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.