CATTLE

The main veterinary talking points this month have been the recrudescence of FMD and the arrival of blue tongue from the continent. Fortunately both diseases are still relatively confined but their impact is being felt across most of the UK. In regards to FMD the outbreak seems to have finished, but its reappearance against all expectations has meant that the pull-out process, including the resumption of exports to the EU, will be longer and more drawn out this time. In regard to blue tongue, we are still fortunate compared to northern Europe where the outbreak is nowhere near under control. Indeed there have been reports that the number of cases has been so large that accurate records of numbers are no longer being kept. Blue tongue looks set to stay in both the EU and the UK; next year, if it follows the same pattern in the UK as in Northern Europe, the disease will probably reappear and spread outwards from its Ipswich base affecting more farms and more animals. The only long term solution is vaccination; another cost for the farming industry to bear.

ADULT CATTLE

Fertility

Overall veterinary reports were down for many diseases in September; however the figures for fertility remained around the seasonal average, again suggesting, as in August, that the limited nature of the FMD and blue tongue outbreaks had not had a major impact on veterinary work so far.

One disease which showed a dramatic decline in September was endometritis. The August figures were the highest for that month since 1997 and higher than any monthly figure since January 2004. In September levels fell back to the long-term average. This clearly shows the perils of looking at one month’s data; nevertheless using non-detected oestrus as a baseline the ratio of endometritis cases to reports of missed heats for this year is higher than that of any other year (Figure 1). This then leads us to ask the question: Is detection getting better or is the disease increasing?



Metabolic disease

After three months of rises, the number of milk fever reports fell dramatically in September. A case of more farmers treating a disease where veterinary involvement is thought of as a luxury or a large number of missed cases?

Since 1997 there has been a gradual decline in the number of reports of metabolic disease with milk fever cases following the same trend (figure 2).



Clearly the changes in milk fever reports are mirroring those of metabolic disease overall. Based on responses from the NADIS vets an increase in the number of farmer treatments is the main reason behind the declining trend in cases treated by vets. One reporting vet stated that farmers are generally more technically aware and able than they used to be so that milk fever treatment is less of an issue. This was supported by another who reported that this meant that vets tended to see only the complex cases. A third reported that they don’t see straightforward cases unless the responsible staff member is away. There is variability across the country in the proportion of farmers treating milk fever intravenously, but general agreement that those who do use intravenous treatment have got better at it, in many cases because veterinarians have trained staff to treat and diagnose milk fever. Clearly there is a downside to this in that the veterinarian will tend to be presented with the cows which have complications or have not responded to “several bottles of calcium by various routes” , but overall early intravenous treatment that actually goes in the vein is likely to prove better than waiting for the vet. Indeed one vet stated that he feels that the downer cows that he sees are often the result of inadequate or incorrect initial treatment by the farmer and subcutaneous calcium may often not have sufficient “oomph” to have a clinical effect.

It was also suggested that as well as better farmer treatment reducing the number of veterinary treatments, part of the reduction was due to the actual incidence of primary milk fever and its complications being less due to improved management of both dry cows and transition cows; keeping them in the correct body score condition and having better nutritional management at transition. The same vet also suggested that his herds are also younger than they have been in the past – further reducing milk fever risk. A Lancashire vet reported that he has seen a number of unresponsive cases which have already had 2-3 bottles of calcium, that when he has investigated further have an ‘out of balance” calcium to phosphorus ratio. He is not sure if this is a clinical phenomenon or a farmer induced condition.

Mastitis

The very low cases of summer mastitis in August were followed by an even lower number of reports in September. Barring an unexpected number of cases in October, the number of reports this year looks to be less than half the long-term average. Are we looking at untreated cases because of movement restrictions? We would welcome comments on why summer mastitis has not been bad this year. Is it a legacy of the appalling wet start to the summer?

Cattle lameness

Lameness cases took an unusual dip in September with all of the major diseases showing significant falls. Contrary to last months prediction the number of white line disease cases failed to rise; indeed this month’s figures were the lowest September figures ever. October is usually the peak month for this condition but it’s looking unlikely that it will be the peak month this year.



Other diseases

A particularly bad wooden tongue problem in 2 cows was reported on an organic dairy farm in Lancashire; in one case the mandibular lymph gland had ruptured. The vet reported that in the past he had only seen such bad cases on farms with especially tough grass on a salt marsh and high moorland. The grass of this organic farm was particularly woody and he wondered whether organic farms have a higher incidence of wooden tongue than normal because they are more likely to have tough grass and would welcome others thoughts on this. To follow up on this, the incidence of wooden tongue in New Zealand, where grazing old and sometimes rough pasture is far more routine than in the UK, is higher than in the UK (as is the number of bizarre presentations such as skin infection with actinobacillosis spreading down the neck), which would fit this vet’s suggestion.

A Northumberland vet also reported a couple of interesting cases this month. Firstly an unusual case in a beef cow. The farmer diagnosis was of wooden tongue. However the cow had the same problem the year before so the vet is not convinced. The cow is losing weight and scouring, but is negative for Johnes, fluke and worms.

Secondly he examined a 2 year old Holstein cross bullock that was being fattened. About ten days ago the bullock had been diagnosed as having a wound below its accessory digits on its back leg which had resulted in profound swelling. Antibiotics and non-steroidals had resulted in initial improvement but the condition had then deteriorated. On examination he found a dramatic lymphangitis combined with about 100 skin lumps all over the body, resembling those seen in bovine farcy (a disease that does not occur in the UK). Histology samples have been taken and the results are awaited.

CALVES

The NADIS data show no large effect so far of the overcrowding resulting from movement restrictions on calf disease (or at least veterinary involvement in such disease). Reports of scours, joint ill and pneumonia all remained well below average

The September figures for lungworm showed a reduction in the number of cases, again contrary to predictions. Even so figures for this year have been higher than in 2006, and if there is significant rain then outbreaks may continue until well into November. There was an apparent failure in Shropshire of an ivermectin pour-on to treat chronic respiratory disease in 6-9 month old calves at grass, with 4 out of 10 calves failing to respond completely to anthelminthic treatment.

Further Reading

- You can view the full article by clicking here.

TheCattleSite News Desk