Canine Parasites And Prevention - Carolina Animal Hospital of Creedmoor - Creedmoor, NC

Carolina Animal Hospital of Creedmoor

2552 Capitol Drive, Suite 103
Creedmoor, NC 27522



Canine Parasites


Internal Parasites



Unlike other parasitic worms which live in the intestines, Heartworm are a large worm (up to 14 inches long) which, as an adult, lives in the heart and pulmonary arteries of an infected dog. Dogs acquire this infection through mosquito bites. Mosquitoes readily pick up larval heartworms (teenage) from infected dogs and carry them to new dogs. Heartworm infection and disease is a very large problem in North Carolina.

Treatment for the adult heartworm infection is both very costly and can result in significant complications. Untreated most pets will develop symptoms of heart disease such as chronic coughing, lethargy, fluid accumulation and ultimately leading to heart failure and death

Fortunately, there is a simple, inexpensive and effective way to dramatically reduce or eliminate the risk of heartworm parasite infection in your pet - We recommend the monthly use of heartworm prevention pills all year-round. We also advocate yearly blood testing for heartworms in all of our adult dog patients.



This is a common worm of puppies and kittens, but can be seen in any age dog or cat. Diagnosis is made from a microscopic examination of the feces or from a description of the worm if it is seen in the stool or vomit. Treatment is an oral medication given at 2 week intervals. Symptoms will vary from none to marked vomiting and diarrhea, and abdominal swelling. Transmission to adult dogs and cats occurs by infected feces contaminating the yard. As a result, prevention is accomplished by isolating your pet from infected feces of other animals. For dogs, the heartworm preventatives also reduce or prevent roundworm infection.

Transmission to humans is rare; young children can develop "visceral larval migrans" - round worm migration in the skin or into the eye (leading to loss of vision in the affected eye) - by eating dirt contaminated with feces, including playground sand.

  • Round; white; 2-4 inches long: may curl up when seen; resemble "spaghetti"
  • May be vomited up from stomach; or coughed up from the lungs.
  • Most commonly found in young puppies.
  • May cause intestinal blockage when found in large numbers.



This is also a common intestinal worm of puppies and kittens but is seen with equal frequency in adults. This parasite sucks your pet's blood and can cause a severe anemia. Diagnosis is made from a microscopic examination of your pet's stool. Treatment is generally an oral medication. This is repeated 2 weeks later. Symptoms will vary from none to blood in the stool (dark tar-colored stool) with diarrhea. Severe cases of anemia may need a transfusion and hospitalization. Transmission to adults occurs via infected feces contaminating the grass or soil. Prevention, therefore, requires that the pet be kept away from contaminated areas. Some types of heartworm preventative can also reduce or prevent hookworm infections in dogs.

Transmission to humans is uncommon and is usually in the form of skin lesions.

  • Very thin, almost transparent; 1/4 -1/2 inch long.
  • Normally not visible to the naked eye.
  • Hook on to the intestine and suck blood, which causes anemia.
  • The mother may infect puppies through the milk when nursing.
  • May be ingested orally or may actually penetrate the skin (usually through feet).
  • Causes bloody diarrhea and death when severe.
  • Probably the most harmful of all intestinal parasites!



This worm affects dogs only. Diagnosis is also made from a microscopic exam of the feces. Eggs from this parasite pass intermittently, however, so it may be necessary to check several fecal samples before a diagnosis is made. Treatment is an oral medication given at 2 to 6 week intervals depending on the severity of the infection. Symptoms vary from none to a severe watery diarrhea, vomiting, and marked weight loss. Some dogs require hospitalization for treatment of dehydration, malnutrition, and infection.  

There is no human transmission.

  • Inhabit the lower part of the intestine - colon.
  • Can cause chronic diarrhea, sometimes containing blood.
  • Normally not visible to the naked eye.
  • Eggs are ingested off the ground.



This worm affects both dogs and cats. Interestingly the most common route of transmission occurs when your dog or cat chews and "eats" a flea. The intermediate form of the tapeworm lives inside the flea's body and it then attaches to the intestine where it begins to grow "segments". In about 3 weeks, these segments begin to pass in the stool. They are approximately ¼ to ½ inch long, flat, and white. After a short time in the air, they dry up to resemble a small yellow flat seed - usually stuck to the hair around your pet's anus. Diagnosis is made from seeing these segments on the stool or on the pet's back end rather than a microscopic fecal exam. Treatment is either by oral tablets or by an injection. The tapeworm treatment kills existing tapeworms but it does not prevent future infection. The only prevention is strict flea control. 

