Urology in Ag Animal Medicine Flashcards
History and signalment info to gather for urologic problems
- Age and sex
- Duration
- Dietary history
- Breeding history
Physical exam things to get for urologic disease
- Observe urination
- Get a urine sample
Appearance of dysuria, stranguria, incontinence
- They may look like they have abdominal pain
- They may be planking
- Camelids start squatting whether or not they are trying to urinate or defecate
Common causes of stranguria or dysuria
- Urethral obstruction or inflammation
- Neurologic issues
- This is more consistent with UMN
Causes of incontinence
- Impaired neuromuscular control of urination, congenital abnormalities
- This is more consistent with LMN
Differentials for a rectal prolapse?
- Parasites
- Blocked animals and urethral obstruction
Hematuria
- Blood in the urine
Hemoglobinuria
- Hemoglobin in the urine
Myoglobinuria
- Myoglobin in the urine
Bilirubinuria
- Bilirubin in the urine
Pyuria
- White blood cells in the urine
Differentials for hemoglobinuria?
- Leptospirosis, bacillary hemoglobinuria, copper toxicity, post-parturient hemoglobinuria, water intoxication
Goat RBCs
- Very thin cell walls and very sensitive to hypo-osmolarity
What is the pathogenesis of water intoxication?
- Massive water intake –> hypotonicity of body fluid –> hemolysis of RBCs
- Sudden decrease in osmolality
Clinical signs of water intoxication
- Neurologic signs
- Respiratory distress
- Hemoglobinuria
- Death
Treatment for water intoxication
- Temporarily restricting water intake
- Supportive care
- Restore Na to 140-155 mmol/L without overcorrection
When do you see hemoglobinuria during urination?
- Throughout
Color of hemoglobinuria
- Deep red to black
- Doesn’t spin out
- hard to tell apart from myoglobinuria
What does hemoglobinuria suggest about plasma?
- hemolytic state with icterus possibly developing
Hematuria
- Blood in urine if you spine down the urine
Color of hematuria?
- Red, pink, or brown
Urine cytology of hematuria
- RBCs seen on microscopic examination
What does timing of hematuria during the stream tell you about where hematuria localizes?
- Beginning? End? Throughout urination?
- Beginning of urination - urethra, reproductive tract
- End of urination from bladder
- Throughout urination: kidney, ureters
Appearance of myoglobinuria?
- Red/brown urine
Clues that red or brown urine might be myoglobinuria?
- Blood CK, AST may be markedly elevated
Differentials for myoglobinuria?
- Clostridial disease
- Myopathies
- Plant toxicosis
Bilirubinuria appearance of urine
- Dark brown
Which type of bilirubin is excreted?
- Conjugated bilirubin
Diagnosis of bilirubinuria
- Strong positive on the dipstick
Approach to diagnosis of hematuria and pigmenturia
- PE
- CBC and/or examine serum or plasma
- Full UA, centrifugation, and sediment exam
- Look for any chance of toxins
What is important t odo when you see pigmenturia?
- Maintain perfusion of the kidneys as pigments are nephrotoxic**
Pyuria definition
- Gross or microscopic evidence of inflammatory cells and debris
What can cause pyuria?
- Septic or nonseptic inflammatory disease
Approach to diagnosis of pyuria?
- History and PE (including rectal palpation to check for pyelonephritis and transabdominal ultrasound)
- Urinalysis
- Culture
- Determine source of pyuria
What finding on urinalysis suggests urinary tract inflammation?
- > 10 WBC/HPF
Collection of urine for urinalysis
- Midstream voided or catheterized, but CANNOT catheterize male ruminants
What are two reasons why it’s so challenging to catheterize male ruminants?
- Sigmoid flexure
- urethral diverticulum
What finding on cultures suggests UTI?
- Bacterial counts >1 x 10^4 bacteria/mL of urine
What suggests contamination on urine culture?
- Large variety of bacterial species
Crystalluria significance
- Can lead to formation of calculi
- May see crystals on the hair
Polyuria definition
Passage of abnormally large amounts of urine
Causes of polyuria
- Renal failure: tubular function is impaired or loss of nephrons
- Neurogenic or nephrogenic diabetes insipidus
- Renal medullary washout
- Excessive drinking
- Liver failure
- Other electrolyte abnormalities
Approach to diagnosis of polyuria
- HISTORY (have you seen them urinate more often or less)?
- Clin path
- Water deprivation test (ONLY in stable patients**)
- Fractional clearance
Clin path changes possible with PU
- Hyposthenuria (USG <1.007)
- Isosthenuria
Fractional clearance vs creatinine clearance - for which do you need to know the flow rate?
