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A message from Russell...
This page contains information on a serious health issue and threat for us common wombats - sarcoptic mange (also referred to as 'mange' within the context of this page). Again, my foster parents have written this piece. Some readers might find this information a little disturbing, but the education of people is foremost in our minds.
Introduction
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| Australia's wild dog, the Dingo |
Sarcoptic mange is a killer of common wombats. In some areas within New South Wales and other parts of Australia, it is a large and growing problem.
Sarcoptic mange also occurs amongst canines (dogs) and is known as canine scabies or canine mange. Contrary to what some people believe, the spread of mange is not entirely the fault of the wombat. European red foxes contribute to spreading mange throughout the country as well, as at times they utilise wombat burrows for rest.
Sarcoptic mange could have possibly arrived in Australia with the Dingo approximately 4,000 years ago, although more likely with the dogs, animals and red foxes that the European settlers brought to Australia some 200 years ago. It is unfortunate that the wombat is also acquiring a bad name for spreading mange.
What Causes Sarcoptic Mange?
Sarcoptic mange is caused by a tiny mite, Sarcoptes scabiei. Sarcoptes scabiei has many different varieties which effect a number of different animals. However, the sarcoptic mite is transferable amongst a number of different host animals, including man. The Sarcoptes scabiei which effects wombats is known as Sarcoptes scabiei var. wombati.
Scientific Name: Sarcoptes scabiei
Classification: Kingdom - Animalia
Phylum - Arthropoda
Class - Arachnida
Order - Acarina
Family - Sarcoptidae
The sarcoptic mite which effects dogs is known as Sarcoptes scabiei var. canis. The mites are easily transferable amongst both dogs (including foxes and dingoes) and wombats.
The sarcoptic mite is microscopic and approximately 0.2-0.4mm in size. The mite is easily transmitted to and from infected animals as well as any surrounds that the animal has been in contact with. Dogs, foxes and wolves (the Dingo is an Asiatic wolf) are also affected by the sarcoptic mite. However, the mites are more suited to thriving on their individual host creature, but will try and attack a new host should the opportunity arise.
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A young adult common wombat with serious mange (later put to sleep) |
Foxes sometimes use and frequent wombat burrows and can spread the sarcoptic mite. A fox (infected with mange) that brushes up against the wall of a burrow will deposit sarcoptic mites on the surface of the burrow wall. If a wombat comes through the burrow within the next 3 weeks, brushes against the same spot in the burrow that the fox did, there is a strong chance the wombat will contract the sarcoptic mites and mange will develop. The same can be said for an infected wombat to brush up against a wall of a burrow and transmit the mange to an uninfected wombat that brushes against the same spot (or to a fox as well).
A wombat burrow is an ideal environment for the sarcoptic mite to survive without a host. It is cool, out of direct sunlight and has the right amount of humidity that can enable the sarcoptic mite to live for approximately 3 weeks.
The mites can also be transmitted to human beings who are caring for manged wombats. Symptoms for humans include a rash on the arms, legs or abdomen (where the wombat has been handled and nursed). Male humans may be slightly less prone to skin irritations owing to their generally higher acidic skin type (lower pH level) than females. However, the sarcoptic mite is not suited for humans and just burrows in a short way before it dies. The result is a number of welts around the infected area of skin (see next page - Can I catch mange from a wombat?)
Life Cycle of the Sarcoptic Mite
The male and female sarcoptic mites first mate on the skin of the wombat (or host animal), with the male sarcoptic mite dying off soon afterwards. The female mite then burrows under the skin of the wombat leaving honeycombed tunnels and laying eggs in these tunnels (which can stretch up to several centimetres). After laying her eggs, the female mite dies at the end of the tunnel. However the eggs within the tunnel are nurtured via the wombat's blood serum along the tunnel wall and hatch within 3 - 8 days into larvae.
After a short period of time, the larvae moult into nymphs, all the while still feeding on the wombat's blood serum (the 'clear' component of blood). The nymph finally moults into an adult and returns to the skin surface to mate and the cycle begins again. Total time from hatching to dying of the sarcoptic mite is around 2 - 3 weeks. During this time, if the mite is dislodged from its host's body, it can survive without feeding until another unfortunate animal comes into contact with it.
Symptoms of Sarcoptic Mange
The irritation caused by the sarcoptic mites burrowing and moving under the skin cause the wombat to scratch to try and alleviate itchiness and irritation. This intense scratching in an attempt to relieve the discomfort of the burrowing mites is known in medical terms as 'pruritus'. Hair loss (known as 'alopecia') starts to occur along with the scratching and general self-mutilation of the skin area where mites are present. Generally, mange will start to occur on areas of the wombat's body which came into direct contact with the sarcoptic mite (i.e., the rump, head and back of the wombat), but will gradually spread from these areas.
The wombat will scratch the itchy places on its body until
it is raw and layers of skin are taken off. The tunnels caused
by the burrowing mite allow blood serum to seep out onto
the surface of the skin and scabs to form, with fluid loss
also causing dehydration. Lesions, deep fissures in the skin
and ulceration occur. The wombat's continual scratching in
an attempt to relieve itself, opens the wounds up to secondary
infection, not to mention the additional irritation caused
by insects, blowflies and the like which are attracted to
the open wounds. In severe cases of mange, the wound eventually
scabs over with a very thick layer of scabbing, under which
the mite just keeps on breeding. Bacterial infection causes
pus to accompany the scabs and further encourages insects
to collect near the wombat. Fly strike is also common with
wombats who have contracted mange.
Wombats will also rub up against various items such as tree trunks, burrow walls and the like to try and relieve the constant irritation. This is likely to cause new infections in other wombats who use the same areas to scratch themselves, or brush up against the same area. Re-infection of sarcoptic mange is also a strong likelihood amongst animals that have been treated and cured of mange in the past.
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| A juvenile wombat with mange on its back |
Mange causes great stress for a wombat, especially a juvenile
wombat as they do not have the energy reserves or the body
resources of adult wombats. The wombat will start to lose
condition very fast as it cannot travel as far to eat, it
might lack the energy to look for water, food, shelter and
so on. All of this further adds to weakening the animal and
a downwards spiral of the animal's health.
Apart from the exterior and visible effects of mange, internal damage to the organs is also done to the wombat. The wombat's body is trying to fight the mange, as well as any other infections that occur as a direct result of open wounds and scabbing. The wombat's body will develop high levels of white blood cells to combat the infections. For a short period of time, having a high white blood cell count is fine, as this is the body's natural way to fight off infections. However, the white blood cells do not kill the sarcoptic mite and the wombat is subjected to continuously fighting infection after infection (as well as being in a weakened state and having a low immune system which cannot recover). Thus, the white blood cell count in a wombat with mange remains at an elevated level for an indefinite period. Sustained high levels of white blood cells attack the liver and kidneys of wombats. A wombat that has sarcoptic mange might not look 'too bad' on the outside, but may have various internal problems and be suffering from liver damage and or kidney damage/failure.
 Next page... Can I catch mange from a wombat?
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