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User Guide

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New Quick Guide Factsheets

• Bovine Sample Guidelines

• Ovine Sample Guidelines

• Porcine Sample Guidelines

• ISU VDL User Guide

• ISU VDL submission forms



General Submission Guidelines

Specimen Submission

  • The VDL only accepts specimens referred by a licensed veterinarian.
  • The VDL does not accept submissions for disposal purposes only.
  • The appropriate submission form must accompany all specimens. Download VDL submission forms here.
  • See individual sections for complete instructions on packaging and shipping specimens.

Specimens should be sent to the following address:

Veterinary Diagnostic Laboratory
Iowa State University
1600 South 16th St
Ames, IA 50011-1250
Download an address label pdf

Submission Forms

Submission forms are legal documents designed to be concise, yet complete. The information requested is needed to determine which laboratory tests are appropriate, to minimize your laboratory testing charges, and to produce your results as quickly as possible. Please be as specific as possible in your testing requests.

Download ISU VDL Submission Forms here.

  • Diagnostic Examination Submission Form - use for all submissions except serologic assays and requests for rabies examinations.
  • Serum Submission Form - use for routine serum assay requests. NOTE: Serum samples submitted to comply with EIA, Brucellosis , and PRV Disease Programs require special submission forms. Call 515-284-4140 to request EIA and Brucellosis Disease Program forms. Call 515-281-5155 to request PRV Forms.
  • Toxicology / Nutrition Forms
  • Rabies Examination Form - NOTE: If additional tests are desired, it is necessary to attach a completed Diagnostic Examination Submission form, as well.

These submission forms may be downloaded or ordered from the lab.

Requests for specialized testing will be managed on an individual basis in consultation between the referring veterinarian and the receiving diagnostician, and with the approval of the laboratory director. Please call the VDL at 515-294-1950 for information if you have questions concerning a particular submission.

Guidelines for Packaging Specimens

The goals of packaging are to protect the specimens from temperature extremes (freezing and heating) and to protect persons who may come into contact with the package from exposure to infectious agents. For this reason, it is extremely important to prevent leakage of specimens. Neither commercial carriers nor the U.S. Postal Service will deliver containers that leak. Additional fees will be assessed if the VDL is required to pick up leaking packages that carriers will not deliver. Leak-proof specimen containers, abundant icepacks with chilled fresh specimens, and an insulated leak-proof transport container lined with a plastic bag are required.

Check with your local post office or commercial carrier for current requirements of the Department of Transportation for shipping biological diagnostic materials. These include specifications for approved package liners and exterior labels.

  1. Label all samples with the owner's name in waterproof marker. Please do not use stick-on labels as they often come off. Be sure the contents of the box, as well as the outside of the box, are identified.
  2. If multiple cases are submitted in one box, package each case separately to ensure that all samples are assigned to the proper case. This is especially important if the package includes multiple serology submissions.
  3. Place tubes in serum shipping boxes (i.e., brucellosis boxes) or similar boxes with dividers to separate tubes from one another. Do NOT package loose blood tubes in crumpled paper or styrofoam bits.
  4. Enclose sufficient ice packs to preserve the quality of fresh tissues. This should be at least a 2:1 ratio of ice to tissues. If available, insulated styrofoam-lined containers should be used.
  5. Plastic leak-proof jars can be used for formalin-fixed tissues. Whirl-Pak® bags are excellent for holding fresh tissues. Squeeze the air out of the bag, then fold the end over several times before bending over the tabs. Double-bagging tissues improves the biosecurity of the specimen.
  6. If inside packages have the potential to leak, line the box with sealed plastic bags to prevent leakage. Pack with absorbent materials to soak up spills should they occur. All specimens should be packed in a manner to avoid leakage or breakage, and to withstand the trauma of mailing. Shipping agencies may choose not to deliver leaking packages because of new Department of Transportation regulations on shipment of potentially biohazardous materials. In addition, a special permit may be required for interstate transportation of certain veterinary viruses within the United States. Practitioners are referred to published federal guidelines and regulations for details pertaining to packaging, labeling, and interstate shipping of infectious agents (Title 42 CFR Part 72; Title 49 CRF Part 173.386-388).

