Mites

Demodex Mites 

Demodex mites are tiny cigar-shaped parasites with 8 tiny legs which live within the hair follicles of the skin of dogs. They are generally considered to be part of the normal skin flora (that is, found in the skin of healthy dogs) but in some cases can cause disease. 

While most dogs develop a normal immune response to these mites so that skin disease is not seen, there are some dogs that have an inherited inability to create an adequate immune response and these dogs will develop “demodectic mange”. 

Mange occurs when the demodex mites proliferate in the hair follicles, often causing rupture of the hair follicles and a severe secondary inflammation, infection and sometimes itch. Often these dogs lose a lot of their hair and their skin appears thickened and flaky. 

Diagnosis is by doing a deep scrape of the skin and examining the scrapings under the microscope. The mites are easily identified. 

These days treatment is rather simple. Several products are available as monthly or even 3-monthly chews or spot-ons, though typically ongoing treatment is recommended. The ease of current treatment is a far cry from the previous daily doses of ivermectin (cattle drench) and sometimes baths in toxic amitraz. 

Entire female dogs with mange will tend to flare badly during their oestrus cycle. Desexing of any dog affected by demodex mites is strongly recommended to prevent ongoing breeding of this defective immune response and flare-ups when in-season. 

Ear Mites – Otodectes cynotis 

“Really not-fun ear creepy -crawlies” 

https://www.youtube.com/watch?v=6Cf8y06QfQA 

A common grievance of young dogs and cats (though any age can be affected) are ear mites. These tiny white 8-legged creatures prefer to live in the ear canal of your cat or dog and feed off the debris down there. They also like to “jump-ship” and are considered very contagious. Their presence causes an intense itch and sometimes your pet may even have a hypersensitivity reaction leading to a profound inflammatory response. Typically, they cause an ear discharge which is dry, crusty and black-ish or may be described as being like coffee-grounds. Secondary bacterial ear infections or skin infections are not unheard of. 

Ear mites are typically diagnosed during your consultation via a microscope otoscopic examination (looking down the ears). Usually, these tiny creatures can be seen crawling around the waxy debris in the ear. Sometimes they need to be spotted under the microscope itself. 

Treatment is relatively simple. A good first step is to clean out most of the debris in the ears with a safe veterinary ear cleanser. Many times a topical ointment is prescribed and applied twice daily for 5-14 days depending on level of infection and whether a secondary infection is present. Often, a monthly parasite treatment is administered to mop up any extra mites around the ear canal and to prevent re-infection from the environment. 

All animals in a household with ear mites will need to be treated and all bedding washed thoroughly, along with thorough vacuuming. 

Sarcoptic Mange/Scabes –Sarcoptes scabiei 

This is quite an uncommon infection in our region though you may encounter it if you’re travelling to Northern and regional parts of our country where there are many dogs which are largely unowned. 

Sarcoptes mites crawl across the skin, then bury into the skin to lay their eggs. Both of these processes cause an intense itch. They prefer the un-haired areas of the body and have a typical pattern of causing itch and hair loss around the ear flaps, groin and armpits (unfortunately, this pattern is also quite typical for many allergies). They are very contagious and can even temporarily infect humans. Cats are rarely infected by Sarcoptes but can be affected by another mite with a similar pattern and treatment (Notoedres cati). 

Definitive diagnosis is by recognising the Sarcoptes mite under the microscope after a skin scrape. Sadly, this is only successful in about 50% of cases as the yield is low. Diagnosis is often by a treatment trial – that is, to treat for Sarctopes (and many other parasites with the same treatment) and monitor for improvement/resolution. 

Many common parasite treatments are effective against Sarcoptic mange. All dogs in the house need to be treated. Secondary skin infections may require antibiotics. Generally, treatment of the environment is not required as they don’t live long off the host. 

Cheyletiella Mites 

Cheyletiella are a group of relatively large mites which can infect cats, dogs and rabbits (occasionally will cause a temporary infection on humans too). This infection is often referred to as “walking dandruff” due to the large white mites sometimes seen walking across the skin/fur and the high degree of scaling that goes along with the infection which seems to spread/walk across the animal. 

The level of itch is variable. 

Many veterinary flea control products can rid this infection though treatment is technically “off label” since these products are not registered to treat this particular mite. 

Along with parasite treatment, regular bathing to remove the scale and scurf build-up will be required to fully rid the infection. Some long-haired animals require clipping to help with this process.