The possibility that high doses of folic acid might cause harm cannot be excluded, albeit there is no evidence of harm in previous trials (32).
Nonetheless, it is now clear that SIV can lead to serious disease in chimpanzees following chronic infection, and leukemia and lymphoma have been reported in baboons infected with STLV-1, so the potential for STLV-4 to also cause disease cannot be excluded.
Renal causes therefore cannot be excluded.
Reverse causation, illness causing overweight, cannot be excluded, but does not seem a plausible explanation.
The possibility that formaldehyde alone endows protection or that acetaldehyde causes toxicity cannot be excluded.
Therefore, similar consequences for the ATP level, which would also cause metabolic changes, cannot be excluded in the present investigation.
A possible bias in the attribution of the cause of death cannot be excluded, but it seems implausible that it could explain all of the observed benefit.
The possibility of a neurological cause of dysuria cannot be excluded; however, an anatomical difference exists between the urethra of female and male dogs, which may explain why dysuria was present only in male dogs.
On the other hand, there are also weaknesses related to the performance and interpretation of germline analyses (de la Chapelle, 2004; Lynch et al, 2004), and the existence of other, not yet detected, genetic causes of LS cannot be excluded.
However, the possibility of repeated infections being the cause of IgG persistence cannot be excluded.
