Cinco

Chief Complaint:	3 day history of anorexia and weakness
Signalment:	5 year old Spayed Female, Chesapeke Retriever dog, 34.6 kg
History:	Hunting dog; prior medical problems limited to mild otitis externa
Physical examination:	Lethargic, 5 - 8 % dehydrated, midabdominal tenderness.  TPR: Within normal limits.
QUESTION:	What are your big categories of rule-outs for Cinco's  weakness/lethargy ?

Clinicopathologic evaluation:

CBC				SERUM BIOCHEMISTRY PROFILE
TEST	RESULTS	Reference Range		TEST	RESULTS	Reference Range
WBC K/uL RBC M/uL Hbg/dl HCT % MCV fml MCHpg MCHC  RDW Platelets K/uL Eos/uL Bands/uL Polys/uL Lymph/uL Monos/uL Retics %	24.2 4.24 9.5 29.2 69 22.4 32.5 15.9 124 0 0 21538 1210 1452 0.4	6.0-17.0 5.50-8.50 12.0-18.0 37.0-55.0 60-77 19.0-25.0 32.0-36.0 13.2-16.0 200-500 0-1250 0-300 3600-11500 1000-4800 150-1350		Glucose mg/dl BUN mg/dl   Creatinine mg/dl Sodium meq/l Potassium meq/l Na/K Ratio Chloride meq/l Carbon Dioxide meq/l Calcium mg/dl Phosphorus mg/dl Total protein g/dl Albumin g/dl Globulin g/dl Bilirubin mg/dl ALP u/L ALT u/L Gamma gt U/L Cholesterol mg/dl	105 139  5.1  156 4.1 38 121 20 9.2 8.8 4.9 2.6 2.3 0.2 58 25 1 192	65-130 6-29 0.6-1.6 140-158 4.0-5.7 27-40 100-115 18-26 8.0-12.0 3.0-7.0 5.4-7.6 2.3-4.0 2.7-4.4 0.0-0.5 10-84 5-65   2-10 150-275
Urine specific gravity:	1.022

Based on the history, physical examination, and clinicopathologic examination, the following medical problems were identified.

Medical Problems Identified:	Azotemia
	Neutrophilic & Monocytic Leukocytosis
	Thrombocytopenia
	Nonregenerative Anemia
	Hypoproteinemia
	Dehydration
	Lethargy
	Midabdominal Tenderness

 

QUESTION

What are your rule-outs and diagnostic plan for each problem listed above?

ASSESSMENT

The urine specific gravity < 1.030 in a dehydrated dog with azotemia is indicative of renal insufficiency (no other reason for a concentration defect was identified).  The good body condition of the dog and history of acute disease is supportive of acute renal failure.  We can not yet assume that Cinco's other medical problems are definitely associated with the acute renal failure.

 

Question:

What are the big categories of rule-outs that should be considered for acute renal failure in a dog?

In dog's with acute renal failure, the major of the therapy is supportive care.  There are a few specific etiologies of renal failure however, which if identified, may be treated specifically.

Question:

In the Northwestern United States, which etiologies of ARF potentially have specific therapies?

 

Question:

What is your diagnostic plan for Cinco's acute renal failure?

 

Current Status

Urine was collected for an aerobic culture for bacteria and serum was submitted for detection of antibodies to several Leptospira interrogans serovars.

With an inflammatory leukogram in a dog with acute renal insufficiency, an infectious etiology has to be serious considered.  Broad spectrum antimicrobial therapy  that should be 1) effective against spirochetes and E. coli,  and 2) attain high concentrations in the renal parenchyma and urine, should be considered while awaiting the results of the culture of the urine for bacteria and and assessment of leptospiral antibody titers. 

Results of serum antibody titers to Leptospira interrogans serovars were received approximately one week later.

SEROVAR	TITER
Canicola	Negative 1:100
Grippotyphosa	Elevated 1:800
Hardjo	Negative 1:100
Icterohaemorrhagiae	Elevated: 1:1600
Pomona	Elevated 1:3200
Bratislava	Elevated 1:3200

The high titers to bratislava and pomona suggest these are the infecting organism and the positivity of icterhaemorrhagiae and grippotyphosa likely represent cross-reactivity.

Clinically, the dog responded well.

His azotemia and neutrophilia resolved.

