Nontraditional Pets and Children: Beware
A report about the health risks in children associated with nontraditional pets was recently published in Pediatrics, the official journal of the American Academy of Pediatrics. The report also discusses diseases associated with animals in public settings such as petting zoos and pet stores. Although contact with pets and animals can be beneficial to growth and development in children, it is very important to be aware of the risks associated with certain kinds of animals. Physicians, veterinarians and public health personnel can help parents select appropriate pets in order to maximize the benefits while minimizing the risks to children.
One of the most important pathogens discussed in the report is Salmonella. Although Salmonella can be transmitted by many animal species, including traditional pets like dogs and cats, it is a particularly high risk with certain other kinds of pets, including reptiles, amphibians and baby poultry (chicks and ducklings). It has been estimated that direct or indirect contact with reptiles or amphibians is responsible for 6% of all sporadic Salmonella infections in the US, and 11% of cases among people younger than 21 years. There is also a relatively high risk of Salmonella transmission associated with animal-derived pet treats, such as pig ears, and raw meat.
The report makes several recommendations about how to reduce the risk of infection, injury and allergies from nontraditional pets, many of which you may have seen before on the Worms & Germs website. Just a few of these are:
- Always wash your hands after contact with animals, animal products or their environment, and after contact with animal-derived pet treats.
- Supervise hand washing for children less than five years old
Children less than five years of age and individuals with weakened immune systems should avoid contact with reptiles, amphibians, rodents, ferrets and baby poultry. These animals:
- Should not be kept as pets in households where children less than five years of age or individuals with a weakened immune system live.
- Should not be brought to childcare centres.
- Should not be allowed to roam freely in ANY house or living area.
- Should not be permitted in kitchens or anywhere food is prepared.
More information about Salmonella in pets and the risks associated with feeding raw meat and animal-derived treats to pets can now be found on the Worms & Germs Resources page.
Ringworm Part 2: Cleaning Up
For more information on ringworm, see the Worms & Germs post Ringworm: Skin fungus by any other name. The photos here show ringworm lesions on a person's arm and on a cat's face, respectively. (Photo credits: A. Yu, Ontario Veterinary College)
Over the past several years, studies have shown that many environmental disinfectants sold and labeled for use against the fungi that cause ringworm (which are called dermatophytes) in animals and people are, in fact, not effective when used in households and veterinary clinics. The problem is the chemicals are typically tested against a suspension of the organisms in a test tube, but in the “real world” the fungi are usually found on small fragments of infected hairs. Its possible that the hair shaft protects the fungus from the actions of some disinfectants.
There are a few disinfectants that have been shown to be effective against dermatophytes even when they are found on infected hairs and skin cells in the environment. The most readily available one is household bleach, used at concentrations of 1:10 to 1:100. Other effective products include Virkon-S® (a detergent-peroxide based product) and Peroxigard® (an accelerated hydrogen peroxide product) . An environmental spray containing enilconazole (an antifungal agent that is also found in the topical medication Imaverol®) was also found to be very effective. This product is not approved for household use, but it is approved for use in catteries. It is also licensed as a topical treatment for dogs and horses in most of Europe and Canada.
Eliminating ringworm from the household or clinic environment can be difficult, because the fungus can be found anywhere that an infected animal (or person) sheds hair or skin cells. Here are some guidelines for environmental disinfection of dermatophytes:
- All bedding, brushes, combs, rugs, cages, etc. should be vacuumed, scrubbed, and washed with hot water, detergent, and 1:100 chlorine laundry bleach, or another effective disinfectant (see above). It is best to throw out any items that cannot be thoroughly disinfected.
- Walls, floors, lamps, etc. should be scrubbed and cleaned in a similar manner.
- Carpeted areas may be impossible to effectively decontaminate. If possible, remove the carpet and either wash in hot water and bleach, or discard it. Otherwise, frequent vacuuming with immediate disposal of the collection bag is necessary.
- Vehicle interiors should be decontaminated as much as possible in a similar manner.
- Curtains can be “dry-cleaned” at a professional cleaner.
- Clean heating vents (from the house furnace) as well as possible. If the house is heated by hot air, change the furnace filter once weekly throughout the decontamination process.
- Cleaning and disinfection of the environment should be repeated at least once every 4-6 weeks (the more often, the better) until all affected animals and people have eliminated the fungal infection.
Obviously, environmental clean-up for ringworm is quite an undertaking. If infection can be identified early, lesions can potentially be kept covered and movement of pets can be restricted to reduce the extent and amount of environmental contamination.
Special thanks to Dr. Anthony Yu (one of the veterinary dermatologists at the Ontario Veterinary College) for providing much of the information in this post, as well at the photos.
