Mites - Hamsters

Hamsters

Burrowing Mites

Two species of Demodex mites affect the hamster: 40% of infesations are caused by Demodex criceti, a short mite with a short stumpy body that is thought to be non-pathogenic. The remaining 60% are caused by Demodex aurati which is a cigar-shaped mite that burrows into the pilosebaceous unit of the hair follicle.

Signalment

Demodecosis tends to affect hamsters over 1.5 years old and is normally a result of under-nutrition, immunosuppression or concurrent disease. A higher incidence is reported in males.

Clinical Signs

Lesions present as a moderate to severe dry and scaly alopecia that begins begins on the back but eventually generalises. The lesions are generally non-pruritic. Demodecosis in hamsters is not zoonotic.

Diagnosis

Deep skin scrapings or hair plucks followed by microscopic examination to identify the mite.

Treatment

Several treatments are reported:

• Injection of Ivermectin repeated twice at 10-14 day intervals. This may not be effective but is the first line of treatment.
• Benzoyl Peroxide shampoo to flush the hair follicles.
• Amitraz (diluted) applied topically to the lesions is a reported treatment. However it is extremely toxic in hamsters even when diluted so should not be used.
• Oral daily Ivermectin is also reported as a treatment.

Underlying disease such as adrenal gland disease, neoplasia, severe environmental stress, malnutrition and other systemic disease should be identified and treated where possible. Diagnostic tests such as radiography, ultrasonography, hematology, urinalysis and serum biochemistry may be performed to achieve this.

Environmental management:

• The cage should be completely cleaned and non-toxic pelleted bedding used.
  
  

Other Mites

Hamsters may also be affected by the ear mite species Notoedres. The presenting sign is dermatitis of the ears, face, feet and tail.

References

Bond, Hendricks, Loeffler (2009) Veterinary Dermatology RVC Intergrated BVetMed Course, Royal Veterinary College
Brown, SA & Rosenthal KL (1997) Self-Assessment Colour Review Small Mammals Manson Publishing Ltd
Merck & Co (2009) The Merck Veterinary Manual (Ninth Edition), Merial