Spring Flock Health Jobs: Pre Lambing Vaccination for Sheep

Sheep Vaccination Equipment and Simcro Animal Injector Guns for Pre Lambing

Pre lambing

Vaccinating ewes four to six weeks before lambing not only boosts their own immunity as well as increasing the concentration of these protective antibodies in the colostrum. Helping to protect young lambs until they too can then be vaccinated.

Flock vaccination should ideally take place in two blocks with a gap of around ten days so the later lambing ewes gain maximum benefit.

The most common clostridial diseases are Lamb Dysentery, Tetanus, Pulpy Kidney, Black Disease, Blackleg, Struck and Braxy. The vast majority of cases are fatal with sheep simply found dead.

Clostridial disease is a type of bacterial infection. The disease origins are all caused by bacteria spores dwelling in the soil at pasture. These bacteria rapidly multiply producing deadly Endotoxins usually resulting in relatively quick death of the animal.

There can often be a trigger factor allowing the clostridia bacteria to enter such as wounds to the skin, dog bites, shearing cuts, via contaminated needles and injection equipment too. During lambing, the umbilicus of a new-born lamb is a possible route too as well as dystocia (lambing difficulties).

After lambing, sporadic cases of clostridial disease can be seen in young lambs ingesting little or inadequate specific antibody in the all-important colostrum they receive. The lactating ewe may simply have insufficient supply due to her poor condition, poor feeding by the lamb due to mastitis, being a triplet or quad, ewes not being correctly or not vaccinated at all.

Older lambs can succumb to Pulpy Kidney between four to ten weeks of age if mothers are unvaccinated. Offspring from vaccinated ewes eventually become susceptible too, as their passively derived antibodies waive by this time. Braxy can also affect much older lambs ingesting frosted root crops. Follow-up vaccinations therefore are an important part of a flock vaccination protocol.

Pasteurellosis is a respiratory disease found in sheep with the infectious agents Mannheimia haemolytica and Bibersteinia trehalosi causing septicaemia in young lambs, pneumonia in older sheep and mastitis in ewes. Bibersteinia trehalosi is the most common cause of sudden death in lambs in the UK between August and December (Source; NADIS).

Infectious agents of Pasteurellosis are commonly found in animal respiratory systems but susceptibility increases significantly when under stress due to weaning and movement, castration or by having a low immune system.

Vaccination against Clostridial disease and Pasteurella is often used in combination. Very few UK flocks, if any would not benefit financially and from a welfare perspective too.

Vaccination protocols initially suggest two vaccinations given four to six weeks apart followed by annual vaccination four to six weeks before the expected lambing date to ensure there has been a good accumulation of immunoglobulins in colostrum the young lambs receive.

Post Lambing Sheep Vaccination and Animal Health Devices for Lamb Protection

Using Simcro Vaccinators and Sheep Injector Guns for Accurate Treatment

Post lambing

Lambs whose mothers have been vaccinated pre-lambing need further vaccination from three to four month-old with the programme complete before weaning unless sold for slaughter before the waning of maternal antibody is seen at around this time. Timing and planning of your treatment protocols with advice your local vet or RAMA is key and vaccinating lambs too young will mean maternal antibodies derived from colostrum may block the action of the vaccine, failing to produce the best protection and outcome. On the other hand, vaccinating too late and lambs may already have contracted the disease and losses can occur as a result.

Vaccinating ewes four to six weeks before lambing not only boosts their own immunity as well as increasing the concentration of these protective antibodies in the colostrum. Helping to protect young lambs against Clostridial diseases and Pasteurellosis until they can then be vaccinated.

Flock vaccination should ideally take place in two blocks with a gap of around ten days so the later lambing ewes gain maximum benefit.

Another recent threat to flock health is Bluetongue with several hundred confirmed cases. The Bluetongue virus is non-contagious and transmitted by biting midges. It affects domestic and wild ruminants and camelids, but not people. Outbreaks can result in a range of symptoms including abortion, foetal deformities, stillbirths, fever, lameness, lethargy, ulcers and milk drop. Calves and lambs can be infected from their mother and can be born small or be weak, deformed and/or blind, and can die. This is a serious welfare issue and prolonged animal movement and trade restrictions can also result (Source; https://ruminanthw.org.uk/bluetongue-virus-hub/).

It may be a flock treatment consideration if not already undertaken and advice should be sought and as the season warms so does the midge population. The ambient temperature must be above 12°C for the virus to multiply in midges (Source; https://ruminanthw.org.uk).

Animal Health Devices: Best Practice When Using Sheep Vaccination Equipment

Why Simcro Sheep Injectors and Proper Vaccine Storage Matter

Many vaccines need to be refrigerated, this is often overlooked. If they are left in a warm vehicle for example, they will not be as active or effective as they should be and should be placed in a well functioning fridge as per the product instructions.

Another common mistake is using the same equipment for different vaccines which may cause cross contamination with insufficient cleaning of equipment. The investment in additional vaccination devices is not hugely prohibitive, although correct cleaning after use should always be practised.

A recent UK survey also suggested that almost 20 per cent of sheep farmers did not vaccinate their sheep on a regular basis and the cost benefit is proven on most units (Source NADIS).

Sheep Vaccination Best Practice Using Simcro Animal Injector Guns

Getting Accurate Doses with Professional Livestock Injectors

A number of factors affect vaccine efficacy (ensuring maximum treatment effectiveness), not only for the ewe, but the unborn lambs too.

When a vaccine is given, it is detected by white blood cells, which react as if the real infection is present and has entered the body. These white blood cells multiply and start to produce antibodies to fight the disease. These remain in the system and are therefore ready to attack and repel the disease if the animal later comes into contact with the real thing.

However, if the animal is already under disease pressure, or the vaccine is administered incorrectly or at the wrong time, the sheep may not be able to produce as strong a reaction as it should, leaving the door open for potential later infection.

Sheep Vaccination Checklist: Using Simcro Injectors Safely and Effectively

Points to consider include;

Animals in poor condition and already under disease pressure may not be able to produce as strong a reaction

Reducing stress to all concerned is deemed essential, patient handling of pregnant ewes is a must. Speed is not important and farm dogs out of the way if possible

Subcutaneous injection of ewes onto a dry fleece as when wet, a fleece can contaminate needles

Vaccinate into the neck approximately 5cm from the base of the ear as shown in Figure 1. A poor injection site choice can affect the animal’s uptake of, and response to, the vaccine

Injecting at 45 degrees to the skin is most likely to successfully deliver the vaccine by subcutaneous means (under the skin). Choose bottle mounts where the bottle position can be adjusted

Shorter needle size for subcutaneous than intramuscular, dependent on wool cover also

Change needles regularly so they are sharp and penetrate the skin easily

Dirty needles and equipment increase painful abscesses and infection risk, major welfare issues and costly carcass trimming and degrading

Use vaccinators suitable for smaller dosage delivery both quickly and accurately. Bottle mount or tube fed injectors are personal choice although bottle mounts are increasingly popular and lessen the risk of air or contamination with bottles connected directly eliminating the need for tubing

Calibrate all equipment beforehand including Selectable ‘dial-a-dose’ devices. Ensure all pipes on tube fed injectors are allowing free flow of product without kinks or blockages

Injectors must be in good working order, are clean with no accumulated debris in the draw off tubes and chamber. If in doubt, replace the equipment

Ensure free barrel movement so the correct dosage is drawn up each time, re-lubricate with vegetable (NOT mineral) oil on the plunger O-ring after cleaning if necessary

Assessing the correct animal weight is always important dosing to the heaviest weight and consider splitting batches