Ringworm: skin fungus by any other name
Ringworm infection is not caused by a worm at all - it's actually a skin infection caused by certain kinds of fungus called dermatophytes. The scientific name for ringworm is dermatophytosis, or dermatomycosis. Some of the more common zoonotic species of dermatophytes found in animals include Microsporum canis, Trichophyton verrucosum, T. equinum, and T. mentagrophytes. There are also some dermatophytes that are primarily transmitted from person to person that are not carried by animals. These include the fungi that cause athlete's foot and jock itch.
.jpg)
Like many fungi, dermatophytes grow best in warm, moist environments, but they can grow almost anywhere on the body. They tend to grow around hairs and in the superficial layers of the skin, and the infection can be quite itchy. A ringworm skin lesion tends to spread out from one point on the skin, causing hairloss as it progresses, resulting in a bald patch (see picture right). The outside (most active) edge of the infection often appears as a red ring, from which "ringworm" gets its name. The centre of the lesion may begin to heal, and the hair may start to grow back, even as the bald patch gets bigger. It may take anywhere from a few days to a few weeks for visible lesions to develop after a person or animal has been infected. (Photo credit: A. Yu, Ontario Veterinary College)
Ringworm is quite contagious. The fungi are present in the large numbers on hair and skin cells that are shed by infected individuals. People or animals can be infected through contact with these infected hairs and skin cells, either directly on the affected person or animal (i.e. direct contact), or on things like clothing, blankets, hairbrushes etc. that have touched the affected skin (i.e. indirect contact).
Ringworm occurs all over the world, but no one knows exactly how common it is because there are so many different kinds of fungus that cause it, it's not reportable, and many cases probably go undiagnosed. Signs of ringworm in animals are often the same as in people, however not every animal that is infected with ringworm develops signs of infection. It has been estimated that ~90% of cats that are carrying dermatophytes do not show any signs of infection, but they can still transmit the fungus to other animals and people. (NB: this does NOT mean that ~90% of cats carry dermatophytes!) Almost any animal can be infected by at least one dermatophyte or another - cats, dogs, rabbits, rodents... even horses and cattle!
- Early identification of ringworm is important to reduce the risk of transmission to people and other animals. If your pet develops bald patches, particularly if they're itchy, it should be examined by your veterinarian to determine if a fungal infection may be present.
- If you or anyone in your household develops an area of skin that appears infected (especially if it appears as a red "ring"), keep it covered with a piece of clothing or a bandage and see your doctor.
- Most cases of ringworm can be treated with either topical (e.g. ointments) or oral anti-fungal medication.
- Clean your pet's grooming supplies (e.g. brushes, combs) regularly.
- Always wash your hands after handling your pet.
Watch for another Worms & Germs blog post about ringworm and how to clean up if you or your pet is infected, coming soon! More information about ringworm and dermatophytes can be found on the CDC's Dermatophytes website.
Your mother was right! Wash your hands
You may notice a recurring theme in many of our posts and on virtually all of the information sheets on the Worms & Germs Resources page: an emphasis on handwashing. There is increasing emphasis on hand hygiene (i.e. hand washing and use of alcohol hand sanitizers) education in hospitals because the hands of healthcare workers are a major (if not the most important) means of disease transmission between patients. Despite hand hygiene being easy, cheap and effective, people rarely wash their hands as often as they should, and they often don't do it properly.
Most of the research about hand hygiene that has been published has focused on its use and impact in human hospitals, but this area is now also being studied more with regard to animals and veterinary medicine. A study published earlier this year in Veterinary Microbiology provided more evidence that hand hygiene is a critical infection control measure when dealing with animals. The study, coordinated by Dr. Maureen Anderson (of Worms&Germs fame) looked at MRSA carriage rate in veterinarians who work with horses. In addition to finding a high rate of MRSA carriage among these veterinarians (which was consistent with other reports indicating that equine vets are at higher than average risk for exposure to MRSA), the study looked at factors associated with MRSA carriage. Vets that reported routinely washing their hands between farms and those that reported washing their hands after contact with potentially infectious cases had a significantly lower rate of MRSA carriage. That should come as absolutely no surprise, but it's one more piece of evidence that we need to pay more attention to this routine infection control measure, in human hospitals, in veterinary environments and in households.
Remember, the 10 most important sources of infection are the fingers on your hands!
Click here for instructions on how to wash your hands properly.
Happy Household Hamsters
Hamsters can be wonderful pets, and overall, hamsters are relatively low-risk when it comes to diseases they can potentially transmit to humans. However, they can sometimes carry bacteria like Salmonella in their feces, and the virus that causes lymphocytic choriomeningitis, to name a couple. But there are a few simple things you can do to help greatly reduce the risk of transmission of these and other diseases from hamsters. Doing many of these things will also help keep your hamster as healthy as possible. It is very important to learn about what a hamster needs and how to take care of hamster (or any kind of pet) before you decide to get one.Here are a few important hamster care tips to keep in mind:
- Keep your hamster in a clean enclosure with good ventilation and enough space for your hamster to have separate areas to eat, sleep, exercise and poop/pee.