- For creatinine you need to know the flow rate, but not for fractional clearance of sodium
- This makes fractional clearancce of sodium more practical
Normal fractional clearance of Na
- Don’t need to know the flow rate
- More practical
- Normal is 0-4% (usually greater than 1% except in dairy cattle)
Equation for fractional clearance of sodium
[Na in urine]/[Na in serum] x [Creatinine in serum]/[creatinine in urine]
What is anuria?
- Absence of urine production
pre-renal causes of anuria?
- Dehydration, decreased perfusion
Renal causes of anuria
- Acute tubular nephrosis
- End stage renal disease
Post renal causes of anuria
- Urethral obstruction
Oliguria
- Scant or subnormal urine production
Oliguria causes
- Dehydration and acute and chronic renal disease
Glucosuria
- glucose in urine
What is the renal threshold for glucose in most large animal species?
> 150 mg/dL
Other findings on urinalysis?
- ketonuria
- Proteinuria
What can cause a false positive with proteinuria on a dipstick?
- Alkaline urine
What can cause increases in urinary protein?
- Glomerulonephritis or amyloidosis
- UTI
Normal urinalysis in an adult cattle/sheep/goat/camelid?
USG: Protein Glucose Ketones Blood pH WBC RBC Casts Crystals Urine culture results
- USG >1.022
- Protein neg to 1+
- Glucose, ketones, blood: negative
- pH 7.0 to 8.5
WBC: 0-3/HPF
RBC: 0-5/hpf
Casts: none
Crystals: rare
Urine culture: sterile with catheter
What are casts?
- Protein or cellular material from renal tubules
What do casts indicate?
- renal damage or tubular disease
Occult blood on urinalysis significance?
- Hard to interpret
Meaning of transitional cells on urinalysis?
- Neoplasia
Hyposthenuria definition
USG below 1.010
isosthenuria
USG around 1.010
Hypersthenuria
> 1.030-1.035
What are the three possible categories for azotemia?
- pre-renal
- Renal
- Post-renal
What is BUN?
- Urea is non-toxic means of excreting ammonia
What determines urea excretion in ruminants?
- Nitrogen intake
Where is urea nitrogen secreted and metabolized?
- Urea nitrogen is secreted in saliva and metabolized by ruminal flora
High BUN but normal creatinine?
- Less reliable for specific kidney function
Where does creatinine come from?
- Generated by muscle metabolism as a constant
Creatinine excretion and reabsorption
- Excreted by kidney and not reabsorbed
Sensitivity of creatinine
- Very sensitive and early indicator of renal insufficiency
Creatinine as an indicator compared to BUN?
- More reliable
Physiologic increase in creatinine?
- Double muscled animals
What can lead to a more acidic urine in ruminants physiologically?
- High concentrate forage
What can lead to hyperphosphatemia?
- Decreased GFR
Significance of hyperphosphatemia in ruminants?
- Less significant because kidney is not the major excretory route for phosphorus
What can lead to hypocalcemia in ruminants?
- Renal disease
Fibrinogen levels in bovine renal failure?
- Can be very high (exceeding 1800 mg/dL)
Collecting urine:
- Cattle
- Sheep
- Camelids
- Cattle you can tickle the vulva in females
- In sheep you can hold off their nose
- Camelids are tough
What should you think with a paradoxical aciduria?
- Abomasal outflow tract obstruction
Signs of paradoxical aciduria?
- Ruminants with a hypochloremic, hypokalemic, metabolic alkalosis
- urine pH 5-6
Paradoxical aciduria pathophysiology
- Abomasum/rumen fluid retention –> decreased circulating fluid volume –> hypovolemia –> aldosterone –> Na resorption and cation secretion –> K+ depletion (due to decreased K intake and sequestration) therefore H+ secreted leading to lower H+ in blood and paradoxic aciduria
- Abomasal HCl reflux and sequestration also leads to H+ and Cl- depletion and metabolic alkalosis, which drives K+ into cells and H+ out of cells futher contributing to the K+ depletion
Protein in urine
- Normal?
- Significance?
- Not normal
- GN or amyloidosis or UTI
Other diagnostics for urologic problems
- Rectal examination to feel bladder and kidneys
- neuro exam
- Radiology, US, scintigraphy, biopsy, and endoscopic exam (special)
Ulcerative posthitis and vulvitis - what is it?
