Prednisone-induced morphologic and chemical changes in the liver of dogs

International Harmonization of Nomenclature and Diagnostic Criteria (INHAND): Nonproliferative and Proliferative Lesions of the Dog

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions) Project (www.toxpath.org/inhand.asp) is a joint initiative of the societies of toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP), and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying lesions observed in most tissues and organs from the dog used in nonclinical safety studies. Some of the lesions are illustrated by color photomicrographs. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions, lesions induced by exposure to test materials, and relevant infectious and parasitic lesions. A widely accepted and utilized international harmonization of nomenclature for lesions in laboratory animals will provide a common language among regulatory and scientific research organizations in different countries and increase and enrich international exchanges of information among toxicologists and pathologists.

Body weight, blood pressure, and systemic changes following low-dosage prednisolone administration in dogs

OBJECTIVE To investigate systemic changes following low-dosage prednisolone administration in dogs. ANIMALS 4 healthy purpose-bred adult male Beagles. PROCEDURES Dogs were administered prednisolone PO at a dosage of 2 mg/kg/d for 2 weeks, 1 mg/kg/d for 4 weeks, and 0.5 mg/kg/d for 3 weeks. Body weight, blood pressure, hepatic size and echogenicity, percentage of vacuolated hepatocytes, serum hepatic enzyme activities and glucose concentration, adrenal gland size, and pancreatic echogenicity were evaluated weekly for 9 weeks. RESULTS The only significant change identified was an increase in hepatic echogenicity, assessed by measuring liver-kidney contrast on ultrasonographic images. Increases in hepatic size and percentage of vacuolated hepatocytes were identified, but values did not differ from baseline values. Similarly, serum hepatic enzyme activities increased, but changes were mild and not significantly different from baseline values. Body weight, pancreatic echogenicity, and serum glucose concentration did not show noticeable changes. Mild systemic hypertension was seen, but blood pressure was not significantly different from the baseline value. Similarly, adrenal gland size steadily decreased during the first 6 weeks and increased again after the prednisolone dosage was decreased to 0.5 mg/kg/d. However, mean adrenal gland size was not significantly different from the baseline value at any time. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that in dogs, administration of prednisolone at a low dosage was associated with minimal systemic effects.

Negative hepatic computed tomographic attenuation pattern in a dog with vacuolar hepatopathy and hepatic fat accumulation secondary to cushing's syndrome

This report describes an unusual computed tomographic (CT) hepatic pattern, characterized by negative attenuation values (from -19.59 to -28.85 Hounsfield Units, HU) in a canine patient with severe Cushing's syndrome. Attenuation values of the splenic parenchyma (63.26 HU) and abdominal fat (-118.34 HU) were within normal limits. The negative hepatic attenuation values allowed a CT diagnosis of severe hepatic fatty infiltration that was subsequently confirmed by tissue-core biopsy and histopathological examination.

Chronic Corticosterone Treatment During Adolescence Has Significant Effects on Metabolism and Skeletal Development in Male C57BL6/N Mice

Glucocorticoids are potent modulators of metabolic and behavioral function. Their role as mediators in the "stress response" is well known, but arguably their primary physiological function is in the regulation of cellular and organismal metabolism. Disruption of normal glucocorticoid function is linked to metabolic disease, such as Cushing syndrome. Glucocorticoids are also elevated in many forms of obesity, suggesting that there are bidirectional effects of these potent hormones on metabolism and metabolic function. Adolescence is a time of rapid physical growth, and disruptions during this critical time likely have important implications for adult function. The hypothalamic-pituitary-adrenal axis continues to mature during this period, as do tissues that respond to glucocorticoids. In this work, we investigate how chronic noninvasive exposure to corticosterone affects metabolic outcomes (body weight, body composition, insulin, and glucose homeostasis), as well as changes in bone density in both adult and adolescent male mice. Specifically, we report a different pattern of metabolic effects in adolescent mice compared with adults, as well as an altered trajectory of recovery in adolescents and adults. Together, these data indicate the profound influence that adolescent development has on the metabolic outcomes of chronic corticosterone exposure, and describe a tractable model for understanding the short- and long-term impacts of hypercortisolemic states on physiological and neurobehavioral functions.

