Signs of ill health are the most important signs of the health status in your dogs. For example, if the dog has continuous nasal discharge, it indicates the presence of nasal congestion and if the discharge is thick, most of the times, the dog may have pneumonia.
If the dog vomits one or two times occasionally, this may not be taken as a serious sign of ill health but if the dog continues this vomiting, then this is something significant to be looked into.
If the dog has continuous itching, then one needs to check up the dog first by closer observation and examination of skin by separating the hair material especially in case of long haired breeds. You may also come across a lot of ticks or lice on skin, which may look apparently normal at a distance.
If the dog passes loose stool for one or two times, this need not be given more emphasis but if there is continuous passing of loose stool, then the dog is understood to suffer from bowel disorders. If the dog does not pass stool for two to three days, the digestive upsets needs to be ruled out carefully.
Just patiently observe the dog's walking movements and rule out any abnormal movements in the dog. If the dog is limping, the animal may have foot lesions. Similarly, if the aged dog has reluctant walking and less feed intake along with repeated vomiting, then acute renal disorders like nephritis needs to be ruled out.
If there is whiteness in eyes, suspect the corneal opacity that may occur in diseases like trypanosomosis. When the dog becomes anemic, the mucous membrane of the eyes becomes paler and in severe cases, this may have wall white color. If the dog bites chain and owners or others, look for behavior disorders and rabies needs to be ruled out.