- ulcerative bacterial infection of the mucous membrane
Etiology of ulcerative posthitis and vulvitis
- Corynebacterium renale
Risk factors ofr ulcerative posthitis and vulvitis
- males are more predisposed because the prepuce can pool the urine
- Increase or excessive dietary protein concentration
How long can corynebacterium renale persist?
- Can persist in wool, hair, and scabs for as long as 6 months
What are main losses with ulcerative posthitis and vulvitis?
- Production losses
Pathophysiology of ulcerative posthisis and vulvitis?
- Corynebacterium renale
- High protein diets –> increased ammonia production in the rumen –> converted to urea in the liver –> urea is eliminated through the renal system –> C. renale proliferates
- urease in organism converts urea back to ammonia –> chemical irritation and ulceration of the prepuce and surrounding skin
Clinical signs of ulcerative posthitis and vulvitis?
- Dysuria, vocalization while voiding
- Inflammation progresses, ulceration may result in fibrous adhesion between the penis and prepuce
- Severe inflammation can lead to obstruction of the urethra
- Impairment of breeding soundness
- Weight loss in chronic cases
Dfdx for ulcerative posthitis and vulvitis
- Ulcerative dermatosis
- Contagious ecthyma
- Urolithiasis
- Caprine herpesvirus
- Mycoplasma mycoides subspecies Mycoides large Colonya
Treatment for ulcerative posthitis and vulvitis
- Reduce protein and NPN intake (* THE BIGGEST THING)
- Limit contact
- Clip wool or hair from skin surrounding the prepuce or vulva (goes quite a ways)
- Topical abx (Petercillin, mastitis treatment tubes, triple abx)
- Systemic antibiotics (Penicillin, ampicillin, oxytetracycline but careful with cephalosporins)
- NSAIDs
- Surgery
What three things should you be using ceftiofur for?
- Respiratory, metritis, and foot rot
Prognosis for ulcerative posthitis and vulvitis
- Poor if diet not changed
- Recovery for breeding? (GUARDED)
Prevention of ulcerative posthitis and vulvitis
- Limit protein and NPN
- Slow weight gains
- Separate affected males to decrease spread
- Shear at the time of highest protein intake
Etiology of urolithiasis
- Metabolic disease in all livestock species
- Disease due to trauma of the urinary tract and obstruction of urinary outflow
- Diagnosis in a single animal = all males in a group at risk
What does it mean if one male gets urolithiasis in a group? Are the others at risk?
- All males in a group are then at risk
Environmental risks for urolithiasis
- Cold weather
- Drink a lot less
Why are males more predisposed to urolithiasis?
- Longer, narrow, and contains the sigmoid
Special anatomical features of male cattle?
- Distal sigmoid flexure, near the insertion of hte retractor penis muscle
Special anatomical features of male small ruminants?
- Urethral process and distal sigmoid flexure
Age of castration with urolithiasis?
- Castrating younger raises the risk, but castrating older is harder to do
Which breed is classic for urolithiasis?
- Nigerian Dwarf Goats
Pathophysiology of urolithiasis?
- Supersaturation of urine with calculus-forming crystalloid (this is why hydration is huge in prevention)
- Capabilities of crystallization inhibitors in urine are overwhelmed
- Dehydration
- Urinary pH
- UTIs
- Anatomy of the ruminant urethra contributes to obstruction
Phosphatic stones - risk factors in diet for formation?
- Rations high in phosphorus (grain-based rations)
- Calcium/Phosphorus ratio less than 2:1
Struvite calculi fancy name
- Magnesium ammonium phosphate hexahydrate
Apatite calculi fancy name
- Calcium phosphate
What can phosphatic stones look like?
Single stone or sand-like debris
What type of cattle tends to get phosphatic stones?
- Feed lot steers due to high phosphorus grain-based diets
Three primary type of calculi
- Phosphate, calcium, and silica
Silica calculi feed risks
- Primarily grazing native rangeland grasses or western North America
How does water deprivation factor into silica calculi formation?
- Periods of water deprivation and urine becomes concentrated
Appearance of silica calculi?
- Typically hard, smooth white to brown, radiopaque, and layered
Incidence of silica calculi in urinary tracts of range cattle
- 50-80%
- Obstruction is variable however
What are the two calcium based calculi?
- calcium carbonate and calcium oxalate
Risk factor for calcium carbonate?
- Ruminants grazing lush, rapidly growing clover pastures or being fed alfalfa hay
- Rich in calcium, low in phosphorus and magnesium
- Increased urinary calcium excretion and alkaline urine –> calcium carbonate calculogenesis
Urine pH that can contribute to calcium carbonate?