Bacteriology Submission Guidelines

General guidelines for submission are found in the Pathology section. If you are requesting bacteriology tests, remember to keep samples moist, cool, and send by overnight transport. The following are important points to keep in mind:

  • Tissues should be VERY fresh and collected aseptically.
  • Collect samples prior to antibiotic treatment.
  • Submit generous portions of tissue or several milliliters of pus, exudate, or feces.
  • Avoid swab submissions whenever possible.
  • Submit samples individually in separate bags or jars with correct and clear identification.
  • Maintain samples at refrigeration temperature (40ºF/4ºC) and send with ice packs. Freezing is generally not recommended.

Anaerobic Cultures

  • Care in collection is essential. Do not contaminate the samples with surfaces which have resident anaerobic bacteria. Exposure to air for more than 20 minutes can be detrimental.
  • Samples from animals that have been dead longer than 4 hours are usually unsuitable.
  • Tissues and liquid exudates are recommended (ship in anaerobic pouches or tubes).
  • Swabs are not acceptable unless shipped in proper containers. Special collection devices and transport tubes with reduced oxygen environment are available.


  • Collect milk in sterile snap cap or screw cap tubes. Do not ask owner to collect milk samples without first providing training in proper sampling technique.
  • Cool samples before submitting to the laboratory, and mail with ice packs. Samples may also be frozen without altering recoverability of pathogens.


  • Not normally used for recovery of animal pathogens because bacteremia is intermittent. Call the laboratory for recommendations.


  • Collect by cystocentesis (best), catheter, or mid-stream catch. Submit a 3 ml sample.

Skin Lesions

  • To collect from pustules or vesicles, disinfect surface with alcohol, allow to dry, and aspirate material with syringe and needle.
  • Pluck hair from lesion and scrape edge of lesion when ringworm in suspected. Submit hair, skin scrapings, scab material, and toe nails.

Molecular and Viral Diagnostics Submission Guidelines

Successful isolation and/or detection of viruses in clinical materials depends largely on proper collection and handling of specimens. Care should be taken to protect the virus in specimens from environmental damage and maintain virus infectivity by using the proper transport system.

In general, specimens intended for virological testing should be collected as early as possible in the course of the disease, i.e., within the first 7 days after the onset of illness. Samples collected during the acute phase of viral infection usually contain adequate amounts of virus for detection in available assays. Samples collected later in the course of infection usually require more laboratory time and often yield poor or negative results. Since certain viral infections may predispose the host to secondary viral or bacterial infections, samples collected late in the disease process may lead to a misdiagnosis when secondary infection is involved.

The appropriate samples for virus detection include bodily fluids and secretions (e.g., nasal or conjunctival secretion, genital swabs, urine, saliva, vesicle fluid, semen, milk), feces, blood samples, and skin biopsies from infected, live animals (i.e., antemortem), and relevant tissues and organs from necropsied animals (i.e., postmortem). The collection of antemortem samples from sick animals should be based on clinical manifestation. For example, nasal or nasopharyngeal swabs should be collected from animals with respiratory diseases; fecal samples from animals with enteric diseases; cerebrospinal fluid (CSF), nasal secretion and feces from animals with CNS signs; vesicle fluid and biopsies from animals with skin lesions. The same principle can be applied to the collection of postmortem samples. As a general practice, whole blood* and serum should always be collected from animals with suspected viral diseases, regardless of clinical manifestations. Secondary lymphoid tissues (e.g., tonsil, lymph nodes, spleen) are always good specimens for viral diagnosis.

*For collecting whole blood, citrate is preferable to EDTA as an anticoagulant because EDTA may inactivate some viruses due to its chelating activity.

For best results in isolation and detection of viruses, clinical specimens should be aseptically collected, kept fresh, and transported immediately to the laboratory. If delays are unavoidable or any detrimental affects on virus in samples are anticipated during transport, samples should be refrigerated at 40ºF (4ºC) for no more than 2 days. For longer storage periods, freeze samples at - 70ºC, but NEVER at - 20ºC. Self-defrosting freezers in conventional refrigerators are not appropriate for storage. NEVER freeze whole blood samples. Ideally, frozen samples should be submitted on dry ice, but commercial refrigerant packs can be used if necessary.

