Spatiotemporal patterns and agroecological risk factors for cutaneous and renal glomerular vasculopathy (Alabama Rot) in dogs in the UK

Clinicopathological features of cutaneous and renal glomerular vasculopathy in 178 dogs

BACKGROUND

One hundred seventy-eight dogs with cutaneous and renal glomerular vasculopathy (CRGV) were evaluated to further the understanding of the natural course of CRGV. CRGV, a form of thrombotic microangiopathy, can cause skin lesions and potentially acute kidney injury (AKI) with a high mortality rate.

METHODS

Cases were submitted from multiple practices from 2012 until June 2019. Clinical histories and laboratory data were reviewed to describe the features of CRGV.

RESULTS

Most cases (91%) occurred between November and May. Fifteen dogs (8.4%) with CRGV were in contact with another dog that developed skin lesions +/- AKI. Limb lesions were present on 144 dogs (80.9%) at presentation. Median time from appearance of a lesion to AKI was 3 days (range -4-45 days). Neurological signs occurred in 33 dogs (18.6%) including at presentation in 2 (1.1%). Systemic signs were present in 13 dogs prior to a skin lesion (7.3%). Non-steroidal anti-inflammatory drugs were prescribed prior to AKI identification in 92 of 170 dogs (54.1%). Thrombocytopenia was present in 115 of 137 (83.9%) of dogs.

CONCLUSION

The timeframe over which AKI may develop is longer than previously reported, neurological signs can be identified at presentation or during hospitalisation, and thrombocytopenia is even more common than previously reported.

Pathology and Epidemiology of Cutaneous and Renal Glomerular Vasculopathy in Dogs

Cutaneous and renal glomerular vasculopathy (CRGV) has been recognized as a potentially life-threatening condition of dogs in the UK since 2012, although there was a single (non-azotaemic) case reported in the UK in 2000. Prior to that, CRGV was recognized in the 1980s in southern USA as a disease affecting solely racing greyhounds (which gave rise to the colloquial name of 'Alabama rot'). CRGV manifests as ulcerative skin lesions, generally sparing the dorsum. It is variably associated with systemic signs including anaemia, thrombocytopenia and acute kidney injury, which, when it develops, is often severe and fatal. CRGV is characterized histopathologically as a thrombotic microangiopathy. To date in the UK, more than 230 dogs of varying breed and age have been humanely destroyed and histopathologically confirmed to be suffering from CRGV. The aetiology remains unknown, but the seasonal distribution (highest case incidence November-May each year) suggests that environmental or climatic factors may play a role in disease development. Further research to determine the aetiology and improve ante-mortem diagnostic testing, therapeutic options and preventive strategies is urgently needed.

Canine cutaneous and renal glomerular vasculopathy in the Republic of Ireland: a description of three cases

Background

Cutaneous and renal glomerular vasculopathy (CRGV) is a condition of unknown aetiology involving microvascular thrombosis. It has recently been described in over 160 dogs in the United Kingdom and usually has a grave prognosis. To date, this condition has not been described in dogs residing in the Republic of Ireland.

Case presentation

Three dogs presented to University College Dublin Veterinary Hospital (UCDVH) for investigation of rapidly progressive skin lesions. All dogs were diagnosed with CRGV on post-mortem examination. All three dogs had azotaemia on presentation or rapidly developed azotaemia, and all were euthanased because of progression of clinical signs and likelihood of CRGV. One dog was affected by seizure-like episodes and had thrombotic microangiopathy evident within the cerebrum.

Conclusions

CRGV occurs in dogs residing in the Republic of Ireland and is a differential for cases presenting with skin lesions and azotaemia. The histopathological lesions of CRGV can also affect the brain leading to neurological signs such as seizures. Owners and veterinarians should be aware that this condition can occur in dogs in Ireland.

Cutaneous and Renal Glomerular Vasculopathy: What Do We Know so Far?

Cutaneous renal glomerular vasculopathy (CRGV), colloquially named "Alabama rot," is an emerging condition in the United Kingdom, previously reported from the United States and Germany. The cause of CRGV is not yet determined; no definitive link to an infectious agent has been made. Dogs diagnosed with CRGV initially develop cutaneous lesions, and a proportion of these dogs go on to manifest acute kidney injury, which may result in oligoanuric acute renal failure. Antemortem diagnosis is challenging given the lack of a specific diagnostic test, and confirmation of CRGV is therefore currently dependent on identification of thrombotic microangiopathy on renal histopathology.