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 insensitive
microcytosis (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 =
Creatinine =
Glucose =
5 mg/dl (8-20)
0.5 mg/dl (< 2.0)
90 mg/dl (75-133)
Total protein =
Albumin =
6.1 gm/dl (5.5-7.5)
2.7 gm/dl (2.5-4.4)
ALT =
SAP =
104 IU/L (< 130)
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 =
TP =
Albumin =
BUN =
Na =
K=
ALT =
SAP =
Bilirubin =
313 mg/dl (120-247)
6.5 gm/dl (5.7-7.8)
2.8 gm/dl (2.4-3.6)
17 mg/dl (8-29)
144 mEq/L (138-148)
4.3 mEq/L (3.5-5.0)
105 U/L (< 130)
129 U/L (< 147)
0.6 mg/dl (< 0.8)
TAMU #115907
Serum bile acids:
normal:
19.6
86.4
< 13
< 30
TAMU #115907
Serum bile acids:
normal:
19.6
173
86.4
236
< 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:
normal:
19.6
173
86.4
236
< 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
PSS
Significant clinical signs
OR Very small liver
OR Very low albumin
Minimal or no signs (depending on age)
AND Serum albumin > 2 gm/dl
AND Liver not very small
Corrective
surgery
Can wait and monitor
Can treat if has minimal HE
(Depends upon age)
PSS
Significant clinical signs
OR Very small liver
OR Very low albumin
Minimal or no signs (depending on age)
AND Serum albumin > 2 gm/dl
AND Liver not very small
Corrective
surgery
Might wait and monitor
Can treat if has minimal HE
(Depends upon age)
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)
Medical Management
• 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