Congenital Portosystemic Shunts

Relatively common

Yorkshire terriers, Maltese,

Schnauzers, Pug,

Shih Tzu, Havanese,

Irish Wolfhound, Poodle,

Golden retriever,

Laborador retriever

Is definitely genetic in some breeds

Congenital Portosystemic Shunts

Relatively common

Broad spectrum of signs

“Poor do’er”

Vomiting

Polyuria-polydipsia

Hematuria

“Drooling” in cats

Hepatic encephalopathy

“Classic” Hepatic Encephalopathy

Post-prandial:Seizures

Convulsions

Head pressing

Acting drunk

Nice dogs bite

Bad dogs kiss

“Common” Hepatic Encephalopathy

Often not clearly associated with

eating (~ 30-50% of cases)

Signs often very subtle

Just a “Slow” dog

Has always been “Quiet”

Not too active

“Getting old”

Congenital Portosystemic Shunts

Relatively common

Broad spectrum of signs

Diagnosis

Routine lab tests insensitivemicrocytosis (MCV)

hypoalbuminemia

low BUN

hypocholesterolemia

ammonium biurate crystals

Congenital Portosystemic Shunts

Relatively common

Broad spectrum of signs

Diagnosis

Routine lab tests insensitive

Pre and Post Prandial Bile Acids

Blood Ammonia

Congenital Portosystemic Shunts

Relatively common

Broad spectrum of signs

Diagnosis

Routine lab tests insensitive

Pre and Post Prandial Bile Acids

Blood Ammonia

Abdominal Imaging

plain radiographs

Case #161134

Case #161134

Case #190418 – 6 year old Pug with urate calculi

TAMU #176441: PSS + iatrogenic Cushings

Congenital Portosystemic Shunts

• Plain radiographs

– microhepatia is seen in:

• 60-100% of dogs with PSS

• 50% of cats with PSS

– sometimes see renomegaly

Congenital Portosystemic Shunts

Relatively common

Broad spectrum of signs

Diagnosis

Routine lab tests insensitive

Pre and Post Prandial Bile Acids

Blood Ammonia

Abdominal Imaging

ultrasound

The sensitivity of ultrasound for finding portosystemic shunts is very dependent upon

the ultrasonographer

A major value of ultrasound is detecting intrahepatic shunts versus extrahepatic

shunts

Congenital Portosystemic Shunts

Relatively common

Broad spectrum of signs

Diagnosis

Routine lab tests insensitive

Pre and Post Prandial Bile Acids

Blood Ammonia

Abdominal Imaging

scintigraphy, contrast, MRI

Congenital Portosystemic Shunts

Relatively common

Broad spectrum of signs

Diagnosis

Routine lab tests insensitive

Pre and Post Prandial Bile Acids

Blood Ammonia

Abdominal Imaging

Histopathology of liver

TAMU #119449

Sig: 10 month F Bichon

CC: Vomiting

HPI: Vomits mucus and food 3 times

per week since it was obtained

Loss of stamina 4 weeks ago

PE: Normal

TAMU #119449

Cholesterol = 147 mg/dl (120-247)

BUN = 5 mg/dl (8-20)

Creatinine = 0.5 mg/dl (< 2.0)

Glucose = 90 mg/dl (75-133)

Total protein = 6.1 gm/dl (5.5-7.5)

Albumin = 2.7 gm/dl (2.5-4.4)

ALT = 104 IU/L (< 130)

SAP = 117 IU/L (< 147)

TAMU #119449

Resting bile acids = 64.7 umol/L (0-13)

Post-prandial = 12.4 umol/L (0-30)

TAMU #119449

Resting bile acids = 64.7 umol/L (0-13)

Post-prandial = 12.4 umol/L (0-30)

Blood ammonia = 351 ug/dl (< 50)

183 ug/dl (< 50)

TAMU #115907

Sig: 13 yr F(s) Schnauzer

CC: Diarrhea

HPI: Diarrhea began yesterday

Dog had 3 watery stools without

mucus

Vomited food and bile for 3 days

Poor appetite

PE: Depressed

TAMU #115907

1/93: Liver biopsy: marked periportal

swelling with mild multifocal

necrosis

11/98: Cognitive dysfunction: CT-scan

shows cerebral cortical atrophy

CSF: Albuminocytologic

dissociation: Treat with Depranyl

TAMU #115907

Cholesterol = 313 mg/dl (120-247)TP = 6.5 gm/dl (5.7-7.8)Albumin = 2.8 gm/dl (2.4-3.6)BUN = 17 mg/dl (8-29)Na = 144 mEq/L (138-148)K = 4.3 mEq/L (3.5-5.0)ALT = 105 U/L (< 130)SAP = 129 U/L (< 147)Bilirubin = 0.6 mg/dl (< 0.8)

