Caprine retrovirus control scheme

Version: 8 Amended 18 August 2006 - Schedule of fees effective from 1 July 2006

Appendices

Flow chart
Scheme Application form
Property Inspection Report form
Recommendation of Veterinary Practitioner form
CRV Schedule of Fees

Caprine retrovirus control scheme protocol

1. Introduction

Caprine retrovirus (CRV) formerly known as caprine arthritis encephalitis (CAE) and "Big Knee", is a serious disease of goats which affects production and can limit export markets. Interstate and local buyers also want evidence of freedom from CRV.

A survey of Queensland goats showed there was a higher level of infection in dairy goats than in meat or fibre goats.

On 1 July 1987, DPI&F commenced a voluntary, user pays CRV control scheme. A register of CRV certified herds is kept by the DPI&F and is available to intending buyers or exporters of goats.

Agricultural shows in Queensland will only permit dairy goats from certified herds to enter.

2. The disease

2.1 Clinical signs

CRV occurs only in goats. It causes arthritis, encephalitis and pneumonia.

Arthritis occurs in mature goats, mainly involving the knees, but sometimes other joints. The joints become enlarged and painful (hence the name of the disease "Big Knee"). The condition is chronic and steadily gets worse. Affected goats become lame, have a rough coat and gradually lose weight.

Encephalitis affects young kids 2 weeks to 5 months old. It shows as lameness, incoordination, progressive paralysis and finally death. This form of the disease has only rarely been seen in Queensland.

Pneumonia is seen in some infected goats, mainly adults. These show respiratory distress and loss of weight, and progressively become worse.

There is no response to antibiotics, with any of these forms of CRV.

2.2 Transmission of infection

The main method of spread is from doe to kid via the milk or colostrum, so that kids are infected after birth.

Some spread of infection occurs by contact between adults especially in intensively managed herds, such as occurs with dairy goats. The disease is less common under extensive grazing conditions, such as may occur with meat, fibre and feral goats.

3. Supervision of scheme

3.1 (i) The Scheme is supervised by the Chief Veterinary Officer, Queensland Department of Primary Industries and Fisheries.

(ii) The Department of Primary Industries and Fisheries will maintain overall supervision of the scheme and reserves the right to reassess the Scheme and individual properties at all times.

(iii) The Chief Veterinary Officer will prepare and issue Certificates of Control to goat herd owners and maintain a public register.

3.2 A Veterinary Practitioner is to supervise and conduct the 'on property' activities for the Scheme.

4. Entry to the scheme

To participate in the Scheme, an owner must:

(i) Have, or apply for a DPI&F registered property identification code (PIC) also known as a property number or tail tag number prior to blood sampling.

(ii) Submit a completed application form and property inspection report.

(iii) Undertake the prescribed testing and management requirements.

(iv) Continue to adhere to these conditions.

5. Management and husbandry

5.1 All goats over 6 months of age are to be permanently and individually identified.

5.2 All goats must be permanently and securely contained within the borders of the property at all times. There must be no contact with uncertified goats on neighbouring holdings. Isolation areas are essential for:

(i) segregation of animals which give a positive or suspect reaction to the test and

(ii) for uncertified goats undergoing testing prior to introduction to the main herd.

Two separate isolation areas are needed if both situations arise at the same time.

5.3 Isolation areas must have secure fencing with adequate separation between paddocks. The following are acceptable:

(i) Double permanent fixed wire fencing no less than 1.2m (4ft) high with posts no less than 1.8m (6ft) apart. The two lines of fencing to be no less than 1.8m (6ft) apart.

(ii) Two lines of electric fencing with no less than four strands of active electric tape in each row of fencing with posts no less than 1.8m (6ft) apart.

(iii) A single solid wall of no less than 1.2m (4ft) high constructed of corrugated iron or solid timber palings.

Gateways should be such as to prohibit any access to and from the segregated herd by kids under the gate, or by squeezing through between the gate post and the gate.

6. Certification procedures

6.1 The Veterinary Practitioner will

(i) personally inspect the property and record information on:

(a) property management;

(b) adequacy and condition of facilities, including fencing for the purposes of containment, segregation and isolation of goats;

(d) property plan.