Sensitivity and Specificity of Plasma ALT, ALP, and Bile Acids for Hepatitis in Labrador Retrievers

Background

Biochemical indicators for diagnosing liver disease are plasma alanine aminotransferase activity (ALT), alkaline phosphatase activity (ALP), and bile acid concentration (BA).

Objectives

To determine the sensitivity and specificity of ALT, ALP, and BA for detecting primary hepatitis (PH) in clinically healthy Labrador retrievers and investigate whether ALT and ALP can discriminate between dogs with PH and nonspecific reactive hepatitis (RH).

Animals

191 clinically healthy and 51 clinically ill Labrador retrievers with hepatic histopathology.

Methods

Retrospective study. Medical records were reviewed for ALT, ALP, preprandial BA, liver histopathology, and hepatic copper concentrations.

Results

In 64% (122/191) of the clinically healthy Labrador retrievers, hepatic histology revealed inflammatory infiltrates. This frequency might be biased because part of them was included as first‐line relatives of dogs with copper‐associated hepatitis. Sensitivity of ALT, ALP, and BA in this population for detecting acute hepatitis was 45, 15, and 15%, respectively. For chronic hepatitis, sensitivity was 71, 35, and 13%, respectively. Specificity of ALT, ALP, and BA was >90% for AH, CH, and RH. When increased liver enzymes were present, median ALT was significantly higher in PH cases (312 U/L, range 38–1,369) compared to RH cases (91 U/L, range 39–139) (P < .001). There was no difference in ALP between dogs with a PH and a RH (P = .361).

Conclusions and Clinical Importance

Histopathologic abnormalities in the liver were present in the majority of apparent clinically healthy Labrador retrievers. The sensitivity of ALT, ALP, and BA for detecting acute and chronic hepatitis in this population was low. More sensitive biomarkers are needed for early detection of liver disease in apparent clinically healthy dogs.

An unusual lipomatous brain mass in a Golden Retriever dog

A 9-year-old Golden Retriever dog was presented to the Veterinary Medical Center with a 3-week history of grand mal seizures and was subsequently euthanized. At autopsy, a discrete, firm, expansile mass was found in the right pyriform lobe, which compressed the ipsilateral hippocampus, thalamus, and cerebral cortex. Histologically, the mass was composed of well-differentiated adipose tissue supported by fibrous and mucinous stroma. Adipocytes exhibited strong immunoreactivity for vimentin and were negative for pancytokeratin (AE1/AE3), glial fibrillary acidic protein, neuron-specific enolase, and synaptophysin. These findings are most compatible with an intracranial lipomatous hamartoma, which is an extraparenchymal lesion that has been identified in several species. The current report describes an intracerebral lipomatous hamartoma in a veterinary species.

Hepatic neosporosis in a dog treated for pemphigus foliaceus

A 4-year-old, female, spayed Border Collie dog was presented for progressive lethargy, inappetence, and weakness of 4 days duration. The animal had been diagnosed with pemphigus foliaceus 3 months prior and was receiving combination immunosuppressive therapy. Serum biochemistry revealed severely elevated liver enzymes and bilirubin, and humane euthanasia was elected. Gross postmortem examination revealed a diffusely pale tan to slightly yellow, enlarged, markedly friable liver with an enhanced reticular pattern. Histologically, the hepatic changes consisted of multifocal to coalescing areas of severe vacuolar degeneration, numerous coalescing foci of hepatocellular necrosis, and myriad intra- and extracellular protozoa that reacted immunohistochemically with polyclonal antibodies to Neospora caninum, and not Toxoplasma gondii. Neosporosis in the current case is thought to be due to reactivation of latent N. caninum occurring with the administration of glucocorticoid therapy. The severe complication in the present case highlights the importance of early detection and mitigation of common infections in immunosuppressed animals.

