Question: My husband retired in 1996 and since has developed Diabetes, there is not a family history. How can we tell if this is service connected or not? He served in the USCG from 1974 to 1996. Also is there any connection with asthma and Trichloroethylene?
The only diabetes that is automatically (presumptively) service connected is for Vietnam veterans who served with boots on the ground and were exposed to agent orange. There are some limited cases elsewhere, such as in Korea. If diabetes is diagnosed on active duty or within the first year after ETS, that may also be service connected.
Adult onset diabetes is a very common disease in America that affects many men as they get older. VA won't recognize it as service connected unless there is evidence that military service caused it.
To prove that any health condition is service connected requires evidence of that fact. For example, to try to show that asthma is caused by TCE would require an expert (usually a physician) to write a nexus letter that clearly says that the asthma is "more likely than not" caused by exposure to TCE.
Even before you can do that though, the veteran must prove he was exposed to TCE and document when, where and how much. Vets can't simple tell VA that they were exposed, they have to prove it.
Of course, we were all exposed to TCE. I used the stuff all through my time in the Army. If I had to prove that today, I don't know how I would do it.
But...there are many successful claims for TCE and many diseases. Those claims are usually finalized at the BVA.
You can research successful claims here http://www.index.va.gov/search/va/bva.html Choose a year to query and then enter key words like <Trichloroethylene> and review the cases that will be presented to you.