What s Hiding in your Pet? by Erin Quigley, DVM Potentially harmful parasites! A parasite is an organism that lives on (external) or in (internal) an organism of another species (such as dog, cat or human), known as the host. The parasites live and reproduce by feeding on the host directly or by taking in a portion of the host s nutrients. This month we will be talking about internal parasites that affect your dogs and cats and potentially you and your family. Internal parasites Last month we talked about a common internal parasite that lives in heart, lungs and blood vessels of dogs and cats called Heartworms. This month we will be talking about another common classification of internal parasites called intestinal parasites. Intestinal parasites can live anywhere in the body but tend to populate in the gastro- intestinal tract. The two main categories of intestinal parasites are Helminths (aka. worms) and Protozoa (single cell organisms). Let s start with worms Roundworms Roundworms are among the most common intestinal parasites of dogs and cats. These worms are large as adults (3-18 cm in length) and when passed they resemble spaghetti noodles. Transmission Dogs and cats of any age may get roundworms but they are most vulnerable when they are young. In fact 90% of puppies fewer than three months of age can be infected. That s because these worms are often passed from a mother to her puppies before birth through the placenta and shortly after birth through her milk. All ages can become infected by ingestion of fecal material of an infected animal. This can happen easily by a dog stepping in soil contaminated by an infected animal for example at a park, or even in your yard if a stray animal or wildlife has passed through. When your dog licks its paws, it becomes infected. Symptoms In puppies or kittens common symptoms include failure to gain weight, poor hair coat, and pot-bellied appearance. In heavier infections 2 MetroPet Magazine St. Louis - May 2014
the young puppy or kitten may expel worms in their vomit. Adult dogs and cats may show signs of diarrhea, blood in stool, weight loss or vomiting. ** Very commonly a dog or cat may act completely normal yet still be shedding the worm eggs in the stool, without any visual evidence, contaminating the environment (your home and yard). Prevalence How common are Roundworms. As stated above, roundworms are extremely common in puppies. Every puppy should be tested, ideally before coming home to your family and your other pets. In adult dogs according to the Companion Animal Parasite Council, the current statistic for Missouri matches the National prevalence of 1 out of 45 dogs tested are positive for round worms. This includes dogs both on and off preventative. Diagnosis It is true that a diagnosis can be made by seeing adult worms in the stool, but this is a rare occurrence. The majority of the time our pets are shedding microscopic eggs without our knowledge or any evidence so a diagnosis needs to be made by fecal flotation. This is the definitive diagnostic test that uses special solutions, centrifugation and microscopic exam to detect the parasite in your dog or cat. Take Away Point: You cannot look at your dog or cats stool and know if he or she has intestinal parasites! Most of the time worms are diagnosed in dogs and cats with normal appearing fecal matter. This is why your veterinarian recommends yearly fecal examination. Zoonotic Yes, roundworms can be transmitted to people, most vulnerable are children. How? The most common way is through fecal-oral transmission. Dogs and cats contaminate homes and yards with infective eggs and larvae passed in their stool. These eggs and larvae are resilient and can survive in parks, playgrounds and yards, 3
even inside homes. People get infected through direct contact with infected feces. This can happen if a dog has recently licked their contaminated paws and then pass that material by licking a child s face. Most commonly transmission occurs when children play in contaminated soil or sand boxes when hands or contaminated objects go in the mouth. Immune compromised adults also are also at an increased risk. When infection occurs in people the ingested eggs hatch into larvae, these larvae travel through the liver, lungs and other organs. In most cases, these wandering worms cause no symptoms or apparent damage. However, in some cases they may produce a condition known as visceral larva migrans. The larvae migrate and cause damage to tissue, affect the nerves or even lodge in the eye, and potentially cause blindness. Prevention So, what can we do to protect our pets and family? Here is a list of things we can all do to prevent the spread of worms. Take your puppy or kitten immediately into the veterinarian when you adopt them so they can be screened for parasites with a fecal exam and dewormed before exposing your family or other pets. Have your adult dog and cat tested annually for intestinal parasites by a fecal examination at your veterinarian s office. Place your pet on a monthly parasite preventative. There are oral and topical preventatives appropriate for dogs and cats that their doctor can recommend. Give these preventatives to indoor and outdoor animals all year round. Because parasites live inside our pets and shed any time of year, preventatives should not be viewed as seasonal. Indoor animals, like our feline companions, are exposed by tracking in parasite eggs on the bottom of feet by the family or the family dog. At home you can promptly remove animal feces from the yard or litter box to prevent contamination and spread between animals. Keep dogs on a leash or in fenced yard and keep cats indoors. Monitor children when they are playing outside in the yard, playground and sandboxes. Cover sandboxes to prevent contamination. Children and adults should wash hands frequently, especially if at risk of feces handling or exposure to feces. For people with weakened immune systems, be especially careful of contact with animals that can transmit these infections. Hookworms Hookworms are short (6 to 12 mm), thick worms that are whitish to reddish brown with a hooked front end. They are rarely seen as adults so diagnosis is necessary by fecal flotation to find eggs. Transmission Puppies can contract worms from crossing the mother s placenta and through the mother s milk similar to Roundworms. Hookworms are not transmitted to kittens in pregnancy. All ages of dogs and cats can obtain hookworms from ingestion of contaminated fecal material. Something unique about Hookworms is they can penetrate through skin of a dog, cat or person, from infected soil. Symptoms Infected puppies and kittens can be anemic and show pale gum color, and fail to gain weight. They can also have a dull hair coat and become dehydrated or have dark, tarry, soft stools. When people are infected they have red, itchy skin with a worm like lesion under the skin. Prevalence Nationally one out of every 51 dogs tested are positive for hookworms. Missouri has an increased risk with one out of 35 tested dogs being 4
