Treatment of extrahepatic congenital portosystemic shunts in dogs - what is the evidence base?

Serum Amino Acid Profiles in Dogs with a Congenital Portosystemic Shunt

Background/Objectives: A functional liver is vital for normal protein metabolism. Alterations of circulating amino acid (AA) concentrations have previously been reported in dogs with hepatocellular carcinoma, chronic hepatitis, and hepatocutaneous syndrome. The purpose of this study was to compare serum AA profiles between dogs with a congenital portosystemic shunt (CPSS) and healthy control dogs. Methods: Serum samples were collected from 50 dogs with an extrahepatic congenital portosystemic shunt (eCPSS) and 10 dogs with an intrahepatic congenital portosystemic shunt (iCPSS) at time of surgical intervention and from 21 healthy control dogs. Serum AA and other nitrogenous compounds were measured with a dedicated amino acid analyzer. The concentration of each AA was compared between groups using a Kruskal-Wallis test followed by Dunn's multiple comparisons tests, as appropriate. The Benjamini-Hochberg procedure was used to control for false discovery. Significance was set at q < 0.05. Results: Compared to healthy controls, dogs with a CPSS had significantly increased serum concentrations of ammonia, asparagine, glutamic acid, histidine, phenylalanine, serine, and tyrosine and had significantly decreased concentrations of isoleucine, leucine, threonine, urea, and valine. There were no significant differences in serum AA concentrations between dogs with an eCPSS and dogs with an iCPSS. Conclusions: Dogs with a CPSS had altered serum AA concentrations compared to healthy control dogs, including decreased branched-chain amino acids (BCAAs) and increased aromatic amino acids (AAAs). In summary, serum AA profiles can differentiate dogs with a CPSS from healthy dogs but not dogs with an eCPSS from dogs with an iCPSS.

Clinical presentation and short-term outcomes of dogs ≥15 kg with extrahepatic portosystemic shunts

OBJECTIVE

To describe demographics, clinical presentation, shunt anatomy, clinical progression, and complications in large dogs ≥15 kg with single extrahepatic portosystemic shunts (EHPSS) treated with or without surgery.

STUDY DESIGN

Multicenter retrospective (10 university hospitals, one private referral institution).

ANIMALS

Dogs ≥15 kg (n = 63).

METHODS

Medical records of dogs ≥15 kg diagnosed with EHPSS between January 01, 2005 and December 31, 2020 were reviewed. Dogs had a minimum follow-up of 90 days. Signalment, clinical signs, diagnostics, shunt anatomy, treatment interventions, and perioperative complications were assessed.

RESULTS

Median age was 21.9 months (IQR: 9-36.8). The breed most represented was the Golden retriever (17/63 dogs). Portocaval (17/63) and splenocaval (15/63) shunt configurations were most common. Portal vein hypoplasia was noted in 18 imaging reports. Of the surgically treated dogs, 14/45 (35.6%) had short-term complications, and 3/45 (6.7%) had shunt-related deaths. Medical management was discontinued in 15/40 and reduced in 9/40 of surviving dogs who had surgical attenuation. All medically managed, nonattenuated dogs (18/18) were maintained on their original shunt-related medication regimens.

CONCLUSIONS

Clinical presentation of dogs ≥15 kg with extrahepatic portosystemic shunts was similar to the more commonly reported small breed dogs. Surgical management of single EHPSS in large dogs ≥15 kg had similar clinical short-term outcomes as small breed dogs.

CLINICAL SIGNIFICANCE

Clinicians should be aware that large breed dogs with EHPSS share similar characteristics and clinical outcomes to small breed dogs. The significance of the presence of a hypoplastic portal vein warrants further research. Surgical treatment is a viable option for large breed dogs with EHPSS.

Congenital Portosystemic Shunts in Dogs and Cats: Treatment, Complications and Prognosis

Congenital portosystemic shunts (CPSS) are a common vascular anomaly of the liver in dogs and cats. Clinical signs of CPSS are non-specific and may wax and wane, while laboratory findings can raise the clinical suspicion for CPSS, but they are also not specific. Definitive diagnosis will be established by evaluation of liver function tests and diagnostic imaging. The aim of this article is to review the management, both medical and surgical, complications, and prognosis of CPSS in dogs and cats. Attenuation of the CPSS is the treatment of choice and may be performed by open surgical intervention using ameroid ring constrictors, thin film banding, and partial or complete suture ligation or by percutaneous transvenous coil embolization. There is no strong evidence to recommend one surgical technique over another. Medical treatment strategies include administration of non-absorbable disaccharides (i.e., lactulose), antibiotics, and dietary changes, and are indicated for pre-surgical stabilization or when surgical intervention is not feasible. After CPSS attenuation, short- and long-term post-surgical complications may be seen, such as post-operative seizures and recurrence of clinical signs, respectively. Prognosis after surgical attenuation of CPSS is generally favorable for dogs and fair for cats.

