Information about ADV Testing

 

United Vaccines, Inc.
Guidelines for Eradication/Reduction Of Aleutian disease using the CEP Test.

Compiled by: Dr. G. R. Hartsough
Dr. Herbert Kammer (1990 Edition)

PURPOSE OF GUIDELINES:

These guidelines are intended as an aid to mink ranchers in establishing a testing program to eradicate or reduced Aleutian disease using the counterelectrophoresis (CEP) laboratory test. No one program will fit the circumstances on every ranch; therefore, ranchers should use these guidelines in conjunction with a knowledgeable epidemiologist or veterinarian familiar with their ranch to establish their specific testing program. Eradication requires a commitment to multiple tests for several years and annual spot-checking to prevent reinfection. These guidelines apply to small and large ranches.

Factors to consider before starting a CEP testing program:

• What is the existing percentage of infected mink on the ranch?

• How virulent is the virus (are mink actually lost to AD)?

• What are the mortality rates at various times of the year?

• What color phases of mink are raised (some have been found to be more susceptible to AD)?

• What are the current costs of testing?

• What strain(s) of AD exists on the ranch?

• Will all positive animals be pelted?

 

AD ERADICATION CAN IMPROVE

• PRODUCTION: Reduce aborted litters, increase percentage of whelp and increase kit average.

• LIVABILITY: Reduce stillborn kits, early kit losses and losses during stress periods

• GENERAL HEALTH: Reduce noticeable weight loss, susceptibility to bacterial infections and possible interference with vaccinations.

• AUCTION RESULTS: Reduce percentage of low-grade pelts, discoloration of pelts and increase numbers.

• INCOME: Breeding stock sales.

 

WHAT IS A CEP TEST?

Counterelectrophoresis (CEP) is a laboratory test for the detection of antibodies in the blood of mink. All AD infected mink eventually develop antibodies in their blood that can be detected with a CEP test. This was not possible with the iodine test (IAT). At present, the CEP test is the most practical mass screening method available for the identification of AD infected mink.

 

GETTING STARTED

When is CEP testing the most effective? Using these guidelines you can start at any season of the year.

• Prior to separation (July):
  Prior to separation, test all females with four or more kits. Negative females and their litters should be segregated from all other positive or untested females with litters.

• Grading time (November):
  Pick 10% of the males and females randomly from each color phase: then test them to determine their percentage of infection. Test all potential breeders (males and females) just after grading.

• Prior to breeding (February):
  Test all potential breeders (males and females) as close to breeding as is practical.

• When mink are purchased (anytime):
  Test once before they are brought to the farm and buy only negatives. House them at least 30 feet from your own mink and test them again at least 30 days after purchase.

 

DEFINITION OF A NEGATIVE RANCH:

A ranch that has no CEP positive reactors for three tests of all breeder animals during a twelve month period.

First Year:

JULY (before kit separation)

• Potential breeders: Test females that you would consider keeping for breeders.Segregate all negative mink as far as possible from positive and untested mink.

• NOTE: The entire litter is scored either positive or negative on the basis of the results of the female.

• Pens that contained positive animals should be cleaned and disinfected before negative mink are placed in them.

OCTOBER OR EARLY NOVEMBER (Pregrading test)

• Young females: Select and bleed 100 kit females or 10% sample at random from each color phase, making sure the kits are not sisters. Kits from the same litter will most likely have the same AD status.

• Old females: Randomly select and bleed 100 old females or a 10% sample from each color phase.

OCTOBER & NOVEMBER (Grading Period)

• Now is the time to evaluate the CEP results from the October or November pregrading test:

• Less than 35% Positive: When grading, save enough extra mink based on the results from your previous testing. After grading, test all potential breeders and save only negative animals, keeping additional mink to allow for elimination of all positives on the February test.

• Greater than 35% Positive: At some point near or above this percentage of infection, CEP testing may be an ineffective approach to the problem. If the strain of virus can be identified, then additional decisions can be made. It may be necessary to pelt out and restock the ranch. This is a decision that should be thoroughly considered.

FEBRUARY

• Ranch with CEP Negative Breeders only: If all mink were negative on the previous CEP test, test all mink and pelt any new positives.

• Ranch with both CEP Negative and Positive Breeders: Retest all mink that were negative on the previous test and remove any new positives.

• Ranch that has not been tested: Early February, sample 20% of approximately 100 mink (whichever is fewer) from each color phase. If positives are found, test all males and females prior to breeding. Segregate or pelt positives and disinfect pens of positive mink.

NOTES:If you find FEWER THAN 10% CEP POSITIVE, pelt all positive mink. If you find GREATER THAN 10% CEP POSITIVE, take out all the negative females and males and place them in separate sheds segregated from positive mink. Be sure that their pens have been cleaned and disinfected prior to moving clean mink in.

 

SECOND YEAR

JULY

• Follow the first year program.

OCTOBER or EARLY NOVEMBER:

• Ranch with only CEP Negative breeders as determined by the previous test: Test all graded potential breeders and eliminate any positives.

• Ranch with CEP Negative and Positive breeders as determined by a previous test: Test all graded kits from negative females. Pelt all CEP positives when possible. If necessary, additional breeders may be found by testing kits from CEP positive females and keeping only the negatives.