Unbleached swabs (e.g., Dacron swabs are available from Baxter) are strongly recommended for collecting nasal and fecal swabs. Standard cotton swabs contain residual bleach that can inactivate viruses. Swabs MUST be prevented from drying. For that reason, swabs may need to be placed in a viral transport system. Ideally, swabs should be placed in a broth medium or balanced salt solution supplemented with 0.5% gelatin, serum, or bovine serum albumin, to protect the viability of viruses in transit plus antibiotics to prevent bacterial and fungal growth. Minimally, physiological saline or Lingo solution could be used on an emergency basis. Specimen collection and transport systems (e.g., Viral Culturette® Becton Dickinson) are available.

It is important to choose not only the most appropriate specimen, but also to collect an adequate amount of specimen for virological testing. Submit a minimum of 3-4 ml serum and 3-5 grams or 5 ml wet volumne of fecal material. Insufficient amounts of sample are a potential cause of inconclusive diagnosis or false-negative result.

When it is necessary to ship a specimen, use a leak-proof container (e.g., tubes, plastic bags) enclosed in a second watertight container containing absorbent material. Ideally, the specimen container should be placed in a Styrofoam box with commercial refrigerant packs or dry ice. Avoid using wet ice because it will melt and leak from the package. Dry ice is preferable if transport requires more than 3 days.

All specimens should be packed in a manner to avoid leakage or breakage, and to withstand the trauma of mailing. Shipping agencies may choose not to deliver leaking packages because of new Department of Transport regulations on shipment of potentially biohazardous materials. In addition, a special permit may be required for interstate transportation of certain veterinary viruses within the United States. Practitioners are referred to published federal guidelines and regulations for details pertaining to packaging, labeling, and interstate shipping of infectious agents (Title 42 CFR Part 72; Title 49 CRF Part 173.386-388).

All specimens should be properly labeled and accompanied by the proper VDL submission form. Please provide all information requested on the form: animal identification, age or body weight, gender, date of onset of disease, major clinical signs, days of gestation if samples originate from abortions, herd size, number of animals affected or dead, date of collection, animal source and location, vaccination history, and differential diagnosis. This latter information is essential for the selection of the most sensitive test system in the laboratory when samples are submitted by mail.

Pathology Submission Guidelines

Submission of tissue specimen(s) is usually the best method of obtaining a diagnosis of a clinical disease. However, proper selection and preservation of samples is essential to make the most efficient and economical use of the laboratory. The two conditions that most frequently interfere with diagnosis are (1) post mortem autolysis, and (2) sample collection too late in the course of disease.

Fresh specimens should be large enough to demonstrate the lesion yet small enough to allow for rapid chilling (tennis-ball sized). In some cases (e.g., bronchoalveolar lavage for PRRS virus isolation) submission of an entire organ may be preferred. Ideally, fresh samples should be packaged individually to prevent cross-contamination. Please do NOT to package fresh intestine with other tissues, as this results in fecal contamination of other organs. At a minimum, intestinal samples should be submitted separate from all other tissues. Samples should be shipped in leak-proof containers with artificial freeze packs. Please line shipping containers with additional sealed plastic bags to avoid leakage in transit. Carriers will not deliver leaky packages resulting in delays in processing.  A fee of $25 may be assessed for packages that leak.

Specimens for histopathology should include thin (0.5-1.0 cm or 1/2 inch) slices of the appropriate organs, including the lesion, transitional zones, and adjacent grossly normal tissue, in 10% buffered formalin in a leak-proof, wide-mouthed solid container. Do not use glass containers. When in doubt, collect specimens from multiple organs, including brain. The pathologist can then select the most appropriate specimens for complete microscopic examination. Unless it is important that individual animals be examined and reported separately, specimens from each individual animal can be pooled in a single container - provided the specimens are small enough to maintain a 10:1 formalin:tissue ratio. The ratio of formalin:tissue should be at least 10:1 to allow optimal fixation.

A minimum of 48 hours is required for histopathology, 24 hours for fixation and 24 hours for processing. Consequently, specimens for histopathological examination should be collected and placed in formalin at the time of necropsy in order to minimize autolysis and generally allow results to be available the day after the specimen is received.

