Texas Equine Veterinary Association

www.texasequineva.com • 21 the required specimen is an air-dried slide and indicate sample source. For the best results, multiple unstained slides are preferred. TVMDL does not charge per number of slides submitted from a single source. Cytologic evaluation should be performed with knowledge of the sample origin and a brief clinical description of the lesion. Providing this information on the submission form allows the pathologist to correlate cytologic findings with the clinical findings. An example description would be "FNA from a 2 cm, ulcerated, dermal mass, located right below the left eye. Has been present for at least two weeks." Cytology – Body Fluids For cytology (body fluids) the requirement is 0.5 mL fluid sample in EDTA or non-additive tube. For the best results, provide fluid sample in EDTA and non-additive tubes and a freshly prepared slide. EDTA is beneficial for cytologic examination; however, a bacterial culture cannot be performed (if indicated) on EDTA samples. Therefore, a small amount of fluid in a non-additive tube is recommended. Freshly prepared slides allow for evaluation of fresh cells in case there is any degeneration during shipping. Provide clinical information such as sample origin (i.e., abdominal fluid, left carpus) and presenting complaint/brief history of the patient. Endogenous ACTH For endogenous ACTH, the requirement is 0.5 mL frozen EDTA plasma. For the best results, endogenous ACTH is very fragile and collection and shipping methods must be followed to allow for accurate results. Variations in these standards can cause either increases or decrease in endogenous ACTH, making interpretation impossible. The processing procedure is as follows: • Draw blood and immediately place in EDTA (purple top tube). • Within one hour of collection, centrifuge sample. • Immediately remove EDTA plasma (supernatant) from the cells (sediment). • Place EDTA plasma in a plastic, non-additive tube with a secure top. • Discard the cells (sediment). • If shipping a sample, place EDTA plasma sample in the freezer until shipping. You can also place the EDTA plasma tube in a secondary container (i.e., specimen cup) and fill slightly with water before freezing. This will allow to sample to freeze and provide a cohesive ice source during shipping. • Ship overnight with extra ice packs. Parasite & Ova Count (McMasters) For parasite and ova count, the requirement is 3 grams of feces. For the best results, use fresh feces. Place into a plastic, sealable bag. Express excess air from the bag and seal to maintain moisture. Refrigerate after collection but do not freeze. Ship overnight with ice packs. Eggs can hatch in samples that become warm. Do not crush feces or place in a test tube or vial (since excess air cannot be expressed). More than 5 grams of feces is not needed. Q: What samples are best for analytical chemistry requests? Drug testing Suitable samples for drug testing analyses include serum/ plasma, urine, and hair (beta-agonists). Hemolysis can affect drug detection and quantitation. Therefore, blood samples should be collected in a serum separator tube and/or centrifuged, and shipped overnight with cold packs. Most drug tests involving serum/plasma require a minimum of 2 cc. Urine should be placed in a leak-proof container and shipped overnight with cold packs. Most drug tests involving urine require a minimum of 5 cc. Hair for beta-agonist drugs should be pulled, ensuring follicles are intact. A total bundle of hair approximately 1 cm in diameter (i.e. thickness of a pencil) should be bunched, keeping the root end together, placed in a folded paper towel and then into a plastic baggie. Hair samples can be mailed, un-chilled. However, to avoid delays in testing we recommend shipping hair samples overnight, unchilled. Toxicology Serum and whole blood are the best samples for vitamins A and E, and minerals, such as selenium (Se). A minimum of 1 cc of non-hemolyzed serum is required for vitamin E and vitamin A testing. Remove serum from the clot to avoid hemolysis. Samples for vitamin A testing should be wrapped in aluminum foil or a paper towel to protect the tube from light. Whole blood (EDTA preferred) is the best sample to indicate Se status, as the Se in the whole blood is mostly incorporated into the antioxidant glutathione peroxidase. Serum or plasma Se can also be measured, but the concentration varies depending on the day's dietary intake, while the whole blood concentration is more stable over time. For Se, please send 0.5 cc EDTA whole blood. An entire Trace Mineral Panel (Co, Cu, Fe, Mn, Mo, Se, Zn) or Metal & Mineral Panel (Trace + As, Cd, Pb, Tl) can be performed using a combination of 0.5 cc EDTA whole blood and 0.5 cc serum (remove from the clot). Metals and minerals can be measured in a liver biopsy as small as 50 mg. A Heavy Metal Panel (As, Cd, Pb, Tl) can be performed on 0.5 cc EDTA whole blood or 3 g liver tissue. Post mortem, vitamins and minerals are all measured in liver, and 3 g in a baggie with no fluid is a good sample. Please note that tissue degradation adversely affects vitamin concentrations. Always keep blood, serum and liver samples chilled, and ship with ice packs. Ingesta (200 g minimum) can be evaluated for toxins like cantharidin, ionophores and toxic plants. Cantharidin testing can also be performed on serum or urine (2 cc minimum). Feedstuffs (500 g minimum) can be analyzed for the presence of ionophores, aflatoxin and fumonisin. Hay can be submitted for toxic plant identification. Submit at least 500 mL water for blue-green algae evaluation and/or water quality analysis. Pesticide testing is not as simple as it used to be, since a variety of different chemistries are available—it's important to know what is suspected in order to apply the best test. The so-called pesticide screen includes organochlorines, organophosphates, some carbamates, permethrin, petroleum products and a few drugs; it can be applied effectively to ingesta/vomitus or bait/ source, less effectively to liver (10 g minimum). The more specific Carbamate Screen, Herbicide Screen, 4-Aminopyridine (Avitrol), Metaldehyde or Strychnine test can also be applied to ingesta/vomitus or bait/source material. Urine (10 mL) can be assayed for strychnine. Brain tissue is the sample of choice

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