- Alkaline urine
Calcium carbonate urolith appearance?
- Typically round, smooth shape and golden and are often present as multiple uroliths scattered throughout the lower urinary tract
Appearance of calcium oxalate
- Typically dense, hard, white to yellow, and either smooth or jagged
Signs of acute urinary obstruction
- Bladder distention
- Stranguria and abdominal pain, anuria, or dribbling urine
- restless, tread, swish tails, grind their teeth (bruxism), may vocalize
- Tachycardia, tachypnea, and mild bloat secondary to ruminal stasis
- may see secondary rectal prolapse due to straining
- Crystals or blodo on the hairs of preputial tuft, dry
- Rectal exam shows pulsation of the pelvic urethral
- Abdominal palpation possible in small ruminants and camelids
What are common sequele to urolithiasis?
- urethral rupture
- Bladder rupture
Urethral rupture signs
- Ventral edema***
- Depression
- Inappetence
- bilateral pitting edema in the ventral perineum, inguinal region, prepuce, ventral abdomen
Bladder rupture clinical signs
- Relief of bladder distention causes cessation of stranguria
- Distention of abdomen develops within 1-2 days after rupture, ballottement of abdomen may elicit a flluid wave
- Depression anorexia, weakness, dehydration, and shock
- Animal’s breath may smell like ammonia
Diagnostics for urolithiasis?
- Abdominal ultrasound to reveal distended bladder
- Radiographs
- Examination of the urethral process in small ruminants
What size bladder on ultrasound is considered significant in small ruminants?
- > 8 cm
How to do examination of the urethral process?
- Tip them and take the penis out
- Light sedation and lidocaine in the prepuce
- Anesthetize goats
- Allis tissue forceps and pull out the stone
- Hard to do
Clin Path with Acute Urolithiasis
- May be unremarkable
- Hyperglycemia and stress leukogram
- Hemoconcentration and azotemia
- Hematuria and proteinuria
Clin Path with chronic urolithiasis
- Hyponatremia, hypochloremia , hypocalcemia, hyperphosphatemia, and severe azotemia with isosthenuria (extensive nephron damage)
Potassium with bladder rupture
- Don’t worry so much about it as hyperkalemia isn’t always a thing
Treatment of urolithiasis
- Salvage (reasonable if feedlot steer)
- Medical management
- Surgical management
Medical management for urolithiasis?
- Antispasmotic tranquilizer (Acepromazine)
- Bladder drinage (percutaneous infusion with Walpole solution)
- Fluid therapy
Walpole solution
- Acetic acid
- May help dissolve struvites
Should you also give pain management if you’re giving acepromazine?
- YES
Fluid therapy for urolithiasis?
- be VERY judicious
- Patients with uroperitoneum to stabilize hypovolemia and correct electrolyte abnormalities
- Avoid supplementation of potassium as hyperkalemia is still a risk
- Watch for fluid overload
Fluid overload signs in small ruminants
- Pulmonary edema
Surgical management of urolithiasis
- Urethral catheterization and retrograde flushing
- Amputation of urethral process
- Perineal urethrostomy (PU)
- Urethrotomy and stone removal
- Tube cystotomy
- Bladder marsupialization
Catheterization and retrograde flushing difficulties
- Very hard to catheterize male ruminants
Perineal urethrostomy
- Used in feedlot steers a bit
- Not meant to be long-term but more salvage
Tube cystotomy
- Often preferred
- Gives time for inflammation to go down
Pain medications post-op
- Meloxicam (if well-hydrated)
- gabapentin
How do you close the urethra for a urethrotomy?
- Let it heal by second intention
Perineal urethrostomy surgery
- Last ditch effort
- Going into the perineum and cutting the urethra as it comes down
Cons of perineal urethrostomy vs tube cystostomy?
- You don’t get to look at the bladder to know if it’s compromised or not
What determines prevention and management for urolithiasis?
- Depends on forage and stone analysis
Silica stone management
- Restricting silica intake is not feasible in ruminants grazing native grasses
- Dietary management limited to salt supplementation to increase water consumption (diuresis)
Prevention of phosphatic calculi
- Dietary calcium/phosphorus ratio to a level of 2:1 or greater
- Decrease the amount of grain or other high-phosphorus dietary components
- Increase the quantity of long-stem forage in the ration to increase salivary flow and fecal phosphate excretion (salivary gland helps with phosphorus recycling)
- Or, increase calcium in the diet with forages like alfalfa (BE CAREFUL)
Why do you have to be careful with increasing calcium in the diet to prevent phosphatic calculi?
