The importance of a good quarantine procedure is important from two perspectives – to safeguard your investment and also reduce the risk of introducing costly diseases on to your farm. There are very few farms who can operate a 100% closed flock policy with rams purchased periodically.

The extent of the quarantine protocol will depend on the farm’s current health programme, the information known about the sheep being purchased and the potential risk factors identified. There are a number of common variables that should be considered.

Timing of purchase

Before getting into the disease risks, it is worth highlighting that when it comes to a quarantine protocol, the longer newly purchased animals can be kept away from animals currently on the farm the better.

As a general rule, animals should be quarantined for a minimum of 21 days and preferably 28 days before joining the rest of the flock.

On arrival to a farm, sheep should be housed or held in a yard for a period of 24 to 48 hours until the initial health treatments are administered.

For ram lambs, ewe hoggets or ewe lambs that require preferential treatment before the start of the breeding season, this is especially important.

Ram lambs that are transitioning from an intensive cereal or forage-crop-based diet will need a period of a few weeks to acclimatise to their new environment.

Anthelmintic resistance

Despite efforts to increase awareness the incidence of anthelmintic resistance continues to grow across all livestock enterprises.

It has long been known that there are issues with benzimidazoles or white drenches, but more farmers are now worryingly identifying resistance avermectin- and levamisole-based products.

The latest advice is to treat sheep with a moxidectin-based product and a new-generation wormer on arrival to the farm.

Startect is still not available to farmers, so Zolvix is the only available option in this regard.

Zolvix is a prescription-only medicine and as many veterinarians do not stock it as standard, it is important to order it well in advance of when it will be required.

Where there is no chance of implementing this option, then the next best option for most farms is treating purchased sheep with a moxidectin-based product and a levamisole-based wormer.

Sheep should be treated on arrival and kept off pasture for 24 to 48 hours, so that worm eggs present in the gut will not pass on to pasture.

Following treatment, sheep should be turned out to pasture that is referred to as dirty; that is ground that has been previously grazed by sheep.

Liver fluke

The risk of liver fluke will be influenced by the ground on which sheep were grazing prior to purchase and the time of year. Where the health status cannot be identified, then animals should be treated as potentially posing a liver fluke risk.

The current advice is to use a product containing trichlabendazole and another product with an active ingredient, such as closantel, to safeguard against liver fluke resistance to trichlabendazole.

External parasites

When it comes to external parasites, then dipping is the optimum method for controlling external parasite risks, such as sheep scab, lice, ticks, etc.

For complete control, sheep should be immersed for 60 seconds, with their head plunged under the solution two to three times.

There is no one product outside of dipping that will control external parasites.

There are injectable products that will treat sheep scab, while certain pour-ons will provide cover for lice, ticks, etc.

Given the increase in anthelmintic resistance to avermectin-based products, Teagasc is recommending against the use of avermectins for routine treatment to control sheep scab.

Lameness control

In terms of lameness, the most damaging risk is the introduction of contagious ovine digital dermatitis (CODD).

It can be identified by an infection at the coronary band and, in advanced cases, the hoof horn will be lifting away from the band.

It is important to check sheep closely for this ailment as once it establishes in a flock it is hard to get on top of.

The next infectious disease is footrot and again sheep should be examined for signs of the disease.

Sheep should be footbathed as a precautionary measure and a treatment plan should be put in place for any lame sheep.

The commonly used products are copper and zinc sulphate (10% solution) and formalin (3%), although other products are available on the market.

There is one option for vaccination for footrot, with the Footvax vaccine offering preventative and also treatment properties.

Vaccination considerations

Vaccinations are not cheap to administer, but they can be a small cost given the level of damage that can occur if there is an outbreak of an abortion-causing agent, pneumonia or clostridial diseases or, as mentioned already, footrot.

Their use can be reduced in some cases by purchasing from known high-health status flocks.

The three main ones to consider are clostridial disease, enzootic abortion and toxoplasmosis. Where the status is unknown for clostridial diseases, sheep will need a primary treatment post-arrival followed by a booster vaccine.

Unfortunately, the incidence of enzootic abortion or chylamdia abortus, a highly contagious abortion-causing disease of sheep that hits in late pregnancy, is steadily increasing.

The only vaccine available is Enzovax, which is administered at least four weeks before the start of the breeding season.

It can be administered at the same time as Toxovax, which prevents toxoplasmosis, and must be administered at least three weeks before the start of the breeding season.

Purchased-in sheep can be especially at risk to toxoplasmosis, as they may not yet have developed an immunity resulting in high levels of barrenness, abortion and the birth of weak lambs.

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