Effects of Hepatic Drug-metabolizing Enzyme Induction on Clinical Pathology Parameters in Animals and Man

Hepatic drug-metabolizing enzyme (DME) induction is an adaptive response associated with changes in preclinical species; this response can include increases in liver weight, hepatocellular hyperplasia and hypertrophy, and upregulated tissue expression of DMEs. Effects of DME induction on clinical pathology markers of hepatobiliary injury and function in animals as well as humans are not well established. This component of a multipart review of the comparative pathology of xenobiotically mediated induction of hepatic metabolizing enzymes reviews pertinent data from retrospective and prospective preclinical and clinical studies. Particular attention is given to studies with confirmation of DME induction and concurrent evaluation of liver and/or serum hepatobiliary marker enzyme activities and histopathology. These results collectively indicate that in the rat, when histologic findings are limited to hepatocellular hypertrophy, DME induction is not expected to be associated with consistent or substantive changes in serum or plasma activity of hepatobiliary marker enzymes such as alanine aminotransferase, alkaline phosphatase, and gamma glutamyltransferase. In the dog and the monkey, published studies also do not demonstrate a consistent relationship across DME-inducing agents and changes in these clinical pathology parameters. However, increased liver alkaline phosphatase or gamma glutamyltransferase activity in dogs treated with phenobarbital or corticosteroids suggests that direct or indirect induction of select hepatobiliary injury markers can occur both in the absence of liver injury and independently of induction of DME activity. Although correlations between tissue and serum levels of these hepatobiliary markers are limited and inconsistent, increases in serum/plasma activities that are substantial or involve changes in other markers generally reflect hepatobiliary insult rather than DME induction. Extrahepatic effects, including disruption of the hypothalamic-pituitary-thyroid axis, can also occur as a direct outcome of hepatic DME induction in humans and animals. Importantly, hepatic DME induction and associated changes in preclinical species are not necessarily predictive of the occurrence, magnitude, or enzyme induction profile in humans.

Alkaline phosphatase: beyond the liver

The alkaline phosphatases comprise a heterogeneous group of enzymes that are widely distributed in mammalian cells. They often are associated with cell membranes, but their exact physiologic function is unknown. Despite this, alkaline phosphatase activity is a very useful serum biochemical indicator of liver disease, particularly cholestatic disease. However, increases in the activity of alkaline phosphatase in serum and other body fluids may reflect physiologic or pathologic changes beyond those of hepatic origin. For example, nonhepatic increases in serum alkaline phosphatase activity are found in young animals, in pregnant and lactating females, and in association with high fat diets. Bone disease, endocrine disease, neoplasia, and other disorders can result in increased alkaline phosphatase activity. In addition, alkaline phosphatase activity may be increased due to induction by certain drugs such as glucocorticoids and anticonvulsants. In this article, we will review the physiologic and pathologic factors influencing the activity of alkaline phosphatase in serum and other body fluids, with an emphasis on disorders beyond liver disease.

Vacuolar hepatopathy in dogs: 336 cases (1993–2005)

OBJECTIVE

To determine disorders associated with vacuolar hepatopathy (VH), morphologic hepatic and clinicopathologic abnormalities, and affiliation with steroidogenic hormone excess in dogs.

DESIGN

Retrospective case series. Animals-336 dogs with histologically confirmed moderate or severe VH.

PROCEDURES

Information on signalment, results of diagnostic testing, definitive diagnoses, and exposure to glucocorticoids (ie, exogenous glucocorticoid administration or high endogenous concentrations of steroidogenic hormones) was obtained from medical records. Dogs were grouped by underlying disorder, glucocorticoid exposure, acinar zonal distribution of lesions, and histologic severity.

RESULTS

12 disease groups (neoplastic, acquired hepatobiliary, neurologic, immune-mediated, gastrointestinal tract, renal, infectious, cardiac disease, diabetes mellitus, portosystemic vascular anomaly, adrenal gland dysfunction, and miscellaneous disorders) were identified. There were 186 (55%) dogs with and 150 (45%) dogs without evidence of glucocorticoid exposure. Acinar zonal distribution of hepatic vacuolation and clinicopathologic values did not differ between dogs with and without evidence of glucocorticoid exposure. However, a 3-fold increased likelihood of severe VH was associated with steroidogenic hormone exposure. Of 226 dogs with high serum alkaline phosphatase activity, 102 (45%) had no evidence of glucocorticoid exposure.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that neoplasia and congenital or acquired hepatobiliary disease are common in dogs with VH and provide support for the suggestion that VH, high alkaline phosphatase activity, and illness-invoked physiologic stress may be associated. Histologic confirmation of VH should initiate a diagnostic search for a primary disease if glucocorticoid treatment and hyperadrenocorticism are ruled out.

