Ataxia and weakness as uncommon primary manifestations of hepatic encephalopathy in a 15‐year‐old trotter gelding

A 15‐year‐old trotter gelding was evaluated because of an acute onset of ataxia in all 4 limbs. There was no known history of trauma. The gelding showed grade 2/5 ataxia in all 4 limbs, which was localised after clinical neurological examination to the cervical vertebral spinal cord. Initial therapy consisted of oral anti‐inflammatory doses of prednisolone and antimicrobial treatment with potentiated sulphonamides. The ataxia progressed to grade 3/5 at Day 10 of hospitalisation. Additionally, the horse was slightly depressed and showed spontaneous yawning during examination. Facial sensation was blunted. Blood chemistry revealed a marked elevation of liver specific enzymes and blood ammonia levels. Transcutaneous abdominal ultrasonography revealed hepatomegaly. Due to a guarded prognosis, the horse was subjected to euthanasia. At necropsy the left lateral liver lobe was markedly enlarged and showed a firm texture, whereas the cranial part and the right and quadratic liver lobe displayed a severe and diffuse atrophy. Histopathologically, the left lateral liver lobe revealed a moderate to severe cirrhosis with a severe, diffuse hepatocellular iron‐accumulation. Increased numbers of Alzheimer type II astrocytes in the cerebral cortex and cerebral white matter vacuolisation were indicative for encephalopathy. These findings were interpreted as haemosiderosis and cirrhosis of the liver with consecutive hepatic encephalopathy. Aetiologically, haemosiderosis should be considered as a cause of liver cirrhosis with consecutive hepatic encephalopathy. Although hepatic encephalopathy in horses usually presents with predominating cerebral signs, it has to be taken into account as a differential diagnosis in cases of acute onset generalised ataxia.     

Surgical management of an extrahepatic portosystemic shunt in a foal: A multidisciplinary problem

A 5‐week‐old American Miniature filly was referred due to intermittent neurological signs of 4 weeks' duration. Clinicopathological findings showed increased ammonia and bile acids in venous blood samples. Abdominal ultrasonography detailed a portosystemic shunt (PSS). The foal underwent laparotomy and operative mesenteric portovenography, which further defined the PSS as extrahepatic portocaval in configuration. The PSS was occluded and intraoperative portovenography confirmed successful shunt occlusion. The foal made a good recovery from surgery and had a successful showing career until she succumbed to colic just over 3 years after surgery.     

Portosystemic shunts: A diagnostic challenge

The case report in this issue by Woodford et al. (2017) describes the surgical management of an extrahepatic portosystemic shunt in a 5‐week old miniature foal. Only a handful of reports exist in the literature describing surgical procedures for repair of these congenital abnormalities in foals. One of the important aspects of the accompanying case report was the multidisciplinary approach taken in handling, imaging and surgical repair of the extrahepatic shunt. Small animal internal medicine specialists and surgeons diagnose portosystemic shunts much more frequently than equine veterinarians, regardless of whether they are general practitioners or specialists. It is therefore important to work as a team with small and large animal practitioners. The case described by Woodford et al. (2017) had a positive outcome.     

Hepatic encephalopathy in a pregnant mare: identification of histopathological changes in the brain of a mare and fetus

An 11-year-old Thoroughbred broodmare was evaluated for suspected hepatic dysfunction. Clinical signs of hepatic encephalopathy were evident at admission. Hepatic ultrasonographic evaluation revealed an increase in hepatic size, rounded borders and normal echogenicity. There was no evidence of cholelithiasis or bile duct distention. Increased activity of hepatic enzymes, increased bile acid and bilirubin concentration and an increased ammonia concentration were supportive of a diagnosis of hepatic disease and hepatic encephalopathy. Histopathological evaluation of a liver biopsy specimen was consistent with chronic active hepatitis. The mare was treated with intravenous fluids and antimicrobials, pentoxyfilline, branched-chain amino acids and dietary manipulation. Clinical improvement was observed initially; however, 3 weeks later, deterioration in the mare's condition necessitated euthanasia. Pathological lesions at necropsy were restricted to the liver and brain. The liver was diffusely firm with a prominent reticular pattern on the cut surface. A large choledocholith was present in the main bile duct of the left liver lobe. Histopathological examination of the liver revealed severe fibrosis, with hyperplastic bile ducts and mononuclear and neutrophilic inflammation. Pathological changes consistent with hepatic encephalopathy, (Alzheimer type II cells), were evident in the cerebrum of both the mare and the fetus.     

