The most up-to-date information re mites and herps was published by Andrea Reiss in Wildlife in Australia - Healthcare and Management (Proceedings 327 of the Post Graduate Foundation in Veterinary Science) in the chapter titled Current Therapy in Reptile Medicine, and I summarise it here for the information of the list.

Introduction

The reptile mite (Ophionyssus natricus) is a common and serious pest of reptile collections. These blood sucking parasites play an important role in a number of serious herp diseases. They most noticeably affect snakes and lizards.

Diagnosis

Reptile mites are small but visible to the naked eye. Fully engorged mites may be several millimeters long. Nymphs and unengorged adults are very much smaller, and even in very large numbers may be overlooked. Mites are dark or black when engorged with blood, but paler before feeding. They are frequently seen around the eyes, ears, lips, cloaca, and other crevices of the host's body. "Mite dust" or faeces is seen as pale or white specks on the host's scales or enclosure. Mites may also be seen in the water following soaking. Reptiles with mites often have dull skin with a pitted appearance to the scales.

Biology

Mites are highly active and able to travel at least several meters. They are strongly attracted to the smell of reptiles. Once a female has fed she seeks out a dark moist place and lays many eggs over many months without mating! The larvae and 2 nymph stages do not feed, but the last nymph stage eats, as does the adults. At cooler temperatures mites, or their eggs, can survive for prolonged periods off their host.

Principles of Treatment

1. we must treat both herp and enclosure - if only treating the herp you will fail to eradicate!
2. some life stages are very difficult to see so if in doubt assume mites are present and treat!
3. dark, moist and rough surfaces with organic debris provide excellent environment for mite survival
4. adult mites and nymphs can survive for 45 days off the host, so successful treatment programs require repeated treatments of both host and environment
5. very little scientific information is known about the safety of insecticides in herps
6. no one treatment is 100% safe and 100% effective

The treatment employed currently at both Taronga and Melbourne Zoos (to the best of my knowledge) is Orange Medic Head lice treatment (Emerald Forest) (2mg/mL or 0.2% permethrin) diluted 1:1 with warm water. Treatments should be carried out in well ventilated areas and all workers should wear appropriate protective clothing.

Treating the animal

Remove the reptile from its enclosure prior to treatment. Lizards should have a drop of Liquifilm Artificial tears placed in each eye to protect the cornea - snakes do not require this 'cos they have protective spectacles. Spray the animal's body all over with the insecticidal solution. Wipe the head with a cloth soaked in solution, or use a light spray. Keep the animals’ nose pointing toward the ground with the mouth closed to avoid any liquid running into the mouth or nostrils. Concentrate on the eyelids, corners of the mouth and other crevices such as the axilla (arm pit), or cloaca. Allow medication to stay on animals for 2-3 minutes. Contact longer than 5 minutes can be dangerous. The animal can be placed in a bucket for this time. Ensure that it can not drink the liquid around its mouth. Wash all the solution off thoroughly with plenty of pure warm water, and place the animal into a very well ventilated mite free enclosure. Animal treatments should be repeated no more frequently than 7 days. At the Sugarloaf Animal Hospital we recommend initially 3 weekly treatments, then 3 fortnightly treatments.

Any reptile entering the collection should be isolated in a mite-free enclosure and receive 3 weekly treatments before entering the group.

In very debilitated animals veterinary support may be required, and insecticidal drugs may be inappropriate.

Treating the enclosure

All reptiles must be removed, and the enclosure completely stripped, including all plants, substrate, branches, and hides. Any enclosure furniture that can be discarded should be! The enclosure is then thoroughly cleaned and scrubbed with hot water, concentrating on cracks and inaccessible places.

Spray the solution over the entire enclosure, ensuring excellent wetting of all the aforementioned cracks and inaccessible places. Allow to sit for 30 minutes and then wipe out with copious quantities of water, and allow to dry. Leave the enclosure empty for as long as possible. Ideally leave the enclosure empty for 60-80 days, and then repeat treated before re-establishing inhabitants.

Other drugs and chemicals which have been used include: Dichlorvos (pestrips) - no longer recommended because dangerous to reptiles; trichlorphon (neguvon) is a oral powder for worming horses, but is sometimes difficult or expensive to obtain; ivermectin has been reported to be toxic in some herps, and so can not be recommended; the newer insecticides such as selamectin, fiprinol, or imadocloprid used in other small animals have yet to prove themselves safe and useful for herps.

Freezing and microwaving will kill these persistent little pests. They are not transferred on birds to reptiles.

[Disclaimer – most medications have not been formally registered for use in herps, and dose rates are generally extrapolated using sound scientific principles from our knowledge of other species, or are generally accepted as a result of the experience of experts in reptile medicine. While all due care is taken to ensure the appropriate recommendations are made concerning medications, where medications are used "off-label" the client accepts all risk of adverse reactions and there is no liability on the manufacturer, the author, nor the Sugarloaf Animal Hospital.]

Hope this is of some use!

Cheers

Mark Simpson BVSc

Sugarloaf Animal Hospital

Carrington Street West

Wallsend NSW 2286

ph 02 4955 1833      fax 02 4955 1970