Call Us
Goosnargh:
01772 861300
Lytham Road:
01772 718774
Kirkham:
01772 681992

Tag: sheep

TACKLING LIVER FLUKE

TACKLING LIVER FLUKE

Liver Fluke (Fasciolosis) is a disease caused by the flatworm Fasciola hepatica. It affects a wide range of animals, including sheep and cattle, and although humans can become infected, although this is very rare in the UK. The disease is estimated to cost the UK livestock industry around £300 million every year due to liver condemnations, animal deaths, and reduced productivity.

WHERE DOES IT COME FROM?

The liver fluke life cycle begins when eggs are passed onto pasture in animal faeces. These hatch and infect a small mud snail (Galba truncatula), where they multiply and develop. Under suitable wet conditions, immature fluke called cercariae leave the snail and encyst on vegetation as metacercariae — the highly infectious stage.

Animals become infected when they graze contaminated pasture. The ingested metacercariae develop into juvenile flukes that migrate through the liver, causing significant damage, before moving into the bile ducts where they mature into adults. Adult fluke produce eggs that pass out through the digestive tract and continue the cycle.

It takes approximately 10–12 weeks from ingestion of metacercariae for adult fluke to be present in the bile duct.

Unlike gut worms, animals do not develop immunity to liver fluke, meaning all ages are susceptible.

CLINICAL SIGNS

Sheep

  • Acute fasciolosis

Caused by large numbers of migrating juvenile fluke. Can lead to sudden death from internal bleeding or secondary clostridial infections (Black Disease). Signs may include extreme lethargy, abdominal pain, reluctance to move, and collapse. Most common in late summer and autumn.

  • Sub-acute fasciolosis

Fewer migrating fluke cause rapid weight loss, poor fleece quality, inappetence, weakness and depression. Death can occur without treatment. Typically seen in autumn.

  • Chronic fasciolosis

Caused by adult fluke in the bile ducts. More common in late winter and early spring. Signs include poor body condition, anaemia and bottle jaw (fluid swelling). Results from impaired liver function and inflammation.

Cattle

Cattle typically develop chronic disease, shown by poor weight gain and anaemia. Sub-clinical infection can reduce milk yield. Diarrhoea is possible but usually linked to secondary Salmonella infection.

DIAGNOSIS – PREVENTION – TREATMENT

Diagnosis

Liver fluke can be detected through bulk milk, blood tests, or faecal testing. Different tests identify infection at different stages, so test choice depends on the time of year and level of risk.

Prevention

Fluke risk varies greatly between farms and even between fields. Wet, boggy or slow-draining areas are high-risk grazing zones. Identifying and, if possible, fencing off or avoiding known “flukey” areas during peak risk periods can reduce infection.

Treatment

Choosing the correct treatment depends on the age and stage of the fluke present, as not all products are effective against every stage. Understanding seasonal risk and test results is essential when planning treatments.

Please get in touch for any information regarding fluke and its treatment.

Sheep – The Big Five diseases

The Big Five Diseases in Sheep

Maedi Visna

Maedi Visna - sheep diseaseMaedi Visna is a wasting disease causing chronic pneumonia. It is caused by a highly contagious virus. Most sheep are infected as lambs via colostrum or aerosol, however generally do not show signs until they are 4 years old.

The main signs are:

[checklist icon=”fa-arrow-circle-right” iconcolor=”#39aa87″ circle=”yes”]

  • Thin ewes/wasting away
  • Pneumonia
  • Mastitis
  • Arthritis
  • Reduced fertility
  • Smaller weaker lambs which grow poorly due to a lack of milk

[/checklist]

Blood tests are commonly used to diagnose MV. Selecting thin cull ewes to test will help identify the disease if present within the flock.

If you suspect MV in your flock or wish to know your MV status we can do a 12 cull ewe screen.
Please call 01772 861300 to discuss.

Ovine Pulmonary Adenocarcinoma – OPA

Ovine Pulmonary Adenocarcinoma - OPA - sheep diseaseOvine Pulmonary Adenocarcinoma is caused by a virus leading to a progressive and fatal infectious lung cancer of sheep. The virus is spread from infected sheep by aerosol and nasal discharge. It is often seen in older thin sheep. There is no treatment.