TIME
	INITIAL	ONE WEEK	TWO MONTHS
Laboratory Test
BUN (mg/dl)	139	34	14
Creatinine (mg/dl)	5.1	1.3	1.2
Neutrophils/ul	21,538	23,901	3,072

 

Summary & Conclusions

Although Cinco presented with fairly nonspecific complaints, with a complete history, physical examination and laboratory data base, several specific medical problems were identified, and ultimately lead to the diagnosis of leptospirosis.   It is important to have bacterial infections (pyelonephritis and leptospirosis) on the rule out list for dogs with acute renal failure, especially when there is a concurrent inflammatory leukogram or thrombocytopenia.

 

What are your rule-outs for Cinco's  weakness/lethargy  (big categories)?	Metabolic
	Cardiovascular
	Respiratory
	Limited Oxygen-carrying Capacity in Blood
	Neurologic
	Musculoskeletal
	Joint
	Polystemic (sepsis, neoplasia)
	Pain

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PROBLEM	BIG CATEGORIES OF RULE-OUTS	ASSESSMENT	DIAGNOSTIC PLAN
Azotemia	Pre-renal Renal Post-renal	Cannot predict source of azotemia based on BUN alone.  Usually there is a component of dehydration.	Urinalysis. Observe micturition and palpate bladder after dog voids, palpate urethra (digital per rectum)
Neutrophilic & Monocytic Leukocytosis	Infection, Noninfectious inflammation (trauma, necrosis, neoplasia, immune-mediated)		Look for source of inflammation.  If azotemia is renal, need to evaluate the kidneys as a source.
Nonregenerative Anemia	Bone marrow suppression Acute hemolysis  or hemorrhage	Anemia is currently mild, and may be associated with chronic disease. The concurrent hypoproteinemia suggests acute hemorrhage should not be ruled-out.	Monitor for hemorrhage/hemolysis (dropping HCT & erythrocytic response)
Thrombocytopenia	Decreased production Increased utilization Destruction Sequestration	Thrombocytopenia not severe enough to cause spontaneous hemorrhage,	Evaluate platelet size Assess coagulation status and evidence of recent hemorrhage. Consider assessing for sepsis (look for source) and rickettsial disease (depending on geographic history)
Hypoproteinemia	Hemorrhage GI loss  Exudate  Iatrogenic	Suspect protein will be lower after the dog is rehydrated and may become hypoalbuminemic at that time	Examine feces (melena?  ova? inflammatory cells? identifiable pathogenic organisms?)
Dehydration	Decreased Fluid Intake Increased Fluid Loss		Check urine specific gravity, offer water for oral intake
Lethargy	Probably associated with the underlying disease process		Consider problem as part of others
Midabdominal tenderness	Abdominal Pain  Referred Pain	With the data base results, problem maybe related to hemorrhage, acute renal failure, vasculitis, peritonitis	If repeatable, consider complete neurologic/orthopedic exam to rule out referred pain. Abdominal Imaging

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What are the big categories of rule-outs that should be considered for acute renal failure in a dog?	Dehydration/Vascular/ischemia AKA Prerenal
	Dehydration, hypotension, hypoperfusion, trauma, thromboembolism. Hypoadrenocorticism
	Postrenal
	Obstruction, retention
	Primary Renal
	Infectious (Pyelonephritis, sepsis, leptospirosis, fungal, rickettsial)
	Toxin (Ethylene glycol, heavy metals, aminoglycoside, etc)
	Neoplasia
	Hypercalcemia

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Which common etiologies of ARF can be treated specifically?
Obstruction	Potentially can be relieved
Pyelonephritis	Specific antimicrobial therapy should decrease inflammation and may result in resolution or improvement in azotemia
Leptospirosis	Specific antimicrobial therapy should decrease inflammation and may result in resolution or improvement in azotemia
Lymphosarcoma	Chemotherapy may result in resolution of or improvement in renal dysfunction

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What is your diagnostic plan for Cinco's acute renal failure?	After acute renal failure has been diagnosed and attending fluid, electrolyte, acid-base abnormalities, and other clinical problems (vomiting) are being addressed, determination of any underlying, potentially treatable etiologies should be assessed, specifically, should include:
	Culture urine for aerobic bacterial growth
	Image the urinary tract; preferably ultrasonographically (evidence of obstruction, masses, blood flow).
	Serum titers for leptospirosis; consider determining acute titers. Although these may be diagnostic, more often, a convalescent titer is necessary to determine if active disease is present.
	Measure systemic blood pressure (hypertension may accompany renal failure and left unattended, may contribute to the progression of the renal deterioration.)

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