Cat Saliva. A Discussion

Cat saliva is similar to human saliva. It contains bacteria as does human saliva. It also contains antibacterial agents that helps prevent infections. Cat saliva does not contain antiseptics or disinfectants. Here is the detail….

When people, who know a bit about cats, think of cat saliva they might think of four things (a) it is used to clean a cat (b) it helps to cool a cat through evaporation (c) it contains a protein, the Fel D1 allergen, that causes about 10% of people to be allergic to cats and (d) it contains bacteria that can be transmitted to other cats and people causing a bacterial infection in the person or cat. The classic situation is the cat abscess around the head after a fight between cats. As for a cat to human transmission, cat scratch disease (CSD) is the one that is always quoted on the internet.

Also people ask whether cat saliva contains antiseptic substances. Antiseptics are substances that help prevent infection by slowing down the growth of microorganisms.

There seems to be good and bad all bundled together within the gooey liquid that is in the cat’s mouth. I’d like to try and clarify one or two aspects.

Cat Saliva Transmits Disease

I have mentioned cat scratch disease.Yahoo Answers contains misleading statements such as:

…feline saliva is a source of hundreds of microscopic pathogens and is not antiseptic, it’s septic, very septic…

The first point is that human saliva can also transmit disease. Human saliva is a major carrier of diseased and infections. However we rarely discuss it. Here are some examples¹:

• Glandular fever (mononucleosis) is transmitted from person to person through saliva. It is called the “kissing disease”.
• Colds (viral infections) are transmitted through saliva. And….
• Hepatitis A, B & C
• Polio
• Bacterial meningitis
• Cold sores (oral herpes)

The first point to make is that if we are to criticize the cat for transmitting disease through saliva we should balance it with an acceptance that humans are no better and may be worse. We should remember that cat and human anatomy is fundamentally similar and if we comment on the anatomy of one, it may well apply the other. Let’s keep things in perspective, please.

Antiseptics in Saliva?

It seems odd that there could be anti-bacterial substances in cat and/or human saliva while at the same time the saliva contains bacteria. However, it is true. There is a battle going on in the mouth.

Right away I’ll state that researching this topic was tricky. There is nothing on the internet in one place that is clear, sound and totally reliable. I could piece things together though, bit by bit.

I came to these conclusions:

1. Cat and human saliva contains “Immunoglobulin A” (IgA)².  It is an antibody. Antibodies are substances that neutralize antigens. Antigens include include toxins and bacteria. So, we can see that cat saliva plays a role in creating what is called “mucosal immunity”. Immunity to disease on the linings of the mouth. Antibodies are not antiseptics. Antibodies react to the presence of an bacteria whereas antiseptics help to prevent infection. However, the end result is very similar – protection from disease as killing bacteria results in the prevention of a developing infection.
2. Cat and human saliva contains “Lysozymes“³. These are enzymes that “damage bacterial cell walls”⁴. Lysozymes are part of the cat’s immune system. Once again this substance in a cat’s saliva helps to kill bacteria in the mouth. This is not a preventative role as is the case for antiseptics but the end result is similar.
3. Cat and human saliva contains “Peroxidase”. This is a substance that “functions as a natural antibacterial agent”⁴.

Refs:

1. http://health.wikinut.com
2. http://www.ncbi.nlm.nih.gov
3. http://ep.physoc.org/content/27/4/381.full.pdf
4. http://en.wikipedia.org/
5. Photo (modified) on Flickr jeici1