Location patterns and risk factors for Alabama Rot in UK dogs

Kim Stevens, Dan O’Neill, Rosanne Jepson, Laura Holm, David Walker and Jacqueline Cardwell have a paper published in Vet Record (1), available for free courtesy of Sci-Hub  sci-hub.tw/10.1136/vr.104892

AlabamaRot.co.uk blogged about the funding for this Kim Stevens managed project, in October 2017.

Abstract

“The annual outbreaks of cutaneous and renal glomerular vasculopathy (CRGV) reported in UK dogs display a distinct seasonal pattern (November to May) suggesting possible climatic drivers of the disease. The objectives of this study were to explore disease clustering and identify associations between agroecological factors and CRGV occurrence. … The majority of diagnoses (92 per cent) were reported between November and May while the number of regions reporting the disease increased between 2012 and 2017. Two significant spatiotemporal clusters were identified—one in the New Forest during February and March 2013, and one adjacent to it (April 2015 to May 2017)—showing significantly higher and lower proportions of cases than the rest of the UK, respectively, for the indicated time periods. A moderately significant high-risk cluster (P=0.087) was also identified in the Manchester area of northern England between February and April 2014. Habitat was the predictor with the highest relative contribution to CRGV distribution (20.3 per cent). Cases were generally associated with woodlands, increasing mean maximum temperatures in winter, spring and autumn, increasing mean rainfall in winter and spring and decreasing cattle and sheep density. Understanding such factors may help develop causal models for CRGV occurrence.”

When does CRGV occur?

See figure 1 below:

The heat map shows that the much higher prevalence of CRGV in November-May compared to June-October.

Where are most cases?

See Figure 3 below

CRGV by Breed

Of the five most commonly specified breeds in the study population (labrador retriever, Staffordshire bull terrier, Jack Russell terrier, cocker spaniel and German shepherd dog), three were under-represented among CRGV dogs: Staffordshire bull terriers, Jack Russell terriers and German shepherd dogs. Conversely, breeds that were over-represented among CRGV dogs were generally the less common breeds such as English springer spaniels, Whippet, Hungarian Vizsla, Flat-coated retriever and Manchester terrier. See Table 1 in the report.

Predicting CRGV location

 

Conclusion

“In conclusion, the results of this study suggest that gun dogs and hounds have an increased risk of developing CRGV in the UK, while toy dogs and terriers appear to be the breed groups least at risk. Specific breeds with increased odds of CRGV included Hungarian vizslas, flat-coated retrievers, whippets and English springer spaniels. As well as helping veterinarians develop an index of suspicion for the disease, an understating of the breeds at risk may help to develop causal models for CRGV, and potentially play a role in identifying the aetiology of the disease. However, further studies investigating the distribution of specific breeds and breed groups in the UK, and the factors driving these distributions, would help to determine whether the high-risk breeds and breed groups identified in this study are indeed inherently more disposed to being diagnosed with CRGV or whether the results stem from an increased proportion of such breeds in areas of greater risk.”

References

(1) Stevens, KB., Jepson, R., Holm, LP., Walker, DJ., Cardwell, JM. (2018) Spatiotemporal patterns and agroecological risk factors for cutaneous and renal glomerular vasculopathy (Alabama Rot) in dogs in the UK Veterinary Record Published Online First: 27 August 2018. doi: 10.1136/vr.104892

Red-leg syndrome disease in amphibians may be related to CRGV (Alabama Rot) in dogs

Vet Times October 12th 2018 reports that fish vet Dr Fiona Macdonald has revealed further possible links between cutaneous and renal glomerular vasculopathy (CRGV) affecting dogs, and the UK amphibian disease red-leg syndrome (see 2015 blog post by AlabamaRot.co.uk).

Aeromonas hydrophila (A hydrophila) bacteria may be involved in the cause or aetiology of CRGV (Alabama rot). The bacterium is found in watercourses and soil and is associated with diseases of fish and amphibians. A hydrophila causes ulcerative skin lesions in fish, with subsequent kidney failure. In amphibians (frogs, toads and newts} the bacteria causes ‘red-leg syndrome’ -redness of the skin, open sores which can result in death.

Serology test

“Dr Macdonald developed a serology test with Biobest Laboratories to look at the possibility of antibodies to A hydrophila. Samples were obtained from veterinary practices around the country – from Aberdeenshire to the south-west of England – mainly from both suspected and confirmed cases of CRGV, as well as in-contact dogs”, reports Vet Times.

She found some dogs showed antibody response to A. hydrophila which has a similar UK geographical spread pattern to CRGV.

Dr Macdonald observed: “Although A hydrophila is implicated in a major disease problem in amphibians – red-leg syndrome – this is associated with a Ranavirus*. There is some evidence the Ranavirus may be the primary pathogen, with the A hydrophila as an opportunist”, reports Vet Times.