FEBRUARY

• Ranch with only CEP negative breeders as determined by previous test: Test all negative breeders and remove any positives.

• Ranch with CEP positive and negative breeders: Test all negative breeders and remove any positives.

 

CONCLUSIONS

Disease control or eradication is rarely easy and can be expensive. The time required to eliminate or reduce AD depends largely on two factors:

TESTING FREQUENCY

Ranches where the goal is eradication and positives and exist should consider three cycles of testing scheduled during the first 12 months, followed by at least two tests per year over an 18 month period, a ranch may be presumed to be AD free. Negative herds should be monitored by CEP testing every year. Monitoring may be to test all males prior to breeding, all barren females in late spring or summer, and any sick mink during the year.

MANAGEMENT PRACTICES

• Purchasing Animals: Before new breeding animals are purchased, they should be CEP tested negative within the last month before bringing them to your ranch. They should also be segregated and retested at least 30 days after the last test. Using them for breeding before these two tests are negative puts your other animals at risk to infection. This same testing procedure applies to "borrowed" males during breeding time.

• Cleaning Facilities: All pens which have held AD positive mink should be thoroughly cleaned and disinfected. (Example: Cleaning – low pressure, hot water; Disinfecting – 2% lye solution for pens and ground, 10% laundry bleach for nest boxes). Try to remove manure during periods of minimum wind and low animal populations. Follow label direction to get the full benefit of any disinfectant.

• Positioning Animals: When there are both negative and positive mink on the ranch, they should be kept in separate sheds with the negative mink upwind, if possible. Farms with trough watering systems should place positive mink in the far (low) end of the shed.

• Working with Animals: All work on segregated farms should be done with negative mink first (Example: feeding, vaccinating, grading or separating kits). Separate equipment (gloves, nets, etc.) should be used in two sections of the farm. Fostering kits from positive females to negative females can spread the virus. Escaped mink that get to the ground on AD infected farms should be considered as positives.

---

United Vaccines, Inc.
P. O. Box 44220,
Madison, WI 53744-4220, USA

Counterelectrophoresis (CEP) testing

For Aleutian Disease in Ferrets

INTRODUCTION

United Vaccines, Inc. has been CEP testing mustelid serum samples for Aleutian disease (AD) antibodies for twenty years, performing hundreds of thousands of tests annually. Over the years, ferret, mink, raccoon and skunk samples have tested positive for ADV antibodies. The virus causes pathology follwed by terminal disease in mink, and in some cases, ferrets. It has been reported that a ferret strain of AD virus is more likely to show clinical symptoms in ferrets than mink strains. At least five strains of the mink virus have been identified using PCR. To our knowledge, ferret strains have not been identified using this same technology.

COLLECTION AND SUBMISSION OF BLOOD SAMPLES

Collection:
Collect sufficient blood to fill a heparinized capillary tube. Plug one end. Identify each sample in the shipment. Whole blood or serum samples in Vacutainer tubes are also acceptable. 10 Micro liters or more is sufficient.

Shipment:
Package samples so that they are not crushed in shipment. We recommend UPS Next Day service from most areas, but other overnight services are acceptable.

Send the samples to the following address:

United Vaccines, Inc
ATTN: Customer Service
2826 Latham Drive
Madison, WI 53713

Be sure to include your clinic name, address, phone and fax number in the package as well as the name of a contact person.

Payment:
Enclose with each shipment a check or credit card information (cardholder name, card number and expiration date) for a current Master Card or VISA only. The charge for the first sample in each shipment is $10.50; each additional sample is $8.50

Scheduling:
Prior to shipping your samples, call Customer Service (1-800-283-6465) to schedule the testing with the laboratory.

Results:
Normally, results are available within 24 hours after receipt of the sample(s). You can call for the results, wait for them in the mail, or if you request it in the shipment, we can fax you the results (fax number, please).

Collecting Blood Samples:

• Clip the toenail above the vein line (pink area of the toenail). It is a good idea to use disinfectant between ferrets. Wipe the clippers on a clean cloth after disinfecting.

• Fill each capillary tube ¾ full by holding it in the drop of blood from toenail at a slight downward angle.

• Plug one end of the tube with sealing clay to a depth of ¼ inch.

• Lay the tubes onto the grooves on top of the cardboard as illustrated.

• Write the animal ID number or name of each sample on the white tape using a black or blue permanent ink pen.

• Roll cardboard into tight roll and secure with a rubber band.

• Refrigerate samples until day of shipment. Do not keep samples more than 3 days prior to shipping,

Shipping Samples:

• Pack samples in a small box with newspaper, no ice is required.

• Send samples via Next Day service (UPS, Federal Express, etc.).

Send to:

United Vaccines, Inc.
Customer Service Dept.
2826 Latham Drive
Madison, WI 53713

Receiving Results:

Results are usually available in 48 hours after receipt of the samples. United will fax or call results to you or you may call 1-800-283-6465 three working days after shipment.

United keeps a copy of all CEP test results on file for 1 year in the event the results are lost.

The following symbols could appear on your test:

• + The sample is positive (ferret has been exposed to AD)

• NT A sample was received, but no conclusive test results were obtained from the sample. Submit another sample.

• E The sample was broken during centrifuging. Submit another sample.

• NS No sample was received.