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431.e2 Hemolytic Uremic Syndrome

Hemolytic Uremic Syndrome Client Education
Sheet
VetBooks.ir Clinical Presentation

BASIC INFORMATION
DISEASE FORMS/SUBTYPES • Any disease causing AKI or vasculitis
• Immune-mediated hemolytic anemia
Definition HUS and CRGV are similar, although
An uncommon, severe thrombotic micro- HUS typically does not have the cutaneous Initial Database
angiopathy that mainly affects the kidney lesions associated with CRGV. The UK • CBC, serum biochemistry profile, urinalysis
is characterized by hemolytic anemia, acute cases appear to start with ulcerations of the ○ Anemia, schistocytosis, and thrombocy-
kidney injury (AKI), and thrombocytopenia. distal limbs. topenia are typical.
This disease in humans is usually associated with ○ Azotemia and isosthenuria may pre-
Shiga toxin–producing Escherichia coli (STEC) HISTORY, CHIEF COMPLAINT cede, coexist, or be absent. Generally,
infections and diarrhea or other gram-negative • History may include feeding raw or under- increased blood urea nitrogen, creati-
bacteria that produce Shiga toxins. A similar cooked beef. Although not always reported, nine, and phosphorus are seen. Hyper-
syndrome has been reported in dogs and cats the initial complaint is usually hemorrhagic kalemia or other electrolyte changes are
with recent outbreaks in dogs in the United diarrhea. Diarrhea episodes may occur up to possible.
Kingdom. 2 weeks before the onset of HUS-associated ○ Proteinuria possible with glomerular
clinical signs. disease (CRGV)
Synonyms • Lethargy or cutaneous lesions may be the ○ Hemoglobinuria is common (discolored
Alabama rot, cutaneous and renal glomerular primary complaint, along with vomiting, urine; positive hemoprotein result on
vasculopathy (CRGV) of greyhounds, Green- limb edema, and anorexia. dipstick but no erythrocytes on sediment
track disease • History may include walking in UK damp exam).
forest regions. • Coagulation panel with D-dimer or fibrin/
Epidemiology fibrinogen degradation product (FDP) analy-
SPECIES, AGE, SEX PHYSICAL EXAM FINDINGS sis: evidence of thrombosis (e.g., increased
• Mainly dogs; rare in cats • In CRGV, cutaneous lesions are multifocal D-dimer or FDPs, decreased platelet count),
• No age or sex predisposition erythematous swellings commonly located normal to slightly prolonged PT, increased
on the tarsus, stifle, medial thigh, and rarely, or normal fibrinogen
GENETICS, BREED PREDISPOSITION forelimb. Lesions may become ulcerated with • Urine culture: rule out urinary tract infection
Reported originally (and most often) in racing serosanguineous discharge. as cause of proteinuria.
greyhounds. Genetic predispositions are difficult • Physical findings common to CRGV and • Arterial blood pressure measurement: rule
to evaluate because of outbreaks in affected HUS include those typical of anemia and out systemic hypertension associated with
kennels among littermates with a common acute oliguric or anuric kidney injury, with renal disease.
food source. Recent infections in the United hemoglobinuria often present.
Kingdom involve non–greyhound dogs. Advanced or Confirmatory Testing
Etiology and Pathophysiology • Abdominal ultrasound ± renal biopsy. Assess
RISK FACTORS • Circulating Shiga toxins from STEC, usually blood pressure and platelet count first.
A diet including raw or undercooked meat serotype 0157:H7, cause endothelial injury • Skin biopsy of representative lesions
may predispose to STEC infections. Certain that generates a systemic prothrombotic • Culture of feces on sorbitol MacConkey agar
UK regions of moist forest are suspected of response, microangiopathic hemolytic for STEC 0157:H7
harboring a causative organism. anemia, and kidney injury.
• Complement hyperactivation leading to TREATMENT
CONTAGION AND ZOONOSIS endothelial damage and subsequent micro-
Contaminated beef ingestion is most widely vascular thrombosis may be a significant Treatment Overview
responsible for hemolytic uremic syndrome contributor to the pathophysiology of HUS. Treatment mainly consists of aggressive
(HUS) in humans, and common-source • Glomerular disease causing proteinuria and intravascular fluid/volume replacement, blood
exposure can affect pets. There have been reports potentially kidney injury noted in cutaneous transfusions as needed, blood pressure lowering
of outbreaks among children associated with and renal glomerular vasculopathy agents as needed, and general supportive care
petting zoos. (e.g., nutrition, soft padded bedding, urinary
DIAGNOSIS catheter). Early referral to a regional dialysis
GEOGRAPHY AND SEASONALITY center should be considered for animals with
• First noted in Alabama dog racing tracks Diagnostic Overview oliguric/anuric AKI.
and, most recently, outbreaks associated with Diagnosis is suspected based on the history of
multiple UK counties exposure to raw or undercooked meat and the Acute General Treatment
• As of May 2017, there were 102 confirmed clinical signs of diarrhea, possibly cutaneous Aggressive intravascular volume expansion with
cases reported in the United Kingdom. lesions, and the laboratory signs of azotemia, crystalloids during the diarrhea phase (early)
anemia ± thrombocytopenia. Confirmation appears to be preventive for the renal failure
ASSOCIATED DISORDERS requires a positive fecal culture for STEC component of this disease in children.
• Similar condition noted in some cats after 0157:H7 on sorbitol MacConkey agar. Recent • Treat oliguric or anuric kidney injury
renal transplantation outbreaks are diagnosed based on a lesions intensively (p. 23).
• Important to distinguish the thrombotic of the distal limbs followed by acute renal ○ Transfusion if severe anemia, physical/
signs of HUS from those associated with failure. laboratory signs of decreased perfusion
disseminated intravascular coagulation such as depressed mentation, weak pulses,
(DIC). Prothrombin time is normal or Differential Diagnosis cold extremities, increased lactate
slightly increased, and fibrinogen is normal • Leptospirosis, sepsis, systemic inflammatory ○ Consider early referral to a regional dialysis
or high with HUS compared with DIC. diseases center.

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