Estradiol inhibits hepatic stellate cell area and collagen synthesis in the chicken liver

Hepatic stellate cells (HSCs) are the main collagen‐producing cells in the liver. The HSC area and amount of collagen fibers are different between male and female chickens. This study was performed to confirm the effect of estradiol on collagen synthesis in the growing chicken liver. Blood estradiol levels in chicks were compared at 4 and 8 weeks of age, and the collagen fibril network in liver tissue was observed at 8 weeks by scanning electron microscopy. Intraperitoneal administrations of estradiol and tamoxifen to male and female chicks, respectively, were performed daily from 5 to 8 weeks of age. The areas of HSCs and collagen contents were measured in the liver tissue. The blood estradiol level was higher in females than in males, and the collagen fibril network was denser in males than in females at 8 weeks of age. Estradiol administration in males induced decreases in the HSC area and collagen content of the liver. Conversely, tamoxifen administration in females induced an increase in the HSC area but did not facilitate collagen synthesis. Based on these results, estradiol inhibits the area and collagen synthesis of HSCs in the growing chicken liver under normal physiological conditions.     

犬腹腔镜肝部分切除术对肝、肾功能的影响

选择8条健康杂种犬进行腹腔镜下肝部分切除,于麻醉前、术后4h及术后第1、3、5、7、9、11、13、15天采取静脉血进行肝肾功能指标监测.结果显示,天门冬氨酸氨基转移酶、丙氨酸氨基转移酶及碱性磷酸酶于术后第1天升到高峰;尿酸、尿素氮和肌酐于术后4h即达到高峰;白蛋白和总蛋白略微有所下降,于术后第1天降到最低;而r谷氨酰基转移酶术后变化不大.结果表明,犬腹腔镜肝部分切除术仅仅短期内对肝、肾功能产生影响,且肝、肾功能在术后一段时间内可恢复.     

Hepatic and metabolic changes in surgical colic patients: a pilot study

Objective – To determine: (1) changes in blood ammonia, bile acid (BA), bilirubin, triglyceride, and glucose concentrations and liver enzyme activities in perioperative colic patients and (2) the association between these laboratory findings and short‐term survival. Design – Prospective observational clinical study. Animals – Thirty‐two adult horses undergoing exploratory celiotomy for colic. Interventions – None. Measurements and Main Results – Blood samples were collected preoperatively and at 24–36 and 72–84 hours postoperatively and analyzed for blood ammonia, BA, bilirubin, triglyceride, and glucose concentrations and sorbitol dehydrogenase (SDH) and gamma glutamyl transferase (GGT) activities. Short‐term survival was defined as survival to hospital discharge. Data were analyzed using a Fisher's exact test and analysis of variance. Mildly increased blood ammonia concentrations were present in 2 horses at admission. Postoperative blood ammonia concentrations were within reference intervals in all horses. There were increases in liver enzyme activities as well as in BA, triglyceride, and total bilirubin concentrations. Horses with markedly increased admission BA concentrations and SDH activities did not survive. BA concentrations and SDH activities decreased postoperatively. There was no association between GGT activity and survival; GGT activity remained increased postoperatively. Blood triglyceride concentration was increased in almost all horses postoperatively; horses that did not survive had higher triglyceride concentrations at 24–36 hours postoperatively than horses that survived. Conclusion – Alterations in metabolism and hepatobiliary function are common in colic patients. The results of this study provide further prognostic indices for colic patients and highlight areas for improvement in patient management.     