- Could lead to a calcium stone
Prevention of calcium carbonate calculi
- feeding or supplementing with grass hay instead of feeding alfalfa
- Salting grass hay to increase water consumption to help dilute urine
- Acidifyng urine
Ammonium chloride uspplementation - what’s hte idea behind it?
- 0.5% to 1.5% of ration dry matter decrease urine pH to 6-6.5
In theory should increase the solubility of struvite and apatite crystals
Cons of ammonium chloride supplementation
- Long term complications can lead to chronic metabolic acidosis with decrease in bone density
- Renal adaptation and will go back to normal
- Not palatable and animals may stop eating the ration
What is the MOST important aspect of prevention of urolithiasis?
- Maximizing water intake!!!!
Reoccurrence with urolithisis - how common?
- VERY COMMON
Definition of urachal disorders
- Abnormalities of the umbilicus and umbilical remnants are frequently seen in neonatal calves - urachus included
What is associated with urachal disorders?
- Omphalitis
Pathophysiology of urachal disorders
- Bacterial infection of the urachus –> inflammatory response in the abdomen –> fibrinous adhesions form between the urachus and surrounding viscera –> abscess formation
- Urachal fibrosis and adhesions may interfere with bladder emptying –> urine retention and secondary cystitis
What is the most common bacteria associated with urachal disorders?***
- Trueperella pyogenes or E. coli
Clinical signs with urachal disorders
- > 4 weeks old
- Omphalitis
- Fever, lethargy, poor body condition, rough hair coat, and poor growth
- Dysuria, pollakiuria, stranguria, and colic, hematuria, or pyuria
- May palpate an enlarged and painful umbilical remnant
- may see urine dribble from umbilicus
- Signs of UTI
Differentials for urachal disorders
- Urolithiasis, urethritis, or neurologic disease
How acute are urachal disorders usually?
- Often the owners will see them suddenly, but they aren’t considered that acute
Diagnosis of urachal disorders
- Transabdominal ultrasound of the umbilicus and ventral abdomen***
- Clin path variable
Clinical pathology findings with a urachal disorder
- Variable
- Inflammatory leukogram
- Hyperfibrinogenemia
- Hyperglobulinemia
Treatment of urachal disorders
- SURGERY
- Ventral midline celiotomy, paramedian celiotomy, laparoscopy under general anesthesia is recommended
- Perioperative and postoperative antibiotics are essential
Prognosis for urachal disorders
- Guarded to poor if adhesions are extensive and severe peritonitis
What causes enzootic hematuria?
- Bracken fern (Pteridium aquilinum)
How acute or chronic is Bracken fern toxicity (i.e. enzootic hematuria)?
- Poisoning requires prolonged exposure
- Characterized by intermittent hematuria and anemia
Carcinogenic properties of Bracken Fern
- Continued ingestion and infection with bovine papillomavirus type 2
What is acute Bracken Fern poisoning?
- An acute coagulopathy or fulminant septicemic crisis associated with severe bone marrow suppression
Distribution of enzootic hematuria
- Wide distribution
- PNW and upper Midwest
- Grows in well-drained fertile soils
Who gets enzootic hematuria?
- Primarily seen in adult sheep and cattle
- Not goats
Which parts of the Bracken fern are toxic to sheep and cattle?**
- All parts!**
What properties of Bracken Fern lead to the clinical signs?
- irritant, mutagenic, immunosuppressive, or carcinogenic activities
What is the active agent in Bracken Fern?**
- Ptaquiloside (aquilide A)
Can bracken fern compounds be excreted or secreted by affected cattle?
- Yes, carcinogenic principles are present in the milk of cows grazing bracken fern
- Can cause GI inflammatory disease
- Gastric ulcers in people
Relationship between enzootic hematuria and Bovine papillomavirus-2?
- Compounds may cause recrudescence of latent BPV-2 through immunosuppression
- Mutagenic compounds interact with BPV-2 in bladder –> neoplasia
Clinical signs of enzootic hematuria?
- Hematuria is the first clinical sign in most animals
- Chronic blood loss –> tachycardia, tachypnea, exercise intolerance, pale mucous membranes, and decline in productivity
- Bladder wall thickening, and bladder may be palpated rectally
- Dysuria, pollakiuria
- Obstruction of the bladder trigone by blood clots
Are patients with enzootic hematuria ever icteric?
- NO
Key diagnostics for enzootic hematuria?
- History of Bracken Fern ingestion
- Clin Path changes
- Necropsy findings
Clin Path findings with enzootic hematuria?
