Increasing numbers of human beings are immunocompromised as a result of illness or the use of immunosuppressive drugs, and it is estimated that at least 30% to 40% of immunocompromised patients own companion animals.
Increasing numbers of human beings are immunocompromised as a result of illness or the use of immunosuppressive drugs, and it is estimated that at least 30% to 40% of immunocompromised patients own companion animals. Zoonotic and opportunistic infections can be acquired from companion animals, and pet owners who are immunocompromised may not be aware that they may be at risk of acquiring infections from their pets or other animals. Only 10% of 187 AIDS patients who were pet owners had been informed about zoonotic diseases by health care workers, and 4 of these were informed only after being diagnosed with infections that were considered possible zoonoses. It should be emphasized that although pets can be a risk factor for acquisition of zoonotic and opportunistic infections in immunocompromised people, there is not good support for recommendations that such people relinquish their pets in order to improve their own health. Results of one survey showed that patients with AIDS-defining diseases known to be common to animals and human beings were just as likely to be non-pet owners as they were to own pets.
Pets are an important source of camaraderie and support for many immunocompromised people. Pets provide comfort, companionship, and an improved sense of self-worth for HIV-infected patients. Pet ownership also has been shown to benefit the elderly, foster social and verbal interaction among children, and contribute to development of nurturing behavior and responsibility in children. Other health benefits of interactions with pets include: reportedly improved overall health with fewer visits to physicians by elderly pet owners compared to non-pet owners, lowered blood pressure and triglycerides of pet owners compared to non-pet owners, and increased 1-year survival times following myocardial infarction in pet owners compared to non-pet owners. Segregation of immunocompromised people, the elderly, or children from pets is not generally necessary to prevent transmission of zoonoses, and is often the least acceptable means of preventing such transmission. Veterinarians and physicians must be prepared to discuss pet ownership and the bona fide risks for acquisition of zoonotic or opportunistic infections with immunocompromised people, and provide sound plans for maintenance of the health of pet animals and their owners.
In addition to concern for the health and well-being of patients, clients and employees, practitioners should also be aware of potential legal implications of not properly informing clients and employees of the possible risks of zoonotic diseases associated with handling companion animals. Steps recommended to decrease liability include: 1) Keep current on zoonotic disease processes and contemporary standards of care, 2) Educate clients and staff thoroughly regarding the risks, and 3) Keep good records and follow up with clients and staff to help ensure that recommendations are being followed. A specific plan should be developed for each client's companion animals. Some agents are likely to be transmitted directly from companion animals to human beings, whereas others are more likely to be transmitted from a common source in the environment.
Increasing client awareness
Posters and brochures are available from the Centers for Disease Control (CDC), Humane Society of the United States, and other organizations such as Pets Are Wonderful Support (PAWS). These may be prominently displayed in client waiting areas, examination rooms, and staff work / lounge areas. Specific training should be provided for veterinary staff to increase their understanding of zoonotic diseases and opportunistic infections for their own protection and so that they may more effectively communicate with clients. Take advantage of opportunities for client education that occur in common office call situations such as wellness exams for puppies, kittens and other pets, yearly examinations of pets, and evaluation of animals with clinical signs suggestive of possible zoonotic diseases.
Increasing veterinarian and physician awareness
Veterinarians and physicians should be knowledgeable about what animals are the most appropriate pets for immunocompromised people. The CDC has published guidelines, and some guidelines are also available the AVMA and from other organizations such as PAWS. For example, healthy adult animals with known good health histories are acceptable pets, whereas stray animals and young animals are at greater risk for carriage and transmission of infectious agents and should be avoided. Animals without complete health records available are not generally acceptable. Health records should be available and reviewed for all candidates for adoption or purchase by immunocompromised clients. Special efforts should be made to educate children in good hygienic practices and about the risks of acquiring infections from pets. Reptiles, amphibians, and primates should not be kept as pets by immunocompromised people, because of the risk of transmission of diseases such as salmonellosis and tuberculosis.
