- Print Friendly - Help

AgVetLink June 2004: Page 4

Previous page  | Contents |  Next page

---

REVIEWS

Long-acting dexamethasone esters

The long-acting dexamethasone esters have been reassessed under section 29 of the ACVM Act with specific emphasis on the following:

• Residues
  There is concern that the currently approved milk withholding period does not adequately manage the residue risk for some long-acting dexamethasone esters.

• Target Animal Welfare
  The risk to welfare of animals (determined by an assessment of whether the use of the compound could produce demonstrable evidence of unnecessary pain or distress) resulting from treatment has been considered. The welfare issues have been considered in three components:
  1. the welfare of the calf resulting from the birth induced by long-acting corticosteroids;
  2. acute anaphylactic reactions;
  3. other associated negative consequences including acute infections, retained foetal membranes, photosensitization, metabolic disease and immunosuppression.

As a result of this review the following actions were advised as being under consideration:

• a revised meat withholding period of 35 days and milk withholding of 12 days;

• removal of claims on labels relating to non-therapeutic or routine induction of calving in dairy cattle. The proposal is to require the necessary label changes by February 2005.

Impact on animals

The impact of the use of these drugs on the cow and the resulting premature calf is considered to be unnecessary pain and distress. Where there is no resulting benefit to the welfare of treated animals, the likely negative impact on animal welfare is not considered warranted under the ACVM Act.

Some uses unaffected

The following existing therapeutic indications for induction of calving remain unaffected:

1. where dystocia is anticipated either in heifers too small to calve safely or cows with a known dystocia risk due to pelvic fractures or injuries;

2. induction in animals with ‘dropsy’ e.g. hydroallantois;

3. induction in ‘downer cows’ and cows showing a degree of paralysis prior to calving.

Other potential uses of corticosteroids in other species as well as cattle will also be unaffected by this review. These include the following indications:

1. treatment of primary ketosis;

2. orthopaedic conditions including arthritis, tenosynovitis, bursitis;

3. shock, stress;

4. allergic conditions;

5. acute laminitis.

Alternative risk management

This review does not specifically prohibit the use of these drugs in routine inductions. As a result, even if the label claim is removed, there is still the ability for alternative forms of risk management other than that already provided for by PAR conditions and the label. The possibility remains for product registration conditions to allow for an ACVM-approved code of practice and standard operating procedures providing for more intensive management of the induction process. Such a proposal can still be considered not only for the management of animal welfare but also to allow for the degree of control required to reduce the milk withholding period.

Following concerns expressed as to the practicality of meeting the proposed deadlines, particularly for withholding periods, AVMAC has set up a subgroup (led by Fonterra) to resolve the issues.

 

AVMAC

Now that the ACVM Act has been operational for some time, a review of the Agricultural Compounds and Veterinary Medicines Advisory Council (AVMAC) has been undertaken to examine this advisory body and see if it could be used more effectively. Questions being asked include:

• Is AVMAC the right body to take on some of the regulatory functions in the ACVM Act?

• Could it play a larger role in areas such as Technical Consultative Committees and the Antibiotic Steering Group?

 

Antibiotic Resistance Monitoring

The Antibiotic Resistance Advisory Group of the Ministry of Health is considering the requirements for monitoring of antibiotic resistance in food animals. The group concluded that monitoring is required to describe the current situation as well as to establish trends. There is a proposal to develop a preliminary study in a limited range of bacteria, which are considered to be a priority. The likelihood is that monitoring will initially focus on samples collected at slaughter rather than at the retail end of the supply chain.