Black locust (Robinia pseudoacacia) intoxication as a suspected cause of transient hyperammonaemia and enteral encephalopathy in a pony

Two ponies presented with mild abdominal pain and mild diarrhoea one hour after ingestion of roots of a black locust tree. On admission, symptoms had progressed to depression, weakness and the passing of dark, firm faeces. Treatment was symptomatic and supportive, aiming at the evacuation of the toxin from the gastrointestinal tract. One pony developed severe, reversible neurological signs associated with transient hyperammonaemia in the absence of liver disease. After 24 h the ammonia level returned to normal and central nervous signs disappeared. Both ponies recovered completely. This report describes the ingestion of black locust closely followed by the development of central nervous signs and hyperammonaemia. Increased ammonia absorption due to the intestinal wall inflammation caused by the toxins of the black locust tree, as well as increased ammonia production by enteric bacteria is therefore considered a plausible pathophysiological mechanism of the neurological signs displayed in black locust intoxication.     

Equine viral arteritis: A respiratory and reproductive disease of significant economic importance to the equine industry

Equine arteritis virus is the causative agent of equine viral arteritis, a respiratory and reproductive disease that affects the members of the family Equidae. The virus was first isolated from the lung of an aborted fetus after an extensive outbreak of respiratory disease and abortion on a Standardbred breeding farm near Bucyrus, Ohio, in 1953. Since then, periodic outbreaks of equine viral arteritis have been reported in a number of countries around the world. This disease may result in significant economic loss to the equine industry due to the occurrence of abortion in pregnant mares, neonatal mortality, and establishment of the carrier state in stallions. This article provides an extensive review on equine arteritis virus, epidemiology, disease, pathogenesis, and prevention and control measures.     

Equine paranasal sinus disease: a long-term study of 200 cases (1997-2009): ancillary diagnostic findings and involvement of the various sinus compartments

Reasons for performing study: There is a lack of objective information on the value of ancillary diagnostic techniques used to investigate equine sinus disease, and also on which sinus compartments are commonly affected in this disorder. Objectives: To record the ancillary diagnostic findings used to investigate equine sinus disease and to document which compartments are affected. Materials and methods: The clinical case records of 200 consecutive cases of sinus disease, including subacute (<2 months' duration) primary (n = 52); chronic (>2 months' duration) primary (n = 37); dental (n = 40); traumatic (n = 13); sinus cyst (n = 26); sinus neoplasia (n = 10); dental related oromaxillary fistula (n = 8); mycotic sinusitis (n = 7) and intra‐sinus progressive ethmoid haematoma (n = 7) were retrospectively examined. Results: Nasal endoscopy showed exudate draining from the sino‐nasal ostia in 88% of cases and a sino‐nasal fistula was present in 15% of cases. Sinoscopy was performed in 79% of cases and was of great diagnostic value. More recently, 22% of cases had fenestration of the ventral conchal bulla performed to allow sinoscopy of the rostral sinus compartments. Radiography was performed in 97% of cases and showed intra‐sinus fluid lines to be common (69% prevalence) in subacute primary sinusitis. Radiographic dental apical changes were not specific to dental sinusitis, e.g. 29% of chronic primary sinusitis cases had radiographic dental changes. Scintigraphy was performed in 20% of cases and was helpful in identifying dental apical changes when radiography was inconclusive. Overall, the caudal maxillary (78% involvement) and rostral maxillary (61%) sinuses were most commonly affected, with the ventral conchal sinus (VCS) (54% involvement) and conchofrontal sinuses (48%) less so. The VCS showed the greatest tendency to contain inspissated pus (present in 46% of all affected VCS). Conclusions: Nasal endoscopy, sinoscopy and skull radiography are of great value in diagnosing the presence and causes of equine sinus disease.     

Equine odontoclastic tooth resorption and hypercementosis affecting all cheek teeth in two horses: Clinical and histopathological findings

This report describes the clinical presentation and histopathological findings of two horses with equine odontoclastic tooth resorption and hypercementosis (EOTRH) affecting all cheek teeth. Equine odontoclastic tooth resorption and hypercementosis is a well documented condition known to affect the incisors, canines and occasionally the premolars in horses. At this time there have been no documented cases of EORTH affecting all cheek teeth described in the peer reviewed literature. This paper documents the first reported cases of EOTRH affecting the cheek teeth in one horse in the United States and one from Germany.     