- Severe anemia +/- regeneration
- May see decrease in segmented neutrophils and lymphocytes
- Urinalysis shows hematuria, protienuria, and variably pyuria
Necropsy findings with enzootic hematuria?
- Bladder wall is thickened, mucosa hemorrhagic and ulcerated
- Bladder tumors and mixed origin neoplasms
Treatment of enzootic hematuria?
- Limited to reduction or elimination of bracken fern in the diet
Prognosis of enzootic hematuria
- May stop if ingestion is discontinued before neoplasia occurs
- Once you get neoplasia, it’s a pretty poor prognosis
What are different localizations for UTI?
- Cystitis, uteritis, and pyelonephritis
Which bacteria are most commonly implicated with UTI?
- Ascending infections from C. renale or E. coli
Epidemiology of UTI
- Sex predisposition?
- Uncommon
- Females more than males due to a shorter urethra
C. renale infection pathophysiology
- Pathogen adheres to urinary tract epithelium which is enhanced by alkaline conditions –> organism produces ammonium to maintain a high pH
E. coli infection pathophysiology
- Serotypes involved in UTI are unknown at this time
- Infection likely arises from fecal contamination or a loss of natural defenses in the urogenital tract
Clinical signs of UTI
- Dysuria or pollakiuria
- +/- hematuria and pyuria - may not be visible
- May be able to feel a thickened and painful bladder on rectal palpation
Clinical signs of acute cases of pyelonephritis
- Sudden reduction of feed intake or milk production
- Fever, tachycardia, tachypnea, decreased skin turgor, enophthalmos, ruminal stasis, scleral injection, and occasional episodes of mild colic
- Left kidney felt on rectal palpation - may be enlarged and painful
- Right kidney evaluation with ultrasound
Clinical signs with chronic pyelonephritis
- Signs more vague
- Weight loss, muscle wasting, poor growth, anorexia, diarrhea, and reduced milk production
Differentials for mild colic
- UTI, GI, other intrabdominal disorders
- Bloodwork to rule it out
Dfdx for dysuria
- UTI, vaginitis, prevaginal abscess, pelvic entrapment of the bladder, vulvar trauma, postparturient swelling of the vagina or vulva
- Urolithiasis in males
- Neurologic deficits: neuro exam to rule out
Hematuria dfdx
- Parturition
- UTI
- Papillomas in the urinary tract
- Postparturient hemoglobinuria
- Enzootic hematuria
Diagnosis of UTI
- Clin Path and UA
Clin Path findings with UTI
- Neutrophilic leukocytosis with significant hyperfibrinogenemia in pyelonephritis
- With chronicity , hyperglobulinemia
- Anemia due to decreased erythropoietin in the affected renal tissue and from blood loss through urination
- Azotemia (need to differentiate pre-renal, renal, and post-renal)
What is needed for definitive diagnosis of UTI?
- Urinalysis
Treatment with UTI
- Aggressive and long-term antibiotics
- Beta lactams (Procaine Penicillin G or Ampicillin trihydrate at very high doses)
- Ceftiofur is not labeled for this
- Diuresis with oral or parenteral fluid therapy to dilute urine
Prognosis with UTI
- Better the earlier patient is treated
- Cystitis alone yields higher success rates
- Recrudescence can occur
Poor prognostic indicators with UTI
- BUN >110mg/dL and/or creatinine above 1.5 mg/dL
What is renal amyloidosis?
- Deposition of insoluble fibrillar protein in various organs, including the kidney as well as spleen and liver
- Protein losing nephropathy
Pathophysiology of renal amyloidosis
- Reactive type (AA protein) - frequently associated with chronic inflammatory disease
- AA resistant to proteolysis
- Accumulation in glomerulus alters filtration leading to sustained albuminuria and loss of plasma oncotic pressure
What is the precursor to AA?
- Serum amyloid A (SAA) protein
Where is AA made?
- In the liver
What type of protein is AA?
- Acute phase protein
How can amyloidosis cause diarrhea?
