Each veterinary diagnostic laboratory offers a unique set of diagnostic tests that is subject to frequent changes as better tests become available. The protocols for sample collection and submission are therefore also subject to change. The practitioner and diagnostic laboratory staff must maintain good communication to complete their diagnostic efforts efficiently and provide optimal service to the client. Practitioners must be specific and clear in their test requests. The laboratory staff can provide guidance when there are questions regarding sample collection and handling, as well as offering assistance in interpretation of test results. Most diagnostic laboratories publish user guidelines with preferred protocols for sample collection and submission, but the following broad recommendations are fairly standard.
Numerous laboratory tests can be done in a private practice laboratory. Use of a commercial laboratory versus in-house testing should be evaluated to determine whether in-house testing is practical and economical. Because the availability of diagnostic laboratories and their reporting intervals may be problematic (eg, nights and holidays), performing some diagnostic screening tests in-house is often desirable. However, because the people performing these tests often have minimal technical training, quality control procedures must be rigorous. The time and care that must be devoted to quality control issues may preclude in-house testing in many practices. Errors may occur not only in testing procedures but also in sample collection and handling and in recording results.
Radiography (generation of transmission planar images) is one of the most commonly used diagnostic tools in veterinary practice even though other imaging modalities such as ultrasonography, CT, MRI, and nuclear imaging are also very important and commonly available in specialty practices and academic centers. Imaging provides a large amount of information by noninvasive means. It does not alter the disease process or cause unacceptable discomfort to the animal. Although radiography itself is painless, sedation is often desirable to reduce anxiety and stress associated with the procedure, to promote acquisition of good diagnostic studies with minimal repeats, and to control pain associated with manipulation in animals with painful disorders such as fractures and arthritis.
When animals die or are slaughtered on farms, carcasses and parts that are unfit for use as food should be disposed of properly. Safe and environmentally responsible disposal of animal carcasses, whether an individual death or during significant mortality events, is an essential consideration.
Euthanasia is the term used to describe a method of killing that minimizes pain, distress, and anxiety experienced by the animal before loss of consciousness. Techniques used in contexts such as pest control, slaughter, or depopulation may not always meet the criteria of euthanasia due to situational constraints.
Inspection of meat by qualified individuals to eliminate unwholesome, adulterated, or mislabeled meat or meat products from the food supply protects consumers from the physical, infectious, and toxic hazards that may originate in food animals, the environment, or people. The standard procedures do not cover every possibility concerning the acceptability of carcasses, organs, or other animal parts; personal judgment is also required to ensure that only wholesome, unadulterated product is approved for food. (Also All.see page Chemical Residues in Food and Fiber.)
Whenever possible, elimination of a tumor by surgery is preferred and often carries the greatest likelihood of cure. However, in many instances, large neoplasms, or those in critical areas such as the brain, are not amenable to complete or even partial surgical removal. Even when a tumor is grossly removed, microscopic foci of neoplastic cells often extend beyond the limits of the surgical field. This is more common for some tumor types than for others. In all of these instances, radiation therapy, often in combination with chemotherapy, is efficacious in treating cancer.