1 Mites live naturally on dogs, but any mite in sufficient quantity can cause skin problems.  Two common types of mites that can cause mange are Demodex canis, which causes demodectic mange, and Sarcoptes scabei, which causes sarcoptic mange.
Ad. One area in which osmoreceptors are found is in the brain, specifically inside the hypothalamus. They regulate the amount of vasopressin, a hormone which tells the kidneys to retain water, which is expressed by the hypothalamus.
The thirst centre is located in the lateral hypothalamus. It receives input from osmoreceptors in the AV3V region and from the subfornical organ and the organum vasculosum of the lamina terminalis (OVLT) which are sites for angiotensin II action. The OVLT is in the AV3V region.