Glycogenic hepatopathy: an underrecognized hepatic complication of diabetes mellitus

Reported are the clinical and pathologic features of glycogenic hepatopathy, a pathologic overloading of hepatocytes with glycogen that is associated with poorly controlled diabetes mellitus. Fourteen cases were studied by stains, including hematoxylin and eosin, trichrome, periodic acid-Schiff, and periodic acid-Schiff with diastase. Ultrastructural analysis was performed in 2 cases. Medical records were reviewed for clinical presentations, laboratory findings, and clinical outcomes. The individuals ranged from 8 to 25 years of age. All had type I diabetes mellitus with poor glycemic control. The clinical presentations included hepatomegaly, abdominal pain, and elevated transaminases (range, 50-1600 IU/L). The transaminases were dramatically elevated in 3 cases to greater than 10 times the upper limit of normal. All biopsies showed diffusely pale staining hepatocytes on hematoxylin and eosin stains, with excessive glycogen accumulation demonstrated by periodic acid-Schiff stains. Ultrastructural examination revealed marked glycogen accumulation in the cytoplasm and nuclei. Most cases showed no evidence for fatty liver disease: steatosis was absent in 12 of 14 cases, simple steatosis was seen in 1 of 14 cases, and mild steatohepatitis was present in 1 of 14 cases. Mallory hyaline was absent in all cases, acidophil bodies were only rarely seen, and inflammation was absent or minimally present. Fibrosis was typically absent, with only 2 cases demonstrating focal mild fibrosis. Three patients had adequate follow-up and demonstrated improvement of liver enzyme levels with control of blood glucose. We conclude that glycogenic hepatopathy can cause hepatomegaly and significant transaminase elevations in individuals with type I diabetes mellitus. The pathology is distinct from steatohepatitis.

Evaluation of the influence of S-adenosylmethionine on systemic and hepatic effects of prednisolone in dogs

OBJECTIVE

To evaluate the influence of a 1,4-butanedisulfonate stable salt of S-adenosylmethionine (SAMe) administered orally on clinicopathologic and hepatic effects induced by long-term administration of prednisolone in dogs.

ANIMALS

12 healthy dogs.

PROCEDURE

Following a pilot study (4 dogs), 2 groups of 4 dogs received prednisolone (2.2 mg/kg) orally once daily (84-day trial). One group received SAMe (20 mg/kg/d divided in 2 doses) for 42 days and then a placebo for 42 days; the other group received treatments in the reverse order. Before and during the trial, numerous variables were monitored, including serum total alkaline phosphatase (ALP) and glucocorticoid-induced ALP (G-ALP) activities, serum haptoglobin concentration, and total and oxidized glutathione (TGSH and GSSG) and thiobarbiturate-reacting substances (TBARS) concentrations in erythrocytes and liver tissue (days 0, 42, and 84). Hepatic specimens also were examined microscopically.

RESULTS

The stable salt of SAMe was biologically available; plasma concentrations of SAMe or prednisolone were not affected by coadministration. Compared with baseline values, serum ALP and G-ALP activities and haptoglobin concentrations increased and erythrocyte GSSG and TBARS concentrations decreased with both treatments. Erythrocyte TGSH concentration decreased with the prednisolone-placebo treatment. Administration of SAMe appeared to conserve erythrocyte TGSH values and did not inhibit hepatocyte glycogen vacuolation but increased hepatic TGSH concentration and improved the hepatic tissue GSSG:TGSH ratio.

CONCLUSIONS AND CLINICAL RELEVANCE

In dogs, administration of 20 mg of SAMe/kg/d may mitigate the apparent pro-oxidant influences of prednisolone but did not block development of classic clinicopathologic or histologic features of vacuolar hepatopathy.

Comparison of attenuation and liver-kidney contrast of liver ultrasonographs with histology and biochemistry in dogs with experimentally induced steroid hepatopathy

Digital analysis of liver ultrasound images (USGs) was compared to histological and serum enzyme activity results in dogs with steroid-induced hepatopathy. Steroid hepatopathy was used as a model for diffuse liver diseases. Prednisolone administration resulted in increased acoustic backscatter (hyperechogenicity) of the liver with reference to the kidney and significant depth attenuation (hyper-attenuation). Absolute changes were determined by histogram analysis of echo means (Ems) of area samples (1 x 1 cm) of liver and kidney at the depth of 2 cm (liver-kidney contrast) and at 2 cms and 4 cm (depth attenuation). Liver-kidney contrast histograms correlated well with histology but were more sensitive than serum enzyme activity and subjective visual interpretation. Depth attenuation was the earliest detectable acoustic change. These results suggested that depth attenuation is an early and sensitive indicator of steroid hepatopathy. Liver-kidney contrast correlates well with histology and may complement biopsy examination during follow-up studies.