General guidelines for histopathologic examination/submission of formalin-fixed specimens are as follows:

  1. Solid organs: 0.5 - 1 cm slices to include lesion and transitional areas between lesions and normal tissue.
  2. Intestine: 1 - 2 cm lengths held open as they are immersed in formalin or flushed with formalin prior to immersion. Do NOT tie the ends.
  3. Brain (including brain stem): immerse sagittal half of small brain in formalin. One-half of the brain should also be submitted from larger animals. These larger brains should be sliced for better fixation. The preferred procedure is to make transverse slices, 1.0 - 1.5 cm apart that extend to within 1.0 cm of the ventrum of the brain. This allows for more rapid fixation while retaining the architecture of the brain so that specific areas can be sampled. Nerves can be pinned to a tongue depressor and immersed in formalin.
  4. Tumors: immerse in 10% formalin. If greater than 1 cm, incise, leaving a base attachment intact.
  5. Impression smears and needle aspirates of tumors are helpful in a few situations. However, actual biopsies are usually required for definitive diagnosis. Stain and examine smears and aspirates in your practice laboratory and, if a diagnosis is not obvious (i.e., mastocytoma, abscess, etc.), biopsy the mass and forward both the biopsy and the smears to the reference laboratory.

Serology Submission Guidelines

Please submit samples according to the following guidelines in order to expedite testing and shorten turn-around time.

  1. Provide 2 ml of serum per assay requested. Submit serum only. Never submit blood. Even if you use serum separation tubes, serum must be poured off into plastic snap cap tubes. A charge of $.25 per sample will be assessed for processing blood samples.
  2. Submit serum in plastic snap-cap tubes (Falcon 2054 or equivalent). Laboratory equipment is designed to fit these tubes - glass tubes are too large. Avoid leakage - be sure to double snap the caps on tubes!
  3. Number the tubes in consecutive order 1 through 'X' matching the tube number with the tube number on the serology submission form. Use permanent marker to identify tubes. Grease pencil marks are easily rubbed off and labels fall off during the heating process necessary for some assays.
  4. Place the tubes in consecutive numerical order in cardboard boxes designed to hold snap-cap tubes (e.g. brucellosis boxes). Do NOT submit in bags.
  5. Keep samples from each case or client separate. Save a portion of each serum sample in your freezer.
  6. Keep a copy of the paperwork for your files.
  7. Optimize the interpretation of test results by collecting acute and convalescent samples. Paired sera (acute and convalescent) should be submitted together. Alternatively, comparing serum antibody levels in affected vs. unaffected animals can assist in interpretation.
  8. Serology samples submitted to comply with EIA, Brucellosis, and PRV Disease Programs require special submission forms. To obtain forms for EIA and Brucellosis please contact USDA APHIS at 515-284-4140. For PRV forms, please contact the State Department of Ag & Land Stewardship at 515-281-5155.
  9. Because of the number of samples we receive, serum samples can only be saved for 2 weeks after testing. We will gladly return samples to you at your expense upon request.

Toxicology/Nutrition Submission Guidelines

The purpose of the diagnostic toxicology section is to provide consultation, suggestions, and interpretation regarding suspected toxicoses. This consultation includes information about specific samples or specimens useful in confirming diagnoses suspected by the attending clinician. To best accomplish this, a thorough interchange of information between clinician and diagnostician is important. A written or telephone history from the attending veterinarian is useful if the analyses are to be suggested by the toxicologist. A complete account of history (including management and feed type), clinical signs, and lesions submitted with specimens for laboratory evaluation is very important. Currently, the practice of diagnostic toxicology requires that specific analyses or chemical categories be selected. There is no practical or affordable way to check for all possible poisons. The more information provided, the more efficient and useful is the selection process.

The VDL offers services for nutritional monitoring through analysis of feeds, serum and liver for minerals and selected vitamins. Water quality analysis is also available. The VDL does not perform proximate analysis (TDN, protein, etc.) on feeds or forages.

Selecting specimens for toxicology and chemical evaluation requires three main criteria:

  1. The correct specimens must be provided.
  2. Adequate amounts must be available.
  3. Specimens must be properly preserved.

