As Pet Ownership Soars, Understanding the Risks of Zoonotic Diseases
In an era marked by an unprecedented surge in pet ownership, with 69% of Australian households now embracing furry companions, the question of whether it’s safe to share a kiss with your pet has taken center stage. While the benefits of having pets extend to both mental and physical health, it’s imperative to acknowledge that our beloved animal friends can potentially harbor infectious diseases with the capacity to affect humans, albeit the risk remains relatively low for most.
Certain segments of the population, including pregnant individuals and those with compromised immune systems, face an elevated risk of contracting illnesses from animals. Consequently, a fundamental understanding of these risks and the adoption of necessary precautions are paramount in preventing infections.
The Spectrum of Pet-Borne Diseases
Diseases that transfer from animals to humans are termed zoonotic diseases or zoonoses. A staggering list of over 70 pathogens originating in companion animals can be transmitted to people. Adding to the complexity, some pets may carry zoonotic pathogens without displaying any outward signs of illness, making it even more challenging to detect the threat they pose.
Transmission routes for zoonoses encompass direct contact with pets through saliva, bodily fluids, and feces, as well as indirect means, such as exposure to contaminated bedding, soil, food, or water.
Studies suggest that the prevalence of pet-related zoonoses is relatively low. Nevertheless, it’s important to acknowledge that the true number of infections could be underreported due to several factors, including the non-notifiable nature of many zoonoses, the existence of multiple exposure pathways, and generic symptoms.
Dogs and Cats as Reservoirs of Zoonotic Infections
Dogs and cats, as beloved companions in many households, are substantial reservoirs of zoonotic infections. These encompass a wide spectrum of pathogens, including viruses, bacteria, fungi, and parasites. In regions like Africa and Asia, dogs hold the unfortunate distinction of being the primary source of rabies, transmitted through saliva.
Capnocytophaga bacteria, often present in the mouths and saliva of dogs, can be transmitted to humans through close contact or bites. While the majority of individuals remain unaffected, these bacteria can lead to infections in people with weakened immune systems, potentially resulting in severe illness, as demonstrated in a recent case in Western Australia.
Cat-associated zoonoses comprise a range of illnesses transmitted via the fecal-oral route, including giardiasis, campylobacteriosis, salmonellosis, and toxoplasmosis. Thus, rigorous hand hygiene and glove usage when handling cat litter trays are strongly recommended.
Furthermore, cats may occasionally transmit infections through bites and scratches, exemplified by the aptly named cat scratch disease, caused by the bacterium Bartonella henselae.
Both dogs and cats also serve as reservoirs for methicillin-resistant Staphylococcus aureus (MRSA), with close contact identified as a significant risk factor for zoonotic transmission.
Beyond Dogs and Cats: Unconventional Pet Risks
It’s worth noting that diseases can originate from a variety of pets. Pet birds may sporadically transmit psittacosis, a bacterial infection leading to pneumonia. Contact with pet turtles has been linked to Salmonella infections in humans, especially in young children. Even pet fish have been implicated in bacterial infections, including vibriosis, mycobacteriosis, and salmonellosis.
The Role of Human Behaviors
Human behaviors also play a pivotal role in the risk of zoonotic transmission. A study conducted in the Netherlands found that half of pet owners allowed their pets to lick their faces, and 18% permitted dogs to share their beds. These behaviors, although endearing, may increase the duration of exposure to pet-borne pathogens. Additionally, 45% of cat owners allowed their feline companions to access kitchen sinks, which could pose contamination risks.
Surprisingly, the act of kissing pets has been associated with sporadic zoonotic infections in pet owners. For instance, a case in Japan involved a woman developing meningitis due to Pasteurella multicoda infection, a bacterium commonly found in the oral cavities of dogs and cats.
Protecting Against Zoonotic Infections
While anyone in contact with a zoonotic pathogen via their pet can potentially become ill, certain individuals, such as the young, elderly, pregnant, and immunosuppressed, face a higher risk of severe illness. For example, although most toxoplasmosis infections result in mild illness, they can be life-threatening or cause birth defects in fetuses.
To mitigate the risk of contracting zoonotic diseases from pets, the following hygiene and pet care practices are advised:
Handwashing: After interacting with pets, handling their bedding, toys, or cleaning up after them, thorough handwashing is essential.
Avoid Face Contact: Discourage pets from licking your face or coming into contact with open wounds.
Supervise Children: Young children should be closely supervised while playing with pets and should wash their hands properly afterward.
Gloves: When changing litter trays or cleaning aquariums, gloves should be worn.
Bird Cage Cleaning: Wetting bird cage surfaces during cleaning can help minimize aerosolization of pathogens.
Kitchen Restrictions: Keep pets, especially cats, out of the kitchen to prevent contamination of food preparation surfaces.
Veterinary Care: Ensure your pet receives regular preventative veterinary care, including vaccinations and treatments for worms and ticks.
Vigilance: Seek veterinary care promptly if you suspect your pet is unwell.
For individuals at a higher risk of illness, taking extra precautions to reduce exposure to zoonotic pathogens is imperative. If contemplating pet ownership, consult with a veterinarian to determine the most suitable type of animal based on your specific circumstances.
