Non azotaemic cutaneous and renal glomerular vasculopathy/Alabama Rot – Advice Sheet for Vets

Given the high level of public concern re CRGV (or Alabama Rot), you may have been presented with a dog with a skin lesion of unknown cause.

As there is no ante mortem test for this disease, we would like to try to provide you with some useful information regarding approach to these cases.

Current evidence suggests that the median time to development of azotaemia from the onset of a skin lesion is 3 days (range 0-10 days) and in these dogs 50% are thrombocytopaenic at presentation, 30% are hyperbilirubinaemic and 20% are anaemic.

However, there appear to be a subset of dogs that develop a skin lesion(s) without ever developing azotaemia (non-azotaemic CRGV).

The appearance of CRGV skin lesions is variable, although often the lesions are deemed atypical compared to a usual 1st opinion dermatology case load (see images below). The lesions are generally ulcerated, with variable bruising and oedema, and most commonly affect distal limbs, ventrum, muzzle and tongue.

If you are presented with a dog and you are concerned about the possibility of CRGV, and the dog is non azotaemic, then the following options could be considered:

  • Admit for fluid therapy and monitoring. We currently have no evidence regarding whether fluid therapy prior to the development of acute kidney injury (AKI) changes outcome in the euvolaemic patient. The minimum monitoring should be daily BUN and creatinine concentrations; however, urine output and platelet count may fall before development of azotaemia in dogs which develop AKI, therefore haematology and smear to assess platelet count and (at least subjective) monitoring of urine output should also be considered. Haemoglobinuria and proteinuria can also suggest that AKI may be developing, therefore daily urinalysis can also be considered.
  • Outpatient monitoring: Discharge from the clinic with repeat biochemistry (urea and creatinine) and urinalysis +/- haematology (platelet count) q 24-48 hours
  • Discharge with no follow up unless owner has concerns

As there is currently no way to predict which dogs will develop AKI and which will not, the decision regarding admission for IVFT, versus monitoring as an outpatient, depends on your level of clinical concern for the patient and the owner’s level of concern and wishes.

Things that would increase clinical concern re potential development of AKI include (but are not limited to):

  • the presence of multiple skin lesions,
  • skin lesions with a lot of surrounding bruising / oedema,
  • large skin lesions,
  • the presence of pyrexia,
  • dogs which appear systemically unwell - e.g. anorexia, stiffness, pronounced lameness on limb(s) with skin lesion(s)
  • and / or any compatible changes on haematology, biochemistry or urinalysis (e.g. hyperbilirubinaemia, elevated serum liver enzyme activity, mild thrombocytopaenia, haemoglobinuria, proteinuria, presence of casts).
  • NB the absence of any of these unfortunately does not guarantee that the dog will not develop AKI. Neither does the presence of any of these mean that the dog will definitely develop AKI.

For those dogs which do develop AKI, things can change for the worse very rapidly, so close monitoring of these cases is always advised, even though the majority of cases will not develop AKI, and their skin lesions will heal fully with time.

We would suggest that non-steroidal anti-inflammatory drugs are avoided in suspected CRGV cases. Antibiotics may be appropriate if the skin lesion appears to be secondarily affected.

Referral should be strongly considered in azotaemic, suspected CRGV cases. We are always happy to discuss cases on an individual basis.

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Published: 10-06-2015

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