Choice and condition of specimens is extremely important when diagnostic support is required for a suspected toxicology case. The following are guidelines to increase the usefulness of toxicologic submissions.

  1. Specimens should be free of chemical contamination and debris. Contamination of samples with hair, vomitus, dust, dirt, etc., may contaminate the sample and produce erroneous results.
  2. Freeze animal and tissue specimens for chemical analysis and package them to arrive at the laboratory while still frozen. Do NOT freeze whole blood samples, but keep them refrigerated.
  3. Serum, if separated from the clot and not hemolyzed, may be frozen. In some cases, such as analysis for ammonia, this is essential.
  4. Always package specimens from various organs and fluids separately.
  5. Use clean glass or plastic containers that can be tightly sealed.
  6. Label each specimen (container) so it can be clearly identified.
  7. Never add preservative, such as formalin, unless there is a specific reason. If preservatives are added, include a sample of the preservative along with the specimen.
  8. Submit samples for chemical analysis of low level organic contaminants, such as pesticide residues or PCB's, in glass containers (line lids with foil), not plastic. Solid samples for this purpose may be wrapped in aluminum foil.
  9. If ammonia, urea, or cyanide toxicosis is suspected, freeze rumen contents and blood or serum immediately after collection. Keep them frozen.
  10. On all toxicology cases involving a dead animal, submit both fresh and fixed tissues.

Delivery of Specimens

Choose a method of transportation that will ensure timely delivery to the laboratory. We receive U.S. Mail and UPS deliveries Monday through Friday. Other commercial carriers deliver as needed. Upon request, shipping cartons will be returned at the submitter's expense.

To be sure that samples receive prompt and proper care, schedule their arrival during standard business hours. Always consider the potential impact of holidays and weekends on shipping schedules before sending packages by commercial carriers. Personal delivery by the owner is often appropriate. Download a map and directions to the VDL for your convenience.

After-hours emergency service

After-hours emergency service is available on weeknights, weekends, and during University holidays by calling our on-call student at 515-290-1969 who can assist and also provide access to diagnostic pathologists and toxicologists.

After-hours Submissions

Samples delivered to the ISU VDL after-hours can now be placed directly in a refrigerator located inside the VDL submission door foyer.

After entering the foyer, follow the procedure below for leaving samples in the refrigerator for submission:

  • Paperwork MUST accompany the submission. If you do not have paperwork completed, please do so with the forms provided and place the submission form with the samples.
  • Place the sample into the refrigerator.
  • Log your submission on the log sheet provided. Please fill out as much information as possible, so we can contact the submitting veterinarian if there are questions.
  • If you have questions, concerns or submission does not fit in the refrigerator, please contact the after-hours on-call student at 515-290-1969. 

Testing Schedule

Our goal is to provide accurate results and timely service.  However, some diagnostic assays are not performed daily and/or testing schedules may change.  If your case involves testing animals for export, testing show animals, testing animals to be sold, and/or testing a large number of samples, please contact the VDL (515-294-1950) prior to submission to verify the availability and turnaround time of specific assays.  A phone call will often shorten turnaround time by providing us time to prepare for testing prior to receipt of samples.

Biosecurity and Disease Control at the VDL

Admission of unauthorized persons to the post mortem room is prohibited.  Diseased animals with a multitude of infectious agents are handled on a daily basis by the laboratory and we wish to avoid transmission of disease to your clients' animals.  Diagnosticians will discuss case histories outside the post mortem area.

Reporting Results

All submissions received by the VDL are assigned an accession number (case number).  The referring veterinarian will receive an email or FAX listing the species received, the owner, the VDL accession number, and diagnostician(s) in charge of the case.  

Results are reported only to the referring veterinarian.  When calling to inquire about a case, please be prepared to provide the VDL accession number.  If requested, preliminary and/or final results may be FAXed to the referring veterinarian.  The charge for FAX reporting of results is $1 per fax.  Final reports are mailed to the referring veterinarian. 