Changes in collagen fiber content and hepatic stellate cell distribution in the liver of chick embryos and growing chickens

The content of collagen and the distribution of hepatic stellate cells (HSCs) were studied to elucidate the occurrence of sex‐dependent variations in the liver of developing embryos and growing chickens. Chick embryos from embryonic days (e) 12 to e20 and chicks at 1, 4 and 8 weeks were analyzed. Liver tissue was processed using NaOH maceration and freeze‐dried to obtain the collagen fiber specimens. HSCs were identified by double fluorescent immunohistochemistry for desmin and vimentin. There were no sex‐dependent variations in the percentage of collagen fiber per liver weight and HSC area during embryonic stages. However, the content of collagen fiber increased during embryonic development in both sexes. On the other hand, the area of HSCs significantly increased in growing males but did not show any change in females. Importantly, sex differences were observed in both collagen fiber content and HSC area in the liver at 8 weeks. These results indicate that the occurrence of collagen content variations takes place at 8 weeks in chicken liver, suggesting that a sex‐dependent hormone may play an important role on the collagen production of HSCs in the growing chicken liver.     

Epidemiology of Mycobacterium bovis infection in feral ferrets (Mustela furo) in New Zealand: I. Pathology and diagnosis

Necropsies of 228 ferrets captured from eight areas in the North and South Islands provided material for an investigation into the epidemiology of tuberculosis in feral ferrets. Mycobacterial culture of pooled lymph nodes (retropharyngeal, respiratory and jejunal) identified the prevalence of infection to be much higher than that estimated from gross lesions only. Seventy-three of the 228 animals examined (32%) were diagnosed as tuberculous. Fifty-three culture-positive ferrets and 18 seemingly uninfected animals were subjected to detailed histopathological examination. The outcomes of these investigations, including the characteristics of the disease, distribution of lesions and aids to diagnosis, are presented.

Of the feral carnivores found in New Zealand, the disease persists at high prevalence only in ferrets, and is probably maintained principally by ingestion of tuberculous carrion. The course of the disease may be prolonged in some ferrets, but tuberculosis eventually causes the death of many infected animals. Microscopic hepatic granulomas may be considered pathognomonic of the disease, and have potential to be used as a rapid diagnostic tool in ferrets with no gross lesions.     

Prevalence of Clostridium perfringens in faeces and ileal contents from grass sickness affected horses: Comparisons with 3 control populations

Reasons for performing study: While previous studies have demonstrated an association between equine grass sickness (EGS) and the presence of Clostridium botulinum within ileal contents and faeces, no such associations with other intestinal‐derived anaerobic bacteria have been extensively investigated. Hypothesis: The prevalence of C. perfringens in the ileal contents and faeces of EGS horses is greater than control horses; the detection of C. perfringens in faeces by ELISA could be diagnostically beneficial in a clinical setting. Methods: The prevalence of C. perfringens in faeces from EGS horses and healthy grazing control horses was determined by both selective culture and ELISA to permit both validation of the ELISA and inter‐group comparisons. Additionally, the prevalence of C. perfringens (ELISA) in ileal contents from EGS horses was compared with that for control horses with nongastrointestinal disease. Finally, the prevalence of C. perfringens (ELISA) in faeces from EGS cases was compared with that from both horses with which they shared pasture at the time of disease onset and non‐EGS colic horses. Results: When compared with culture, the ELISA had a sensitivity and specificity of 86 and 98%, respectively. The prevalence of C. perfringens in faeces as determined by both culture and ELISA was significantly higher (P<0.001) for EGS horses (7/9 and 15/37, respectively) than for healthy grazing controls (0/60 and 1/74, respectively). The prevalence of C. perfringens in ileal contents from EGS horses (5/10) was greater than that for horses with nongastrointestinal disease (1/12) at a level that approached significance (P = 0.056). EGS cases had a significantly greater prevalence of C. perfringens in faeces (15/37) than co‐grazing horses (1/18) and colic (1/16) horses. The specificity (93%) and PPV (94%) of the detection of C. perfringens by ELISA on faecal samples in relation to disease status (EGS compared with colic horses) was good. Sensitivity (41%) and NPV (39%) were poor. Conclusions and potential relevance: The use of a commercial ELISA to detect faecal C. perfringens may be diagnostically beneficial when differentiating EGS cases from colic cases, although further work is required to fully evaluate its potential.     