The age dependent levels of serum ALP isoenzymes and the diagnostic significance of corticosteroid-induced ALP during long-term glucocorticoid treatment

Three isoenzymes of total alkaline phosphatase (TALP) are known in canine serum: Bone alkaline phosphatase (BALP), liver alkaline phosphatase (LALP) and corticosteroid-induced alkaline phosphatase (CALP). Using an assay developed by combining selective precipitation of BALP by wheat germ lectin (WGA) and an automated levamisole inhibition method for quantifying CALP, age-related reference ranges of the isoenzymes in 75 canine serum samples were investigated. BALP comprised 96, 38 and 26% of TALP in young, middle aged and old dogs, respectively, and CALP was respectively 12, 11 and 27% of TALP. LALP was less than 10% in the young but represented more than 50% of TALP in middle aged and old dogs. Furthermore, the significance of monitoring LALP and CALP and their relationship to hepatopathy in dogs receiving long term prednisolone therapy was assessed. In this study, TALP increased in all dogs receiving prednisolone. But only LALP was responsible in dogs with minor vacuolization of the liver, while in severely degenerated cases both LALP and CALP increased. It is concluded that a high TALP due solely to LALP, rather than LALP and CALP represents lesser liver pathologic involvement. Monitoring the 2 isoenzymes has greater significancy in assessing in the level of liver damage than relying on an increased TALP value alone. Quantifying the individual isoenzymes may further be useful in assessing the clinical significance of these isoenzymes in various conditions that result in elevated TALP values.

Liver injury model induced in mice by a cellular immunologic mechanism--study for use in immunopharmacological evaluations

Various drugs for clinical hepatitis were applied to a new model of liver injury induced in mice by delayed-type hypersensitivity to picryl chloride (PCI-DTH). The hepatoprotective agent, biphenyl dimethyl dicarboxylate showed a remarkable improvement against the elevation of serum transaminase levels as well as the histopathological changes when given during the induction phase but not during the effector phase of DTH reaction. Cyclophosphamide (Cy), an immunosuppressive agent, significantly inhibited the enzymatic elevation given in both induction and effector phases. However, Cy did not affect the sustaining of liver injury 4 weeks after the liver injury eliciting. Moreover, the consecutive administration of prednisolone (Pred), in both induction phase and sustaining process of liver injury, conversely caused a more severe liver damage. Such exacerbation by Pred might be resulted from its toxic action to hepatocytes. As an immunomodulatory and antiinflammatory agent, glycyrrhizin remarkably improved the sustaining process but not the acute phase of the liver injury. Krestin and malotilate also showed an improving effect on the sustaining development of liver injury. These findings that most of above drugs showed an improving action in their respective manner suggest that this model may be useful for the pharmacological evaluation of drugs especially immunomodulating agents for hepatitis.

Ultrasound attenuation and backscatter in the liver during prednisone administration

Ultrasound attenuation and backscatter changes resulting from glucocorticoid administration were investigated in a dog model. Ten beagle dogs were randomized into two groups: five were given 2 mg/kg/day IM injections of prednisone to induce steroid hepatopathy and five served as controls. Histology showed vacuolization in most hepatocytes of treated animals on the third day of treatment, and larger, midzonally distributed vacuoles from day 7 on. An increase in both ultrasonic attenuation and backscatter was observed in treated dogs during in vivo measurements. Pooled data from the two groups suggest that attenuation elevations precede backscatter changes. Attenuation was significantly higher in the treated animals than in the controls by day 7. Both attenuation and backscatter were significantly higher in livers of treated than untreated dogs when measured by direct application of the transducer on the liver following euthanasia. We conclude that attenuation and backscatter coefficients can detect early changes in the liver associated with steroid hepatopathy. This may be a useful model to investigate detection of diffuse liver disease with ultrasound tissue characterization.

