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Thursday 12 February 2015

This site closing, replaced by www.alabamarot.co.uk

After just 6 weeks, I've decided to close this site and replace it with the www.alabamarot.co.uk (Wordpress) website.

This Blogger site will remain open until all posts and links have been forwarded to the new website. All posts reposted at 12th April 2015. This site will close shortly.

Saturday 7 February 2015

7 dogs die of Alabama Rot per million dogs walked in the New Forest


The New Forest National Park has 13.5 million visitor days a year - see table below (2). Assuming 8% of visitors walk their dogs, there are 1.1 million dogs from visitors walked each year in the New Forest.  A further 37,600 dogs are walked by people who live in the New Forest (3). This gives a total of 1,137,600 dogs walked in the New Forest each year.

In two years, between December 2012 and December 2014, seventeen dogs died of confirmed Alabama Rot in the New Forest (4). So about seven dogs die of Alabama Rot per million dogs walked in the New Forest.

However, there are more dog deaths from Alabama Rot in the New Forest than all the other fourteen National Parks put together. Why?

Could it be that vets outside the New Forest are largely unaware of Alabama Rot and therefore not reporting cases? Or because the New Forest has more woodland than other National Parks and Alabama Rot cases are often found in woodland?  Or because the New Forest 'cluster' or 'hotspot' of Alabama Rot simply occurs by chance? Do visitors dogs get Alabama Rot outside the New Forest? Or does the New Forest have an unknown environmental factor that triggers Alabama Rot in dogs? Or some other reason?

Whatever the reason, more Alabama Rot research is needed on the epidemiology of this dreadful dog disease (5).



References (all accessed 7th February 2015)

Wednesday 4 February 2015

If you walk your dog in the New Forest there is a 99.99% chance it will NOT die of Alabama Rot

This post reposted to http://alabamarot.co.uk/99-99-of-dogs-walked-in-new-forest-will-not-die-of-alabama-rot/

The Forestry Commission website reminds us that:
"Many thousands of dogs are walked in the countryside every day and it is important to remember that only a very small number of dogs have been affected [by Alabama Rot]." (1)
A report by England Marketing for the Forestry Commission in 2005 stated:
"in addition to the 37,600 dogs which regularly walk in the New Forest, it is estimated that there are a further 600,000* dog visits per year." (2) 
*There were 7.5m visitor days to New Forest in 2005 - Tourism South East estimates that 8% bring their dogs, so 600,000 dog visits per year (2)

NB. figures for numbers of visitors to New Forest in 2013/14 are not available.

i.e. 637,600 dogs walked in New Forest in 2005

In two years (December 2012 - December 2014) twenty three dogs died of Alabama Rot in the New Forest (sixteen confirmed (red paws) and seven unconfirmed cases (yellow houses). Six dogs survived Alabama Rot (blue anchors) - see map below. (3)

Between December 2012 - December 2014 twenty three dogs died of Alabama Rot in the New Forest - sixteen confirmed (red paws) and seven unconfirmed cases (yellow houses). Six dogs survived Alabama Rot (blue anchors) (3)
637,600 dogs walked in 2005 in the New Forest. Over a two year period between December 2012 and December 2014 twenty three died of Alabama Rot. From these figures, 1 in 13,860 dogs walked in the New Forest died of Alabama Rot (637,600 / 23 / 2).

As expected, the more dogs walked in an area of the New Forest, the larger number of cases of Alabama Rot. Note: the greatest number of cases of Alabama Rot are in the rectangle between Ringwood, Brockenhurst, Sway and Bransgore (map above).

This correlates with the frequency of dog walkers (map below). (2)

Frequency of dogs walked in the New Forest

Other Assumptions

1) The same number of dogs were walked in 2005 and 2013/2014
2) All dog deaths from Alabama Rot are recorded.

Summary

Between December 2012 and December 2014, fewer than 1 in 13,000 dogs walked in the New Forest, died of Alabama Rot. To put it another way, more than 99.99% of dogs walked in the New Forest did not die of Alabama Rot.

References

(1) Cutaneous and Renal Glomerular Vasculopathy (CRGV or ‘Alabama Rot’), Forestry Commission http://www.forestry.gov.uk/alabamarot (accessed 4th February 2015)
(2) Forestry Commission –Dog Walkers, England Marketing, 2005, http://www.forestry.gov.uk/pdf/new-forest-dog-study.pdf/$file/new-forest-dog-study.pdf
(3) Alabama Rot Google Map by Chris Street
https://www.google.com/maps/d/edit?mid=zIJgTtl9x6zk.kif7awTR9hAA

Sunday 1 February 2015

In area between Ringwood, Bransgore and Brockenhurst is it more likely for dogs to be confirmed with Alabama Rot?