This information is to be sent on the prescribed form to the local DPI&F Veterinary Officer, no later than the first whole herd test.

(ii) collect blood samples (10ml of clotted blood or serum) and, where necessary, collect other samples and submit such samples to a DPI&F Veterinary Laboratory. The property identification code (PIC) should be obtained from the owner and entered on the specimen advice sheet.

There is no differentiation between commercial herds and stud goat herds located on the one property (ie. all goats on the property must be tested).

6.2 The blood samples are to be subjected to serological tests for Caprine Retrovirus in such manner and at such time as may be prescribed by the Chief Veterinary Officer.

Animals classified as infected following serological testing, together with any kids raised on their milk, must be isolated immediately and destroyed or sold for slaughter within 30 days This will eliminate potential sources of infection for other herds. No compensation is payable for these slaughtered animals.

Goats classified by the testing laboratory as having an inconclusive result must be isolated and retested in 30 days to clarify their status.

If there is a positive test result for an individual goat in a previously negative herd and there is no history that would indicate a source of infection, then this may be classified as an inconclusive result at the discretion of the local DPI&F Veterinary Officer. This animal should be retested in 30 days.

6.3 If the first herd test is negative, then one further negative herd test, 6 - 12 months later, is required.

If there is a history of CRV infection on the property or if the first herd test includes positive animals, then herd tests at 3 months interval are required until two consecutive clear tests are achieved and these must be followed by another negative herd test 6 - 12 months later.

6.4 If the initial herd test shows there are a large number of positive animals or there are valuable stud stock which are positive, then the owner may be unwilling to have them slaughtered within 30 days. In these cases the owner may wish to run a two herd system (infected and non-infected herds) and in some cases use snatch-birthing to obtain progeny from infected does. In these situations, the herd will not be considered to be part of the CRV Control Scheme. Advice should be obtained from the owners' veterinary practitioner for a suitable program. When all infected goats have been slaughtered, the owner may rejoin the Scheme.

A herd will not be certified while another infected herd is run on the same property or while it is in close contact with an infected herd.

6.5 When satisfied that the herd has met the requirements of the Scheme, the practitioner is to forward his/her recommendation for certification on the prescribed form to the local DPI&F Veterinary Officer.

6.6 The initial Certificate of Control may be issued by the Chief Veterinary Officer when the herd meets the requirements of the Scheme.

6.7 In the case where the Veterinary Practitioner presents a history of previous whole herd testing, herd management and herd segregation on another property which is considered satisfactory by the local DPI&F Veterinary Officer, the certificate may be granted after one further whole herd negative test. Full details should be provided in writing to the local DPI&F Veterinary Officer.

6.8 If all goats in a herd are purchased from certified herds, then the initial Certificate of Control may be issued without further testing. The retest date and the testing interval will be determined after consideration has been given to the herds of origin. Full details should be provided in writing to the local DPI&F Veterinary Officer.

6.9 If goats are purchased interstate, a full CRV testing history of the herd (or herds) of origin should be obtained in writing. Unless the status of the herd of origin is equivalent to a Queensland certified herd, these goats should be regarded as coming from a non-certified herd and tested accordingly. The full testing history of the herd of origin should be provided in writing to the local DPI&F Veterinary Officer.

7. Re-certification procedures

7.1 For herd re-certification all goats over 6 months of age must be retested annually by a veterinary practitioner with negative results.

7.2 Consideration will be given to biennial certification after an initial 3 year period, at the discretion of the Chief Veterinary Officer.

7.3 For herds with more than 100 goats over 6 months of age, a statistical sample of goats only need be tested sufficient to detect a 2% prevalence of infection with 99% confidence. All bucks must be included in the sample. Owners of these herds should contact their local DPI&F Veterinary Officer to determine the numbers to be tested.

7.4 The veterinary practitioner should submit a recommendation for re-certification on the prescribed form to the local DPI&F Veterinary Officer.

7.5 If there is a positive test result in a previously certified herd and there is no history that would indicate a source of infection, the, with the approval of the local DPI&F Veterinary Officer, the positive animal(s) may be retested in 30 days.

