New Castle Disease

It might not seem that important that 9,000 pheasant chicks have been affected by New Castle disease in Surrey and have been slaughtered until you start to find out more about the disease. This is a viral disease that has been absent from the United Kingdom for eight years now, all kinds of birds can be affected. It can be very severe sometimes and have a mortality rate of 100% other birds may show milder symptoms reflected in a reduction of egg production with limited losses. There are a range of symptoms, flock owners report that there birds seem to be quieter than normal for a while then there are either dramatic losses with some birds showing nervous symptoms before they die or green watery diarrhea and weight loss.

Birds from France

The affected pheasants in Surrey were only two weeks old and had originated from a large rearing unit in France. It is thought the virus may have come from wild birds as there is a lake near by frequented by migrating geese and ducks. It is a little strange that nothing was reported in the parent stock and that the disease was not detected until after the chicks had arrived at a new farm in a different country. So far no poultry units have been involved in this outbreak and it is reported that there are no large units in the immediate area. The virus is readily transmitted and it is of concern that it could so easily be brought into this country.

Vaccinating Chicks

Large flocks take precautions against New Castle Disease and vaccinate chicks at least three times on rearing farms. I do not think pheasant chicks are routinely vaccinated and the expectation is that the vaccine would be able to limit the spread of the disease, but not stop it all together. Smaller flocks particularly those with birds that go outside, are vulnerable to this virus as it is difficult to vaccinate them even if the will was there because of the way the vaccine is manufactured and distributed. Losses in small flocks would often not be investigated fully because of the cost of post mortem investigations may exceed the replacement value of the birds. It is quite possible that if the virus has been in wild birds migrating through France it could turn up here as well.

Vaccination Amnesty

We are running a vaccination amnesty for dogs and cats at the moment. Most puppies and kittens start off alright and get their initial vaccinations, but many lapse after a while and miss their annual boosters. We still regularly see dogs with parvo virus and leptospirosis. These are difficult, expensive diseases to treat as often the only way we can combat the problem it to give a blood transfusion and a prolonged course of drugs. Cats too regularly come in with signs of flu that are difficult to treat with antibiotics if they have no natural immunity to the disease. If the interval between injections extended beyond fifteen months a second injection is usually needed to prolong the immunity for a full year. During the amnesty that runs until the end of August we are giving the  second injection for free so get things organized now as we may never do this again.

Calf with Tetanus

I came across a three week old calf with tetanus this month and I cannot remember it ever happening before in a calf of such a young age. Tetanus is fortunately not very common in cattle most of the cases that I have seen have been between one and two years of age. There seems to be a definite higher achy of susceptibility to tetanus horses are up the top followed by sheep and goats, then cats and cattle. Dogs get the disease only rarely. It is caused by clostridial bacteria in the soil. Horses seem to attract it as other species such as goats and cats often pick it up if they are close to horses. The organism gains a foothold from an infected wound, as it multiplies it produces a toxin that ultimately paralyses the animal. Some animals will respond to large doses of antibiotics and courses of antitoxin. It is a nasty disease and the muscle contractions are difficult to control so the chances of recovery are not good. I suspect that the brought in calf that I was treating got the infection from an ear tag. In calves it is possible to administer the anti toxin directly into the spine but in spite of this he did not survive. So far the rest of the calves brought from the same farm have been alright and it is not clear if there is any connection with horses on the farm of origin.

Pigs with Tuberculosis

It was inevitable I suppose that sooner or later Bovine Tuberculosis would move on to infect another species. I understand that two pigs in Cornwall and their offspring have been diagnosed with the disease. I am not sure what the exact circumstances were whether the animals actually died of the infection. Post mortems revealed that the animals had the intestinal form of the disease. These were out door pigs and the assumption is that they have eaten some creature infected with Bovine Tuberculosis. I wonder what that could have been?  It is not thought that the disease will spread amongst the pig population.

Testing Pigs

In the past I was involved with a pig herd that would export gilts all over the world and some countries would ask for a Tuberculin test to be carried out so many days before they went abroad. I remember then the perceived danger then was from Avian Tuberculosis carried by birds that could contaminate the feed bins. I don’t suppose that there are many farmers in the south west that are exporting pigs. It cannot be a good thing that there is so much infection about that now pigs can get involved in the disease process. It might well be that these pigs had been on a field which badgers had infected with their urine on their nightly foraging trips, I don’t suppose that we will ever find out.

Free Ranging

Many free ranging pigs are kept on a small scale and are likely to be processed through a local abattoir or maybe go back to the owner for local sale or consumption. It is not a good thing that we should be exposed to infection in this way or that we should rely only on the vigilance of meat Inspectors to protect us from this disease.

Vaccinating Sheep

It will soon be time to start using the rams so a brief reminder that ewes can be protected against both Enzootic abortion and Toxoplasma abortion by vaccination. Both of these diseases can have a significant impact on the productivity of your flock. Sometimes Toxoplasma goes un noticed as it can cause early embryonic death and infertility rather than aborted lambs.

These are live vaccines so you need to keep them cool before they are used and they should be given at least a month before you use the tups as they work by exposing the ewes to a small dose of the infection which does no harm as long as they are not pregnant at the time that it is given.

Return to Newsletters