  • Short, flat segments (look similar to "rice" or "cucumber seeds").
  • Causes a poor appearance and dry skin.
  • Often seen on the hair around the rectum.
  • Usually it is not diagnosed by microscopic exam like other parasites, unless a segment just happens to be present—segments are not passed every day.
  • Generally spread by fleas, rabbits, birds, and other rodents.



This parasite is not a 'worm' but rather a single-celled parasite. It is seen primarily in puppies and kittens, although debilitated (ill) adults can also be affected. Transmission occurs by eating the infective stage of the parasite. It reproduces in the intestinal tract causing no symptoms in mild cases to bloody diarrhea in severely affected pets.             Diagnosis is made from a fresh stool sample. Treatment varies greatly. Animals showing no signs of illness are sometimes not treated because a mild case is often self-limiting. Pets with diarrhea are treated at home with an oral medication. Severely affected pets may need hospitalization due to dehydration. Prevention involves disposal of all stools and cleaning the pet's living area. 

Human transmission is uncommon but can occur.



This is another parasite which is not a 'worm'. It is a very tiny single-celled parasite that can live in the intestines of dogs, cats, and man. It is seen most commonly in dogs coming out of kennel-type situations (pet stores, shelters, dog pounds, etc.) but its incidence is increasing. Symptoms include intermittent or continuous diarrhea, weight loss, depression, and loss of appetite. 

Diagnosis is made from a very fresh fecal specimen that must be collected at the clinic for optimum results. A surprising number of affected animals are "occult"; that is, they are infected but are negative on these tests even with multiple examinations. As a result, this parasite is often treated without a confirming diagnosis. Treatment is an oral medication administered at home. Prevention involves careful disposal of all fecal material and cleaning contaminated areas. 

Humans can become infected with Giardia so special care must be taken to wash hands and utensils.


External Parasites



Flea infestations are the most common parasite problem of dogs in our area. There are over 2000 species of fleas, but only a few actually feed on dogs and cats. Not only do fleas cause itching and scratching that frequently leads to secondary skin infections, but often fleas also carry tapeworm eggs which may lead to intestinal tapeworm infections of your puppy. Because fleas ingest blood as their food source, severe flea infestations can cause anemia - and even death - in puppies and small dogs. Currently we recommend the use of Nexgard  (Monthly oral pill) for puppies until 6 months of age and then Simparica (Monthly oral pill) from that point forward.



Ticks are another highly visible external parasite on our pets. Pets usually acquire these hitchhikers in wooded areas or in dense vegetation (Very high grass or shrubs). Ticks will bite and attach themselves to your pets generally for 24 - 48 hours while 'ballooning' themselves up with blood. They tend to attach themselves in very hairy or hidden areas on your pet - such as inside ear flaps, 'armpits' and groin regions. Ticks are not only disgusting, but can spread other infectious diseases such as Lyme Disease when they regurgitate or 'spit-up' shortly before they dislodge themselves.Currently we recommend the use of Nexgard (Monthly oral pill) for puppies until 6 months of age and then Simparica (Monthly oral pill) from taht point forward.



In North Carolina, the most common form of skin mite infestation is caused by Demodex mites. Demodex, also known as "Mange", can cause areas of hair loss, skin inflammation and erythema (redness), scratching and biting and secondary bacterial infections. Demodex mites are not contagious to humans.

All dogs are likely born with small numbers of demodex mites that are generally kept under control by the normally functioning immune system in your puppy. However, some puppies seem to be very susceptible to Demodex mite outbreaks. Fortunately, the vast majority of "Mange" puppies respond well to a combination therapy of oral antibiotics, fatty acid / oil supplementation, antihistamines, medicated shampoo and a specific anti-parasitic medication. We strongly recommend any puppy diagnosed with demodex mite infestation be Neutered or Spayed to help decrease repeated outbreaks in your pet, as well as to eliminate the genetic susceptibility to demodex in future generations of puppies.

Any puppy with one or more areas of hair loss, itching and scratching or repeated skin infections should be examined by our veterinarian and a skin scrape performed to look for the mites. Please do not attempt to treat your puppy for demodex, or "mange" on your own - there are many suggested forms of 'treatment' given out or advised by lay people that are at best not effective and at worse may make your puppy very ill.



Although relatively uncommon, we do occasionally diagnose some young puppies with lice infestation of their hair coat. Fortunately, most lice are fairly species specific so it is unlikely you will contract lice from your puppy. Additionally, most puppies respond very well and quickly to topical treatment of lice.