*Ranavirus is a virus that infects amphibians (Wikipedia). Read about co-infection of amphibians with Ranavirus and A hydrophila

Read more in Vet Times October 12th 2018.

MP writes to DEFRA minister about Alabama Rot

On 12th June 2018, Victoria Prentis MP (Conservative, Banbury) wrote:

“To ask the Secretary of State for Environment, Food and Rural Affairs, whether his Department is carrying out research to evaluate the cause of and potential threats posed by Alabama Rot to dogs in the UK; and if he will make a statement.”

George Eustice The Minister of State, Department for Environment, Food and Rural Affairs (DEFRA) replied on 20th June:

“A private veterinary group is coordinating an investigation into the cause of the syndrome known as cutaneous and renal glomerular vasculopathy (CRGV) in the UK, which is sometimes referred to as Alabama rot. The Animal and Plant Health Agency has been engaging with this investigation since the outset and continues to do so.”

Source: Hansard HC Deb, 20 June 2018, cW

 

I assume the private veterinary group is Anderson Moores.

Aeromonas hydrophila bacteria not ruled out as Alabama Rot cause

AlabamaRot.co.uk has covered reports about Aeromonas hydrophila here, here and here. Vet Fiona Macdonald hypotheis is that Aeromonas hydrophila bacteria may be a factor in triggering Alabama Rot when conditions are rainy and cold.

The Vet Times report:

Specialist vet studies bacteria cause of Alabama rot Vet Fiona Macdonald is researching whether Aeromonas hydrophila is a link to identifying cause of deadly canine disease. A specialist fish vet is investigating an organism described as “a possible stepping stone” to identifying the cause of one of the UK’s most baffling and lethal canine diseases.

Fish vet Fiona Macdonald is researching whether Aeromonas hydrophila, a heterotrophic, Gram-negative, rod-shaped bacterium, present in water sources and soil, might be involved in the aetiology of CRGV.

In a document sent to Veterinary Times entitled “CRGV (Alabama rot) – an organism of interest?”, Dr Macdonald explained: “There is a suspicion initial cases of CRGV occurred in areas with substantial amounts of water as a result of unusually high rainfall; both running and standing water was close to 4°C for some weeks around the time of the cases.

“To date, dogs appear to be the only species affected, with no reported cases in wild ponies, foxes, cattle or deer. There have been recorded cases of infection with A hydrophila in dogs, which mirrored Leptospira infections, and this pathogen has been on the list of possible causes of CRGV since early manifestations of the problem.”

Dr Macdonald is receiving funding for her work from the New Forest Dog Owners Group, and is appealing for help from UK vets.

She said: “I want blood samples from suspected CRGV cases and I’m happy to send out swabs along with a sampling protocol to any vet for them to swab any suspicious lesions. Email me at fiona@fish-treatment.co.uk”

David Walker, from Anderson Moores Veterinary Specialists, and the UK’s leading authority on CRGV, said: “It’s a nice piece of work… I’m hoping she publishes because it’s a possible stepping stone for either her, or others, to take on the work and truly include or exclude this organism in the Alabama rot investigation.””

The International Animal Health Journal (1) said:

“A bacterium that causes ulcerative skin lesions and kidney failure in fish could be linked to cases of Alabama rot in UK dogs, current research suggests.

Fish vet Dr Fiona Macdonald is co-ordinating a study into whetherAeromonas hydrophila could be a possible cause of cutaneous and renal glomerular vasculopathy (CRGV), also known as Alabama rot.”

The cause is not known yet…

“While the cause is not yet known, it appears to have a seasonal aspect, with most cases occurring between November and June. Initial cases occurred in areas with substantial amounts of water, as a result of unusually high rainfall, during cold weather. Both running water and standing water were 4ºC for some weeks at the time of the cases.”

Does A hydrophila grow in skin lesions causing Alabama Rot?

“A hydrophila was first recorded in dogs in 1995. It is known to cause ulcerative skin lesions in both ornamental and farmed fish, with subsequent kidney failure. The UK strains prefer cold, which could be why it grows in the skin lesions – as they are cooler than the rest of the body.”

A test for A hydrophila antibodies

“Diagnostic laboratory BioBest, in Edinburgh, developed a specific test for A hydrophila antibodies in serum. Dr Macdonald says a significant number of blood samples submitted from suspected CRGV cases, strongly indicated an immune response to the organism. The samples came from dogs living in rural areas across the UK, from southern Scotland to Devon.”

But the evidence for A hydrophila is weak with only one case

“Specialist transport medium swabs have also been sourced to sample skin lesions on first presentation to a veterinary surgeon. These are subjected to specific culture conditions for Aeromonads. So far, Dr Macdonald says there has been only one positive isolation of the organism from a swab taken from a suspect lesion. This dog also produced a positive antibody response to the organism.”

