Cockatiel parents and their chicks were given tap water treated with 25-30 ppm chloramine or tap water alone in order to evaluate the safety of this chlorine-replacing chemical for chick growth. Twelve treated cockatiel chicks grew and developed normally as compared with eleven controls which had access to untreated tap water.
Chloramine used as disinfectant at 1.5 ppm (parts per million) in municipal water supplies has been suggested to be a cause of leg weakness in growing psittacine birds. The Metropolitan Water District, which provides water to local water districts in Los Angeles, Ventura, Riverside, Orange, San Bernardino and San Diego counties in Southern California, replaced chlorine with chloramine as a water disinfectant in November 1984. The reason was to reduce the possible production of trihalomethanes which result from the reaction of chlorine with organic matter found in the water. These trihalomethanes are suspected of causing cancer so this change was made to protect the health of the 13 million water consumers served by Metropolitan.
Though only recently used by the Metropolitan Water District, chloramine has been used in other areas in the US and Canada for decades with no difficulty except its toxicity to fish and toxicity during kidney dialysis. Chloramine is toxic to fish because it is absorbed directly through the gills into the blood where it binds to the iron of hemoglobin reducing the ability of red blood cells to bind oxygen. Similarly, it is toxic during kidney dialysis because chloramine gains direct access to the blood. Chloramine can be removed from water either by the addition of ascorbic acid or by proper filtration through granular activated carbon filters.
Because chloramine has an adverse effect on fish and in kidney dialysis, all end point users of water chloraminated by the Metropolitan Water District were notified of the disinfectant change-over before November 1984. After the change-over both the Metropolitan Water District and the Department of Avian Sciences, University of California, Davis received calls from people concerned about the health of their growing birds. The most common concern was leg weakness in weaning age birds.
Neither the -Metropolitan Water District nor the Department of Avian Sciences was aware of any reason to expect leg weakness or other toxic effects of giving chloraminated water to growing birds. Given the concerns of the public, however, we at the Department of Avian Sciences undertook the following study to assess the effects of chloraminated water on growing cockatiels.
Materials and Methods
Four pairs of cockatiels were each given six cockatiel chicks hatched in an incubator. Each pair accepted and fed its chicks upon presentation without evidence of parental neglect or abuse of the chicks. Two of the four pairs were offered plain tap water and two were offered tap water containing 25-30 ppm chloramine. One pair of adults on plain tap water received a lutino chick which failed to develop normally. Since we have seen this problem in some lutino chicks before, the chick was excluded from the study. All pairs were offered a nutritionally adequate crumbled diet.
Chloraminated water was produced by adding 2.2 g of household bleach containing 0.15 g chlorine and 0.046 g ammonium hydroxide containing 0.0996 g of nitrogen to 1 liter of water yielding a 1:3 nitrogen to chlorine ratio and a chloramine concentration of 30 ppm. The chloraminated water was sampled daily using a DR 100
Colorimeter test kit to assure that chloramine concentrations did not fall below 25-30 ppm.
All chicks were weighed daily from hatching to fledging and once after fledging. At each weighing chicks were inspected for leg weakness and general condition. Student’s t test was applied to the growth data.
No differences were observed between chicks given chloraminated water and those given plain tap water. None of the chicks showed any sign of leg weakness or other abnormalities. There were no significant differences in growth rate. Fledging ages were not different between the groups and all chicks were self feeding and capable of independent living when removed from their parents at 6-7 weeks of age. None of the chicks which are now 12 weeks old have experienced any apparent health problems.
Chloramine at 20 times the concentration used in municipal water supplies had no adverse effects on growing cockatiels. This study does not support the suggestion that chloramine causes leg weakness or other health problems in growing birds.