This is a really excellent photograph, taken by a camera attached to a microscope, of a group of ear mites and some earwax. You can see their spider-like bodies. They look disgusting. In terms of the discomfort that they cause to cats they are disgusting.
The photograph, in my view, is in the public domain which is why I can publish it on my website.
Almost nobody writes about the anatomy of cat ear mites 😒. Although there are tens of thousands of articles about this ectoparasite. Ectoparasites are those that live on the host’s body without killing it. If they killed the host, they wouldn’t be a very successful parasite, would they?
They feed on earwax and skin oils and lay eggs which take four days to hatch and about three weeks to develop into adults.
Anatomy
There is little on the Internet specifically about the anatomy of cat ear mites but I have found some info. I mainly refer to the anatomy of insects, which is what ear mites are.
Adult cat ear mites are between 350-450 µm (micro metre or 1000th of a millimetre) in length.
The adult male has “short unjointed pedicels and wineglass-shaped caruncles on the distal end of each leg”. “Pedicels” are stems. “Caruncle” describes a growth. “The female has unjointed pedicels with caruncles on the first two pairs of legs” (My thanks to the Companion Animal Parasite Council).
Ear mites don’t have lungs like humans. But they need oxygen like humans which they take in and they emit carbon dioxide like humans. There are some similarities.
Ear mites take in air through holes on the outside of their bodies. These are called spiracles. Another word for them is “trachea”. The body acts a bit like a sponge which allows oxygen to enter the body and it pushes out carbon dioxide.
The spiracles can be opened and closed to control breathing. This is done using muscles. And muscles spread the oxygen throughout their body.
Insects don’t have red blood cells like humans. In fact, insects don’t have blood like vertebrates and mammals.
Insect ‘blood’ is called haemolymph. It is similar to blood in that it plays the same or similar role as blood.
Insects do not have a blood circulatory system with veins and arteries. Haemolymph flows through an insects body cavity, bathing its internal organs.
It’s body is surrounded by an exoskeleton which means “outside skeleton”. It is made of a substance called chitin.
Oxygen exchange in an insect is through “direct diffusion through body tissues”.
That said, insects have some similar organs to humans except the lungs as mentioned and stomachs. They have hearts, brains and intestines and even ovaries or testicles.
The brain is different to that of vertebrates e.g., humans. But it performs similar functions. Insects can be quite intelligent with for example bees counting up to 4 and cockroaches living rich social lives.
Lifecycle
From egg to adult takes about three weeks. There are five stages: egg, larvae, to nymph stages (protonymphs and deutonymphs) and adults. The life cycle, egg-to-egg takes between 18-28 days.
The entire life cycle takes place on the host, within the ear canal of the host. They can travel outside of the ear canal to the head and other areas of the cat.
Ear mites do not burrow into the skin but feed on epidermal (skin) debris.
Female ear mites attach developing eggs to the skin lining of the ear canal. The larvae hatch in a few days. They moult through two nymphal stages as mentioned to the next generation of adults.
Adult ear mites live about two months. They continually reproduce. They can live for a limited time off the host. But they are keen to find a host.
Cat owners should realise that ear mites are very distressing for a cat, and they are one of the most common health problems seen in domestic, stray and feral cats. Their scientific name is: Otodectes cynotis.
Below are some more articles on the ear mite.