9 cases (red paws) of dogs with confirmed Alabama Rot in 45.9 km2 area bounded by Ringwood, Bransgore and Brockenhurst
Between December 2012 and December 2014 there have been 46 confirmed cases of Alabama Rot. (1)

Nine confirmed cases (see red paws in map above) of Cutaneous and Renal Glomerular Vasculopathy (CRGV) aka Alabama Rot are in a 45.9km2 (17.7 mile2) area triangle bordered by Ringwood, Bransgore and Brockenhurst. This represents 1 case per 5.9km2 (45.9/9) (1)

Note: In the map above, the four yellow huts are unconfirmed cases of dogs who died from Alabama Rot; the four blue anchors are unconfirmed cases of dogs surviving Alabama Rot.

In England, there appears to be three Alabama Rot cluster areas - areas with 4 or more confirmed cases of Alabama Rot. The three areas are the New Forest, Greater Manchester and Guildford. In these three areas there have been 26 cases covering an area of 593 km2. (1)

There are twenty one cases of dogs with confirmed Alabama Rot outside the three clusters - in the rest of England.  These twenty one cases are spread over an area of 97,070 km2 (97663-593 km2) or 1 case per 4622 km2. (2)



On a case per area basis, confirmed Alabama Rot cases are reported in the 'Ringwood - Bransgore - Brockenhurst' cluster triangle 783 times (ie 4622/5.9 case per km2) more frequently than in the rest of England.

However, this analysis has several weaknesses:
1) It does not take into account the total number of dogs walked in the area or the total number of miles walked. A map of confirmed Alabama Rot cases versus dogs numbers walked in an area, will be posted.

2) It is possible that cases of Alabama Rot are not reported uniformly by vets throughout England - the lead vets, Anderson Moores Veterinary Specialists, are based in Winchester, Hampshire. So vets in New Forest may be reporting a larger proportion of confirmed Alabama Rot cases than elsewhere in UK. A poll of UK vets would establish this.

3) It makes the assumption that clusters do not occur by chance. Further statistical analysis is required.

(1) Alabama Rot UK Graph: https://www.google.com/maps/d/edit?mid=zIJgTtl9x6zk.kif7awTR9hAA
(2) http://crgv-alabamarot.blogspot.co.uk/2015/01/clusters-of-alabama-rot.html

Sunday 25 January 2015

Clusters of Alabama Rot?

reposted to: http://alabamarot.co.uk/clusters-of-alabama-rot/

Are the 3 'clusters' (see (1) Alabama Rot UK Map) of confirmed cases of Alabama Rot around Greater Manchester, New Forest and Guildford indicative of an Alabama Rot causing environmental factor at a higher concentration relative to other non-cluster areas of England?

There have been 47 confirmed cases (the red paws in the maps below) of Alabama Rot in England between December 2012 and 25th January 2015.

Greater Manchester has a cluster of 6 cases in approx. 122km2 area or 1 case per 21km2 (using the Google map area measurement tool)

Greater Manchester has a cluster of 6 cases in approx. 122km2 area or 1 case per 21 km2
The New Forest has a cluster of 16 cases in approx. 378km2 area or 1 case per 24 km2

The New Forest has a cluster of 16 cases in approx. 378km2 area or 1 case per 24 km2
Guildford has a cluster of 4 cases in approx. 93km2 or 1 case per 23km2.

Guildford has a cluster of 4 cases in approx. 93km2 or 1 case per 23km2.

Adding up all 3 clusters (New Forest, Greater Manchester and Guildford), 26 cases occur in 593 km2 or average 1 case per 23 km2.

Area that bounds all English cases is approx. 97,663 km2.
Area that bounds all English cases is very approx. 97,663 km2.

The 21 cases (47 total less 26 in clusters) not occurring in clusters are spread over an area of  97,070 km2 (97,663-593 km2) or 1 case per 4622 km2.

Therefore dogs walked in the 3 cluster areas (Greater Manchester, New Forest and Guildford) seem to be at x200 (4622/23) greater risk of dying from confirmed Alabama Rot than dogs walked in non-cluster Alabama Rot areas.

But are these 3 clusters statistical flukes? What is likelihood that these clusters could occur by chance?

References
(1) Alabama Rot UK Map: https://www.google.com/maps/d/edit?mid=zIJgTtl9x6zk.kif7awTR9hAA

Friday 23 January 2015

Half Alabama Rot confirmed cases reported in New Forest, Greater Manchester, Guildford

Reposted to http://alabamarot.co.uk/half-of-crgv-cases-are-in-new-forest-greater-manchester-or-guildford/

There have been forty six confirmed cases of Alabama Rot in dogs in England between December 2012 to December 2014 (a further one case was in Northern Ireland):

Twenty five cases - more than half of all cases (54% of all confirmed cases) are in three cluster regions: the New Forest - sixteen cases (34%), Greater Manchester - five cases (11%) and Guildford, Surrey - four cases (9%). (Street 2014c)

A further twenty one cases (46%) were reported in the rest of England.



Further analysis by a statistician is required to determine whether these clusters occur by chance.

Reference

STREET, C.G., 30th December 2014, 2014c-last update, UK map of Alabama Rot (CRGV) cases in dogs since 2012. Available: https://www.google.com/maps/d/edit?mid=zIJgTtl9x6zk.kif7awTR9hAA