dren became seriously ill with salmonellosis shortly after their families purchased pet rodents (5). A national search of the PulseNet National Salmonella Database from December 2003 to October 2004 found 28 matching human-case isolates of Salmonella enterica serovar Typhimurium. Of the 22 patients who were interviewed, 13 (59%) had been exposed to rodents during the 8 days before onset of illness (5). Exotic pets can introduce pathogens previously unknown in the North American continent. For example, the 2003 monkeypox outbreak in the Midwestern United States originated after imported African rodents infected prairie dogs in pet distribution facilities (6). Laboratory- confirmed monkeypox developed in 35 persons (6). No one died, but the outbreak required vaccinating 30 persons with smallpox vaccine, 23 because of potential occupa- tional exposure (6). Occupational risks for exposure to zoonotic diseases are a concern for persons such as farmers, meatpackers, and pet shop employees who work with animals. For example, Streptococcus suis can cause meningitis or occa- sionally fulminant sepsis in pig farmers (7,8) Campylobacter infection is an occupational risk for pack- ers in poultry factories, and Streptobacillus moniliformis can be an occupational risk for pet shop employees (9,10) These examples illustrate that living and working with animals can impact human health at the individual level. Veterinarians who treat animals that suddenly become ill with confirmed infections should assess the risk for zoonotic potential and inform the animals’ owners accord- ingly. From a medical-legal standpoint, veterinarians are obligated to do this, but the extent to which they should inform animal owners and ensure that they seek medical attention varies depending on the circumstances (11). The severity of the risk for zoonotic disease as well as the level of understanding by the animal owner in question would need to be considered (11). For example, the veterinarian may merely advise potentially exposed persons to seek medical attention or may strenuously urge and ensure that the person receives medical attention immediately. However, veterinarians’ roles in assessing risk for potential zoonotic disease transmission could extend beyond this level of involvement. Risk-benefit ratios for ongoing animal exposure could be weighed and discussed by both veterinarians and physi- cians. The roles in these veterinary-physician relationships would need to be established from the start so that the vet- erinarians would not be at risk of appearing to practice medicine. For example, veterinarians could provide an assessment of an animal’s health status to a physician whose patient is immunocompromised and insists on keep- ing his or her companion animal. Since companion animal ownership has psychologic and physiologic benefits, this Zoonoses, Links between Human and Veterinary Medicine type of collaboration and cooperation between the 2 pro- fessions would be invaluable to patients. The veterinarian would provide regular checkups to the companion animal to ensure that its health status is closely monitored. In the occupational setting, regular veterinary monitoring of all involved animals’ health may not be possible; however, if a worker were immunocompromised, then a careful assessment should be made about his or her continuing that line of work. Veterinary input might be helpful in these dif- ficult decisions. Joint medical and veterinary medical workshops on zoonotic risks to human health could help forge ties and facilitate opportunities to establish these types of collaborative efforts. Population Health Collaborations Recognizing whether human and animal outbreaks were simultaneous would provide important information for identifying the causative pathogens and developing control strategies. For example, physicians treating the ini- tial West Nile virus (WNV) patients in New York City in 1999 might have benefited if they knew that for the previ- ous month and concurrently, veterinarians in the surround- ing area had been seeing dozens of dying crows with neurologic symptoms similar to those of the affected humans (12). Depending on the state, animal disease sur- veillance can be fragmented. For example, in New York, human and animal rabies are the responsibility of local and state health departments, livestock are overseen by the state agriculture agency, and wildlife is the responsibility of the state environmental agency (12). In New York, no local or state agency assumed full responsibility for the large wildlife die-off investigation in 1999 since which agency was responsible was not initially clear (12). This situation hindered communications between the veterinarians, public health officials, and physicians who were involved in the outbreak response at the local level. As an emergency, short-term measure, vet- erinarians could have expressed their concerns directly to the hospital epidemiologists in the area to be on the look- out for a possible human impact from an unknown disease that was causing widespread severe neurologic symptoms and death in wild birds. Such rapid, direct communication between veterinarians and physician epidemiologists could be particularly important in states in which local public health agencies either do not exist or are not involved in zoonotic disease reporting or investigation. In some states, animal disease reporting and response are state level functions and are separate from human pub- lic health. I contacted state veterinarians in all 50 states about their states’ animal disease reporting requirements. State veterinarians from 8 (19%) of the 43 responding states replied that veterinarians are required to contact their local public health agencies directly about reportable Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 12, No. 4, April 2006 557