Demodicosis in hamsters – an opportunistic invader

Skin conditions in hamsters are frequently seen in general practice, with the three main presentations being demodicosis, abscesses and cutaneous lymphoma. In this article we take a look at the parasitic complaint, demodicosis.

Posted: 25 June 2020

Demodicosis in hamsters – an opportunistic invader

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There are two Demodex parasites found in hamsters, these being Demodex aurati and Demodex criceti. Fortunately, neither of these are zoonotic.

The main parasite causing clinical demodicosis in the hamster is Demodex aurati. Most hamsters are natural hosts to these mites, and are usually asymptomatic until they are old, weakened, diseased, malnourished or stressed.

Demodex aurati – a secondary invader

This parasite is usually a secondary invader which is associated with a reduced or compromised immune system. Thus, if you suspect and then identify D. aurati, you should also look for another underlying cause.

Look for an underlying cause of demodicosis, such as;

  • Stress – poor housing, lack of environmental enrichment, excessive heat or cold and companion aggression may all contribute to higher levels of catecholamines and reduced immunity.
  • Old age – with increasing age comes a progressive decline in the immune system. Indeed, most cases of demodicosis are seen in older animals, and unfortunately, they usually carry a poor prognosis.
  • Neoplasia – cutaneous lymphoma is the second most common cutaneous neoplasm, most often occurring in older hamsters. The debilitating condition can result in the hamster also suffering from demodicosis.
  • Inadequate nutrition – malnutrition will inevitably result in a compromised immune response. Did you know that at Burgess Pet Care we produce high quality food for hamsters, helping them stay fit and healthy? See our range of products here.
  • Hyperadrenocorticism - Cushing’s disease occurs occasionally in hamsters and can be mistaken for diabetes or cutaneous lymphoma.

What are the signs of demodicosis?

The clinical appearance of a hamster with Demodex aurati are usually quite obvious, and include;

  • Alopecia – the animal may have mild or moderate hair loss, which can be quite patchy.
  • Dry, scaling and crusting lesions – at first, these tend to be on the back of the neck. As the condition progresses, they start to appear ventrally and eventually become more generalised.
  • Some itchy, some not – most hamsters tend to show minimal signs of pruritis, thought this can be variable.
  • Prominent flank scent glands – with the hair loss, these glands can often stand out, and the owners may comment on them.
  • Secondary infections – as with most cases of demodicosis, secondary bacterial infections of hair follicles can occur, with pyoderma. Purulent exudates are not normally present.
  • Depression and weight loss – if the animal becomes systemically unwell, it may lose weight and become quiet and less active.

Diagnosis demodex

  • History and clinical signs – for most cases, the visual evidence may be sufficient to make a diagnosis. The alopecia, crusty lesions and minimal pruritis will be strongly suggestive of demodicosis.
  • Microscopy from hair, tape and skin scrapings – if finances allow, these tests are relatively simple and will yield results. Ensure you take deep scraping to give you the best chance of identifying the mange mite in various stages of development.
  • Biopsy – this is rarely required.

Skin investigations will reveal Demodex mites in one of two places;

  • Demodex aurati – these are found in the pilosebaceous part of the hair follicles. Look for a long bodied demodex mite.
  • Demodex criceti – these mites are found in the epidermis and have a shorter body appearance.

Treating a hamster for demodicosis

Whilst there are no licenced treatments available for hamsters, there are several reported treatment protocols that have been used. Always make sure you get informed owner consent and follow the cascade.

  1. Ivermectin – this has been shown to be effective in many cases. There are different protocols described, ranging from daily oral dosing at a dose of 0.3mg/kg, to subcutaneous injections repeated twice at 1-2 week intervals.
  2. Doramectinthis has been described to treat demodicosis
  3. Benzoyl Peroxide shampoo – this has been used to flush the hair follicles.

Any hamster not responding to treatment or relapsing after treatment is stopped, will usually have a serious underlying disease. Conditions such as adrenal gland disease, neoplasia, severe environmental stress, malnutrition and other systemic disease need to be recognised and treated. Unfortunately, many owners are unable or unwilling to spend too much money on their small pet, which can at times be frustrating.

Warning: Amitraz

Whilst this has been used to treat demodicosis, be aware that it’s known to be extremely toxic in hamsters, so should not be used.

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