- Prevent contact with wild rodents. This means keeping your hamster in its cage and not letting it roam around the house. Also ensure that your hamster cannot escape from its cage and wild rodents cannot get into the cage.
- Most importantly, always wash your hands after handling your hamster.
Also check out the new information sheets about hamsters posted on the Worms & Germs Resources page!
Exposure to animal blood
In people, there are detailed protocols for avoiding blood exposure in healthcare situations, and protocols for managing people exposed to human blood in hospitals and in the community. This is mainly driven by concerns about HIV and hepatitis viruses that can be transmitted by contact with blood. But these viruses are not present in animals, and the risks of transmission of disease from pets to people through blood are very low. Even contact with blood from a rabid animal is not considered rabies exposure, because the virus is found in the saliva, not the blood. This has led to a rather cavalier approach towards blood exposure in veterinary medicine, which is understandable but not ideal. New infectious diseases continue to emerge in animals and people, and eventually there is likely to be one that can be transmitted between species by blood. Therefore, it is prudent to try to reduce exposure to animal blood when possible, but without getting overly concerned (or paranoid).- Direct contact with animal blood should be avoided whenever possible.
- In particular, avoid getting animal blood on any cuts, scrapes or other broken skin, and avoid getting the blood in your mouth, nose or eyes.
- If you do get animal blood on your skin, wash it off as soon as possible.
- While it is extremely unlikely for a person to get sick from touching animal blood, make sure you tell your physician about the incident if you do become ill.
Hazardous hedgehogs
No...hedgehogs aren't sneaking out of their cages and attacking people as they sleep. Rather, they can carry a variety of microorganisms that can be transmitted to people. There have been a few reports describing infections associated with hedgehogs, particularly Salmonella and ringworm. An excellent report in the
journal Emerging Infectious Diseases highlighted the diseases hedgehogs have been shown to, or could, transmit to people. Hedgehogs don't have to be sick to be a source of infection.Hedgehogs have been available for years, but they may be a fad pet at the moment. One breeder is quoted as saying “They are going up these last two months we actually have a waiting list about twenty people,” said Sarah Roberts a breeder in Mansfield. “That's never happened in the year’s of breeding we've done.”
While any pet could transmit infections to people, certain pets are higher risk. Overall, species that are rare or 'fad' pets may be of greater concern because we simply don't know much about them (i.e. what diseases they can transmit, how to reduce risks...).
These small creatures can probably be safe pets in some households, but are they really better than other species? You probably should not have a hedgehog if you or someone else in the household has a compromised immune system or if you have small children. If you do have a hedgehog, don't let it roam freely in the house and wash you hands after handling it.
Pet store sued after hamster-associated death
LCMV is a virus that can cause encephalitis and/or meningitis (inflammation of the brain and associated tissues). Human cases are typically associated with rodent contact; both pets and wild rodents. Infected rodents can appear to be healthy. People can be infected through bites or direct contact with rodents, their droppings, urine, bedding or other contaminated materials. Pet-associated infections are rare, and are of greatest risk in people with compromised immune systems, such as transplant recipients, and pregnant women.
Some key points from this report and LCMV in general are:
- All types of pets, even small ones, can transmit infection.
- Sometimes exposure to infectious agents is unavoidable. You’re not going to turn down a donated organ on the rare chance that the donor had an obscure and undiagnosed disease.
- People that are at higher risk for infectious diseases, such as transplant patients, should consult with their physician and veterinarian before obtaining a new pet.
- Appropriate controls should be used to reduce contact of people and pet rodents with wild rodents
- Wash your hands after touching a rodent or its environment
More information about hamsters and lymphocytic choriomeningitis virus is available in the Resources area.
Information Sheets for Pet Owners
INFORMATION SHEETS specifically for KIDS, for VETERINARIANS and for PHYSICIANS are also available on the Worms & Germs RESOURCES page!
Click on the highlighted topics below for information sheets. Topics that are not highlighted are in development and coming soon. Sheets for other animal species and diseases are also under development and will be added when they are available. 
| Animals | Diseases | Other |
| Dogs | Rabies | Litter Boxes |
| Cats | Giardia | Sandboxes |
| Turtles | Toxoplasma | Cat Bites |
| Hamsters | Leptospira | Raw Meat |
| Rabbits | Clostridium difficile | |
| Birds | Cryptosporidium | |
| MRSA | ||
| Salmonella | ||
| Campylobacter | ||
| Ringworm |
Please Remember:
- Your veterinarian and physician are your ultimate resource for information about the health of your pets or your family.
- Information provided here is accurate to the best of our knowledge, but infectious diseases can be unpredictable and these sheets are for general information purposes only.
- There can be great variation in disease risks in different geographic areas. The information provided was developed for Ontario, Canada, but most of the information is relevant for other regions as well.