New pets should be examined by veterinarians when acquired, and screened for intestinal parasites and ectoparasites. Cats should be tested for feline leukemia virus and feline immunodeficiency virus. Cats that have potentially immunosuppressive conditions may not make good pets for immunocompromised clients because these cats may themselves be more susceptible to infection with zoonotic agents or opportunistic organisms. Develop vaccination protocols for pets based on geographic region and other relevant exposures, and establish a schedule for regular veterinary evaluation of pet health. Aggressively pursue identification of the etiologic agent(s) of parasite infestations, diarrheal conditions, respiratory diseases, and any apparent bacterial infections of pets, and institute timely, thorough treatment for any of these conditions. Counsel clients treating ill pets to use caution and to wear gloves when administering medications to pets and when cleaning the pets or the environment.
Feed only good quality commercial diets. No uncooked materials should be fed, such as raw or undercooked meats of any kind, unpasteurized dairy products, and raw or undercooked poultry products. Pet animals should not be allowed to roam free or to hunt, including chasing flies or other insects. Toilet bowls should be kept closed so that pets cannot drink from them. Pets should not have access to table scraps or garbage, and copophragy should be discouraged. Pets that are allowed outdoors should go outside only when on a leash and under human supervision. Cat litter boxes and bird cage linings should be cleaned daily; gloves should be worn for these tasks and care taken not to create aerosols or fine dust while cleaning.
Pets should be groomed regularly, either professionally or by owners, and flea and tick infestations promptly eradicated. Ectoparasite prevention strategies should be used for all pets. In climates or seasons that require it, pets should be examined daily and any ticks carefully removed and disposed of. Clients should receive instruction on proper tick removal and disposal to avoid exposure to tick-transmitted pathogens. Cat claws and dog toenails should be kept trimmed.
Emphasize good hygiene practices, and recommend that clients wear gloves when cleaning fish tanks, or when gardening or handling objects contaminated with feces, urine, or vomitus. Hands should be washed before and after handling uncooked foods and before and after handling pets. When bite or scratch wounds occur, they should be washed immediately and medical attention sought.
Recommendations that immunocompromised patients relinquish their pets are rarely indicated. As previously noted, one study showed that patients with AIDS-defining diseases known to be common to animals and human beings were as likely to be non-pet owners as they were to own pets. The benefits of pet ownership for all clients, including immunocompromised people, are great. Working together, veterinarians, clients, and others in the community can provide extraordinary service by helping to maintain the health and well-being of immunocompromised people and their pets.
1. Anderson WP, Reid CM, Jennings GL (1992), Pet ownership and risk factors for cardiovascular disease, Med J Australia 157: 298-301
2. Angulo FJ, Glaser CA, Juranek DD, Lappin MR, Regnery RL (1994), Caring for pets of immunocompromised persons, J Am Vet Med Assoc 205: 1711-1718
3. Bender JB, Minicucci L (2007), Diseases pets and people share, Minn.Med 90: 43-47
4. Brickel CM (1980), A review of the roles of pet animals in psychotherapy and with the elderly, International J Aging Hum Dev 12: 119-128
5. Brodie SJ, Biley FC, Shewring M (2002), An exploration of the potential risks associated with using pet therapy in healthcare settings, J Clin Nurs 11: 444-456