TAMU #115907

Serum bile acids: 19.6 86.4

normal: < 13 < 30

TAMU #115907

Serum bile acids: 19.6 86.4

173 236

normal: < 13 < 30

OLD ANIMALS CAN

HAVE CONGENITAL

DISEASE

Retrospective Study

• Miniature schnauzers were 6.3 times

more likely to be diagnosed with

PSS at or after seven years of age

compared to all other breeds (CI =

2.2-18.6; p = 0.001)

TAMU #115907

1/93: Liver biopsy: marked periportal

swelling with mild multifocal

necrosis

11/98: Cognitive dysfunction: CT-scan

shows cerebral cortical atrophy

CSF: Albuminocytologic

dissociation: Treat with Depranyl

SERUM BILE ACID

CONCENTRATIONS VARY

SUBSTANTIALLY FROM

DAY TO DAY

TAMU #115907

Serum bile acids: 19.6 86.4

173 236

normal: < 13 < 30

HOW HIGH SHOULD

SERUM BILE ACIDS BE

IN DOGS WITH

CONGENITAL PSS?

TAMU #160914

7.8 52

TAMU #118840

4.8 25.4

TAMU #144211

7.6 7.7

TAMU #160914

7.8 52

TAMU #118840

4.8 25.4

TAMU #144211

7.6 7.7

TAMU #160914

7.8 52

TAMU #118840

4.8 25.4

TAMU #144211

7.6 7.7

TAMU #165244

Sig: 7 yr F(s) Schnauzer

CC: Pu-Pd, weight loss

HPI: Signs began 3-4 months ago

Has lost 15% body weight

associated with poor appetite

PE: T = 101.7 F, HR = 90/min

Thin dog

TAMU #165244

date 11/29 1/11 3/17

ALT 680 407 1,050

date (TAMU) 3/28 3/31

2,424 1,612

Normal ALT < 130 Units/L

TAMU #167033: PSS + HGE

You may fortuitously

stumble upon PSS when

working up some other,

TOTALLY UNRELATED

problem

TAMU #164612: PSS + DM + Addison’s (12 yr)

Case #201912 – 9 yr old Yorkie in a bad mood

TAMU #117475

Sig: 5 yr F Lhasa Apso

CC: Owner thinks dog has congenital

PSS and wants surgery

HPI: Anorexia and lethargy began 2

weeks ago

Sibling was diagnosed with PSS

PE: Thin, corneal pigmentation

SURGICAL OR

MEDICAL

MANAGEMENT?

Mortality Post-PSS Surgery

Vet Surg 33, 2004: 95 cases, 5.5% mortality

(cellophane banding)

JAVMA 226, 2005: 168 cases, 7% mortality

(ameroid constrictors)

JAVMA 232, 2008: 64 cases, 10% mortality

15 (23%) died of causes associated with PSS (7.9 months later)

JAVMA 236, 2010: 99 cases, 4-10% mortality

TAMU #117475

August: Surgery for single congenital

PSS

Sept: Ascites which is resolved

medically

PSS Surgery

• If dog developes ascites post ligation

– Low salt diet

– Diuretics

• spironolactone

• furosemide

TAMU #117475

August: Surgery for single congenital

PSS

Sept: Ascites which is resolved

medically

1 Year: Pyometra develops. At surgery

discover multiple acquired

portosystemic shunts

Correctivesurgery

Significant clinical signsOR Very sm all liver

OR Very low album in

Can wait and monitorCan treat if has m inimal HE

(Depends upon age)

M inim al or no signs (depending on age)AND Serum album in > 2 gm /dl

AND Liver not very sm all

PSS

Correctivesurgery

Significant clinical signsOR Very sm all liver

OR Very low album in

M ight wait and m onitorCan treat if has m inimal HE

(Depends upon age)

M inim al or no signs (depending on age)AND Serum album in > 2 gm /dl

AND Liver not very sm all

PSS

Conservative management of congenital PSS

• Prevent progression of hepatic damage

– antioxidants

– ursodeoxycholic acid

• Control hepatic encephalopathy

(if the dog is encephalopathic, you need to be

cautious about recommending conservative

management as an acceptable choice)

• Control existing encephalopathy

– Lactulose

• 0.25-0.5 ml/kg bid, then adjust

• Retention enema (10 ml + 30 ml water)

– Lactitol (0.5-0.75 mg/kg bid)

– Metronidazole or oral neomycin

• Rifaximin (10 mg/kg/day) used in people

Medical Management

• Control existing encephalopathy

– “Low protein” diet

• only to treat encephlopathy or decrease

blood ammonia concentrations

• give as much as the patient can tolerate

• prefer milk and vegetable (especially

soy) protein

Medical Management

• Eliminate predisposing causes of HE

– Metabolic alkalosis (hypokalemia)

– Constipation

– Bleeding gastric lesions

– Azotemia

– Sedatives and analgesics

Medical Management