Plasma amino acid profiles in dogs with closed extrahepatic portosystemic shunts are only partially improved 3 months after successful gradual attenuation

Abstract

Background Dogs with portosystemic shunts have an altered blood amino acid profile, with an abnormal branched‐chained amino acid (BCAA)‐to‐aromatic amino acid (AAA) ratio being the most common abnormality. Different liver diseases have distinctive amino acid profiles. Objectives Determine the changes in plasma amino acid profiles in dogs with extrahepatic portosystemic shunts (EHPSS) from diagnosis to complete closure. Animals Ten client‐owned dogs with EHPSS closed after surgical attenuation. Methods Prospective cohort study. Medical treatment was instituted in dogs diagnosed with EHPSS. At least 4 weeks later, gradual surgical attenuation was performed. Three months postoperatively, EHPSS closure was confirmed by transsplenic portal scintigraphy. Clinical signs were scored and blood was taken before institution of medical treatment, at time of surgery, and 3 months postoperatively. At the end of the study, the plasma amino acid profiles were analyzed in batch. Results The median BCAA‐to‐AAA ratio was extremely low (0.6) at time of diagnosis and remained low (0.5) at time of surgery, despite the fact that median neurological score significantly improved from 22 to 2 after starting medical treatment (P = .04). Three months after surgical attenuation, a significantly higher BCAA‐to‐AAA ratio (1.5) was observed (P < .001). Conclusions and Clinical Importance Medical treatment does not improve the BCAA‐to‐AAA ratio in dogs with EHPSS, despite substantial clinical improvement. Although the ratio significantly increased after EHPSS closure, it was still indicative of moderate to severe hepatic dysfunction in all dogs.

Metabolomic serum abnormalities in dogs with hepatopathies

“…4 a). Similar changes in the amino acid panel of dogs with cPSS have previously been reported using other methods 25 , 27 , 50 , 51 . While, increased phenylalanine concentrations have been previously found in dogs with either hepatitis or liver neoplasia, the degree of elevation could not differentiate the two conditions 52 .…”

“…These amino acid changes may be guiding the supplementation and restriction of amino acids in canine hepatopathies. A reduction in phenylalanine and tyrosine, and a rise in valine concentrations were achieved in dogs after shunt surgery, indicating the potential for metabolic reversibility 27 .…”

“…However, other metabolomic methods able to quantify more serum amino acids revealed that alterations in cysteine, serine, methionine, and threonine were additional distinguishing parameters of cPSS and hepatitis in small groups of dogs 25 . As serum serine and methionine concentrations changed during medical treatment in dogs with cPSS 27 , they could also be considered for further studies in hepatopathies. Indeed, the BCAAs (leucine, isoleucine, and valine) and AAAs (phenylalanine and tyrosine) concentrations were altered in both hepatopathy groups of this study.…”

“…Only a few studies have evaluated serum metabolomics with specific MS methods in dogs with liver diseases 25 , 26 . Moreover, determining of distinct groups of metabolites such as amino acids in dogs with cPSS has been reported 27 . Here, we utilize proton ( 1 H) NMR spectroscopy to assess and compare the serum metabolome of dogs with cPSS, dogs with high serum liver enzyme activities (HLEA), and dogs with blood test results in the normal reference intervals.…”

Comparison of diet, lactulose, and metronidazole combinations in the control of pre‐surgical clinical signs in dogs with congenital extrahepatic portosystemic shunts

“…Clinical score was calculated from standardized questionnaires that were filled out by the owners at the different time points (T0, T1, T2), as published before (Table 1 ). 14 , 15 Briefly, any clinical sign occurring often was allocated 2 points and those occurring occasionally were allocated 1 point. The points for gastrointestinal and urinary signs were not multiplied, but those for seizure and coma were multiplied by 3 and all other neurologic signs multiplied by 2, resulting in a maximal clinical sign score of 62.…”