Research thus far has also involved testing canine kidney cells in tissue culture to determine if there are any effects associated with the A hydrophila. Dr Macdonald says the theory is that toxins from the organisms cause kidney problems in affected dogs, rather than direct infection by the organism itself. This could explain why the organism has never been isolated so far in affected dog kidneys.

Results show that both the medium in which the organism has been grown, and the inactivated organism, killed the dog kidney cells in tissue culture – even after significant dilution. Dr Macdonald says this goes a long way to confirming the involvement of bacterial toxins.

Going forward, the project needs many more samples to draw firm conclusions, but the early results have been described as ‘very promising’.

References

  1. 1) International Animal Health Journal http://animalhealthmedia.com/fish-vet-identifies-possible-cause-alabama-rot/ (accessed 30th January 2018)

Alabama rot dog disease cases mostly occur in autumn/winter

The BBC report Royal Veterinary College researcher Dr Kim Stevens who confirms that about 60% of cases of Alabama rot, which has killed more than 100 dogs in the UK, occur in the first three months of the year.

New research by Kim Stevens has started to try and discover more about the risk factors and spread of the disease. The cause of the disease, which first occurred in the UK in 2012, is still unknown. However, researchers have found there are more cases in autumn and winter. Most deaths caused by the disease have happened in Hampshire, Dorset and Greater Manchester*.

The disease causes lesions on the skin and occasionally in the mouth. Some dogs can also develop life-threatening kidney failure.

Dr Kim Stevens, of the Royal Veterinary College, said her research, expected to conclude by the end of the year, would not identify the specific cause of the disease. She said it was instead designed to look for geographical patterns, as well as environmental and climatic risk factors. A “very obvious” pattern already found was linked to seasons, she added:

“There are limited cases over the summer whereas everything starts to pick up in November and at least 60% of the cases occur in the first three months of the year, so it’s very much an autumn/winter pattern that we’re looking at.”

UK dog deaths from Alabama rot since 2012

Berkshire 2
Cheshire 4
Cornwall 1
County Durham 2
Cumbria 1
Devon 4
Dorset 10
Dumfries and Galloway 1
East Sussex 3
Greater Manchester 12
Hampshire 18
Kent 2
Lancashire 2
Lincolnshire 1
London 3
Monmouthshire 5
North Yorkshire 1
Northamptonshire 1
Nottinghamshire 2
Shropshire 1
Somerset 2
Staffordshire 2
Surrey 6
Warwickshire 1
West Sussex 3
West Yorkshire 2
Wiltshire 3
Worcestershire 5
Wrexham 1
Source: Royal Veterinary College/Stop Alabama Rot

*  from the list of dog deaths by county, 40 of the 101 confirmed deaths since 2012 occurred in Dorset, Hampshire or Greater Manchester.

Epidemiology and cause of Alabama Rot project

First some definitions. Epidemiology is defined by Oxford Dictionaries as “the branch of medicine which deals with the incidence, distribution, and possible control of diseases and other factors relating to health”.  It is also the study of the causation of epidemic diseases according to Wikipedia. And CRGV is the scientific name for Alabama Rot.

This week the Alabama Rot Research Fund (ARRF) have reported funding an Alabama Rot / CRGV Epidemiology project by Dr Kim Stevens:

Continue reading “Epidemiology and cause of Alabama Rot project”

Google Trends – Alabama Rot

Awareness about Alabama Rot has peaked since David Walker of Anderson Moores went on Breakfast TV on 10th May to discuss the disease. The last maximum peak was in January 2014 when signs about Alabama Rot were placed in New Forest car parks.

Google Trend – Alabama Rot – Last 5 years


Interest over time

Numbers represent search interest relative to the highest point on the chart. A value of 100 is the peak popularity of the term. A value of 50 means that the term is half as popular. Likewise, a score of 0 means the term was less than 1% as popular as the peak.

Anderson Moores thank AlabamaRot.co.uk – Reading May 10th Conference

I attended the Reading Alabama Rot conference on Wednesday 10th May 2017. The conference was organised by David Walker and Laura Holm from Anderson Moores. There were 30 attendees and Bayer kindly paid travel expenses.

Today I received a very nice email from Anderson Moores:

Subject: RE: May 10th Conference

Dear Chris

David and I would like to extend our sincere thanks to you for attending the meeting yesterday.

Your input was very valuable and we really appreciate you making time to be there. Thank you also for taking time to look into and print off the case distributions by month / season.

Thank you so much again,

With kindest regards,

Laura and David

Laura Holm BVM&S CertSAM MRCVS
RCVS Advanced Practitioner in Small Animal Medicine

David Walker BVetMed (Hons) DipACVIM DipECVIM-CA MRCVS,
American and European Specialist in Small Animal Internal Medicine

Information about the Reading conference will be posted online soon.

Chris Street BSc MSc

AlabamaRot.co.uk

Bransgore, Dorset