MMP13和TIMP2在肝缺血再灌注损伤介导肝纤维化进程中的动态变化及作用

探讨肝缺血再灌注损伤(HIRI)介导肝纤维化进程中基质金属蛋白酶-13(MMP13)和基质金属蛋白酶组织抑制剂2(TIMP2)的动态变化及作用。将70只C57雄性小鼠随机分为假手术组(Sham组)及肝缺血再灌注组(I/R 0 h组、I/R 3 h组、I/R 6 h组、I/R 72 h组、I/R 7 d组及I/R 15 d组)。夹闭肝门静脉、左叶和中叶的肝动脉,缺血90 min后开夹,分别再灌0、3、6、72 h、7 d及15 d,处死小鼠。检测小鼠血清谷丙转氨酶(ALT)、谷草转氨酶(AST)的水平;测定肝组织中羟脯氨酸(Hyp)的含量;免疫组化法检测肝组织中α-平滑肌肌动蛋白(α-SMA)表达量;RT-PCR检测肝组织MMP13和TIMP2 mRNA的表达水平;HE染色观察肝纤维化程度。结果显示,与Sham组相比,I/R 0 h、I/R 3 h及I/R 6 h组血清ALT、AST升高(P<0.05),I/R 72 h、I/R 7 d及I/R 15 d组下降(P<0.05)。I/R各组肝组织Hyp含量随再灌注时间延长逐渐升高,其中I/R 72 h、I/R 7 d、I/R 15 d组显著高于Sham组(P<0.05)。免疫组化显示,肝组织α-SMA的蛋白表达量随再灌注时间延长而逐渐增加。RT-PCR显示,I/R各组MMP13 mRNA的表达水平呈先高后低的趋势,与Sham组相比,I/R 0 h、I/R 3 h组显著升高(P<0.05)。而TIMP2的表达为先低后高,与Sham组相比,I/R 72 h、I/R 7 d及I/R 15 d组显著升高(P<0.05)。HE染色结果与上述变化趋势相一致。结果表明,在HIRI介导肝纤维化形成过程中MMP13与TIMP2呈动态的协同作用,共同促进肝纤维化的发生发展,是肝纤维化形成的关键因素。     

Clinical and Pathological Studies in Cattle with Hepatic Disease

West, H.J., 1997. Clinical and pathological studies in cattle with hepatic disease. Veterinary Research Communications, 21 (3), 169-185In cattle with hepatic lipidosis, hepatic abscessation, leptospirosis, biliary calculi or fasciolosis, the progression of the disease was studied by serial measurements of serum total bile acid concentrations, plasma glutamate dehydrogenase, -glutamyltranserase, 5-nucleotidase and leucine aminopeptidase activities Terminalia avicennioides and by liver biopsy. Regardless of the cause of the hepatic disease, weight loss, anorexia, dullness and depression were consistent features. Signs of hepatic encephalopathy, such as blindness, head pressing, excitability, ataxia and weakness were less common and, together with pyrexia and jaundice, were grave prognostic signs. Plasma ammonia concentrations were significantly elevated compared to clinically normal cattle, but such changes were not always accompanied by a decline in plasma urea concentrations. In normal, healthy cattle, the plasma ammonia:urea concentration ratio is 9:1 and the plasma ammonia:glucose concentration is 11:1. In hepatic disease, a plasma ammonia:glucose ratio >40:1 or plasma ammonia:urea ratio >30:1, particularly with a rising total ketone body concentration and a declining glucose concentration, carried a guarded prognosis. The study suggested that other factors, such as hypokalaemia, alkalosis, short-chain volatile fatty acids, and false and true neuro-transmitters, may be important in the pathogenesis of hepatic coma in cattle.