- Deposition of amyloid in the IGT
Clinical signs of renal amyloidosis
- Weight loss
- Diarrhea
- Ventral edema
- Hypoproteinemia and proteinuria***
Dfdx for hypoalbuminemia, edema, or chronic diarrhea
- Johne’s
- Right heart failure
- Chronic parasitism
- Liver failure
- Chronic Salmonella
- Post caval syndrome
- Copper deficiency
- Also Haemonchus in goats
Clin Path with Renal Amyloidosis
- Marked proteinuria and hypoalbuminemia
- Hyperfibrinogenemia and/or hyperglobulinemia
- Azotemia if it’s in the kidneys
- Persistent heavy proteinuria without RBCs, WBCs, or bacteria in the urine sediment
- +/- hyperphosphatemia
- Be careful interpreting urine dipsticks when urine is alkaline (confirmation via more specific tests)
Necropsy results for renal amyloidosis
- Stain kidneys with Congo Red
Example history of a cow with possible PLN or PLE
- Weight loss, diarrhea, bottle jaw
- BAR
- Non-foul smelling diarrhea
- T: 101.5F, P 60/min, R 20/min
- Rectal shows loose stool and thickened bowel loops
Treatment and prognosis of renal amyloidosis
- Prognosis is poor
- AA persistent in tissues and remains if inflammation is treated
- No specific treatment
How common is glomerulonephritis?
- rare
Underlying cause of glomerulonephritis
- Immune system targeting of glomerular tissues leads to glomerular injury
Pathophysiology of glomerulonephritis
- Antibodies may be directed against host or addition, circulating immune complexes may deposit in the glomerulus –> activation of complement and chemotaxis of leukocytes –> damage of the glomerulus and increased glomerular permeability
CLinical signs with glomerulonephritis
- Hx of weight loss, poor productivity, and chronic diarrhea
- Rectal may reveal an enlarged but non-painful left kidney
- Been associated with persistently infected BVDV, cattle with fascioliasis (flukes), and associated with preg tox in ewes
Dfdx for glomerulonephritis
- SImilar to amyloidosis
Clin Path findings with glomerulonephritis
- Heavy proteinuria, mild anemia, and hypoalbuminemia
- Granular casts, RBSs, and leukocytes may be found in urine sediment
- Azotemia, proteinuria, and ketonuria in a ewe with pregnancy toxemia
Treatment and prognosis of glomerulonephritis
- Most GN advanced once diagnosed
- Prognosis very poor
What is tubular necrosis?
- Acute renal failure
Causes of tubular necrosis
- Can be primary (2° to endometritis or any disease in the animal) or secondary (2° to a toxin) in origin
- Toxin exposure and vulnerable to ischemia and reperfusion injury
- Sudden decrease in GFR, nitrogenous waste accumulation, and loss of the ability to manage electrolytes, protein, acid-base, and water balance
Pathophysiology of tubular necrosis
- Ischemic and toxic damage to tubular cells due to primary issue
- Prolonged ischemia –> destroys basement membrane –> preventing tubular epithelial cell regeneration
- Pigment nephrosis –> endogenous toxicity due to hemoglobin or myoglobin to the kidneys as a result of hemolytic disease or myopathies –> result in renal vasoconstriction and tubular obstruction from protein coagulation
- Any injury is compounded by dehydration
Clinical signs of tubular necrosis
- No specific clinical signs
- Anuria/ oliguria, or polyuria
- Poor appetite, diarrhea, or epistaxis
- Saliva may have an ammonia smell
- Muscular weakness and recumbency from acid-base imbalances
- Renal encephalopathy
Renal encephalopathy
- Intracranial disease
- Altered behavior, weakness, motor dysfunction, convulsions
- Rare
Dfdx for renal encephalopathy
- Generic systemic illness similar to those of renal origin
- Pneumonia, pleuritis, mastitis, metritis, peritonitis, endocarditis, and metabolic derangements
Diagnosis of tubular necrosis
- Inflammatory diseases common
- Electrolytes
- UA
Inflammatory changes seen with tubular necrosis sometimes
- Leukogram may reflect primary causes
- Hyperfibrinogenemia
Electrolytes changes seen with tubular necrosis and underlying cause
- Hypokalemia (anorexia)
- Hypocalcemia (anorexia)
- Hyperphosphatemia (
Purpose of urinalysis with tubular necrosis
- Differentiate prerenal, post-renal, and renal causes
- Proteinuria, hematuria, and granular casts
Phosphate with tubular necrosis
- Primarily excreted through glomerular filtration in the kidneys in most mammals, so decreased GFR leads to increased serum phosphate
- However, cattle and horses with decreased GFR may not always have hyperphosphatemia due to other sources of phosphate elimination such as saliva and GIT
Treatment with tubular necrosis
- Remove and bind toxin or source (promote diuresis through IV fluids and diuretics)
- Activated charcoal
- Prophylactic diuresis
- Restoration of adequate renal perfusion and urine production (isotonic fluids with Ca and K if needed; patient is producing sufficient urine; IVF ideal)
- Supportive care (Broad spectrum antibiotics; parenteral nutrition or rumen transfaunation; use NSAIDs carefully)
What can be given to anuric or oliguric animals with tubular necrosis
- Furosemide
Prognosis of tubular necrosis
- If over 75% nephrons compromised, that’s a poor prognosis
- Best prognosis with intensive care
- Conditions that occlude tubular blood flow warrant a poor prognosis (DIC, renal vein thrombosis)
Maintenance hosts clinical signs with leptospirosis
- Causes little disease
How do incidental hosts get leptospirosis?