Prediction of outcome after ligation or thin film banding of extrahepatic shunts, based on plasma albumin concentration and hematologic expression of 8 target genes in 85 dogs

BACKGROUND

In dogs with a congenital extrahepatic portosystemic shunt (EHPSS), outcome after surgical attenuation is difficult to predict.

OBJECTIVES

Develop a minimally invasive test to predict outcome after surgical EHPSS attenuation and establish risk factors for postattenuation seizures (PAS).

ANIMALS

Eighty-five client-owned dogs referred for surgical attenuation of a single EHPSS.

METHODS

mRNA expression of 8 genes was measured in preoperatively collected venous blood samples. Outcome was determined at a median of 92 days (range, 26-208) postoperatively by evaluating clinical performance, blood test results and abdominal ultrasonography. Multivariable logistic regression was used to construct models predicting clinical and complete recovery. The associations between putative predictors and PAS were studied using univariable analyses.

RESULTS

Five of 85 dogs developed PAS. Risk factors were age, white blood cell (WBC) count and expression of hepatocyte growth factor activator and LysM and putative peptidoglycan-binding domain-containing protein 2. Clinical recovery was observed in 72 of 85 dogs and complete recovery in 51 of 80 dogs (median follow-up, 92 days). The model predicting clinical recovery included albumin, WBC count, and methionine adenosyltransferase 2 alpha (MAT2α) expression, whereas the model predicting complete recovery included albumin, and connective tissue growth factor precursor and MAT2α expression. The areas under the receiver operating characteristic curves were 0.886 (95% confidence interval [CI]: 0.783, 0.990) and 0.794 (95% CI: 0.686, 0.902), respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Two models were constructed for predicting outcome after EHPSS attenuation using venous blood samples. The model predicting clinical recovery showed the best diagnostic properties. Clinical application requires further validation.

Abstract Presentation at Two Veterinary Surgery Conferences and the Impact on Publication Rate

OBJECTIVES

 The aim of this study was to compare the publication rate (PR) and report descriptive findings from abstracts presented at the American College of Veterinary Surgeons (ACVS), the Veterinary Orthopaedic Society (VOS), and those presented at both conferences.

STUDY DESIGN

 All conference abstracts from 2001 to 2010 ACVS and VOS meetings were reviewed. PR in peer-reviewed journals was evaluated and compared between Group 1 (abstracts presented at ACVS only; n = 1,277), Group 2 (abstracts presented at VOS only; n = 645), and Group 3 (abstracts presented at both conferences; n = 121) abstracts. Abstracts were assigned a level of evidence (LoE) score.

RESULTS

 Approximately 6% of all abstracts evaluated were presented at two scientific meetings (Group 3). The PR of Group 1 (66%) and Group 3 (62%) abstracts was significantly higher than that of Group 2 (45%). The majority of abstracts were assigned a low LoE (3 or 4). Once presented, most Group 3 abstracts took <12 months to be submitted and <24 months to be published.

CONCLUSION

 This study found that a limited number of abstracts were presented at both ACVS and VOS, and PR was significantly different between those presented at ACVS only or both ACVS and VOS compared with VOS only. There was no significant difference in PR between Group 1 and Group 3 abstracts. This study has provided the initial comparison between abstracts presented at two veterinary surgical conferences.

Outcomes of treatments for keratomalacia in dogs and cats: a systematic review of the published literature including non-randomised controlled and non-controlled studies

OBJECTIVES

The aim of this review was to interrogate the evidence base for treatment of keratomalacia in dogs and cats, through examination of the applicable literature.