The VDL laboratory information management system (ISULIMS) provides Internet access to laboratory results.  A user name and password may be obtained that will allow access to reports and to a running total of charges for each case as soon as each test is completed and approved.  This allows continuous access to diagnostic results, which can be printed for your files or saved as an Excel spreadsheet.  To sign up for this service, please call the lab at 515-294-1950.

Reportable and Quarantinable Diseases Policy

Several infectious or contagious diseases are considered reportable and/or quarantinable under current regulations.  As required by law, these diseases are reported to the responsible state or federal agencies.  If you are uncertain about the reporting status of a disease, please contact the office of the State Veterinarian.  Notifiable diseases include any livestock or poultry disease designated as a ‘Foreign Animal Disease’ by the United States Department of Agriculture, Animal and Plant Health Inspection Services, Veterinary Services (USDA, APHIS, VS) and also the following:

Bovine spongiform encephalopathy Rabies
Brucellosis Scabies (cattle or sheep)
Chronic Wasting Disease Scrapie
Encephalomyelitis (horses) Swine dysentery
Equine infectious anemia Trichomoniasis
Johne's disease Tuberculosis
Pseudorabies (any species) Vesicular stomatitis
  West Nile Virus
Avian influenza Newcastle disease
Infectious encephalomyelitis Paramyxovirus infection
Infectious laryngotracheitis Psittacosis – ornithosis


Consultation and Interpretation of Results

The VDL faculty and staff are available for assistance with sample and test selection, as well as to offer tips on preservation and transportation of specimens.  The VDL can assist in interpretation of results, but the final diagnosis and plan of action are the responsibility of the referring veterinarian.  Additional animal health expertise and information is available through Veterinary Medicine Extension (515-294-3837) and faculty in Food Supply Veterinary Medicine (515-294-3837).  Refer to Contact Information for additional information. 


See ISU VDL current fee schedule here.

The VDL is authorized to charge fees to users of laboratory services.  User fees support the wide range of diagnostic services offered and supplement state funding.  All fees are billed to the submitting veterinarian.  Please consult the printed fee schedule, the VDL website, or call the VDL for current charges. 

The submission form should be used to indicate specific tests or procedures requested by the referring veterinarian.  If multiple tests are requested and/or the diagnostician is instructed to use their own judgment in requesting tests, then an indication of monetary limitations should be provided by the referring veterinarian.  Requests for specialized or non-routine testing will be assessed on an individual basis in consultation between the referring veterinarian and the receiving diagnostician, and with the approval of the laboratory director.

Invoices and Payment of Fees

Along with the final report, you will receive an invoice showing the case charges.  At the end of the month, a statement is sent from the University Accounts Receivable Office showing each invoice number and the charge.  You are encouraged to keep the invoice received from our laboratory for cross-reference on the billing from Accounts Receivable.  Payment is due on the 15th of the month.  A 1.0% finance charge is added after 30 days.

VISA, MasterCard and Discover credit cards are now accepted as another form of payment.  These transactions can be made in person or by telephone during normal business hours. 

Returning of Bodies and Cosmetic Posting

No animal carcasses body parts or ashes will be returned/released to veterinarians or animal owners.  Arrangement for pickup by authorized crematory service is an option.  No cosmetic necropsies will be performed on animals/bodies submitted to the laboratory for necropsy/testing.

Please call the Laboratory Director with questions and additional details relating to these policies.

Return of Biological Agents to Submitter

Rapid changes in livestock production and disease management coupled with the fast pace of technology in medicine and diagnostics, have resulted in increased requests for the return of biological agents.  The VDL will return isolates either to the submitting veterinarian or to a third party laboratory, e.g., for use in the manufacture of immunizing agents.  Because of issues of safety, efficacy, and ownership, the VDL is required by the University to obtain a signed release form prior to providing agents to the submitter.  Release forms can be faxed to you and the VDL will accept a faxed, signed copy in return.  There is a fee for providing isolates (see the VDL fee schedule here ). Following a request for a virus isolate, 7-10 days is required to propagate sufficient virus for transfer.

If you anticipate multiple requests, we can issue a Memorandum of Understanding (MOU) that will cover all agents requested within a specified time period.  Then with each request you will receive a statement confirming transfer for the specific agent to which the transfer agreement will apply.  You can request it from the VDL.



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