The signs are very similar to chronic pneumonia:

[checklist icon=”fa-chevron-circle-right” iconcolor=”#39aa87″ circle=”yes”]

  • Difficulty breathing
  • Weight loss
  • Excessive watery fluid from the nose
  • Sudden death
  • Secondary infections such as Pasteurella are common.

[/checklist]

Once signs are evident the disease is fatal.

The definitive diagnosis is made by post mortem examination of the lungs.

If there is suspected OPA ultrasound examination of the lungs can be considered.

Johne’s Disease

Johne's disease in sheepJohne’s disease is caused by a bacterium which grows very slowly and lives for a long time in the environment. It is mainly spread through faecal contamination of feed and the environment, ewes also pass it to their lambs across the placenta and in colostrum. It is the same agent that causes Johne’s disease in cattle.

Infection generally occurs early in life, sheep often do not show signs for years and act as carriers, these are referred to as ‘sub-clinically infected’.

Affected sheep suffer from:

[checklist icon=”fa-chevron-circle-right” iconcolor=”#39aa87″ circle=”yes”]

  • Severe weight loss
  • Sudden death
  • Anaemia
  • High parasite burdens
  • Affected flocks suffer from poorer production, more thin ewes and increased culling.

[/checklist]

Testing for Johne’s can be tricky at an individual level. There is no single diagnostic test that can detect the disease at all the stages and sub-clinically infected animals may test negative.

Blood screening groups of cull/thin ewes can be effective at identifying Johne’s disease in your flock.

Border Disease

border disease in sheepBorder disease or hairy shaker disease is a virus which causes birth defects, barren ewes and abortion. It is from the same family of viruses as BVD in cattle.

If a ewe is infected during pregnancy the virus passes through the placenta to the lamb, in some cases this causes embryonic loss or abortion. Some lambs survive and are born Persistently infected (PI). PIs shed the virus continuously and can infect other sheep and lambs. This can be a major problem in naïve flocks unknowingly buying in PIs which can then cause around half of lambs born to be affected by the disease.

[checklist icon=”fa-chevron-circle-right” iconcolor=”#39aa87″ circle=”yes”]

  • Infection in non-pregnant adult sheep is generally short lived and mild, often no clinical signs are seen.
  • Hairy shakers are lambs infected with the virus whilst developing in-utero effecting their nervous system which leads to trembling and incoordination. They also have long curly wool.
  • Some lambs are born completely normal but maintain the infection, these are called Persistently Infected animals (PI).

[/checklist]

Hairy shakers are usually a good way to diagnose the presence of the disease. These lambs can also be blood tested to confirm presence of the virus.

Blood testing a group of ewes can identify if the flock has been exposed to the disease and is likely to be present.

Caseous Lymphadenitis – CLA

Caseous Lymphadenitis - CLA - sheep diseaseCLA is a chronic bacterial infection of the lymph nodes resulting in abscesses. The bacteria often enters via cuts and is commonly spread through close contact when animals are housed or are trough fed. The disease can also be transmitted indirectly such as on shearing equipment.

[checklist icon=”fa-chevron-circle-right” iconcolor=”#39aa87″ circle=”yes”]

  • Infected animals have lumps often behind the jaw, in the arm pit and in the groin. These lumps are often cold and painless but can burst open and drain pus. Once they have healed and scarred over the abscess can re-occur.
  • Abscesses also form inside the sheep causing ill-thrift and weight loss.

[/checklist]

Lumps and abscesses are a classic sign of the disease and should not be ignored.

Diagnosis is either by sampling the intact abscesses and culturing the pus or by blood test.

If you would like further information, please contact our Farm Team.

Neonatal Lamb Care

Neonatal Lamb CareLambing time is the most crucial part of the year for making your sheep business profitable. Lamb deaths from birth to 3 days old should be less than 7% however many farms range between 10- 25%.

