Why would a veterinarian test a healthy dog’s kidneys twice in 3 days?
Because right now it’s the only way of detecting if a dog is at risk of Alabama rot.
Alabama rot is a serious condition that creates headaches (and heartaches) from start to finish: There is no vaccine and no test, the early signs are vague, yet prompt treatment could save your pet’s life.
When Alabama rot is spotted early, aggressive supportive care gives the dog the best chance of recovery. With around 85% of cases not surviving, we need the odds tipping in our favor any way we can.
This is why, one Saturday morning, a dog named Elsa came in for a second blood test.
A Possible Case of Alabama Rot
Elsa the Labrador had been romping around a muddy woodland. The following day, her human noticed an ulcerated sore patch on the top of her paw.
The person had no idea how Elsa had hurt herself, and the area was slowly getting bigger.
Alabama rot is rare but tricky, not least because the early symptoms are vague.
Indeed, it’s not possible to tell an innocent skin sore, ulcer or scrape from the early signs of this serious condition. Elsa’s human was aware of this and eager to do everything possible for her dog.
In clinic, the sore paw looked just that: a small patch of hair loss with inflamed skin and a sticky discharge. It was also quite itchy, causing Elsa to lick at every opportunity.
Alabama rot lesions can be itchy (and painful), so there was little reassurance on the physical exam. The history of recent wintertime contact with mud didn’t ease our minds either — both mud and cold weather are known risk factors.
What to do? Test Elsa’s kidney function.
The Current “Best Test”
When the cause of Alabama rot remains a mystery, there is no diagnostic test.
What we do know is that Alabama rot (more correctly called cutaneous and renal glomerular vasculopathy, or CRGV) damages the kidneys.
Here’s the pattern of disease: It starts with skin ulcers or sores, and then micro-blood clots lodge in the kidney, like a blocked garbage disposal unit, to stop them from working.
This progression from normal kidneys to failure can take 1–9 days, with an average being 4 days.
Hence, the first day the dog is seen in clinic, we take a reference blood sample and repeat the test a few days later. Comparing the 2 results can tell us if the kidneys are completely normal or starting to struggle. If the second lot of test results are worse than the first, this flags Alabama rot as a possibility.
Elsa’s story has a happy ending: Her skin lesion settled down with antibiotics, and both blood tests came back normal.
To this day, her human doesn’t know how she hurt her paw but doesn’t care — because it wasn’t Alabama rot.
Next, let’s talk about symptoms, treatment and possible causes of Alabama rot.
Symptoms of Alabama Rot
Sore skin is common, especially in active dogs, so what else should you be alert for?
Again, the signs are vague and relate to skin sores and worsening renal function. So be vigilant for the following symptoms:
- These are usually below the elbow or mid-thigh, with the muzzle, tongue and belly also being common sites.
- The sores are painful, and the dog wants to lick them.
- The lesions are often circular.
- They range in size, from pinpoint to around 4 inches in diameter.
- Lack of energy
- Increased thirst and passing more urine
- Loss of appetite
- Sickness and diarrhea
In a nutshell, Alabama rot starts with non-healing skin sores, often on the legs or muzzle. After a few days, the dog lacks energy, goes off food and drinks a lot. Then the dog collapses and progresses into renal failure and organ shutdown.
Treatment of Alabama Rot
The problem is not so much the skin lesions (which can be managed with antibiotics and dressings) but rather the kidney damage.
Current treatment aims to support the kidneys and flush them through with intravenous fluids. Then other medications are added in to help:
- Reduce nausea.
- Protect against stomach ulcers.
- Flush the kidneys through.
- Control high blood pressure.
- Keep the dog comfortable.
Specialist centers are trialing new therapies, such as plasma transfusions, but so far, the benefits are largely unproven.
How much better, then, if we could identify a cause and move forward with targeted therapies?
This vet shares that Alabama rot is being found in dogs all around the UK:
Possible Causes of Alabama Rot
For too long, the cause of Alabama rot has evaded investigation. Whatever theory was currently under investigation, blood tests, tissue samples and swabs would come back negative. And without a known cause, vets can only fight the symptoms of this condition.
