A common parasite of dogs and cats, especially puppies and kittens, is Roundworms. The scientific name for their group is called ascarids. We routinely treat puppies and kittens for this parasite for 2 reasons. The first is their prevalence, the second is their potential to infest humans. The larval form of this parasite has the potential to cause serious disease in children. Fortunately it is a rare problem, and can be prevented by worming all puppies and kittens early in life.
Life cycle
The life cycle of this parasite almost ensures that a puppy or a kitten will be exposed. They can get it from their mother while they are in the uterus (dogs), during nursing, and through contamination with infected feces. Larval forms of this parasite migrate through internal organs, get coughed up and swallowed, and become mature parasites in the small intestines. Intermediate hosts like rodents can become infected by eating eggs, and can then infect a dog or cat when they are eaten. Some larvae migrate to the tissues of internal organs and remain dormant until pregnancy where they become active and infect the developing puppies in the uterus.

Symptoms
Common symptoms are a distended abdomen and diarrhea. Some puppies and kittens will be vomiting, lethargic and not eating well, while others will not show any symptoms. On rare occasions the parasite load can be so heavy that the intestines become obstructed. Coughing, fever, nasal discharge and even pneumonia can occur in pups that have large numbers of larvae migrating through their respiratory tract.
Diagnosis
In some cases the Roundworm will be present in your pet's feces or vomitus. It looks like a curled up piece of spaghetti.

The vast majority of Roundworm infestations are diagnosed on fecal analysis for eggs. Young puppies can be infected before the eggs of the parasite appear in the feces.
This is one type of Roundworm egg when viewed under the microscope. The thick membrane around the eggs prevent them from drying out when they are laid in the environment.

Treatment
There are several effective treatments for Roundworms. We can easily treat your pet with an oral version given during a routine office visit. It has to be retreated in 2 weeks due to the migrating larvae since the medication does not kill the larvae. Some pets require several more treatments for a full cure.
Prevention
Roundworm eggs can remain viable for a long time in the environment. Children will get this parasite by eating dirt contaminated with the eggs, therefore cleaning up your pet's feces immediately, and eliminating exposure to the feces of other animals when your pet goes for a walk, are important treatment modalities. Litter pans should be changed frequently and washed thoroughly and then allowed to dry in the sun. Keeping cats indoors also eliminates exposure to the feces of infected pets and the eating of infected rodents.
Public Health Significance
Children are of particular vulnerability to infestation because of their propensity to put things in their mouths and their attractions towards puppies. areas that might be contaminated with dog or cat feces should be off limits to children. This might include public areas such as parks or playgrounds. Even though these infestations in children are relatively uncommon, if they occur there can be significant damage to the internal organs like the liver, heart, brain, lungs, and eyes. This reason alone is why all puppies and kittens should be routinely treated for Roundworms, whether or not their fecal exam indicates they have parasites. also, teach your children to wash their hands frequently after handling pets, and not to put anything unnecessary in thier mouths.
Hookworms
Hookworms are blood sucking parasites that live in the small intestine. The scientific name for the Hookworm we encounter in our area is called Ancylostoma. They can be very pathogenic and even cause death due to anemia and low protein level.
Life cycle
Hookworms are spread by eating infected larvae that are in the environment. These infective larvae can also penetrate the skin and enter the blood stream where they mature into adult Hookworms in the small intestine. Puppies can also get infected while nursing or in the uterus prior to birth. Some Hookworm larvae migrate to muscles where they serve as a source of future infections.

Symptoms
Pets with Hookworms have the potential to be very ill,especially in dogs. Symptoms include lethargy, dark stools or diarrhea, weakness and vomiting. In severe cases they are anemic and debilitated, especially the older and younger pets. The larvae might even irritate the skin when they penetrate between the toes and pads.
Diagnosis
Adult Hookworms are small so they are usually not seen passed in the feces. This diagnosis is made primarily by finding the distinctive egg in your pet's feces. Any pet that is anemic should have its feces checked for this parasite.
These eggs are more oval than Roundworms, and the membrane is thinner.

Treatment
Infected pets might require hospitalization and even a blood transfusion if their symptoms are severe. There are different types of worming medications used, some require retreatment several weeks after the initial treatment because of the larvae that migrate through the body. All require checking your pet's feces to make sure the parasite has been eliminated. Long term treatment and surveillance in the form of fecal exams are necessary. Dogs with chronic problems are put on heartworm preventive medication on a monthly basis since this medication also kills Hookworms. Any dog put on heartworm preventive medication needs to be checked for heartworm disease before we start preventive medication.
Prevention
Fecal exams should be performed frequently on pets that have a history of Hookworm infestation. Prompt removal of feces helps prevent contamination of the yard with larvae. Larvae are killed in cold climates when exposed to freezing temperatures.
Public Health Significance
Hookworm larvae can penetrate the skin of people and cause significant irritation. These larvae can migrate through the body and cause damage to internal organs. Just like in Roundworms discussed above, puppies should be routinely treated for this parasite at a young age.