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Client Information Sheet
Copyright Bilton Veterinary Centre 2012. All rights Reserved
Canine Sarcoptic Mange (“Fox Mange”)
What is Sarcoptic Mange?
This is a description of a skin problem, caused by an infestation of a particular species of parasitic mite called
Sarcoptes spp. Other types of parasite species can cause different types of mange such as Demodectic mange
(due to Demodex spp infestions) and Cheyletielliosis (due to Cheyletiella spp infestations).
In common terminology however, the term “mange” is often used to specifically describe Sarcoptic mange. In
humans, the term “Scabies” is used to describe the same condition.
The mite responsible for sarcoptic mange in dogs is specially a species called Sarcoptes scabei canis. This mite
will only live on canids (such as dogs, foxes etc) and is highly contagious.
What does the mite look like?
The mite is tiny and can’t be seen with the naked eye. It is about 0.3mm long and
so has to be viewed under a microscope. It has four short legs at the front of the
body. The mite has a powerful set of jaws that are designed to chew through the
epidermis of the skin. It creates tunnels through the skin and so this is classed as a
burrowing mite. The female mite is much larger than the male, and it is the female
that is responsible for most of the symptoms of the disease.
Figure 1: Sarcoptes scabei canis x100
What is the lifecycle of the mite?
The cycle starts with the female burrowing from the surface of the skin, into the epidermis. In the tunnels, she
lays a number of eggs which then hatch out into larvae that work their way back up to the surface of the skin
again. These will hatch into juvenile mites (called nymphs), which then moult to become adults. Mating will
then occur on the surface and then the females start to tunnel again for the life cycle to complete.
What the symptoms of Sarcoptic Mange?
The main symptom of Sarcoptic mange is intense itching. This is due both
mechanical effects of the mite burrowing through the skin, as well as an
allergic reaction to the mites’ saliva. The mite prefers areas of the body
where this is not much hair coat. This means that symptoms may often
start in the locations shown in Figure 2.
Figure 2: The typical locations of the symptoms of
Sarcoptic Mange
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Client Information Sheet
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However as the disease progresses the lesions can appear
anywhere on the body and in extreme cases can affect the
entire skin. Other than the itching, other symptoms may
include:
 Hair loss
 Crusting and flaking of the skin – sometimes even
thickening of the skin.
 A red rash
 Secondary skin infections
Figure 3: Puppy with advanced skin disease due to untreated
Sarcoptic Mange
How is Sarcoptic Mange diagnosed?
Your vet may be suspicious of Sarcoptic mange based on the clinical symptoms and the history and lifestyle of
the dog. However further tests may often be performed to aid the diagnosis. These can include:

Skin scrapes – this is where the vet will apply some liquid paraffin to the skin, and then gently scrape the
out layers of skin away using the flat edge of a scalpel blade. You have to scrape quite deep to get to
where the mites may be living and so often the dog will ooze a little blood when a deep skin scrape is
performed. This is not a major procedure and is no worse than a friction burn! The debris is then
collected and examined under a microscope. If the mites (or eggs) are found, then this confirms the
diagnosis.
However, it is quite common not to find the mite as disease can be caused by relatively low numbers of
parasites. In these cases, if the vet is still suspicious of the disease, then a different test may be advised.

Blood test – if the skin symptoms have been present for more than 2-3 weeks, then it is now possible to
perform a blood test that examines if the body has produced any antibody to the Sarcoptes mange mite.
This is quite accurate, but can be flawed as a positive result can merely indicate a previous infestation
that may not necessarily be responsible for the current skin problems. A negative result though does
pretty much rule the mite as the cause of the skin problems. The blood test can take about 10 days to
come back from the day of testing.

Skin Biopsy – this is where a small full thickness “punch” biopsy is taken from the affected area and sent
away to be examined by a histopathologist. This is a very effective method of diagnosis, but has the
disadvantage that it usually requires a general anaesthetic and is relatively invasive. This test is normally
only performed if the other tests are inconclusive.

“Trial by Therapy” – in some circumstances, it may be prudent to commence treatment without having
performed previous diagnostics. This is not ideal as if the skin problem doesn’t settle – it raises the
question of whether the diagnosis was correct in the first place, or if the medication hasn’t worked.
However this method does have its place and is an option to consider.
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How is Sarcoptic Mange treated?
There are several different ways of treating Sarcoptic Mange:
 Selamectin (topical). This is the gold standard for treating the disease and is usually very effective. The
drug is applied as a “spot-on” every 2 weeks for 6 weeks. The treatment is safe and easy to apply.
 Amitraz (bath). This is used in refractory cases or where spot-on treatment isn’t suitable. The treatment
is given as a bath/soak and is repeated weekly until the disease is cured. It is usually very effective, but is
quite labour intensive and precautions have to be taken while washing the dog, and disposing of the
waste water after bathing.
 Ivermectin (injection/oral). This is a non-licensed treatment and involves using a drug that is generally
used as an anti-parasitic for farm animals such as sheep and cows. It also is very effective, but there is a
risk of side effects and the drug mustn’t be used in any Collie breeds or Collie crosses. This is rarely used
these days.
How is Sarcoptic Mange caught/transmitted?
The condition is highly contagious amongst canids (dogs, foxes etc) and whilst actual physical contact is the most
common method of transmission, infection can occur from contact with bedding, sleeping areas etc. The actual
period of contact does not have to be long and so often it is not possible to definitely confirm when the disease
was contracted.
Can it spread to humans?
There is some debate to this question – the exact species of mite that causes
canine Sarcoptic mange is Sarcoptes scabei canis. The species that causes human
mange (called Scabies) is Sarcoptes scabei hominis. It is thought that the canine
mite may try to colonise humans, but fail to establish actual disease. So minor
symptoms may occur transiently, but full blown disease shouldn’t occur. However
there are some medical and veterinary academics that do feel the condition can be
spread from human to animal and vice versa.
Our advice is that as long as there is nobody regularly in contact with an affected
dog who has a poor immune system (someone on chemotherapy or someone with
HIV for example) then there should be no extra precautions taken. It is not
advisable to have prolonged contact with affected animals such as letting them
sleep on the bed etc!
Figure 4: Human Scabies on a
hand
If you do develop a skin condition and your dog has been diagnosed with Sarcoptic mange, then it is always
worthwhile mentioning this to your GP as a precaution.
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