A major factor influencing mortality in neonate (young) lambs is ewe body condition; as this directly relates to lamb body weight, colostrum quality and quantity. It is therefore important to ensure ewes are at BCS 2.5 to 3.0, (so vertebral spinous processes only felt with pressure and transverse processes only felt with hard pressure), and they are on a rising plane of nutrition in the run up to lambing. Energy and protein blood profiles can be taken 2 to 3 weeks before lambing to ensure ewes are receiving the correct nutrition to help reduce cases of twin lamb disease.

Another major cause of neonatal mortality is watery mouth. These lambs typically are lethargic, salivate and have a distended abdomen. It is caused by Ecoli and picked up by ingestion. Treatment involves electrolytes and antibiotics but is often hopeless. Therefore the emphasis should be on prevention which involves keeping pens clean, (especially towards the end of the season), dipping navels with strong iodine and ensuring all lambs get enough good quality colostrum quickly. See below:

Always ensure colostrum is…

QUALITY

Ensure ewes in good BCS, if you’re uncertain as to the quality of colostrum; colostrum quality can be measured using a refractometer: aim for specific gravity >1.05. Only use sheep colostrum replacement (colostrum from a milking sheep farm will usually be better quality than powdered colostrum); cow colostrum can cause a fatal anaemia. Also remember to give your Clostridial and Pasteurella vaccine four to six weeks before lambing to ensure the lambs receive antibodies against these diseases. (Any ewes that haven’t had this vaccine before will need a course of two injections four to six weeks apart).

QUANTITY

200ml/kg within 18 hours of birth, with a maximum of 50ml/kg intake on each occasion.

Remember lambs in adverse weather conditions will require more colostrum or milk as more energy from their feed will be used to keep them warm.

QUICKLY

Within 2 hours of birth.

SQUEAKY CLEAN

Ensure ewe udders are clean and dry and the equipment to mix and administer colostrum is cleaned and disinfected between lambs.

QUANTIFY

We can also look if your lambs have received enough colostrum by blood testing any less than a week old.

Finally, there is continual pressure on antibiotic use. So to ensure we don’t end up with a world full of super bugs we need to be careful how we use antibiotics. Preventative use of antibiotics, such as blanket use of Spectam or Betamox LA for watery mouth needs to be reduced as this will actively select for resistance and there is pressure from Red Tractor Assurance to reduce this practice.

We recommend only using antibiotics….

    • Towards the end of the lambing season, when the sheds have a build up of Ecoli.
    • In triplets, when their ewe may have poorer quality and quantity of colostrum
  • In lambs from ewes in poorer condition, as the quality and quantity of colostrum will be poorer.

Also remember entropion, where the lamb’s eyelid is inverted causing the eye to be held shut, tear staining and damage to the eye. This is a heritable condition so affected lambs should not be kept as replacements, ewes should not be used to breed replacements and consider ram choice if a large percent of flock are affected.

If you have any questions regarding lamb care, please contact the Oakhill Farm Team.

Mastitis in ewes

Mastitis in ewes can be fatal and usually results in the end of her productive life.

The usual presentation is acute gangrenous mastitis (blue or black bag) usually caused by either Staphylococcus Aureus or Mannheimia Haemolytica. S. Aureus is normally present on the teat skin but damage to the teat ends allows it access into the teat canal and causes mastitis.

M. Haemolytica is present in the tonsils of lambs so colonises the udder during suckling. The bacteria produces toxins which prevent blood flow and cause the udder to turn blue/black hence the name. This often occurs around peak lactation (three to six weeks post-lambing) and the initial clinical signs may be as subtle as a ewe looking lame or a lamb bleating because it’s hungry. The disease then rapidly progresses.