MATERIALS AND METHODS

Studies were screened for evidence to answer the following question Which of the treatment options for keratomalacia in dogs and cats offers the best chance of globe survival, the fastest time to resolution with globe survival, and the best visual outcome. The search utilised the PubMed (http://www.pubmed.gov/) and ISI Web of Science (http://wok.mimas.ac.uk/) databases. Databases were searched using the following terms: (keratomalacia OR corneal melt OR corneal malacia) AND (dog OR canine OR canid OR cat OR feline OR felid) AND (treatment OR outcome OR morbidity OR complications). Studies were assessed by one author (CH) and excluded if they related to less than three keratomalacia cases, experimental treatments, in vitro studies, or did not provide information regarding outcome. Studies were classified to a level of evidence according to the system described by the Oxford Centre for EvidenceBased Medicine.

RESULTS

Eighteen (18) studies were identified as providing information to answer the proposed question, one as level 3, 10 as level 4 and seven as level 5 evidence. Only one study compared two treatments, the remaining were prospective or retrospective case series of a single treatment intervention. Study design was highly variable with respect to population size, followup and outcome assessment, making direct comparison difficult, and metaanalysis was not applied.

CLINICAL SIGNIFICANCE

Overall, the evidence for improved outcome of one proposed treatment over another proposed treatment for keratomalacia in dogs and/or cats is very weak.

Outcome of non-surgical dietary treatment with or without lactulose in dogs with congenital portosystemic shunts

Background

Congenital portosystemic shunts (CPSS) are vascular anomalies, allowing portal blood to bypass the hepatic parenchyma, thereby accumulating toxic substances such as ammonia in the systemic circulation resulting in hepatic encephalopathy.

Aim

To evaluate the outcome of non-surgically treated dogs with a CPSS.

Methods

Case records of 78 dogs with a single congenital CPSS confirmed by ultrasound and/or computed tomography between September 2003 and February 2015 were reviewed. Median age at diagnosis of CPSS in dogs was 10.8 months (range 2–133 months). Non-surgical treatment was started as an adjusted diet (a diet restricted in protein) with or without lactulose. Owners were contacted by telephone to determine survival time and presumed cause of death, if applicable. In addition, a questionnaire was used to retrospectively assess quality of life (QoL) and CPSS scores in 37 dogs before and during non-surgical treatment. Differences between Kaplan–Meier curves were tested by a Log rank test.

Results

Overall estimated median survival time (EMST) was 38.5 months (range 1 day − 91 months; 78 dogs). No significant differences between EMSTs were found between dogs with extra- (n = 48) or intrahepatic (n = 29) shunts, nor between treatment with only an adjusted diet, or an adjusted diet combined with lactulose. During non-surgical treatment, significant improvement in perceived QoL and CPSS scores were found (P < 0.01).

Conclusion

Our study demonstrated that an overall median EMST of 3.2 years was reached and that owners retrospectively perceived that non-surgical treatment resulted in an improved QoL and clinical performance, irrespective of intrahepatic or extrahepatic CPSS location.

Publication Rate and Evidence-Based Evaluation of Abstracts Presented at the Annual Veterinary Orthopedic Society Conference

OBJECTIVES

 Scientific abstracts are a common method for disseminating new research. There is no information on the publication rate of orthopaedic surgery abstracts presented at the annual Veterinary Orthopedic Society (VOS) Conference. The objectives of this study were to document the publication rate, the publication timeline and the level of evidence (LoE) of abstracts presented at an annual orthopaedic meeting.

STUDY DESIGN

 All conference abstracts from the 2001 to 2014 annual VOS meeting were reviewed, and final publication was determined through a comprehensive bibliographic search.

RESULTS

 Over 14 conferences, 1,112 scientific abstracts were presented with an overall publication rate of 47%. The majority of abstracts had low LoE scores, and those abstracts were published less timely than ones with higher LoE scores. Once presented, most abstracts took 1 year to be submitted and 2 years to be published. Dog (45%) and ex vivo (19%) studies were the most common. Publication occurred most frequently in Veterinary Surgery (40%), Veterinary and Comparative Orthopaedics and Traumatology (17%) and the American Journal of Veterinary Research (12%).

CONCLUSION

 The publication rate for abstracts presented at the annual VOS meeting is lower than those from a more generalized veterinary surgery conference. Publication occurs most frequently in a select group of journals, and the subject matter is limited in scope with a focus on dog and ex vivo studies. Overall, most abstracts presented at VOS contain a lower LoE.

