David L. Morris: Vet Column 3-7-11
In a recent publication from the Centers for Disease Control and Prevention, United States Department of Health and Human Services, authors from the University of California-Davis and the California Department of Public Health shared a perspective regarding pets and human households. Since many livestock, including equine, owners share an appreciation for all creatures great and small, they are frequently accompanied by traditional pets. When these pets enter the household, are there potential issues of concern?
As modern society has become more urbanized, the presence in households of traditional pets has increased in popularity. In many situations, pets have become an integral part of the family unit and are often considered to be extended family. Having pets can be beneficial in terms of psychological support, friendship, and when involved in exercising or reducing stress, even promoting good health practices.
In the United States, greater than 60 percent of households have pets, increasing from 56 percent in 1988 to 62 percent in 2008. Among dog owners, 53 percent consider their dog to be a member of the family. Perhaps surprisingly, 56 percent of dog owners sleep with their dog next to them. Approximately 50 percent of dogs sleep on the bed. Among dogs that sleep with their owners, 62 percent are small dogs, 41 percent are medium sized, and 32 percent are large sized dogs. In a 2005 American Kennel Club survey, 21 percent of dog owners slept with their dogs regularly; 25 percent women and 16 percent men. Among cats, 62 percent slept with their adult owners and another 13 percent slept with children.
Does this close contact with traditional pets create cause for concern? The authors then searched PubMed for peer-reviewed publications that clearly documented human exposure to zoonotic (human to animal or animal to human transmission) diseases by sleeping with, sharing a bed with, kissing, or being licked by pets. The offering below is by no means complete.
From 1974 through 2008, at least 29 cases of bubonic plague were documented. The preponderance of exposure came from cats, especially those with outdoor/indoor activity, serving as a vector for fleas. One case actually involved a dog. Sleeping with or having the cat on the bed was common in the history.
Cat-scratch disease results generally from being scratched by a cat that harbors Bartonella henselae-infected fleas and flea feces. The literature reports that a 9-year-old girl who had been sleeping with a cat became infected and had not been scratched.
A study of Chagas disease showed that dogs and cats infected with the Chagas disease agent can be problematic to humans. Infection rates were higher when infected dogs shared sleeping areas with humans than when they did not.
Confirmed reports exist that close sharing with pets, including sharing a bed, being licked by, or kissing the pets can be problematic. In 1985, a case of meningitis caused by Pasteurella multocida was reported after the individual admitted to regularly kissing the family dog. Isolates from the inside of the dog’s mouth were identical to the isolate from the patient. One doesn’t have to be directly licked either. Another case with this same bacteria occurred when two dogs licked the hands of a 2-year-old who then had an infant sibling suck on his little finger. Multiple post-operative human complications have been documented when dogs and cats lick operative wound sites of their owners.
It’s not just bacteria either. Hookworms and roundworms from dogs can be transmitted to humans, especially children. Giardia and toxoplasmosis are also possibilities.
For those pets that frequent corrals and livestock areas, one can only imagine the possibilities with manure, sometimes blood, sometimes abscesses, placentas, carrion, etc., that ranch and farm dogs and cats can be exposed to. And then when they come inside the home, issues of biosecurity become even more important than urban households. Something to think about.