Cerebral Microangiopathy in Two Dogs with Cutaneous and Renal Glomerular Vasculopathy.

Cutaneous and renal glomerular vasculopathy (CRGV) is an emerging disease in the UK, but its aetiology remains unclear. It is considered a thrombotic microangiopathy (TMA) in which the kidney and skin are the most commonly affected organs. We now document two cases of CRGV with brain lesions, which may have accounted for neurological signs displayed by these animals. The histopathological brain lesions were similar to TMA lesions in humans with thrombotic thrombocytopaenic purpura (TTP) and complement-mediated haemolytic uraemic syndrome (CM-HUS), in which the neurological signs are more associated with TMA than with any systemic disease or electrolyte imbalance. Fibrinoid necrosis in brain arterioles and associated lesions in these dogs were similar to those in human CM-HUS, indicating that the alternative complement pathway may play an important role in the pathophysiology of CRGV.

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.

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.

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

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. Kernel-smoothed maps were generated to show the annual reporting distribution of CRGV, Kuldorff's space-time permutation statistic used to identify significant spatiotemporal case clusters and a boosted regression tree model developed to quantify associations between CRGV case locations and a range of agroecological factors. 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 of such factors may help develop causal models for CRGV occurrence.

Signalment risk factors for cutaneous and renal glomerular vasculopathy (Alabama rot) in dogs in the UK.

Seasonal outbreaks of cutaneous and renal glomerular vasculopathy (CRGV) have been reported annually in UK dogs since 2012, yet the aetiology of the disease remains unknown. The objectives of this study were to explore whether any breeds had an increased or decreased risk of being diagnosed with CRGV, and to report on age and sex distributions of CRGV cases occurring in the UK. Multivariable logistic regression was used to compare 101 dogs diagnosed with CRGV between November 2012 and May 2017 with a denominator population of 446,453 dogs from the VetCompass database. Two Kennel Club breed groups-hounds (odds ratio (OR) 10.68) and gun dogs (OR 9.69)-had the highest risk of being diagnosed with CRGV compared with terriers, while toy dogs were absent from among CRGV cases. Females were more likely to be diagnosed with CRGV (OR 1.51) as were neutered dogs (OR 3.36). As well as helping veterinarians develop an index of suspicion for the disease, better understanding of the signalment risk factors may assist in the development of causal models for CRGV and help identify the aetiology of the disease.