Are you kidding me? I just spent 20 minutes writing a reply, and got disconnected - stupid hotel internet.
Ugh, trying to remember what I wrote... after
no less. First of all, see
http://www.dutchshepherds.us/health/ I wrote that about a year ago, but the info. is still current.
Re: "heat intolerance" there is no confirmed cases and part of that is the difficulty in testing for the disease even in affected animals. The most understood type is "Exercise Induced Collapse" in Labrador Retrievers and there is a genetic test for that. But in an affected system (ie in this case muscle cells) there are thousands of proteins involved. Usually just ONE is affected, and then there might be just ONE base pair in the thousands coding for a protein, that is mutated to cause the disease. In dogs, similarly expressed syndromes are usually caused by different, separate mutation events. So one genetic test does not detect in other breeds. Same for example, Progressive Retinal Atrophy - affects over 20 breeds, but at different ages of onset and via different gene mutations. So most breeds (esp. rare breeds) must rely on vigilance and phenotypic testing.
Re: "digestive problems" that is a pretty broad topic, so I would address the two more common - 1. Pancreatic Insufficiency, as known in GSDs - no highly suspicous or confirmed cases in Dutch Shepherds that I know of 2. Inflammatory Bowel Disease (IBD) is most certainly present in the breed, as it seems to be in
every purebred dog breed and also in cats. Problem is, it is an immune system malfunction, and of course the immune system is incredibly complex. The ONLY way in any animal to definitively diagnose it is intestinal biopsy. The ways to noninvasively look for it is watching for "signs" (which can vary from sensitive stomach - diarrhea with new treats/foods, vomiting once a month for no reason, general ill thrift or poor coat, and everything in between) - ultrasound by a really good reader, and finding enlarged lymph nodes or changing to an exclusion diet with resolution of signs are the best evidence we usually get if everything else is normal. There is also blood testing for Trypsin and Folate, but they are just not definitive. There is NO genetic test in any breed, or to my knowledge any species. It is unfortunate, because I am convinced it is so prevalent. One discussion with an internist, intermittent vomiting came up and I said "cats just vomit sometimes though" and he said "would YOU go to the doctor and have it figured out if you vomited once a month for no reason??"
So especially in a rare breed, monitoring, education and vigilance is most important, with at least phenotypic testing when possible.
Please let me know if clarification is needed!
Stupid computer!