Wiener Tierärztliche Monatsschrift – Veterinary Medicine Austria 101 (2014) From the Department of Medicine and Clinical Biology of Small Animals1, the Department of Medical Imaging of Domestic Animals and Small Animal Orthopaedics2, and the Department of Nutrition, Genetics and Ethology3, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium, as well as Medvet Veterinary Pathology Services4, Antwerp, Belgium Congenital extrahepatic portoazygos shunt in combination with hepatic microvascular dysplasia in a Yorkshire Terrier N. DEVRIENDT1, D. PAEPE1, E. VANDERMEULEN2, G. QUIST-RYBACHUK3, H.E.V. DE COCK4, J.H. SAUNDERS2, T. BOSMANS1, G. PAES1 and H. DE ROOSTER1* received April 27, 2013 accepted November 12, 2013 Keywors: Dogs, portoazygos shunt, hepatic micro- Schlüsselwörter: Hunde, Portoazygos-Shunt, hepati- vascular dysplasia, imaging, histology. sche mikrovaskuläre Dysplasie, Bildgebung, Histologie. Summary Zusammenfassung A ve-year-old, female castrated Yorkshire Terrier Kongenitaler portosystemischer Shunt in was presented with complaints of decreased activity Kombination mit hepatischer mikrovaskulärer and appetite, fever, a painful abdomen and lower Dysplasie bei einem Yorkshire Terrier urinary tract symptoms. Based on blood and urinalysis there was a strong suspicion of liver Eine kastrierte fünfjährige Yorkshire Terrier- disease and a urinary tract infection. Abdominal Hündin wurde mit Symptomen verminderter Akti- ultrasound revealed a portoazygos shunt, bilateral vität, verminderten Appetits, Fieber und Abdo- nephrolithiasis and pyelectasia raising the suspicion minalschmerz sowie Symptomen des unteren of pyelonephritis. However, pyelonephritis could not Harntraktes vorgestellt. Die Laboruntersuchung be con rmed because urine culture – while the dog von Blut und Harn deutete auf eine Leber- received antibiotics – was negative. A shunt fraction erkrankung und eine Infektion der Harnwege of 99% was con rmed on scintigraphy. After medical hin. Die Ultraschalluntersuchung des Abdomens stabilization, the shunt was surgically attenuated zeigte einen Portoazygos-Shunt, eine bilaterale using a cellophane band. Postoperatively, conserva- Nephrolithiasis und Pyelektasie, was den Verdacht tive treatment was continued and the dog became auf eine Pyelonephritis ergab. Jedoch konnte clinically asymptomatic, although serum pre- and eine Pyelonephritis mittels Harnkultur nicht postprandial bile acid concentrations remained bestätigt werden, da diese während der Antibio- elevated. Six months after the surgical intervention, tikabehandlung durchgeführt wurde. Die Szinti- a persistent or acquired shunt was excluded by graphie bestätigte eine Shunt-Fraktion von 99 %. subsequent scintigraphy (shunt fraction 0.88%). Nach medikamentöser Stabilisierung wurde der Surgical liver biopsies were taken and routine histo- Shunt chirurgisch mit einem Zellophanband pathology revealed hepatic microvascular dysplasia. reduziert. Die medikamentöse Therapie wurde postoperativ fortgesetzt und die Hündin zeigte keine erkennbaren Symptome mehr. Jedoch blieben die präprandialen und postprandialen Gallensäure-Konzentrationen dauerhaft erhöht. Sechs Monate nach der Operation konnte durch eine weitere Szintigraphie ein persistierender oder erworbener Shunt ausgeschlossen werden (Shunt-Fraktion 0.88 %). Die pathohistologi- sche Untersuchung der durchgeführten Leber- Abbreviations: PPS = portosystemic shunt; EHPSS = ex- trahepatic portosystemic shunt; HMD = hepatic microvas- biopsie ergab das Vorliegen einer hepatischen cular dysplasia; IH = immunohistochemistry mikrovaskulären Dysplasie. 58 Wiener Tierärztliche Monatsschrift – Veterinary Medicine Austria 101 (2014) Introduction isothenuria (Tab. 2). No crystals were detected during microscopic evaluation of the urine sample and A portosystemic shunt (PSS) is an abnormal vascu- bacteriological urine culture was negative. lar communication between the portal venous and On abdominal ultrasound, the liver was considered systemic circulation that causes the majority of blood normal in size and shape and had a homogeneous to ow from the intestinal tract directly to the right parenchyma. An aberrant blood vessel was visible, heart, bypassing the liver. Portosystemic shunts are originating from the portal vein and running dorsally the most common congenital diseases of the hepato- towards a blood vessel near the aorta. Examination of billiary system of dogs and can occur intrahepatically the kidneys revealed bilateral nephrolithiasis and mild or extrahepatically (BROOME et al., 2004). After por- pyelectasia at the level of the nephroliths (Tab. 3). tocaval shunts, portoazygos shunts are the second The dog was diagnosed with a congenital EHPSS most common type of extrahepatic portosystemic