No, you cannot catch the common cold from a cat sneeze. The common cold is a mild viral infection of the upper respiratory tract, characterized by symptoms like a runny nose, sneezing, and coughing. The pathogens responsible for this illness are highly species-specific, meaning they have evolved to infect people and generally cannot infect cats.
The Species Barrier: Why Viruses Are Specific
Viruses are highly specialized biological agents that function much like a lock and key. A virus must possess the correct surface proteins (the “key”) to bind to specific receptor sites (the “lock”) found only on the cells of a particular host species. This requirement creates a biological species barrier that prevents most viruses from jumping between different types of animals.
The most common causes of the human cold are Rhinoviruses, along with certain types of Coronaviruses and Adenoviruses. These viruses are biologically incompatible with feline cells because the necessary cellular receptors are either absent or structured differently in cats. Consequently, a human cold virus cannot effectively invade, replicate, or establish an infection in a cat’s respiratory system.
Similarly, the primary causes of upper respiratory infections in cats, often referred to as a “cat cold,” are Feline Herpesvirus-1 and Feline Calicivirus. These viruses are highly contagious among felines, but they lack the necessary mechanisms to infect human cells. This specialized nature ensures that a cat cannot transmit its viral illness to a human, even through direct respiratory droplets from a sneeze.
The True Causes of the Common Cold
The common cold is an entirely human affair, maintained through human transmission. This illness is caused by over 200 viral strains, with Rhinoviruses being the most frequent culprit, accounting for up to 80% of all colds. Other pathogens like human Coronaviruses and Parainfluenza viruses also contribute to the annual cold season.
These viruses spread efficiently through several direct and indirect methods. The most common route is through the inhalation of airborne respiratory droplets expelled when an infected person coughs or sneezes. Transmission also occurs when someone touches a contaminated surface, such as a doorknob, and then touches their own mouth, nose, or eyes. The cold results from viral contact with the mucous membranes of the human upper respiratory tract.
Actual Risks: What Can Be Transmitted by a Cat Sneeze
While a cat cannot transmit the common cold to a human, a forceful sneeze can aerosolize substances that may cause a reaction or, rarely, transmit a different type of pathogen. The most frequent non-infectious reaction is the aerosolization of cat dander, a common allergen. Dander consists of microscopic flakes of skin that carry proteins from the cat’s saliva and urine, and inhaling these can trigger allergic respiratory symptoms in sensitive individuals.
A rare but more specific concern is the aerosolized transmission of the bacterium Bordetella bronchiseptica. This organism causes respiratory disease in cats, sometimes resulting in sneezing, and can be transmitted to humans through infectious droplets. Transmission to humans is uncommon and usually only causes mild respiratory symptoms in healthy people.
The risk is significantly higher for individuals who are immunocompromised, such as those with chronic lung conditions or weakened immune systems. Another potential, though rare, risk is the transmission of the bacterium Chlamydia psittaci, which causes feline chlamydiosis. If the aerosolized droplets enter a human’s eye, they can cause a mild, localized eye infection.