The effect of neuraxial morphine on postoperative pain in dogs after extrahepatic portosystemic shunt attenuation

OBJECTIVE

To investigate the analgesic effect of epidural morphine after surgical extrahepatic portosystemic shunt (EHPSS) attenuation.

STUDY DESIGN

Randomized clinical trial.

ANIMALS

A total of 20 dogs with a congenital EHPSS.

METHODS

Dogs were randomly allocated to be given either a single epidural dose of 0.2 mg kg^-1 preservative-free morphine (group M) or not (group C) before surgery. All dogs were administered 0.3 mg kg^-1 methadone intravenously (IV) as preanaesthetic medication. Pain scores were determined every 2 hours for the first 24 hours postoperatively using the short-form Glasgow Composite Measure Pain Scale (GCMPS-SF). Dogs with a GCMPS-SF pain score >4/20 or >5/24 received 0.1 mg kg^-1 methadone IV as rescue analgesia and were reassessed 30 minutes later. If more than three doses of methadone were administered in a 2 hour period, alternative pain relief was provided and a treatment failure recorded. The GCMPS-SF pain scores and number of rescue analgesia injections were analysed over 24 hours. The last observation carried forward method was applied in case of treatment failure. Food consumption and time to first urination were recorded. Data were analysed using a Mann-Whitney U test and presented as median (minimum-maximum range), with significance set at p < 0.05.

RESULTS

Group M showed lower GCMPS-SF pain scores [15 (11-41) versus 31 (11-86); p = 0.023] and lower postoperative methadone requirements [0 (0-0.2) versus 0.25 (0-0.5) mg kg^-1; p = 0.029] than group C. There were three treatment failures in group C only. Food consumption and time to first urination did not differ between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Epidural morphine reduced the requirement for postoperative analgesia in this study population.

Treatment of idiopathic chylothorax in dogs and cats: A systematic review

OBJECTIVE

To evaluate the evidence published on the treatment of idiopathic chylothorax (IC) in small animals.

STUDY DESIGN

Systematic literature review.

SAMPLE POPULATION

Dogs and cats with IC.

METHODS

A literature search was performed in three bibliographic databases in July 2018 for publications on IC in dogs and cats. Articles meeting criteria for inclusion were evaluated for treatment, survival, outcome data, and level of evidence (LoE) with a modified Oxford Level of Evidence (mOLE) and GRADE (Grading of Recommendations, Assessment, Development and Evaluations) system.

RESULTS

Eleven of 313 identified articles met the inclusion criteria. Only one study was identified in dogs as having higher LoE by using the mOLE system, whereas no study was identified as such in either species with the GRADE system. Surgery was the primary treatment in all dogs and in 93% (68/73) of cats. Medical therapy was the primary treatment in 7% (5/73) of cats. The most common surgical treatment combined thoracic duct ligation (TDL) and subtotal pericardiectomy (SP; 40%; 34/84) in dogs and TDL in cats (51% [37/73]).

CONCLUSION

The body of literature for IC treatment in small animals was limited to one higher LoE study in dogs and none in cats. No strong conclusion could be drawn regarding the effectiveness of any one surgical method in dogs or cats, and no evidence was found to support medical therapy as a primary treatment.

CLINICAL SIGNIFICANCE

The best available evidence regarding the treatment of IC is published in dogs and provides some support for surgical treatment with either TDL + cisterna chyli ablation or TDL + SP. Additional evidence is required to confirm this finding.

Treatment of congenital extrahepatic portosystemic shunts in dogs: A systematic review and meta-analysis

Background

Several options have been proposed for the treatment of congenital extrahepatic portosystemic shunts (cEHPSS) in dogs, but formal comparisons among different treatment options are currently unavailable. A previous evidence‐based review (2012) found low quality of evidence for papers assessing the treatment of cEHPSS in dogs.

Objectives

To assess the quality of evidence available in the treatment of cEHPSS, summarize the current state of knowledge with respect to outcome after cEHPSS management, and compare different treatment techniques.

Animals

Not used.

Methods

A bibliographic search was performed without date or language restrictions. Studies were assessed for quality of evidence (study design, study group sizes, subject enrollment quality, and overall risk of bias) and outcome measures reported (perioperative outcome, clinical outcome, and surgical or interventional outcome), all reported with 95% confidence intervals. A network meta‐analysis was performed.

