Goodbye Mopsy

After struggling with health problems for some weeks, Mopsy, the axolotl, passed away on Sunday, September 9.

Mopsy arrived at Pacific Science Center in 2009, a large, clear skinned animal with a spectacular “mophead” of gills, the origin of her name. Mopsy was somewhat accident prone, getting her foot caught in things, being bitten by tank-mates, hurting her tail. Being an axolotl, she always regenerated tissue quickly when she hurt herself.

Through her resilient nature, Mopsy taught us how to feed and care for her species. It was easy to start thinking nothing could slow her down. Lately, however, even with conditions right, her appetite declined and she became withdrawn. The other axolotls are thriving and even plump and she was slowly wasting. She had been in to the vet and was on medication in late August, and then on a second antibiotic afterwards.

It is sad to watch a vibrantly healthy, active animal decline in health, but beyond that, we wanted to make sure that her passing was not brought about by conditions that could potentially harm the other axolotls. Especially because of their recent relocation all of us were somewhat anxious to learn more about her cause of death.

We brought her remains to the Center for Bird and Exotic Animals for necropsy (animal autopsy). The results have now come back.

Mopsy had tissue changes to her kidneys, liver and ovaries. Her ovaries and liver had increased cells and enlargement typical of an older animal. They weren’t signs of disease as such, but part of the aging process.

The kidneys had dilation and cell accumulation; there was inflammation from her kidneys to her vent. She may have had a blockage somewhere in that pathway, meaning difficulty eliminating waste. She had some spinal damage which the vet initially thought happened after death, but may have been an old injury. If so, it may have damaged her kidneys as well as her spine and contributed to her problems.

There was no sign of infectious disease that we would need to worry about with the other axolotls. It also doesn’t look like water conditions played much of a role.

I asked if there was any way we could have detected the problem earlier. The vet said probably not. He lack of appetite and change in behavior were signs of pain, but it would have been difficult even with ultrasound imaging for them to have seen where the pain was coming from.

So. The good news is we probably didn’t do anything that made Mopsy sick, or that made her existing condition worse. The bad news is if she was old, so are two others in the tank.