Dogs potentially harbor a number of different parasites, viruses, bacteria, fungi and insects that can cause human illness. These furry friends are an important part of many pet owners' lives, offering companionship and affection. Risk of contracting an illness from a dog can be minimized through good hygiene practices, and by keeping pets clean and healthy.
The term "ringworm" is somewhat misleading, as it is not caused by a worm, but a contagious fungus. The condition creates a flat ring of red, scaly, itchy skin on the scalp, or other parts of the body. The inner surface of the ring often appears smooth and healthy. If the infection occurs on the scalp it leaves bald patches. Fingernails sometimes become infected with ringworm causing them to thicken, and crumble. Dogs carrying the fungus can transmit the infection to people through direct contact with their skin or hair. Treatment with topical anti fungal medications usually clears up ringworm infection in about four weeks.
Campylobacteriosis is a bacterial disease caused by various campylobacter species. It is a very common cause of intestinal illness in the United States with over 2.4 million cases annually, reports the Centers for Disease control and Prevention, or CDC. Dogs are sometimes infected with campylobacter, and spread the bacteria through their stools. People with campylobacteriosis experience fever, abdominal pain, and diarrhea. The symptoms can be more severe with bloody diarrhea and vomiting. Those with weak immune systems may have life-threatening complications. Most people get over this disease without treatment, but antibiotics are sometimes needed to recover from severe illness. If a person comes into contact with dog feces, thorough hand washing can prevent this illness.
Leptospirosis is a disease caused by several different Leptospira species. Dogs sometimes carry the spiral shaped bacteria, and shed it in their urine. Urine from an infected dog can contaminate water or soil, and linger there for months. A person might contract leptospirosis by getting this tainted water, soil or urine into a scratch or cut. The bacteria can also enter the body through the mucus membranes of the mouth, eyes, or nose. Leptospirosis symptoms are quite variable, and some people have no symptoms at all. The illness typically involves high fever, headache, stomach pain, muscle aches, a rash, diarrhea, and vomiting. Left untreated, leptospirosis can infect the brain, and cause liver and kidney damage. Antibiotics are used to treat the disease.