Taking a microscopic look at live ear mites

As Itchy Pet Month comes to a close, Christopher Lee, DVM, MPH, DACVPM, takes viewers into a live, microscopic look at the ear mite, Otodectes cynotis, differentiating male from female and highlighting features that distinguish this species from other mites.

Otodectes cynotis, which can be found on cats, dogs, and ferrets, is a common culprit of ear disease and infection, and pruritus.¹ Clinical signs may vary, but can include¹:

• Ear irritation that leads to scratching at the ears
• Head shaking
• Discharge from the ear that is dark, waxy, or crusty
• Alopecia caused by excessive scratching or grooming
• Crusting dermatitis in and around the ear.
• Aural hematoma, caused by scratching at the ears—a blood-filled swelling of the ear pinna resulting from the rupture of small vessels between the skin and cartilage

Transcript

Christopher Lee, DVM, MPH, DACVPM: How often do you find these beautiful creatures hiding out in a cat's ear? How sure are you with what species they are? And what makes a boy mite and a girl mite different? Let's take a look.

Look at these little guys go. They're so cute and so beautiful sitting in that oil. Meet Miss Otodectes cynotis, the glamorous gal of the ear canal. She's single and ready to mingle. Better catch her quick, as she only lives 2 to 3 weeks and wants to lay up to 20 eggs inside of your cat's ear.

We can see here the tick's head. And if we look close at these arms, we can see suckers. We zoom in a little bit, we'll see these suckers, also called caruncles, situated on a very short stalk. By having a short stalk, we know that this is not Sarcoptes, which has a very long stalk, or Psoroptes, which has a segmented stalk.

Now, if we look at the posterior end, we will see these legs that extend beyond the body outline. That tells us that this is likely a non-burrowing mite, rather than a burrowing mite, such as Notoedres cati, which would be another mite that we may see in cats.

We take a look at this, we also will recognize that this is a female, partly because we have on these long setae on the third set of legs, and we have a vestigial set of fourth legs. We can compare that to a male.

Here we will see the male. Here is the head with 4 forearms, and we will have 4 legs with suckers. Yes, these guys are arachnids. They are closer to ticks and spiders than they are fleas or flies.

So here we can see a very active, wiggling male in the oil, next to a more sedentary female at 5 o'clock. And that, my friends, is Otodectes cynotis.

References

1. Barnes C, Weir M, Ward, E. Ear mites in cats and dogs. VCA Animal Hospitals. Accessed August 27, 2025. https://vcahospitals.com/know-your-pet/ear-mites-otodectes-in-cats-and-dogs