Internal disease investigations are carried out for patients who have symptoms of illness in the respiratory, digestive, or urinary tract, or in the endocrine system. The examination begins with a careful evaluation of the symptoms and preliminary knowledge. A thorough general examination of the patient is carried out: temperature is taken, the mucosa is checked, the lymph nodes and stomach are handled, and heart and lungs listened to. On the basis of the symptoms and findings the need for further investigation is defined.
Blood tests are almost always done. The laboratory does a basic blood count and measures the internal organ values of serum samples. Patients in bad shape get their results after a short wait, in other cases the owner is informed of the results by telephone the next working day. Antibody and hormone assays are forwarded to a reference laboratory. Urine sample examination is also a part of the basic examination, even for issues other than urinary problems.
X-rays can usually be taken without sedation if the owner holds the pet. Digestive and urine tract investigation can also be done using angiography. For this prior preparation is necessary, including fasting and other instructions.
For ultrasound examination it is often necessary to shave some hair from the region of the stomach: the investigation is painless and is done without sedation. Dog and cat patients usually accept the investigation easily, in spite of the fact that they have to lie on their backs on a mattress. Sometimes an accurate diagnosis requires collecting samples by either an endoscopy or laparotomy.