By Dr. Kathleen BabbittOne of my favorite things to do, warm or cold, is to go for a walk. I tend to use the Heritage Park paved trail and the Rotary River Walk for these walks. I like the fact that is paved and has beautiful scenery. The thing that disturbs me the most is the amount of poop left behind by other dog owners. Not only is this just gross but it's also a health hazard to other dogs and humans.The disgusting nature of letting your dog go just wherever and not cleaning up after him has resulted in many municipalities in banning dogs from walking trails, etc. The eyesore, the smell and the cost of having someone else clean it up becomes overwhelming for the small staffs of most of our parks. So it is easier to just ban dogs. This is unfortunate because our dogs really like exercise, and it punishes us who do pick up our dog's waste. It is a simple as carrying a few bags with you. When your dog defecates, please pick it up, carry it with you, and drop it off at the next wastebasket. Heritage Park and the other parks in that district even provide you with the bags. Another reason to not be lazy is the risk of zoonotic disease. Zoonotic diseases are those diseases that can be passed from animal to man and man to animal. The most concerning is the intestinal parasite Toxocara canis, or the canine roundworm. A dog may become infected with this parasite in one of four ways:1. Ingesting infective eggs from contaminated soil.2. Nursing from an infected mother dog.3. Consuming a prey animal that is infected, usually a rodent.4. During embryonic development when an infected mother dog is pregnant. This is the most common way a dog is infected.To understand how this parasite moves from dog to human we must understand its life cycle first. 1. Eggs are passed when the host defecates. The eggs stay in the environment for about a month. During that time, they develop into infective second-stage larva. The eggs are not infective until they have undergone this development, which means fresh poop is not a problem but soil that has been contaminated with infective feces is dangerous. Eggs can remain in the soil for months to years despite freezing, thawing, drought, etc. 2. The infective egg can now be picked up by a dog or another animal. This usually happens with normal exposure to the infective soil. The eggs then hatch into small worms in the intestines that burrow out of the intestine and become cysts in other body tissues. If the host is a dog, the life cycle proceeds. If not, the cysts remain in the tissues.3. The cyst can remain in the dog for years. When the timing is right they develop, travel to the lungs, get coughed up, swallowed, and enter into the intestines for the second time in their life. If the host is pregnant they instead travel to the fetus and then travel to the puppies' lungs to infect the puppy.If the host is nursing, the larva migrate to the mammary glands and infect the puppies while nursing.4. Once in the intestine, the worms mature and mate. The first eggs are released about a week later. The entire life cycle takes about four to five weeks.Humans can become infected when they come in contact with the infective eggs. This occurs most often in children because of their poor handwashing skills. Humans are not a natural host for the worm, but it tries to complete its life cycle anyway. This results in “visceral larval migrans” in which the larvas migrate randomly throughout the body and eventually die, causing a massive inflammatory reaction. The eye is a common place for the larva to end up and can result in blindness. We can prevent this from happening in several ways. First, pick up the poop. Removing the feces right away prevents the spread of the eggs into the soil. All puppies and new dogs should be given a dewormer several times, and all dogs should be maintained on monthly parasite prevention. Most heartworm preventers control roundworm infections, which is why year-round use is a good idea. Also, teach your children good hygiene.So, please pick up after your dog. Let's keep our parks clean, open to dogs, and prevent our children from getting a terrible disease.Dr. Kathleen Babbitt is the owner of Lima Animal Hospital. She has six dogs that she likes to take to the park. She picks up a lot of poop.