More about Bluetongue

Information is only slowly emerging about the Bluetongue outbreak. So far sixty premises have been know to have been infected, most of the incidents involve cattle on eight farms sheep were blood tested and showed signs of the virus in their blood, a single goat with the infection has been found on a farm with infected cattle. DEFRA has published a report about the progress of the disease so far. It makes interesting reading because the initial clinical signs have not been severe in either cattle or sheep. These are the reported findings from the sheep

Findings in Sheep

“The most commonly recorded clinical signs observed in sheep havebeen: lethargy and depression, recumbency, respiratory difficulty, pyrexia(104-105F), oedema of face (especially lips), mucopurulent nasal discharge,Increased salivation and hyperaemia of the nasal mucosa, and oedema of coronary band.

Animals that were ill

 With the exception of three of the eight premises from which clinical Bluetongue disease was reported in sheep only one animal was affected at the time of the first visit. Two sheep were affected in a flock of 58. In another flock two sheep were affected in a group of 40 and in the other flock on sheep had died overnight and another sheep was in extremis, and therefore euthanased, having shown the same clinical signs. No other deaths attributable to bluetongue were observed in the other flocks.

Affects on Goats

 BTV was not confirmed in any goat herds or other ruminant species as a result of reporting suspect clinical cases of bluetongue. (One of two goats was serologically positive at the follow-up visit to a mixed farm in which one cow was clinically affected.)

 The above findings relate to the early course of infection and disease in these herds and flocks. Follow-up studies are therefore being planned inorder to monitor the clinical incidence and the mortality rates in a sample, at Least, of infected flocks and herds”

Lack of Information

It is still too early to tell if Bluetongue will continue at this level or whether it will become more severe as time goes on. There is still little information on how it affects production in Dairy Herds or on which breeds of sheep are showing the more severe symptoms when the virus strikes.

Movement Rules

There are a host of new rules relating to transport of animals and what can be moved in and out of the protection zone. I am not quite sure why DEFRA thought it would be a good idea to try and control Bluetongue by drawing lines on a map. The edge of the protection zone is mainly the Welsh Border which weaves about somewhat through Shropshire. Oswestry is still in the clean area. You need to have a high level of local knowledge to know exactly where the boundaries of the Oswestry District Council and the Welsh border are. If we must have a Protection Zone it would have been better to have the boundary at the river Severn or the A5 perhaps so that it is something that everybody can recognize.

Spraying Insecticide

Some Welsh abattoirs have now been licensed to take stock from the Protection Zone. Before the animals are loaded the inside of the vehicle should be sprayed with a residual insecticide containing pyrethrum. It is permissible to venture into the protection zone with stock that are being transported from one clean farm to another. When this happens the animals themselves need to be treated with an insecticide such as Cooper’s Spot On or Intervet’s Butox Swish that is licensed to deter biting flies. These products cannot be used on animals going to slaughter as they all have a meat with hold time.

Help Line Numbers

DEFRA have set up a twenty four hour recorded information line with up to date information about the Bluetongue situation on 0844 884 4600 or you could try the help line on 08459 335577 which operates from 8am to 8pm weekdays and 9am to 5pm at weekends.

Milk Residue Poster

The Milk Development Council has produced a poster to help you to avoid antibiotic residues in milk. I understand that every milk producer should have received one of these by now. If yours has not arrived yet please phone the surgery and we will order one for you. The poster gives general advice about treating cows with mastitis and the use of antibiotics and identifying treated cows during the dry period.

Acorn Poisoning

There seems to be good crop of acorns about this year and already we have had reports of a lamb that has been poisoned by them. Sheep and cattle will not normally show an interest in acorns unless they are very short of grass. At the moment they shouldn’t need to touch them unless they are very tightly stocked. Acorns contain a toxin that is able to damage the kidneys of cattle and sheep when they eat them. If you see this happening and are able to move the animals away from the oak trees they will recover if you are able to treat them with drugs to stimulate their renal function. Cattle that have recovered from acorn poisoning should be watched in future years as they have been known to try and poison themselves for a second time if they get a chance.

New Blood Test

We are now able to diagnose Caseous Lymphadenitis in sheep from blood samples. This is the disease where small abscesses grow around the head and neck after an infection with Corynebacterium pseudotuberculosis. CLA is a particular problem for pedigree sheep as it can spread undetected once it is introduced to a flock by purchased animals. There is a strong argument for testing introduced sheep while they are quarantined from the rest of the flock to stop this disease spreading as it is getting more common each year.

Cows with Fog Fever

In contrast Fog Fever is not as common as it once was, but it will still affect some animals from time to time. This is an allergic reaction triggered by a fungus on the pasture. It usually happens when Hereford cross cows are moved onto better grazing at the end of the year. It might be that it is not so common now because our wormers are more effective and adult cows do not have to cope with lungworm infections which may predispose them to the condition. Once Fog Fever starts it should be treated as an emergency. More and more fluid will build up on the lungs, it can get difficult to stop it. Affected animal should be housed if at all possible, we find that most cows with Fog Fever will not recover until they have had cortico steroid injections. There is a danger that some treated animals will abort their calves on this treatment, but it is better to loose the pregnancy and save the cow. Some cows seem to get Fog Fever without a sudden change of grazing and there is little that you can do to prevent all cases of the disease.

Evening Meeting

Dr Frank Jackson from the Moredun Foundation is giving a talk at Gregynog Hall, Tregynon, near Newtown at 7.30pm  on Wednesday 21^st  November  about liver fluke in cattle and sheep and pneumonia caused by lungworm infections.

These are usually helpful talks full of advice and tips to manage these problems with the modern drugs that are available.

Admission is free but please phone the Moredun Office on 0131 455 5111 if you would like to go.

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