and was suspected of having a pyelonephritis, based shunts (EHPSS) in dogs (KUMMELING et al., 2004). on the presence of pyelectasis, active sediment, Hepatic microvascular dysplasia (HMD) is a con- decreased kidney function and fever. genital disease in which microscopic intrahepatic The dog was hospitalized and infusion therapy portovenous shunts are present (SCHERMERHORN initiated at 100 ml/kg/24 hours (NaCl 0.9%). Antibiotic et al., 1996; ALLEN et al., 1999). Microscopic shunting therapy was instituted, combining metronidazole/ may occur in isolation or may coexist with a macro- spiramycine to decrease the number of urease- scopic PSS and has a similar clinicopathological pre- producing bacteria in the intestines (Stomorgyl®, me- sentation to a PSS (SCHERMERHORN et al., 1996; tronidazole 12.5 mg/kg and spiramycine 25 mg/kg ALLEN et al., 1999; LANDON et al., 2008). The pre- BID p.o.) and amoxicillin/clavulanic acid to treat the valence of HMD is suggested to be twice to 30 times suspected urinary tract infection (Augmentin P500® higher than the prevalence of PSS (SCHERMERHORN 20 mg/kg TID i.v.) Additionally, lactulose (Lactulose et al., 1996; CENTER, 2009). EG® 0.5 mL/kg TID p.o.), ranitidine (Zantac® 0.5 mg/kg A Yorkshire Terrier with a combination of an EHPSS BID i.v.), metoclopramide (Primperan® 0.3 mg/kg TID and HMD will be described. The simultaneous i.v.) and methadone (Mephenon® 0.2 mg/kg q4 hours occurrence of both congenital diseases has been pre- i.v.) were administered. A highly digestible liver diet viously reported in veterinary literature (ALLEN et al., (Hill’s Prescription Diet Canine l/d®) was fed, with the 1999; LANDON et al., 2008). However, special daily amount divided into ve meals. On day three, the attention will be given to the challenges of diagnosing dog developed stupor. An enema was performed with HMD in the presence of a patent macroscopic PSS. a solution of 20 ml/kg lactulose and 45 ml/kg luke- warm water, after which the overall clinical state of the Case report dog improved. A transsplenic scintigraphic scan was performed at day ve, under total intravenous anaes- A ve-year-old, female castrated Yorkshire Terrier thesia using propofol (Propovet® up to 6 mg/kg i.v. was presented with a history of chronic recurrent to effect). Sodium 99mTc pertechnetate (±0.2 ml; bacterial cystitis. During the ve days prior to presen- 118.4 MBq) was injected into the splenic parenchyma tation, the dog was lethargic, partially anorectic and under ultrasound guidance and a dynamic frame developed pollakisuria, stranguria and haematuria. mode acquisition was used (Toshiba GCA single-head The referring veterinarian detected an elevated rectal gamma-camera with low-energy, high-resolution temperature (40 °C), a heart murmur and a painful ab- (LEHR) collimator; acquisition protocol: four frames domen. Blood samples were taken and revealed mild per s total 240 frames or 1 min acquisition time). A leucocytosis, mild azotaemia, severe elevated post- shunt fraction of 99% was present (Fig. 1). prandial bile acids and moderate hypoalbuminaemia The dog was discharged at day seven with (Tab. 1). The dog was injected on two consecutive amoxicillin/clavulanic acid (Clavubactin® 12.5 mg/kg days with anticholinergics and antibiotics (preparation BID p.o.), to be continued for another two weeks, to and dosage unknown), without clinical improvement. treat the suspected urinary tract infection. The PSS On admission (day zero) the dog was still partially therapy included the liver diet, lactulose and anorectic and lower urinary tract signs persisted. On metronidazole/spiramycine. physical examination, the dog was calm but alert, had A week after nishing the antibiotics (day 28), a body condition score of 5/9 (Purina BCS), a mild previous abnormalities detected on renal ultra- systolic heart murmur and was normothermic sonography, blood and urinalysis had improved (38.4 °C). Abdominal palpation was very painful but (Tab. 1–3). The owners did not report any clinical symp- the origin of pain was dif cult to assess. Blood ana- toms and physical examination was unremarkable. lysis was repeated and revealed similar abnormalities, At day 47, the shunting vessel was surgically including severe elevated pre- and postprandial bile attenuated. Premedication consisted of methadone acids (Tab. 1). Urinalysis revealed moderate (0.2 mg/kg i.v.) and induction was performed using proteinuria, severe pyuria, severe haematuria and propofol (up to 6 mg/kg i.v. to effect). Anaesthesia was 59 Wiener Tierärztliche Monatsschrift – Veterinary Medicine Austria 101 (2014) Tab. 1: Haematology and serum biochemistry of a Yorkshire Terrier with a combination of extrahepatic portoazygos shunt and hepatic microvascular displasia from the rst