Results

Forty‐eight studies were included. Six retrospective studies (grade 4b) compared 2 techniques and 7 were abstracts (grade 5). The quality of evidence was low and risk of bias high. Regarding surgical outcome, statistically significant superiority of ameroid constrictor over thin film band was observed (P = .003). No other comparisons were statistically significant.

Conclusions and Clinical Importance

The evidence base of choice of treatment of cEHPSS in dogs remains weak despite recent publications on the subject. Ameroid is superior to thin film band in causing EHPSS closure. Blinded randomized studies comparing different treatment modalities, which routinely include postoperative imaging to assess cEHPSS closure and acquired portosystemic shunt development are essential.

Outcomes of dogs treated for extrahepatic congenital portosystemic shunts with thin film banding or ameroid ring constrictor

OBJECTIVE

To compare the outcomes of dogs treated at a single institution for single extrahepatic congenital portosystemic shunts (CPSS) by thin film banding (TFB) or by placement of an ameroid constrictor (AC).

STUDY DESIGN

Retrospective case series.

ANIMALS

Seventy-six client-owned dogs with CPSS treated with TFB (n = 53) or AC (n = 23).

METHODS

Records were reviewed for signalment, preoperative, intraoperative, and postoperative management and short-term outcomes. Data on second surgeries were reviewed. Long-term outcomes were obtained via an owner-directed health-related quality of life questionnaire. The rates of complications, mortality, and revision surgery were compared between the treatment groups.

RESULTS

Postoperative complications occurred in 15 (28%) dogs with TFB (9% mortality, n = 5) and 8 (35%) dogs with an AC (4% mortality, n = 1). Long-term follow-up was available in 41 of 56 dogs at a median of 55 months (range, 15-89). Revision surgery for persistent shunting was performed in 14 (29%) dogs treated initially with TFB and in no dogs treated initially with AC (P = .007). Median long-term outcome scores were good in both groups; nine of 14 revision surgeries led to favorable outcomes.

CONCLUSION

Persistent shunting requiring revision surgery was more common when CPSS were treated with TFB than with an AC, but both treatments achieved favorable long-term outcomes.

CLINICAL SIGNIFICANCE

Treatment of CPPS by placement of an AC rather than TFB seems more reliable for shunt attenuation and prevention of revision surgeries.

Health-related quality of life following surgical attenuation of congenital portosystemic shunts versus healthy controls

OBJECTIVES

To design a health-related quality of life questionnaire for dogs with congenital portosystemic shunts, use it in a cohort of dogs treated with suture attenuation and compare results with those obtained from a healthy control cohort.

MATERIALS AND METHODS

Data were collected from the hospital records of dogs treated with suture ligation of an intrahepatic or extrahepatic congenital portosystemic shunt at two referral centres. Owners were asked to complete a questionnaire assessing their dog's health-related quality of life preoperatively (retrospectively) and at the time of follow-up. Owners of control dogs also completed the questionnaire.

RESULTS

One hundred and twenty-eight dogs with congenital portosystemic shunts and 131 control dogs were recruited. Median follow-up time was 64 months (range 19.7 to 157.2). The median long-term health-related quality of life score was excellent for both intrahepatic and extrahpatic shunt cases and similar to that of control dogs. The long-term portosystemic shunt clinical sign scores for both intrahepatic and extrahepatic congenital portosystemic shunt dogs were significantly worse than the those of the control group.

CLINICAL SIGNIFICANCE

Suture attenuation of congenitial portosystemic shunts is associated with an excellent health-related quality of life score at long-term follow-up.

Erosion of the medial compartment of the canine elbow: occurrence, diagnosis and currently available treatment options

Erosion of the medial compartment of the elbow joint refers to full thickness cartilage loss with exposure of the subchondral bone (modified Outerbridge grades 4–5) of the medial part of the humeral condyle (MHC) and the corresponding ulnar contact area. This finding may appear in the absence of an osteochondral fragment or a cartilage flap, or in combination with fragmentation of the medial coronoid process (MCP) or osteochondritis dissecans (OCD) of the MHC. With regard to the prognosis, it is important to diagnose these severe erosions. Imaging of cartilage lesions by means of radiography, ultrasonography, computed tomography or magnetic resonance imaging is challenging in dogs. In contrast, direct arthroscopic inspection provides detailed information about the cartilage.

