Causes, Prevention, and Treatment of Snake Mites, Acariasis
Ophionyssus natricis is very common in snakes and occasionally infests lizards. Trombiculid mites (chiggers). Ophionyssus acertinus is the “lizard mite” which is rare on snakes. There are more than 200 mites and ticks that parasitize reptiles.
KEVIN WRIGHT, DVM, DABVP (RA)
This kingsnake has a mite lodged in its eye.
Ophionyssus natricis has been well-studied as a pathogen compared to other mites. It has a direct life cycle and is parthenogenetic. A single unfertilized female mite is capable of producing offspring numbering in the thousands under appropriate conditions.
All species of snakes and lizards. More common in snakes that are wild-collected or exposed to large numbers of other reptiles (e.g., recent imports, purchased at shows or pet shops).
A reptile that is soaking constantly in its water dish is often infested. You may see specks floating in the water. You may see tiny moving objects in the cage or on the skin of the snake, often around eyes, in labial pits where present, or in the skin folds beneath the lower jaw of snakes. You may find these organisms crawling on your skin after handling the reptile or anything from its cage. You may feel one or more raised scales which are often more easily detected by running your hand against the grain of the scales. Many infested reptiles have dysecdysis. The reptile may have swollen eyes due to mites beneath the scales surrounding the spectacle. Often infested reptiles are irritable and have reduced appetite.
Predisposing captive conditions and/or other factors
Mites require warmth and moderate levels of humidity to successfully molt and grow. Mites are a sign of poor sanitation and quarantine practices. Mites are suspected of transmitting many blood-borne diseases so a finding of mites warrants a more thorough health assessment by an experienced reptile veterinarian.
Diagnostic tests a veterinarian may recommend
Bring a sample of specks from the water bowl to a veterinarian along with the snake. Mites are readily confirmed with low magnification but specification of a mite may require submission to a specialized lab. Black to grey specks are most likely Ophionyssus natricis, red specks are most likely trombiculid mites or Ophionyssus acertinus.
A glue trap used for cockroaches placed in the cage while the reptile is removed may sometimes collect mites which can be brought to the veterinarian for identification.
A skin scrape may be needed to detect some trombiculid mites which live beneath the skin.
Safe Practices / Prevention
- Isolate: Isolate all mite-infested cages using one or more of the following techniques:
- TAPE - A low-tech isolation practice places duct tape or heavy duty masking tape around the exit points of the cage or on the shelf surrounding the cage. The edge of the tape facing the cage should be rolled back or loosened to expose the sticky underside. This may trap any mites trying to crawl away from the cage.
- MOAT - A cage may be placed in a moat of water. This is very effective for small plastic shoe boxes and small aquariums that can be placed inside larger water-tight container. Add a couple of drops of dish-washing soap to the water as this decreases the water’s surface tension and will more quickly drown any mites trying to crawl away from the cage.
- PESTICIDE - Spray the shelf and floor around the cage with Pro-vent-a-Mite or Frontline spray to kill mites in the environment. Be sure to keep the room well-ventilated so the fumes do not affect you or your reptiles.
Next, assess all other reptiles in the household for mites since mites can crawl surprisingly long distances. If any others are infested with mites, isolate them as above.
Completely clean all mite-infested cages. Throw out all substrate. Throw out porous wood furnishings or place in black plastic bag, seal tightly, and place outside. A single mite that escapes treatment can become several thousands mites within a few months. Ask yourself if that decoration is worth risking another outbreak of mites!
If you must save the problematic decoration, open the bag and spray the interior of the plastic bag with Pro-vent-a-mite or Frontline or add a “no pest” strip to the bag. Close the bag tightly and place it in a protected area for one week. Take the decoration out of the bag at the end of the week and rinse it in hot water. Repeat the process once. In warm weather, you may consider using sun instead of insecticides. Placing the black bag in a bright sunny place and make sure the temperature inside the bag is over 120°F for several hours.
- Wash cage and all remaining furnishings in hot soapy water, rinse well.
- Use an easy-to-change substrate (like newspaper) and nonporous cage furnishings until your reptile has been free of mites for 3 months.
- Do not place the reptile back into the cage until it has been treated for mites.
- Repeat the above cleaning process after every mite treatment.
Soak all incoming reptiles in shallow water for 30 minutes and inspect reptile and water carefully for mites. Discuss with your veterinarian if a preventive mite treatment is appropriate. Quarantine for 60 days and closely monitor cage and reptile for mites.
Proper Hygiene / Sanitation
Handle the mite-infested reptiles, tools, cage, and other paraphernalia only after you have finished all activities with your healthy reptiles. Wash your hands with warm soapy water after handling the reptile. Use a disposable paper towel to dry your hands.
To reiterate, never go back and handle a healthy reptile after you have handled a mite-infested reptile. A shower and complete change of clothing is needed to reduce the chance of you spreading the infection.
Treatments a veterinarian would likely recommend
Acaracides - Be aware that many flea and tick sprays safe for dogs and cats contain active ingredients at concentrations that are toxic for reptiles. Also, many over-the-counter mite treatments for reptiles may not be effective. While there are other products that may be effective other than those listed, do not apply an unfamiliar product without researching its use and consulting with an experienced reptile veterinarian. Safe products include Pro-vent-a-mite, Frontline spray, Ivermectin spray; Ivermectin may be given orally or as an injectable ancillary treatment. Never use ivermectin on turtles or tortoises as it can cause a fatal paralysis. Make sure a reptile is well-hydrated before applying any acaracides. Soak in shallow water for 30 minutes to allow reptile a chance to drink and also remove more mites, then pat dry and apply the acaracide.
Predatory mites may work in large complex enclosures but there is no guarantee they will kill off all of the parasitic mites.
Consider bloodwork and other diagnostic tests to rule out more serious underlying health issues, particularly if a snake is acting abnormal in any way. Mites may spread inclusion body disease of boids and other diseases.
Additional medications and treatments may be recommended depending on the snake’s overall health.
Good if you are prepared to thoroughly clean all cages and follow appropriate medical advice and start quarantining all incoming reptiles. Poor if you skip steps, do not follow medical advice, or you do not have a quarantine system in place for new reptiles.
Editor’s Note: Dr. Wright died unexpectedly on September 26, 2013. He was 51. He had just finished a series of 50 disease profiles forwhen he passed.