Exotic pets and exotic diseases

Photo by michelleness via Flickr

Each year literally hundreds of millions of legally imported exotic pets flood into the United States and Europe. Many of these animals can be happily hopping, swimming or crawling in the wild in South America, Asia or Africa one day, and find themselves in a cage in some child’s bedroom in say, Ohio, less than a week later. Very often many of these pets are not subject to quarantine or any form of screening and come straight from the bush into our homes. Unfortunately many exotic pet owners are completely ignorant of the risks these animals may pose to their health.

Zoonotic Diseases

A zoonotic disease is one that can jump from animals to humans.  The latest “Swine Flu” outbreak is very good example of a zoonotic disease. The Centers for Disease Control and Prevention say that these types of diseases account for 75% of all emerging infectious threats. Here is just a small sample of the diseases that exotic pets have passed or could pass on to humans, i.e. your family.

  • Cowpox – In a recent case in France four people were infected by cowpox after being scratched by pet rats that were all bought from the same pet store. In three of the cases surgery was required to treat the disease.(1)
  • Salmonella – The majority of Salmonella infections originate from contaminated food. However it is estimated that 5 % of infections are linked to pets. It is believed that around 90% of reptiles, especially iguanas and turtles, carry Salmonella. The CDC estimates that 70,000 people in the USA are infected with Salmonella by pet reptiles every year. Between 2003 and 2004 many people in ten states all over the USA were infected with a drug-resistant form of the disease which was subsequently linked to pet hamsters and other rodents. (2)
  • EDIT: This part of the article previously dealt with an outbreak of 20 cases of Salmonella allegedly linked to pet hedgehogs. To put this number in perspective, there are 1 to 1.4 million Salmonella  infections in the USA each year, the overwhelming majority of which are caused by eating contaminated food. I have since been informed that the report on which alleged link to pet hedgehogs was based was fatally flawed and was provided with evidence which convinced me that this was indeed the case. I apologise for my error and any alarm it may have caused amongst pet hedgehog owners. I would like to thank  Z. G. Standing Bear of hedgieflash.com for making me aware of the facts behind the story.
  • Psittacosis – According to the CDC there are about 50 confirmed cases of Psittacosis each year in the USA, although they believe there may be many more cases that remain misdiagnosed or unreported. The disease is transmitted by pet birds such as parrots, parakeets, macaws, and cockatiels. Psittacosis can cause severe pneumonia and there have been several fatalities.(4)
  • In New England in 2005 three transplant patients died after receiving organs from a human donor who had been infected with the lymphocytic choriomeningitis virus by a pet hamster. (5)
  • Monkeypox – In 2003 there was an outbreak of Monkeypox in Illinois, Indiana, and Wisconsin. Monkeypox is related to Smallpox and its symptoms include fever and the development of a papular rash. In all cases the people with the disease had been in contact with pet prairie dogs that had all come from the same source. (6)
  • Ringworm – Despite its name ringworm or Tinea is actually a fungal skin infection. One source of ringworm is known to be pet and wild hedgehogs. Over the past few months regular readers will know that this blog has been covering a story where three people were infected with ringworm by two hoglets bought from the same breeder. This story is all the more disturbing as the breeder in question somehow managed to circumvent the UK’s stringent quarantine laws and import several African Pygmy Hedgehogs directly into the country from Germany. She claims that the Department for Environment Food and Rural Affairs (Defra) allowed her to “home quarantine” the hedgehogs. It later transpired that the German breeder’s herd was infected with ringworm. While at the breeder’s home this infection was spread from the “German” hedgehogs to the “parents” of the two hoglets that later infected their new owners and a family member. It should be noted that Defra state that “home quarantine” would not be allowed under any circumstances. (7)
  • EDIT: Paragraph removed. See above explanation.

What can you do to reduce the risk of infection?

Many researchers in the field of infectious diseases actively discourage ownership of any kind of exotic pet. However, exotic pet ownership is a fact of life and millions of them share our homes all over the world. The Centers for Disease Control and Prevention have several web pages that provide some excellent advice about reducing the risk of infection and information about the diseases themselves: HEALTHYPETS.

If you do decide to purchase an exotic pet, buying it from a reputable breeder rather than a pet store or pet distributor, should provide you with more guarantees about the animal’s origins. While the risk of catching some terrible disease from your pet is extremely small, owners must be aware that the risk is real and does exist. If you follow the advice given on the CDC web site that risk is greatly reduced.

References:

  1. Ninove L, Domart Y, Vervel C, Voinot C, Salez N, Raoult D, et al. Cowpox virus transmission from pet rats to humans, France. Emerg Infect Dis. 2009 May; [Epub ahead of print]
  2. Morbidity and Mortality Weekly Report – Centers for Disease Control and Prevention – May 6, 2005 / 54(17);429-433
  3. Centers for Disease Control and Prevention website.
  4. Margaret Ebrahim and John Solomon Associated Press Article – Nov. 27, 2006
  5. Morbidity and Mortality Weekly Report – Centers for Disease Control and Prevention June 13, 2003 / 52(23);537-540
  6. Author’s blog