Ammonia is the most common poisoning of captive amphibians.  The signs of ammonia poisoning depend on the length of exposure and the intensity of exposure.  Ammonia exposure usually results in dull skin colors, mouth gaping and dyspnea, reddened skin, excess mucus, bright red gills, disorientation, seizures, failure to gain weight, and sudden death.

Diagnosis is difficult.  Ammonia should be suspected as the culprit if the amphibian has been kept in a vivarium without filtration or one with biological filtration of the water and the system has been restarted or otherwise manipulated or stressed (e.g., recent water change, overpopulated, antibiotic treatment, or filtration interrupted by power outages, etc.).  When fresh tap water is used as a water source, it may be a source of ammonia as well as chlorine from chloramines used to disinfect a community’s water source.

If chloramines are present in your tap water, an appropriate dechlorinator should be used that that splits the chlorine-ammonia bond and neutralizes the resulting ammonia.  It is recommended that the chloraminated water be adequately aerated for 24 to 48 hours prior to use even if a dechlorinizer has been used to allow exhaust of the free chlorine in solution.

Readily available colorimetric tests for ammonia are available in pet stores carrying tropical or marine fish and can be used to assess the current concentration of ammonia in the moisture of an amphibian’s enclosure.  Ammonia levels above 0.2 ppm are supportive of a diagnosis of ammonia toxicosis, and a level above 1 ppm should be considered verification of ammonia as one etiology for the clinical signs.  A complete water change is the best therapy for ammonia poisoning.  Sodium formaldehyde bisulfate (e.g., Amquel®) may be used to temporarily bind the ammonia if a water change is not immediately practical.  In the event this agent is used, a water change should be done at the earliest opportunity.  Running the water through clay kitty litter has been suggested as another possible method of ammonia removal if a water change is impractical.  Aerating and oxygenating the water should also be done to help outgas the ammonia.

Amphibians that have been poisoned and recover often are susceptible to secondary infections by bacteria and other pathogens.  An examination by a veterinarian is recommended as part of the follow-up care.

Copyright 2009
Drs. Kevin Wright and Jay Johnson
Arizona Exotic Animal Hospital, LLC
744 N Center Street
Mesa, AZ 85201
info@azeah.com