The risk factors include:

[checklist icon=”fa-arrow-circle-right” iconcolor=”#39aa87″ circle=”yes”]

  • Under feeding ewes round lambing or ewes in poor condition, as lambs to these ewes will cross suckle or create teat lesions by over suckling.
  • Damaged teat end or Orf on teats
  • Lumps in the udder
  • Lambing inside (the longer the time spent inside the greater the risk of developing mastitis)
  • Dirty, wet pens and dirty hands when handling udder/ underneath of sheep
  • Harsh, cold weather

[/checklist]

Treatment is unlikely to save the udder but may save the ewe’s life:

[checklist icon=”fa-arrow-circle-right” iconcolor=”#39aa87″ circle=”yes”]

  • Remove lambs from the ewe and ideally artificially rear as rearing these lambs on another ewe may spread the mastitis
  • Antibiotic injectable AND non-steroidal anti-inflammatory such as Loxicom
  • A ewe that has had mastitis will be more likely to get fly strike so preventative fly treatment is essential.
  • There is a vaccine against S. Aureus available; VIMCO. This has to be given three and five weeks pre-lambing. Most of the trial work has been done in dairy ewes and it is licenced to reduce to the incidence of subclinical mastitis. Potentially this could also help to reduce the incidence and severity of black bag in your flock however at the moment there is limited evidence to prove this.

[/checklist]

If you have any questions regarding mastitis in your flock, please contact our Farm Vet Team.

Extended liver fluke season and climate change

Fascioliasis

An important stage of the Liver fluke life cycle takes place in mud snails and requires wet and warm conditions (above 7 – 10°C) during the summer months. Over the last couple of years unseasonal weather has seen these conditions well into autumn and winter. This means that sheep and cattle are still being infected later in the season and more frequent testing and treatment may be required.

Fascioliasis can have a serious financial impact on a sheep farm with immediate losses up to 10 per cent caused by acute/subacute disease. Chronic disease could half profits by reducing lamb crop and increasing ewe mortality. Lack of treatment in cattle will lead to reduced growth and yields and discarded milk if treatment is no targeted.

We recommend testing your sheep and cattle for the presence of Liver fluke. Treatment needs to be targeted at your flock/herd and will vary from farm to farm. Please discuss your individual requirements with your vet to develop a treatment plan for the coming months.

liver fluke life cycle

Border Disease

Border disease or hairy shaker disease is a virus which causes birth defects, barren ewes and abortion. It is from the same family of viruses as BVD in cattle.

If a ewe is infected during pregnancy the virus passes through the placenta to the lamb, in some cases this causes embryonic loss or abortion. Some lambs survive and are born Persistently infected (PI). PIs shed the virus continuously and can infect other sheep and lambs. This can be a major problem in naïve flocks unknowingly buying in PIs which can then cause around half of lambs born to be affected by the disease.

 

[checklist icon=”fa-arrow-circle-right” iconcolor=”#39aa87″ circle=”yes”]

  • Infection in non-pregnant adult sheep is generally short lived and mild, often no clinical signs are seen.
  • Hairy shakers are lambs infected with the virus whilst developing in-utero effecting their nervous system which leads to trembling and incoordination. They also have long curly wool.
  • Some lambs are born completely normal but maintain the infection, these are called Persistently Infected animals (PI).

[/checklist]

Hairy shakers are usually a good way to diagnose the presence of the disease. These lambs can also be blood tested to confirm presence of the virus.

Blood testing a group of ewes can identify if the flock has been exposed to the disease and is likely to be present.

To discuss with our Farm Team further, please contact us

 

Fertility in sheep

Fertility in sheep

For those early lambers!

Whether it’s to get the premium Easter prices, utilise the spring grass or produce good lambs for show time and sales, it can be advantageous to lamb early and here are a few options to advance your lambing:

 

Method

 Advanced

Synchronisation
Ram (vasectomised or not) No Can do depending on stage of cycle
Melatonin (manipulating light hours or implant Regulin) Yes No
Prostaglandin No Can do depending on stage of cycle
Progesterone (chronogest sponge or new for this year CIDR- ovis) Yes if used with PMSG (ECG) Yes

Abortion rate from your flock

As the lambing season for most has finished and the focus no doubt moves to growing lambs it is worth just taking 5 minutes to think back to lambing and your flock abortion rate.

Ideally you would want a target of below 2% of the flock either barren or had an abortion. Anything more than this could be due to infectious cause and should be investigated to prevent the same again in future years.

Abortions are costly – recent estimates suggest each case costs £85 per ewe

 

Infectious abortion is common in sheep and 70% of these abortions are associated with 3 infectious agents – Toxoplasmo, Chlamydophila/Enzootic abortion and Campylobacter. We have diagnosed all 3 agents in multiple abortion outbreaks this spring.