positive. This increased prevalence may have something to do with the fact that we do not tend to see adults in stool, where occasionally we will see adult roundworms. This is why it is so important we test our dogs and cats stool annually. Diagnosis Diagnosis is made by fecal flotation test at your veterinarian s office. Zoonotic Yes, similar to roundworms people, particularly children, are at risk by a fecal-oral route. Contaminated soil, sandbox or stool that is on your pet or in your home is transferred to your hands and then to your mouth. Unique to hookworms and more common transmission in people is penetration through the skin. Commonly it occurs when not wearing socks or shoes while gardening or playing in sandboxes that are contaminated. Prevention The steps to preventing hookworm infection are identical to roundworms with deworming of puppies and kittens, monthly prevention and annual fecal examinations. In addition to removing feces from the yard to prevent ingestion it is also recommended to wear shoes and gloves while gardening. Whipworms Whipworms are named for their characteristic whipshaped body and infect dogs, foxes and coyotes; cats are not affected. Adult worms are 4.5- to 7.5-cm long and are rarely seen in stool. Transmission is through ingestion of contaminated soil, and not through maternal placenta or milk. Symptoms include diarrhea with bright red blood or mucus, staining to defecate, and weight loss. Diagnosis is made by fecal flotation and treatment is an oral deworming medication. The national prevalence for whipworms is 1 out of 116 dogs tested. The prevalence in Missouri is 1 out of 31 dogs tested. The good news about Whipworms is that they are not zoonotic (contagious to people). The bad news about Whipworms is they are impossible to get rid of from your environment. Whipworm eggs can persist in soil for several years, surviving winter freezing and even burning of top soil. So once your dog is infected and yard is contaminated monthly preventative specific to prevent whipworms must be given every 30 days all year round. Dogs that visit dog parks or live in communities where land is shared between several pets are at increased risk. Tapeworms Tapeworms have a flattened, ribbon-like appearance and are often seen in motile segments that resemble white rice directly in stool, near the anus of an infected dog or cat, or in the environment. Transmission is through ingestion of fleas or animals that carry fleas such as rodents and rabbits. Often our pets carry tapeworms for months at a time without any symptoms. Tapeworms may absorb nutrients in the intestinal tract, but rarely cause disease. If signs are present it is commonly itching or dragging their hind ends. Unique to tapeworms is that diagnosis is typically by observation of the segments on the animal or in the environment; these parasite eggs are rarely detected on fecal examination. Treatment of this parasite is by oral medication and prevention is by a high quality monthly flea preventative. As far as risk of infection to people, it is through contact with the fleas on your pet and in your home or by accidental ingestion of fleas. Most people infected do not show symptoms, but diarrhea, abdominal pain and anal itching are possible. Protozoa Giardia - is a microscopic two-celled organism with flagella (whip like tails) that lives and reproduces in the small intestines of infected humans or other animals. 5
Individuals become infected through ingesting or coming into contact with contaminated food, soil, or water. The Giardia parasite originates from contaminated items and surfaces that have been tainted by the feces of an infected carrier. Commonly dogs ingest this parasite by drinking water from creeks, rivers and rain puddles. The symptoms of Giardia, which may begin to appear 2 days after infection, include violent diarrhea, excess gas, stomach or abdominal cramps, upset stomach, and nausea. Resulting dehydration and nutritional loss may need immediate treatment. Diagnosis can be made at your veterinarian, and treatment includes specific course of antibiotics and anti-parasitic drugs with supportive care, such as fluid therapy. Coccidia is a single-celled organism that infects the intestinal tract of dogs and cats, particularly kittens and puppies in shelter environments. Infection causes diarrhea with weight loss, dehydration, and (rarely) hemorrhage. Severely affected animals may present with anorexia, vomiting, and depression. Death is a potential outcome. Dogs and cats may shed coccidia in feces but remain asymptomatic. Many times an asymptomatic or mild infection may become significant during times of stress such as changing environments to a new home. Published surveys indicate that coccidia are present in from 3% to 38% of dogs, and 3% to 36% of cats in North America. Diagnosis is made strictly by centrifugation fecal exam. Treatment is a sulfa-type drug for duration of 7-20 days. Prevention is soley based on environmental control, and disinfectants of surfaces and treating exposed animals. Unfortunately in some environments there is much resistance in coccidiosis infection, despite medicating and disinfecting. Because humans are not susceptible to the species of coccidia that infects dogs and cats, canine or feline coccidia are not considered zoonotic agents. Summary Whether its worms or protozoa, microscopic organisms may be shedding off your family pet at any time without any evidence. Speak with your veterinarian today so she can help you protect your pet and your family from all of these harmful parasites with one simple yearly test, as well as provide a preventative fit for your dog or cat and lifestyle needs. Erin Quigley, DVM, Member of AVMA, MVMA, grew up in Florissant, MO, and received a Bachelor s degree in Biology at Missouri State University. After college I worked as a receptionist at Rock Road Animal Hospital, a zookeeper at the St. Louis Zoo and a veterinary assistant at Howdershell Animal Hospital until attending Veterinary School at University of Missouri-Columbia. I graduated with my Doctorate of Veterinary Medicine and have lived in O Fallon, Missouri since I graduated. I have worked as a veterinarian in Troy, Wentzville, and Florissant, MO, until purchasing Animal Medical Center of Wentzville in 2010. I married in 2011 and live with my husband Ryan and boxer dog Finnegan in Lake St. Louis/O Fallon. When my husband and I have free time from the clinic we enjoy spending time with our dog, family and friends. Our hobbies include attending Cardinal baseball and Mizzou football games. We also enjoy the outdoors biking, boating and horseback riding.