Article Title: OXALOSIS IN WILD DESERT TORTOISES, GOPHERUS AGASSIZII

Elliott R. Jacobsen, Kristin H. Berry, Brian Stacy, Louis M. Huzella, Victor F. Kalasinsky, Michelle L. Fleetwood, and Mark G. Menses

The Deseret tortoise species (Gopherus Agassizii) is a life threatening species in the southwestern United States. Causes of illnesses and death are part of the research involved ill moribound or severely injured tortoises for necropsy to determine causes and contributors towards death. A research program targeted them in 1989 to determine these differences. Primarily they were from Southern California, 2 were from Western Arizona and one was from Southwestern Utah. Most of these tortoises were already ill and the goal was to determine the cause of the illness. Several illness were described such as mycoplasmosis, cutaneous dyskeratosis shell necrosis, urolithiasis sacrocystosis renal and polyarticular gout, and pneumonia.

There were several cases with research on different tortoises. Tests were performed on 66 additional desert tortoise that were necropsied throughout 1992 and 2003. There was 54 thyroid gland and kidneys from 65 being available for examination but there was one in 2003 that was particularly looked into which was Deseret tortoise 75. This tortoise was a wild adult male detected with Renal and thyroid oxalate. The tortoise was lethargic and had clinical signs of upper respiratory tract disease typically mycoplasmosis. This tortoise also exhibited changes in its nasal cavity which was tested with cultures.

The tests were ran through healthy and ill tortoises. They tested by a plasma chemistry panel. Blood in the Urea was 415 mg/dl, uric acid 11.8 mg/dl Sodium>180 mmol/l and Chloride 139 mmol/l. Crystals in the urine were seen and identified as oxalates. These tests were ran on several others and it was speculated on the effects and towards the tortoise age. The crystal analysis were collected by there tissue and were mounted on slides to be analyzed under an electron microscope. There were also tested by using an enzyme –linked immunosorbent assay.

It was determined that the healthy tortoises were those who died of trauma. 95% reference intervals for healthy tortoises. The levels did diagnose the renal failure and 84% had similar birefringent crystals scattered. Tortoise 75 was lethargic and detected to have dried yellow exudate over its nares. There was ocular discharge with swelling and crusting around his eyes. Which was determined by observation studies and the urinalysis, chloride and sodium panels. It exceeded 95% reference intervals for the healthy tortoises in Mojave. These results were supported with the diagnosis of renal failure. The spicules and arrays from inflammatory cells that ranged from loosely arranged pigments macrophages to a particular granulomas with multinucleated giant cells.

Tortoises with oxalates in the thyroid gland were common in both ill and healthy groups comparing tortoises in the kidneys also had oxalate in the thyroid gland, which occurred in the ill group. No correlation was found between health status and presence of crystals in the thyroid. Their presence was found to be an incidental finding. It was not determined that age nor accumulations of oxalates factors because there was no significantly difference statistically in juvenile and adult tortoise. Dehydration and starvation was figured to be a cause of the disposition in the kidneys.

I feel like there was this was a good research and I also believe there could have been a bit more of testing. There was a time frame through age in a certain tortoise and they were from different places. The testing was ran only on a various amount of tortoises others were without testing. The way the testing was accounted could have resulted differently if the ones who weren’t tested would have been tested with similar situations to compare. This could result with quite a bit of failure towards obtaining accurate results. As well as having the same species. Age can be a contributing factor but it was not enough evidence and they were testing for only specific illnesses such as the oxalate and crystals. The changes seen in the kidneys associated with crystals of calcium oxalate that were observed under a light microscope, which were considered sufficient evidence to compromise renal failure. The amount of crystals was found to be an incidental finding. If there could have been a bit more testing in different situations or comparing the same age of tortoises with the same issue and different test, much more could have resulted about the illnesses or causes of death in these tortoises.