7.6
(i) Following a re-certification test and any approved retesting of positive animals, if there is a single animal classed as infected, the certified status will be lost. Two negative herd tests are required to regain certification, the first at 3 months and the second at 6-12 months interval.

(ii) If there are 2 or more positive animals classed as infected at a re-certification test, then 3 tests are required to regain certification, the first two at 3 months interval and the third at 6-12 months interval.

8. Costs of scheme

8.1 The Veterinary Practitioner will negotiate fees for service with the owner. The Veterinary Practitioner will be responsible for payment for serological testing.

8.2 Owners will be responsible for payment of the certification and re-certification fee to the Department of Primary Industries and Fisheries These fees will be periodically revised to reflect increased costs. Fees are not payable until testing conditions have been met.

9. Movement of goats and breeding material (semen & ova) to and between goat herds

9.1 Goats introduced directly from herds with a current Certificate of Control require no testing.

9.2 Where a goat from a non-certified herd is introduced it must be isolated until it has been tested twice in isolation with negative results, at a 6 monthly interval.

Goats introduced when under 6 months old must not be tested until 6 months old and they must be kept isolated prior to as well as during the testing period.

9.3 Goats purchased interstate - see Section 6.9.

9.4 Semen from any buck may be used for artificial insemination provided the buck is tested for Caprine Retrovirus with negative results within 30 days prior to semen collection and it shows no clinical signs of Caprine Retrovirus. However it is recommended that the buck comes from a certified herd or an AI centre at which all the resident bucks are tested twice prior to entry and at least annually for Caprine Retrovirus with negative results.

9.5 Embryos may be introduced from donor does which originate from a certified herd or which have been subjected to two negative serological tests at a 6 monthly interval while in isolation, prior to collection.

9.6 Does from a certified herd may be mated naturally only by bucks derived from a certified herd or bucks from a non-certified herd which have had two negative serological tests 6 months apart while in isolation.

9.7 Goats from herds with a Certificate of Control may be returned to their home property after showing or sale if the particular event is run as:

a) a certified show or sale

or b) all stock present at such shows or sales are either from certified herds or have been subjected to two serological tests at 6 monthly intervals with negative results while in isolation

or c) where the period of absence was not more than 48 hours (except for Royal Shows where the absence may be up to 10 days) and the goats have had no contact with other non-certified goats either directly or indirectly and did not share feed or water containers with non-certified goats. Goats must also be kept isolated from non-certified goats during transport to and from the fixture.

Goats returning from events which do not comply with the above conditions will be placed in isolation and treated as for introductions from non-certified herds.

10. Notification of suspected caprine retrovirus infection

The Veterinary Practitioner or the owner must advise the local DPI&F Veterinary Officer of any suspicion that Caprine Retrovirus infection is occurring in the herd.

11. Cancellation of certificate of control

The Certificate of Control will be cancelled where any of the following occur:

(a) If positive or infected animals are found at any test.

b) If there is no report of whole herd tests within thirteen (13) months of the last test (or 25 months if biennial certification is granted).

(c) If animals have been introduced to the property or returned from show or sale without testing or certification or approval from the local DPI&F Veterinary Officer.

(d) If the Veterinary Practitioner is unable to provide a recommendation for re-certification or provides a report that the conditions of the Certificate of Control have been breached.

12. Summary of paper flow

1. On entering the scheme

owner must have, or apply for a DPI&F registered property identification code (PIC) prior to blood sampling.
owner's application form and veterinarian's property report plus property plan to be sent to local DPI&F Veterinary Officer.

2. When herd is eligible for certification

veterinarian sends recommendation form plus summary of test results plus owner's cheque to local DPI&F Veterinary Officer.

3. When herd is eligible for re-certification

veterinarian sends recommendation form plus latest test result plus owner's cheque to local DPI&F Veterinary Officer.

Note: Documents should be held by the local DPI&F Veterinary Officer. When testing and other procedures have been completed, the Recommendation of Veterinary Practitioner plus supporting papers should be sent by the local DPI&F Veterinary Officer to the CRV Coordinator who will issue Certificates of Control on behalf of the Chief Veterinary Officer.

Appendix A