Barbervax®, used under the prescription and supervision of a veterinarian, has the potential to improve the control of barber’s pole worm in goats in Australia.
In Australia, many goat owners have an ongoing problem with barber’s pole worm due to frequent rainfall and mild temperatures. Many are smallholders who cannot effectively “clean” pastures of worm larvae with grazing management practices.
Drench resistance is very common in goat herds, especially with barber’s pole worms, therefore drench-based control may have poor outcomes where drench resistance is severe. This is common where smallholders use older, single-active drenches that many worms are already resistant to and it accelerates further development of drench resistance.
Barbervax® is a vaccine against barber’s pole worm and is only registered for use in sheep in Australia, but it may be of use in goats. Therefore, the use of Barbervax® in goats is “off-label” and requires a veterinarian’s prescription prior to use.
In sheep, it has shown to be a long-term, easy to use, environmentally friendly solution that suppresses worm egg production and has no withholding period or export slaughter interval and there is no indication that resistance to the vaccine should develop.
Registration of Barbervax® in goats in Australia did not proceed because of poor results from one of the three registration trials, however poor condition of some participating goats may have been a factor (see the MLA report on Barbervax® Vaccine in Goats).
Preliminary overseas trials and off-label use in Australia indicate that the Barbervax® vaccine can be beneficial for goats, with results very similar to those recorded with sheep and lambs.
Because Australian registration trials had mixed results it is strongly recommended that the prescribing veterinarian oversees a monitoring program in association with vaccine use to assess the value of the product in each goat herd.
Ideally, evaluate the vaccine in a portion of a herd and monitor and compare treated and untreated animals.
A vaccination and monitoring schedule is provided below.
The vaccine is given to goats of any age as a series of subcutaneous injections of 1 ml, at no more than 6-week intervals when protection is required during the barber’s pole worm-risk season. Note that animals in very poor condition or ill-health may not develop the required level of immunity.
In the first season, the first two vaccinations do not provide protection, but they prime the goat’s immune system. Protection occurs about 10 days after the third vaccination, and lasts for up to 6 weeks.
The first 3 vaccinations are generally given 4 weeks apart and further vaccinations no more than 6 weeks apart while there is a barber’s pole worm risk, or more frequently (for instance, each 4 weeks) in those years and situations where animals are exposed to very heavy challenge from barber’s pole worm.
The initial 3 vaccinations can be given as fast as 2 weeks apart if priming and immunity needs to be achieved very rapidly, such as starting a herd on Barbervax® when the barber’s pole risk is already high. Likewise, they can also be given further apart if there is no hurry to develop the immunity, for example, if administered at convenient times during a low barber’s pole risk time of year (so that immunity is ready when the risk increases).
It is likely that, similar to sheep, once goats have received an initial course of vaccine in one barber’s pole worm season, a single booster injection in a subsequent season will typically provide protection from about 10 days post-vaccination for up to 6 weeks without the need for a second priming dose. Subsequent vaccinations are continued 6-weekly (or sooner) during the risk period.
Using small amounts of vaccine
The Barbervax vaccine comes in 250 ml and 100 ml packs. It includes a standard statement to use the contents within 12 hours of broaching the pack. However, veterinarians may need to dispense small amounts. The best approach is to use an aseptic technique and divide the entire contents of the pack into sterile syringes (sizes to suit clients) at the same time, keeping them refrigerated—not frozen—until use, but no longer than the pack expiry date.
Start the Monitoring schedule and the Vaccination schedule at the same time.
First season of use
Subsequent seasons of use (for animals that have received priming doses in a previous year)
Pour-on products can be less effective and their use overseas has led to widespread resistance. Similarly, long-acting injections should be avoided as they increase the likelihood of drench resistance developing. Always use an effective, short-acting, multi-active drench. This will help to slow the development of drench resistance. The more actives, the better. Rotating drenches does little to slow drench resistance.
It is better to continually use a combination of 4 actives, where most of the individual actives are fully or highly effective in their own right, than to rotate between less effective or single-active products. However, drench resistance is widespread. Do not assume that 3- or 4-way multi-active commercial products are 100% effective on all properties; do a DrenchCheck to be sure.
You will need to use more than one drench concurrently (not mixed together) to achieve the desired combination effect, as ready-made combination drenches do not have enough required actives for this purpose.
Use at least 4 of these actives with either or both derquantel and monepantel as mandatory inclusions:
BZ drenches (if not in a combination): 2 x sheep dose rate.
All others, including commercial combination products: 1.5 x sheep dose rate.
It is recommended that all drenches be used off-label, even those registered for use in goats, because all should be administered at dose rates higher than shown on the label. As such, they all require a veterinary prescription.
Each veterinarian should consider their decision about the withholding period based on:
Startect® and Zolvix Plus® (but not Zolvix®) also contain abamectin. To avoid toxicity from overdosing, do not use them with another drench that also contains abamectin, moxidectin or ivermectin, e.g. Q Drench®, most triple actives, and single-active ML products.
The organophosphate active, Naphthalophos, is not recommended in smallholder flocks due to the risk of fatality from drenching into the trachea.
Barbervax® does not stimulate immunity to scour worms, which can build up over time during a Barbervax® program. When monitoring indicates a scour worm treatment, ensure the drench combination contains at least 1, but preferably 2, of the following actives: monepantel, derquantel or an ML.
Closantel is not active against scour worms and there is widespread resistance of scour worms to BZ and levamisole.
Examples of drenches that could be used concurrently for barber’s pole worm control
Startect®, Zolvix® and Zolvix Plus® degrade some plastics and syringes. Veterinarians should ensure they are dispensed in an appropriate container. A copy of the original labels should also be provided with all drenches dispensed.
Proprietary names have been used above where they are the only commercially available product for that active/s.
The other actives are available in a number of commercial single and multi-active formulations.
Many product labels state that the drench must not be used on animals whose milk may be used for human consumption. A veterinarian’s prescription cannot override a “DO NOT USE” statement on the label. Labels must therefore be read very carefully. Some BZs and Caprimec® and Virbamec Oral® are registered for use on dairy goats and have a milk withholding period. In addition, Copper Oxide Wire Particle (COWP) boluses can be used in goats to treat barber’s pole worms and, if combined with a drench, can improve the efficacy of drenches where some resistance may be present. These are already registered for use in goats for preventing copper deficiency and have a nil withholding period.