines used against coccidia are called coccidiostats. They inhibit coccidial reproduction. Once the numbers stop expanding, it is easier for the patient’s immune system to catch up and wipe the infection out. This also means, though, that the time it takes to clear the infection depends on how many coccidia organisms there are to start with and how strong the patient’s immune system is. A typical treatment course lasts about a week or two, but it is important to realize that the medication should be given until the diarrhea resolves plus an extra couple of days. Medication should be given for at least 5 days total. Sometimes courses as long as a month are needed. In dogs and cats, sulfa-based antibiotics are the most commonly used coccidiostats.
The use of sulfa drugs in pregnancy can cause birth defects. Sulfa drug use can also lead to false positive test results for urine glucose.
There is another medication that is worth mentioning and that is Ponazuril, a large animal product. This medication is actually able to curtail a coccidial infection in five doses or less and has been used in thousands of shelter puppies and kittens with no adverse effects. This product would seem to be superior to the usual sulfa drugs, but the problem that keeps it from becoming a mainstream treatment is the fact that it is available only as a paste for horses and must be diluted down to create an appropriate small animal formula. The large volumes of product yielded are not cost effective if only occasional patients are treated for this parasite. Ponazuril is thus most commonly used in kennels, catteries, and animal shelters though one may be pleasantly surprised to find it in stock at one's regular veterinary office.
CAN PEOPLE OR OTHER PETS BECOME INFECTED? While there are species of coccidia that can infect people (Toxoplasma and Cryptosporidium, for example), the Isospora species of dogs and cats are not infective to people. Other pets may become infected from exposure to infected fecal matter but it is important to note that this is usually an infection of the young (i.e. the immature immune system tends to let the coccidia infection reach large numbers whereas the mature immune system probably will not.) In most cases, the infected new puppy or kitten does not infect the resident adult animal.
Guide to Giardia in Dogs: Diagnosis, Treatment and Prevention
Giardia in dogs (also known as giardiasis) became well known several decades ago when a different strain of the organism was identified as causing persistent diarrhea in people. Once an understanding was developed that the condition is spread through feces contaminated swimming pools, food, drinking water, and surfaces, did the awareness of the disease increase. This awareness led to an understanding of giardiasis in animal health and improvements in detection methods.
Causes of Giardia in Dogs (Left and right: Giardia Protozoa ; Center: Cyst) Source: CDC Studies show that approximately 4% to 6.8% of dogs shed giardia cysts. The cysts are shed by infected dogs from the small intestines and are passed through the feces. Rates of infection are higher in younger dogs with 12% of dogs under age 6 months testing positive for the disease. This rate is significantly lower in dogs 3 and older, where only 1%$ shed cysts.
The protozoa that causes giardia in dogs are transported in protective cysts which protect the protozoa until they reach the next host. Giardia can last in the environment for several months.
How Giardiasis is Spread from Dog to Dog The infection spreads when a dog ingests cysts found in feces after ingesting contaminated water, food, or from fomites in the environment such as a park, improperly cleaned kennel or dog run. Once the cysts are ingested, the giardia protozoa begin to multiply and attach to the dog’s small intestine. As they feed off the dog, they rob the dog of nutrients through mal-absorption and problems with the digestive system through mal-digestion (incomplete digestion). Protozoa that feed on a host are referred to as trophozoites. Any surface that is contaminated, including food, play toys etc that came in contact with feces from a dog that is shedding giardia cysts, can be one of thecauses of giardia in dogs.
A dog will start shedding cysts in 5 to 7 days after being infected.
Each Person, Dog or Cat is infected with a different strain of Giardia
The giardia that infects dogs (giardia canis) is different than the giardia that infects cats (giardia felis) or the strain seen in humans. In general, dogs in the Northeastern United States have a higher incidence of the disease over the Southeastern United States (DD Bowman 2011, Carlin 2006).
Dog Giardia Symptoms The most common giardia dog symptoms are moderate to severe diarrhea with or without mucus. It is rare for the diarrhea to contain blood. Other symptoms includes vomiting. Most dogs that shed giardia cysts are asymptomatic, which means that they do not show any giardia symptoms.
Diagnosis of Dog Giardia
Giardia diiagnosis in dogs is accomplished in the veterinarian’s office with one of several types of tests. This includes a centrifugal fecal flotation test or fecal ELISA test. Note that the majority of dogs are asymptomatic or symptom free. In this case, giardia in dogs is detected as part of tests conducted during a checkup, called fecal centrifugation. If this is the case, your veterinarian will discuss with you the pro’s and cons of treating a dog that does not show symptoms.
Canine Giardia Treatment There are several prescription medications available for giardia dog treatment. This includes:
Fenbendazole/febantel (50 mg/kg for 5 days) is effective in most dogs.
Metronidazole (25 mg/kg 5 days). In some dogs Metronidazole can be toxic (Per 2010 CAPC Guidelines).
Drontal Plus (3 days)
Homeopathic supplements can help to restore digestive health after prescription treatment.
If a dog becomes severely dehydrated from the diarrhea, fluid therapy in the veterinarian’s office will be necessary.
Dog Giarda Vaccine The dog giardia vaccine is not considered a core or mandatory vaccine. Exposure of a dog to potential sources of giardia such as other dogs and contaminated waterways should be considered as part of the decision to vaccinate.
Can Humans Catch Giardia from Dogs (Zoonotic)? The strain of giardia found in humans has been found as the source of infection in a limited number of dog giardia cases. For this reason, there is some risk that giardia can pass from human to dog. If a dog is infected with a human strain it could theoretically pass back to humans, although this is considered to be rare. Because of this, proper hygiene should be followed when handling an infected dog. Always be careful when disposing of feces.
Giardia Dog Prevention Only give your dog fresh drinking water when outdoors. Avoid allowing your dog to drink from any standing water that could be contaminated. If your dog defecates outdoors, such as in a backyard, clean-up all feces. Dogs that have been positively diagnosed should have a bath to remove any cysts that could be hiding in the coat.
These hygienic steps are necessary to prevent reinfection, as it is common for this to occur in giardia in dogs cases.