Earlier this year, a fish veterinarian, Dr. Fiona MacDonald, made a breakthrough. She discovered that a large percentage of Alabama rot cases tested positive for a bacterium, Aeromonas hydrophila, which is found in soil and water.
Aeromonas causes disease in fish and amphibians. This fits nicely with the pattern of sick dogs having exercised near standing water or in muddy conditions.
In addition, in fish and amphibians, Aeromonas is linked to a condition called red-leg syndrome. The latter bears a spooky resemblance to the symptoms of Alabama rot.
But is Aeromonas the whole story? Probably not.
Looking deeper into red-leg syndrome, a virus seems to be involved. Scientists now believe Ranavirus is the main cause. Think of Ranavirus as the ringleader, with Aeromonas an accomplice.
In science-speak, Ranavirus is the causative agent, while Aeromonas is an opportunistic invader.
So could this be the case with Alabama rot in dogs?
As yet, Dr. MacDonald has no proof. But she is amassing an impressive stack of clues. Much like assembling a jigsaw puzzle, these pieces fit nicely together … considering many are still missing.
Let’s take a closer look at the suspects.
All About Aeromonas
Did you know Aeromonas is implicated in biofilms?
This is the misty bloom on the stainless steel of your dog’s water bowl.1 No one is suggesting a dirty water bowl causes Alabama rot, but it’s one heck of a reason to keep that bowl clean.
Aeromonas loves brackish, stagnant water. In people, it has been linked to stomach upsets. Fish living in a soup of Aeromonas can become very sick. Indeed, sudden death may be the first symptom. But the fish also suffer a disease involving skin ulcers, decline and death.2 Sound familiar?
But here’s a puzzle: Aeromonas infections respond to antibiotics.
Although resistant to a widely used antibiotic (amoxicillin), it is sensitive to:3
Why, then, do dogs with suspected Alabama rot not get better when treated with antibiotics?
Could Ranavirus be the key?
Ranavirus in Fish and Amphibians
In the 1980s, a new disease decimated the UK frog population.
A project was set up to look into this (the imaginatively named Frog Mortality Project). With data collected from 85,000 frogs, the results pointed to infection with Ranavirus.
Where Did the Ranavirus Come From?
DNA analysis showed strong similarities with a strain of Ranavirus found in the North Americas. A coincidence?
Signs and Symptoms of Ranavirus in Frogs
Just as with Alabama rot, a precise diagnosis is tricky during life. A firm diagnosis is made at postmortems.
However, the following signs are common:
- Lack of energy
- Skin ulcers and sores
- Reddened skin
- Tissue death
- Bleeding and clotting disorders
- Organ failure
So could it be that Alabama rot is the product of not 1 but 2 infections?
With each infection deeply unpleasant in its own way, when combined together, they could indeed make for a deadly combination.
A lab test is pending that can detect Ranavirus from tissue samples. This will help work out if really sick dogs are actually co-infected.
One puzzle piece that needs solving is that Ranavirus prefers cool temperatures. Since dogs are warm-blooded, wouldn’t this stop the virus in its tracks?
Is there a clue in that the sores start on the extremities, such as the paws and legs, which are cooler than the rest of the body?
I will update this article as new developments emerge.
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- Smith, J., P.M. Fratamico and G. Uhlich. “Molecular Mechanisms Involved in Biofilm Formation by Food-Associated Bacteria.” Biofilms in Foods and the Beverage Industry (2009): 42–98. https://doi.org/10.1533/9781845697167.1.42.
- “Diagnosis of Aeromonas Hydrofila Infection in Fish.” Indiana Animal Disease Diagnostic Laboratory. 1991 Newsletters. https://www.addl.purdue.edu/newsletters/1991/aeromonas.shtml.
- Stevens, Dennis L. “Cellulitis, Pyoderma, Abscesses, and Other Skin and Subcutaneous Infections.” Infectious Diseases (Fourth Edition) 1 (2017): 84–94. https://doi.org/10.1016/B978-0-7020-6285-8.00010-1.