The treatment of these severe erosions is difficult because of the limited regenerative capacity of cartilage and presumed mechanical or physical triggering factors. Several conservative and surgical treatment methods have been proposed to treat elbows with severe cartilage defects. However, due to irreversible loss of cartilage, the prognosis in these cases remains guarded.

Therapeutic Management of Feline Chronic Gingivostomatitis: A Systematic Review of the Literature

Feline chronic gingivostomatitis (FCGS) is a disease characterized by protracted and potentially debilitating oral inflammation in cats, the etiology of which is currently unknown. The purpose of this review is to apply an evidence-based medicine approach to systematically review and critically evaluate the scientific literature reporting the outcome of medical and surgical management of FCGS. Those articles meeting inclusion criteria were reviewed and assigned an "Experimental Design Grade" (EDG) and an "Evidence Grade" (EG) in order to score relative strength of study design and produced data. Studies were evaluated and compared, especially highlighting the treatments, the outcomes, and the therapeutic success rates. This review found a lack of consistency between articles' data, rendering direct comparison of results unreliable. The field of FCGS research, and ultimately patient care, would benefit from standardizing studies by adopting use of a consistent semi-quantitative scoring system and extending follow-up duration. Future researchers should commit to large prospective studies that compare existing treatments and demonstrate the promise of new treatments.

Long-term survival and quality of life in dogs with clinical signs associated with a congenital portosystemic shunt after surgical or medical treatment

OBJECTIVE

To compare long-term survival and quality of life data in dogs with clinical signs associated with a congenital portosystemic shunt (CPSS) that underwent medical or surgical treatment.

DESIGN

Prospective cohort study.

ANIMALS

124 client-owned dogs with CPSS.

PROCEDURES

Dogs received medical or surgical treatment without regard to signalment, clinical signs, or clinicopathologic results. Survival data were analyzed with a Cox regression model. Quality of life information, obtained from owner questionnaires, included frequency of CPSS-associated clinical signs (from which a clinical score was derived), whether owners considered their dog normal, and (for surgically treated dogs) any ongoing medical treatment for CPSS. A Mann-Whitney U test was used to compare mean clinical score data between surgically and medically managed dogs during predetermined follow-up intervals.

RESULTS

97 dogs underwent surgical treatment; 27 were managed medically. Median follow-up time for all dogs was 1,936 days. Forty-five dogs (24 medically managed and 21 surgically managed) died or were euthanized during the follow-up period. Survival rate was significantly improved in dogs that underwent surgical treatment (hazard ratio, 8.11; 95% CI, 4.20 to 15.66) than in those treated medically for CPSS. Neither age at diagnosis nor shunt type affected survival rate. Frequency of clinical signs was lower in surgically versus medically managed dogs for all follow-up intervals, with a significant difference between groups at 4 to 7 years after study entry.

CONCLUSIONS AND CLINICAL RELEVANCE

Surgical treatment of CPSS in dogs resulted in significantly improved survival rate and lower frequency of ongoing clinical signs, compared with medical management. Age at diagnosis did not affect survival rate and should not influence treatment choice.

Attenuation of congenital portosystemic shunt reduces inflammation in dogs

Liver disease is a major cause of morbidity and mortality. One of the most significant complications in patients with liver disease is the development of neurological disturbances, termed hepatic encephalopathy. The pathogenesis of hepatic encephalopathy is incompletely understood, which has resulted in the development of a wide range of experimental models. Congenital portosystemic shunt is one of the most common congenital disorders diagnosed in client owned dogs. Our recent studies have demonstrated that the pathophysiology of canine hepatic encephalopathy is very similar to human hepatic encephalopathy, which provides strong support for the use of dogs with a congenital portosystemic shunt as a naturally occurring model of human hepatic encephalopathy. Specifically, we have demonstrated an important role for ammonia and inflammation in the development of hepatic encephalopathy in dogs with a congenital portosystemic shunt. Despite the apparent importance of inflammation in driving hepatic encephalopathy in dogs, it is unclear whether inflammation resolves following the successful treatment of liver disease. We hypothesized that haematological and biochemical evidence of inflammation, as gauged by neutrophil, lymphocyte and monocyte concentrations together with C-reactive protein concentrations, would decrease following successful treatment of congenital portosystemic shunts in dogs. One hundred and forty dogs with a congenital portosystemic shunt were enrolled into the study. We found that the proportion of dogs with a monocyte concentration above the reference range was significantly greater in dogs with hepatic encephalopathy at time of initial diagnosis. Importantly, neutrophil and monocyte concentrations significantly decreased following surgical congenital portosystemic shunt attenuation. We also found a significant decrease in C-reactive protein concentrations following surgical attenuation of congenital portosystemic shunts. Our study demonstrates that haematological and biochemical indices of inflammation reduce following successful treatment of the underlying liver disorder.

