St. Michaels Companion Animal Hospital Greeley, CO 970.330.9400

Picking up after your dog is the ethical and responsible thing to do as a pet owner and community member of St Michaels. But when it’s late, and you’re tired, and Fido just left a nasty pile on your walk, who’s looking, and who will know? What could possibly happen?

The challenge is that Fido’s mess can actually spread diseases and parasites, not only to other dogs but can affect children and people with impaired immune function, also called zoonotic infection.

Zoonotic infections are those that can cause disease not only in the normal host animals but can also infect humans, usually causing aberrant disease processes. Zoonotic infections of the greatest importance for fecal spread include:

Internal Parasites:

  • Hookworms
  • Roundworms
  • Tapeworms
  • Whipworms


  • Cryptosporidium
  • Giardia
  • Toxoplasma


  • E. coli
  • Salmonella

Example of parasite ova seen under microscope. 

Infections are spread through fecal contamination of the areas where dogs have defecated. Unfortunately, there is usually no external signs that a dog is carrying gastrointestinal worms as dogs shed the microscopic eggs produced by the worms. With tapeworm infection, you may see what looks like grains of rice adherent to fur around a dog’s rectum. Parasite infection may only be found by performing a microscopic fecal analysis at your veterinarian’s office.
Hookworm infections are spread when an animal passes hookworm eggs in their stool. These eggs and larvae may be found in the dirt for years following when they are deposited in the ground. People may become infected while walking barefoot or when exposed skin comes into contact with the infected ground (like a playing child). Hookworm infections can cause a condition called cutaneous larval migrans, where the larva of the worms burrows under the skin revealing red, raised tracks to follow the worms migration. The larvae can also infect the intestine causing abdominal pain, diarrhea, and discomfort. Hookworm eggs and larvae are incredibly resistant to weather and dying, so the only way to eliminate infected areas is a removal of the sod and top few inches of soil.

Example of cutaneous larval migrans.

Roundworm infections are the most common parasite of zoonotic concern for humans. People become infected by accidentally ingesting the infective eggs from the soil or other contaminated surfaces. This happens most commonly through children playing on the ground, and putting toys or other objects in their mouths, or even licking their fingers prior to being washed. These infections can manifest in 2 ways;

  • Ocular Toxocariasis- and infection of the eye that can cause blindness
    Example of ocular larva migrants
  • Visceral Toxocariasis- infection of the body’s organs or nervous system, which may cause fever, coughing, asthma, pneumonia, or other symptoms dependant on the affected system.

The best way to keep your dog healthy, and prevent infection and spread of these parasites is to have a routine fecal exam performed at your veterinarian’s office semiannually. Administering a monthly heartworm preventative that includes a broad spectrum gastrointestinal dewormer to your dog, year-round, can also treat and protect your pet and family from these parasites. In our St. Michael’s neighborhood it is important to consider flea and tick prevention for our pets due to the abundant wildlife to prevent tapeworm and other disease spread. Please pick up any fecal material from common areas immediately, and best practices are to clean yards preferably daily, but at least weekly. Keeping your dog leashed while walking in common areas of St Michaels will facilitate removal of waste promptly.

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