The Bare-nosed Wombat and Sarcoptic Mange
by Roz Holme
Sarcoptic mange is a nasty disease that predominantly affects the Bare-nosed Wombat throughout its range. Sadly, the condition has also recently been found in Southern Hairy-nosed Wombat populations in South Australia, however there is no record of the Northern Hairy-nosed Wombat being affected.
Contrary to popular belief, the spread of mange is not entirely due to wombats - the introduced fox and feral dogs are also hosts for mange and contribute to mange dispersal. It is considered that the fox may have initially brought the might that causes the disease to Australia.
The mite is called Sarcoptes scabiei which has many different sub-species that affect a number of different hosts. Although Sarcoptes scabiei is transferable between different hosts - including humans - it is usually host specific and therefore is self limiting. The mite that affects wombats - often fatally - is called Sarcoptes scabiei var wombati.
Sarcoptic mites first mate on the skin of the wombat and the male dies not long after. The female mites then burrow under the skin of the wombat leaving a network of tunnels in the flesh where eggs are laid, the female then dies at the end of a tunnel. The mite eggs are nurtured via the wombat's blood serum and hatch into larvae three to eight days later.
Larvae then moult into nymphs - and nymphs into adults. During this cycle the mite feeds off the wombat's blood serum which is the main contributor to the debilitation of the wombat. Once the nymphs have turned into adults they make their way back to the surface of the skin - creating more tunnels - where they mate and the cycle starts again. The life cycle of the mite is approximately two to three weeks.
Sarcoptic mange is a severe disease and affects the host in several ways. The irritation caused by the mite burrowing under the skin causes the wombat to scratch incessantly which in itself causes often irreparable damage to the skin including mutilation and hair loss. From the constant scratching, skin layers are taken off and raw flesh is exposed. The blood serum seeps through the mites' tunnels to the exposed flesh creating wounds and scabs. Ulcers and deep lesions develop which then cause secondary infection and blow fly strike.
Other visible symptoms of this disease are skin thickening and crusting over the body, including they eye and ear areas causing blindness and deafness. The animal becomes too weak to search for food and malnutrition and dehydration occur. The immune system becomes depleted and the wombat looks emaciated.
In advanced stages sarcoptic mange also has a devastating effect on internal organs, including the heart, liver, kidneys, lungs and reproductive organs. Respiratory infections and pneumonia can deplete the wombat further.
Left without treatment, a wombat with sarcoptic mange will die and death is slow and painful.
We, at Cedar Creek Wombat Rescue, have been caring for wombats for several years and have a continual stream of mange affected wombats passing through our doors. We seem to get mainly females without joeys, as wombats in this condition don't breed. Sadly, if mange is contracted by a female with a joey she will often reject it as she can't cope with the extra burden, so we tend to keep an eye out for abandoned wombat joeys in our area.
Entire colonies of the Bare-nosed Wombat are being lost to this horrible disease; however an affected wombat can completely recover if it is treated early. You can help save these animals by reporting cases to your local wildlife organisation or to your local National Parks and Wildlife Service office. Record the time and exact location of the wombat so that it can be found easily by a ranger or wildlife carer.
And remember - the quicker you act the more chance a wombat has of survival!