Markers of angiogenesis associated with surgical attenuation of congenital portosystemic shunts in dogs

Background

Dogs with congenital portosystemic shunts (CPSS) have hypoplasia of the intrahepatic portal veins. Surgical CPSS attenuation results in the development of the intrahepatic portal vasculature, the precise mechanism for which is unknown, although new vessel formation by angiogenesis is suspected.

Hypothesis

That the degree of portal vascular development and the increase in portal vascularization after CPSS attenuation is significantly associated with hepatic vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2) gene expression and serum VEGF concentration.

Animals

Client‐owned dogs with CPSS undergoing surgical treatment. Forty‐nine dogs were included in the gene expression data and 35 in the serum VEGF data.

Materials and Methods

Dogs surgically treated by partial or complete CPSS attenuation were prospectively recruited. Relative gene expression of VEGF and VEGFR2 was measured in liver biopsy samples taken at initial and follow‐up surgery using quantitative polymerase chain reaction. Serum VEGF concentration was measured before and after CPSS attenuation using a canine specific ELISA. Statistical significance was set at the 5% level (P ≤ .05).

Results

There was a significant increase in the mRNA expression of VEGFR2 after partial attenuation (P = .006). Dogs that could tolerate complete attenuation had significantly greater VEGFR2 mRNA expression than those that only tolerated partial attenuation (P = .037). Serum VEGF concentration was significantly increased at 24 (P < .001) and 48 (P = .003) hours after attenuation.

Conclusions and Clinical Importance

These findings suggest that intrahepatic angiogenesis is likely to occur after the surgical attenuation of CPSS in dogs, and contributes to the development of the intrahepatic vasculature postoperatively.

The C57BL/6J mouse exhibits sporadic congenital portosystemic shunts

C57BL/6 mice are the most widely used strain of laboratory mice. Using in vivo proton Magnetic Resonance Spectroscopy (¹H MRS), we have repeatedly observed an abnormal neurochemical profile in the brains of both wild-type and genetically modified mice derived from the C57BL/6J strain, consisting of a several fold increase in cerebral glutamine and two fold decrease in myo-inositol. This strikingly abnormal neurochemical “phenotype” resembles that observed in chronic liver disease or portosystemic shunting and appeared to be independent of transgene, origin or chow and was not associated with liver failure. As many as 25% of animals displayed the abnormal neurochemical profile, questioning the reliability of this model for neurobiology. We conducted an independent study to determine if this neurochemical profile was associated with portosystemic shunting. Our results showed that 100% of the mice with high brain glutamine displayed portosystemic shunting by concomitant portal angiography while all mice with normal brain glutamine did not. Since portosystemic shunting is known to cause alterations in gene expression in many organs including the brain, we conclude that portosystemic shunting may be the most significant problem associated with C57BL/6J inbreeding both for its effect on the central nervous system and for its systemic repercussions.

Sinonasal aspergillosis in dogs: a review

Sinonasal aspergillosis is an uncommon, yet debilitating and often frustrating condition to treat in dogs despite years of research evaluating pathogenesis, diagnosis and treatment. The disease is most commonly caused by non-invasive fungal infection, thought to be secondary to altered innate and/or adaptive immune responses. Attempts to confirm this have however failed. A variety of conflicting opinions regarding the diagnosis and treatment of sinonasal aspergillosis exist. Often the use of a particular treatment protocol is based upon personal or regional preference. Evaluation of the veterinary literature demonstrates that the evidence base in support of individual treatment recommendations is weak. A number of recent publications have helped to expand the current knowledge base and therefore our understanding of important practicalities for both diagnostic options and treatment protocols. The following review examines the current evidence for the pathogenesis of sinonasal aspergillosis in dogs, as well as the various diagnostic options. The available evidence for frequently utilised -therapeutic options and their likely outcomes is also explored.