6. Cefai C, Ashurst S, Owens C (1994), Human carriage of methicillin-resistant Staphylococcus aureus linked with pet dog, The Lancet 344: 539-540
7. Chang HJ, Miller HL, Watkins N, Arduino MJ, Ashford DA, Midgley G, Aguero SM, Pinto-Powell R, Fordham von Reyn C, Edwards W, McNeil MM, Jarvis WR (1998), An epidemic of Malassezia pachydermatis in an intensive care nursery associated with colonization of health care workers' pet dogs, New Engl J Med 338: 706-711
8. Chomel BB (1992), Zoonoses of house pets other than dogs, cats and birds, Pediatric Infectious Disease Journal 11: 479-487
9. Cimmino MA, Fumarola D (1989), The risk of Borrelia burgdorferi infection is not increased in pet owners, Journal of the American Medical Association 262: 2997-2998
10. Conti L, Lieb S, Liberti T, Wiley-Bayless M, Hepburn K, Diaz T (1995), Pet ownership among persons with AIDS in three Florida counties, Am J Publ Health 85: 1559-1561
11. Eaton KA, Dewhirst FE, Paster BJ, Tzellas N, Coleman BE, Paola J, Sherding R (1996), Prevalence and varieties of Helicobactaer species in dogs from random sources and pet dogs: animal and public health implications, J Clin Microbiol 34: 3165-3170
12. Elliott DL, Tolle SW, Goldberg L, Miller JB (1985), Pet-associated illness, New Engl J Med 313: 985-995
13. Embil JM, Nicolle LE (1997), Salmonella urinary tract infections associated with exposure to pet iguanas, Clin Infect Dis 25: 172
14. Enoch DA, Karas JA, Slater JD, Emery MM, Kearns AM, Farrington M (2005), MRSA carriage in a pet therapy dog, J Hosp.Infect. 60: 186-188
15. Glaser C, Lewis P, Wong S (2000), Pet-, animal-, and vector-borne infections, Ped Rev21: 219-232
16. Goldstein EJC (1991), Household pets and human infections, Infect Dis Clin North Am 5: 117-130
17. Guardabassi L, Schwarz S, Lloyd DH (2004), Pet animals as reservoirs of antimicrobial-resistant bacteria, J Antimicrob Chemother 54: 321-332
18. Guay DRP (2001), Pet-assisted therapy in the nursing home setting: Potential for zoonosis, Am J Infect Cont 29: 178-186
19. Gunby P (1979), Patient progressing well? He may have a pet, J Am Med Assoc 241: 438
20. Kirkwood JK (1987), Animals at home - pets as pests: a review, J Royal Soc Med 80: 97-100
21. Lloyd DH (2007), Reservoirs of antimicrobial resistance in pet animals, Clin Infect.Dis. 45 Suppl 2: S148-S152
22. Loar MG (1987), Risks of pet ownership: The family practitioner's viewpoint, Vet Clin North Am: Sm An Pract 17: 17
23. Mayr B (1993), Pets as permanent excretors of zoonoses pathogens, Zentralbl Hyg Umweltmed 194: 214-222
24. Morrison G (2001), Zoonotic infections from pets, Postgrad Med 110: 24-46
25. Nelson JD (1983), Diseases acquired from pets, Ped Infect Dis 2: 56-60
26. Nosanchuk JD, shoham S, Fries BC, Shapiro DS, Levitz SM, Casadevall A (2000), Evidence of zoonotic transmission of Cryptococcus neoformans from a pet cockatoo to an immunocompromised patient, Annals Intern Med 132: 205-208
27. Plaut M, Zimmerman E, Goldstein RA (1996), Health hazards to humans associated with domestic pets, Ann Rev Publ Health 17: 221-245
28. Riordan A, Tarlow M (1996), Pets and diseases, Brit J Hosp Med 56: 321-324
29. Serpell J (1991), Beneficial effects of pet ownership on some aspects of human health and behaviour., J Royal Soc Med 84: 717-720
30. Stehr-Green JK, Schantz PM (1987), The impact of zoonotic diseases transmitted by pets on human health and the economy, Vet Clin North Am: Sm An Prac 17: 1-16
31. Villar RG, Connick M, Barton LL, Meaney FJ, Davis MF (1998), Parent and pediatrician knowledge, attitudes, and practices regarding pet-associated hazards, Archiv Ped Adolesc Med 152: 1035-1037
32. Wong SK, Feinstein LH, Heidmann P (1999), Healthy pets, healthy people, J Am Vet Med Assoc 215: 335-338
33. Woodward DL, Khakhria R, Johnson WM (1997), Human salmonellosis associated with exotic pets, J Clin Microbiol 35: 2786-2790