Featured Research

from universities, journals, and other organizations

To Stem Disease, Keep Cats Indoors, Stop Feeding Strays, Scientist Urges

Date:
October 24, 2005
Source:
University of Illinois at Urbana-Champaign
Summary:
Keep pet cats inside, stop feeding strays, cook meat sufficiently and reconsider the way the veterinary profession and public health agencies think -- and teach -- about the zoonotic pathogen Toxoplasma gondii. Such are the recommendations of Milton M. McAllister, a professor of pathobiology in the College of Veterinary Medicine at the University of Illinois at Urbana-Champaign.

Milton M. McAllister, a professor of pathobiology in the College of Veterinary Medicine, recommends keeping cats indoors to decrease the transmission of Toxoplasma gondii. Domestic cats and some wild cats are the only animals that can transmit the parasite by shedding the organism in feces.
Credit: Photo by Jim Barlow

CHAMPAIGN, Ill. -- Keep pet cats inside, stop feeding strays, cook meat sufficiently and reconsider the way the veterinary profession and public health agencies think -- and teach -- about the zoonotic pathogen Toxoplasma gondii.

Related Articles


Such are the recommendations of Milton M. McAllister, a professor of pathobiology in the College of Veterinary Medicine at the University of Illinois at Urbana-Champaign. He delivered that message at 8:30 a.m., Oct. 19 (2:30 p.m. CDT Tuesday, Oct. 18) in Christchurch, New Zealand, at the 20th International Conference of the World Association for the Advancement of Veterinary Parasitology.

McAllister, also a clinical professor of pathology in the U. of I. College of Medicine at Urbana-Champaign, made his case based on his review of numerous studies on the animal-carried pathogen during the past decade. His review, prepared for the conference, appeared in the Sept. 30 issue of the journal Veterinary Parasitology.

"Our profession needs to come to grip with the accumulating body of evidence about the tremendous burden wrought on society by toxoplasmosis," McAllister wrote. "Further research is needed to clarify the association between toxoplasmosis and mental health, but until such time that this association may be refuted, it is my opinion that the current evidence is strong enough to warrant an assumption of validity."

Toxoplasma can infect most warm-blooded animals, as well as humans and birds. Domestic cats and some wild cats are the only animals that can transmit the parasite by shedding the organism in feces. Other animals become infected when they consume the organisms shed by cats. This method of parasite transmission is called fecal-oral, but it doesn't actually mean that feces are directly ingested.

The organisms survive in soil long after feces have decomposed. Dust contaminates paws, fingers, feedstuffs and water, ultimately leading to ingestion by animals and people.

McAllister and colleagues are beginning to work on a new vaccine, which, if successful, would be administered to cats orally, possibly incorporated into a treat. The vaccine would be used to prevent cats from shedding toxoplasma.

"Cats usually become infected with toxoplasma by ingesting an infected animal, or raw meat from an infected animal," he said. "So a cat gets infected by catching and eating mice or birds, or by eating meat scraps from such things as poultry, pork, lamb or game."

In his review, McAllister noted a long list of maladies made worse by toxoplasma infection in people with suppressed immunity, and he cited a growing list of studies that link problems in people whose immune systems are not impaired. Among the latter problems are fever, enlarged lymph nodes, weakness and debilitation, damaged vision, or multi-systemic infections with serious complications such as pneumonia and hepatitis. Toxoplasma also is a causative agent of encephalitis in AIDS patients.

People can get infections either by fecal-oral transmission -- even through inhaling oocysts in dusty conditions -- or by eating undercooked infected meat. Oocysts, the egg-like forms of a parasite, can survive for more than a year in soil, dust or water, McAllister said.

"Cats that remain indoors have a low potential to become infected if they don't have access to mice and if they are not fed raw meat or meat products," McAllister said. Owners can safely keep an indoor cat simply by practicing good hygiene with the litter box and washing hands after daily cleanings, he added.

Infected mice, he noted, show altered behavior, including being less aware of cats in an area, leaving the mice open to predation that renews the parasite's life cycle. Mice may not be the only creatures susceptible to behavioral changes from infections, he said.

"Evidence is mounting to link toxoplasmosis with schizophrenia or similar psychiatric disorders (in people)," McAllister wrote. "Recent studies from three countries found that schizophrenic patients had higher antibody levels to T. gondii than did matched control subjects."

He also cited older studies that used a toxoplasma skin test that "showed highly significant associations between toxoplasmosis and psychiatric disorders." Recent studies also have linked infections with reduced average intelligence.

Toxoplasmosis is the third leading cause of food-related deaths in the United States, behind salmonella and listeria infections. Exposure in the womb is considered "one of the most common infectious causes of birth defects, mental retardation and visual problems worldwide, including industrialized nations," McAllister wrote. Studies in the last three years have estimated that toxoplasma has infected 25 percent of adult Americans, 40 percent of adults in the Netherlands and 70 percent in Jakarta, Indonesia.

Marine mammals also are at risk, possibly from cat-feces-contaminated surface water going into the oceans. He cited infections of seals, dolphins and sea otters.

Simply put, McAllister said, domestic cats should not be allowed to roam outdoors. The feeding of stray cats, he added, by cat protectionist groups including some veterinary organizations that wish to spare homeless cats from the threat of euthanasia, unfortunately increases the spread of toxoplasmosis to wildlife, domestic animals and people.

"Public lawmakers should consider developing effective solutions that protect the best interests of society," he wrote. Health educators teaching new students, McAllister writes, "should be careful to distinguish sub-clinical infections from the possibilities of undiagnosed infections and latent disease." He noted that proper diagnosis likely is frequently missed.

If a practical vaccine to prevent cats from shedding toxoplasma organisms can be developed, he said, then its use could be made mandatory, similar to rabies vaccine laws in many states.



Story Source:

The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University of Illinois at Urbana-Champaign. "To Stem Disease, Keep Cats Indoors, Stop Feeding Strays, Scientist Urges." ScienceDaily. ScienceDaily, 24 October 2005. <www.sciencedaily.com/releases/2005/10/051024085202.htm>.
University of Illinois at Urbana-Champaign. (2005, October 24). To Stem Disease, Keep Cats Indoors, Stop Feeding Strays, Scientist Urges. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2005/10/051024085202.htm
University of Illinois at Urbana-Champaign. "To Stem Disease, Keep Cats Indoors, Stop Feeding Strays, Scientist Urges." ScienceDaily. www.sciencedaily.com/releases/2005/10/051024085202.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins