Farm animal Antimicrobial Selection Principles

Question 1

What do you need to remember about the use of Farm Animal Antimicrobial Selection?

Answer 1

Maximum Residue limit which is the maximum concentration of a residue allowed in an animal food product in the EU.

Also Withdrawal periods

Question 2

What are withdrawal periods if a product if used under the prescribing cascade?

Answer 2

 Eggs = 7 days

 Milk = 7 days

 Meat = 28 days

 Fish meat = 500 degree days

Question 3

(Bit off topic…) but what do you do if you wish to treat a horse with a medicine which does not have an MRL but are considered essential for the treatment of equidae

Answer 3

Horses are considered food-producing animals by EU legislation
minimum withdrawal period of 6 months

Or

“signed off” from the food chain by declaring them unfit for human consumption by completing Section IX of the passport then Non food producing animals prescribing cascade applies

Question 4

Revision: If no authorised product exists for a condition in a non-food producing animal …..

Answer 4

Prescribing cascade for non food producing animal:
1. Veterinary medicine authorised for use in another species for that condition, OR Medicine used for a different condition in the same species.

2. Medicine authorised in the UK for human use OR

Medicine authorised in animals in another EU member state.

3. Medicine made up at the time on a one-off basis by a veterinary surgeon or a properly authorised person (pharmacist).

Question 5

If no authorised product exists for a condition in a food producing animal …..

Answer 5

The cascade is similar to NFPA with additional conditions.

1. If a medicine is imported from an EU member state, it must be authorised for use in a food-producing species in that country.
2. The active substance must be listed in Table 1 in the annex to EU regulation No 37/2010
3. The vet must specify an appropriate withdrawal period to farmer
4. The vet must keep appropriate records of what has been given

Question 6

What is the updated cascade?

Answer 6

• Allows for changes in susceptibility. You can cascade to a diff product if found resistance or suspect resistance

Question 7

• Responsible antibiotic use under the cascade requires vets to take into consideration not only the most appropriate active substance(s) but also;

Answer 7

– the most appropriate formulation
– the posology (dosage)
– the current pattern of resistance in their locality
– an awareness of how to reduce selection pressure, and
– related factors eg good biosecurity and husbandry/hygiene, avoiding surgical sepsis etc
– If a vet can demonstrate that these steps have been taken, then cascade use of antibiotics is supported

Question 8

Roughly how have sales of antibiotics in Farm animals changes?

Include the main antiboitics used these days

Answer 8

Total sales have reduced 49% since 2014.
Reductions in 3rd and 4th generation cephalosporins, quinolones, polymyxins.
Big reductions in markets such as game birds (25%), salmon (60%), trout (32%).
Slight increase in Dairy use (9%) (since 2017).
Main reduction is in pig and poultry,
SA not much change
HUGE reductions in Highest Priority Critically Important Antibiotics (HP-CIA) to point where some may be withdrawn by sale!
Main antibiotics used nowadays = beta – lactams, tetracyclines and sulphonamides

Question 9

How have RoA changed in farm animal antibiotic use?

Answer 9

not in feed anymore. More vaccine, pre, pro biotics, good cleanliness,
Also oral and liquid use.
Injectables going up – individual pens/ pigs more common rather than whole shed
Tablets mainly SA
Intramammary – fluctuates
Sales of antibiotics look like they’re starting to level off

Question 10

Case of calves with pneumonia, once treated those affected what should you be thinking…..

Answer 10

Culture and sensitivity

What is the risk factor?High stocking density
soooo
reduce stocking density

Question 11

What is RUMA?

Answer 11

• Responsible use of medicines in agriculture including vets, supermarkets etc.

Question 12

How are antimicrobials categorised?

Answer 12

by the AntiMicrobial Expert Group (AMEG)

Category A = AVOID = not licensde for animals any more

Cat B = Restrict

Cat C = Caution however some diseases can only be treated with these = have to go in straight away.

Cat D = Prudence and should be your first line

Question 13

What are Critically Important Antibiotics

Answer 13

3rd and 4th generation cephalosporins and fluoroquinolones

Question 14

A few things tesco have done to improve their milk supply antibiotic policy

Answer 14

• If Critically Important Antibiotics (CIAs) (3rd and 4th generation cephalosporins and fluoroquinolones) are to be kept on farm they must be stored separately box within the medicine cabinet and clearly marked “Seek Veterinary advice before use” – to try improve the use.
• Culture and sensitivity (To use CIA only in farm supply in TESCO) data will be required to justify ongoing use of all CIA on TSDG farms.

Question 15

What have ARla done to improve Ab use

Answer 15

have to do dry cow therapy- only animals with likelihood off infection in udder – Antibiotics. Those without that just need protection = just sealant

Question 16

How have red tractor tried to improve use of Ab?

Answer 16

Vet has to review use of antibiotics on a farm every year

Requirement of culture and sensitivity to justify use of of CIA

Question 17

e.gs where ab required

Answer 17

• Peracute mastitis
• Endometritis
• Pneumonia treatment, prophylaxis and metaphylaxis.
• Calf scour