Vaccination is advised in flocks with a history of disease and also in those flocks buying in breeding females.

Subsidised lab testing is currently available to help us determine if your flock has been exposed to Toxoplasmo or Enzootic Abortion.

Please contact the practice to discuss the best option for you in terms of testing and vaccination.

For those who use Toxovax and Enzovax please remember to place your order in good time as these products are short dated and are put on a special order.

 

 

Blowfly strike treatment and prevention

Fly treatment

These warmer days, combined with the inevitable rain, provide the perfect habitat for Lucilla sericata more commonly known as the blowfly. We now recognise the blowfly season as being longer with strike seen as early as February and as late as November, so it’s important that our fly prevention adapts to the changing climate too.

94% of farmers admit to being caught out by flystrike

Most will know what a fly struck sheep looks like:

[checklist icon=”fa-check-circle” iconcolor=”#39aa87″ circle=”yes”]

  • Agitated, itchy, away from flock, smell, wool discoloured and eventually loose wool.
  • This progresses to anaemia, septicaemia & ammonia toxicity causing lethargy and then death.

[/checklist]

Early intervention is important not only to prevent deaths but also to reduce the general fly population.

To create a fly control programme it is important to understand what type of conditions these flies thrive in and also to use your knowledge from previous experiences on your own farm with your own sheep.

Blowflies need the following conditions to successfully complete their lifecycle:

[checklist icon=”fa-check-circle” iconcolor=”#39aa87″ circle=”yes”]

  • Soil temperature over 9°C
  • Long periods of rainfall (causes fleece to rot)
  • Low wind speeds (allows increased fly mobility)
  • High temperatures and humidity causes microclimate in fleece that is attractive to flies to lay eggs.
  • NADIS now has a blow fly alert web page which will use data from the Met Office to create a local risk for blow flies.

[/checklist]

In perfect conditions fly eggs hatch in 12 hours and once larvae start feeding they release a powerful odour which attracts more flies causing significant damage within 24 to 36 hours of the first egg being laid. This emphasises the need for daily flock checks.

Losses due to fly strike are seen as: death of individuals, reduced lamb growth rate, reduced productivity, down grade wool clip, cost and time of treatment. Elanco has calculated these costs as shown:

Blowfly losses chart

To prevent Blowfly Strike:

[checklist icon=”fa-check-circle” iconcolor=”#39aa87″ circle=”yes”]

  • Dagging and crutching (start in April and every 4-6 weeks)
  • Keeping breeds of sheep with more open, hairy or self shedding coatsearing (especially thick fleeced breeds)
  • Shearing (especially thick fleeced breeds)
  • Culling ewes with narrow breeches or deformities that result in soiling
  • Tail docking in lowland flocks
  • Reduce incidence of footrot
  • Eliminate scouring issues (for example keep coccidiosis, worm burden and nutrition under control)
  • Frequent flock inspections (at least daily)
  • Appropriate insectide use

[/checklist]

Insecticide use: We recommend starting treatment against flies now to reduce fly populations for the rest of summer. Keep an eye on the NADIS blow fly alert map and ensure your sheep are protected at the high risk times. There are various products you can use to prevent blow fly strike and these are listed in the table below:

Product Drug Length of action Meat withdrawal
Vetrazin Cyromazine (IGR) 10 weeks 28 days
Clik extra Dicyclanil (IGR) 19 weeks 40 days
Clik Dicyclanil (IGR) 16 weeks 40 days
Clik Zin Dicyclanil (IGR) 8 weeks 7 days
Dysect sheep Alpha cypermethrin 8-10 weeks 49 days
Ectofly/ Crovect Cis Cypermethrin 6-8 weeks 8 days
Fly and lice spot on/ Spotinor Deltamethrin 6 weeks 35 days
Paracide 62/ Osmonds
gold fleece dip		 Diazinon dip (Organophosphate)
Cypermethrin		 8-10 weeks 70 days/ 49days
respectively

* IGR products are NOT effective as treatments

To date there has been no resistance of blow flies to any insecticide formally reported.