- Incidental hosts via direct contact from urine from infected maintenance host or through contaminated environment
- Contact with feed, environment, or water contaminated with urine from an infected maintenance host
- Contact with infected fetus or uterine discharge
Appearance of lepto
- Motile, gram-negative, obligate aerobic, tightly coiled
Preferred environments of leptospirosis
- Prefer moist, warm environments pH 7.2-8
Leptospirosis serovars where cattle are incidental hosts
- Leptospira interrogans canicola
- L. interrogans pomona
- L. interrogans icterohaemorrhagiae
- L. interrogans bratislava
- L. kirschneri grippotyphosa
Which leptospirosis serovars are cattle more of a maintenance host?
- L. interrogans hardjo type hardjoprajitno
- L. borgpetersenii hardjo type hardjobovis
Seasonal incidence of lepto
- Higher in summer or fall in temperate regions
Which serovars of leptospirosis are most often implicated in renal infection of cattle?
- Hardjo, pomona, and gryppotyphos
Is leptospirosis zoonotic?
- YES
Pathophys of lepto
- Mucosal surfaces and macerated skin –> organism enters blood stream –> Leptospiremia
- Bacteremia lasts 4-7 days during with time fever and other systemic signs are often present
- Humoral antibodies detectable at this time –> convalescent phase
When are humoral antibodies detectable with leptospirosis?
- During bacteremia that lasts 4-7 days
- This is when they have a fever
Where does lepto localize during convalescent phase?
- Mammary gland, kidney, or genital tract
Virulence factors of Leptospirosis***
- LPS**
- Adhesion to cells and extracellular matrix
- Bacterial motility - contributes to invasion and dissemination of bacteria
- Hemolysins
- Iron sequestration
Clinical signs with non-host adapted serovars
- Severe systemic disease, hemolytic anemia, hepatitis, interstitial tubular nephritis, and tubular nephrosis in calves
- Agalactia and mastitis in lactating cows
- Abortion
- Renal lesions from direct damage to vascular endothelium (hypoxia, hemolysis, tubular epithelial damage from hemoglobin, and interstitial nephritis)
- Fever, anorexia, lethargy, decreased milk production, petechiation, hemolytic anemia, and hemoglobinuria
- Oliguria may be seen with interstitial nephritis or hemoglobinuric nephrosis
Do you get hemoglobinuria with leptospirosis?
- yes
Diagnosis of lepto with serology
- Serology
- Microscopic agglutination test (MAT) showing a fourfold increase in MAT titer between acute and convalescent serum samples
- Conversion from a negative titer to a titer of 100x or greater
Serologic response in vaccinated animals
- May be diminished
When is serology unsuitable for dx of lepto?
- Screening individual animals for carrier status
- Many animals that are chronically infected and shedding ma have negative serologic status
Other ways to diagnose leptospirosis
- Leptospira shedding in urine and semen can be detected by other means (Darkfield microscopy, Fluorescent antibody, PCR)
- Urine culture often unrewarding
- Second-voiding urine samples collection after administration of IV furosemide - discard first voided sample
Treatment of acute leptospirosis caused by non-host-adapted serovars
- Antibiotics (Ampicillin, amoxicillin, procaine penicillin G, tetracycline, tylosin, and tilmicosin)
- IV and oral fluids for diuresis
- Blood transfusion with severe hemolysis
What determines prognosis for acute leptospirosis caused by non-host-adapted serovars?
- Depends on virulence of the serovar, host immunity, and extent of renal lesions
- Poor if >75% of nephrons are affected
Treatment for renal colonization and shedding of lepto in cattle?
- Long acting oxytetracycline
Prevention of lepto
- Draining or fencing off standing water
- Maintain dry, clean environment
- Limit rodent and wildlife contact with cattle
- Cull renal carriers to limit transmission
- Vaccine works well!
Lepto vaccine info
- Works well
- Pentavalent (L. canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and Pomona)
- Whole-cell, inactivated vaccines
- DO NOT resolve current renal infection