Glycogen storage disease type Ia in two littermate Maltese puppies

Glycogen storage disease type Ia (GSD-Ia) (von Gierke's disease) was identified in two 47-day-old littermate Maltese puppies. The puppies were presented for necropsy with a history of failure to thrive, mental depression, and poor body condition. Gross findings included small body size and emaciation (212 and 246 g versus 595 g for normal littermate), severely enlarged pale livers (48 and 61 g), and pale kidneys. Histologically, there was marked diffuse vacuolation of hepatocytes with large amounts of glycogen and small amounts of lipid. Renal tubular epithelium was mildly to moderately vacuolated. Soft tissue mineralization was present in renal tubules and pulmonary alveolar septa. Biochemical analysis showed that levels of glucose-6-phosphatase were markedly reduced in liver (0.3 and 0.4 microM/minute/g tissue versus 4.7 +/- 1.5 microM/minute/g tissue for controls) and kidney (0.45 and 0.4 microM/minute/g tissue versus 4.1 microM/minute/g tissue for controls) and that glycogen content was increased in liver (9.4% and 9.4% versus 1.3% +/- 1.4% for controls). This is the first confirmed report of animals with glycogen storage disease type Ia.

Ultrasonography of diffuse liver disease. A review

Radiographically, the liver may appear normal even if severely diseased. Ultrasonography can be an important adjunct in the evaluation of diffuse parenchymal hepatic disease. Diffuse liver disease appears ultrasonographically as a change in liver echogenicity from normal when compared with the renal cortex or spleen. Diffuse liver disease can be characterized as either hyperechoic due to fatty change, steroid hepatopathy, and cirrhosis or hypoechoic due to congestion, suppurative hepatitis, and lymphoma. Ultrasonographic diagnosis of diffuse liver disease should be substantiated by biopsy and histopathologic evaluation.

Glucocorticoid hepatopathy: effect on receptor-mediated endocytosis of asialoglycoproteins

Histologic and electron microscopic examination of liver tissue from glucocorticoid-treated dogs (GT dogs) showed a markedly abnormal hepatocellular morphology which consisted of severe hepatocellular swelling, vacuolation, and peripheral displacement of subcellular organelles. The abnormal cell morphology was typical of that seen in clinical cases of canine Cushing's Syndrome. The hepatocyte isolation procedure used here works equally well for the preparation of viable hepatocytes from both normal and GT dogs even though GT dogs displayed a pronounced hepatopathy. Cell yields (10(9) cells from a 30-cm3 section of liver) are similar to those reported for rat hepatocytes using whole liver in situ perfusion and cell viability is routinely greater than 85%. The isolation procedure preserved the "abnormal" state or swollen morphology of the hepatocytes from GT dogs and thus can be used in pathophysiological studies of glucocorticoid-induced hepatopathy. The isolated hepatocytes were 3.2 times greater in cell volume than normal hepatocytes. We also observed over a 12.3-fold increase in alkaline phosphatase activity and the appearance in both the liver and the serum of GT dogs of the unique, corticosteroid alkaline phosphatase isozyme (CALP). In spite of the obvious abnormal liver morphology and elevated serum and liver alkaline phosphatase activities, the function of the hepatic cell surface carbohydrate binding protein, the Gal/GalNAc or asialoglycoprotein receptor, was not impaired. We found a trend of about a 1.5-fold increase in the initial rate of ligand uptake as well as 1.6-fold more receptors on GT dog hepatocytes compared to normal hepatocytes. The ligand binding affinity of these receptors, as well as the rate of ligand degradation, was identical in hepatocytes isolated from normal and diseased dogs. When intestinal alkaline phosphatase (IALP) is used as the ligand, approximately 25% was exocytosed intact following endocytosis. These results demonstrate that dogs with glucocorticoid hepatopathy possess a normally functioning Gal/GalNAc receptor. Furthermore, these data are consistent with the hypothesis that structurally related IALP and CALP isozymes may also be metabolically related through the Gal/GalNAc receptor endocytosis pathway. That is, a portion of the IALP normally endocytosed through the Gal/GalNAc receptor pathway in glucocorticoid-treated dogs may be recycled and converted (hyperglycosylated) to the abnormal serum CALP isozyme rather than being degraded.

Neosporosis in dogs

A bitch was inoculated subcutaneously and intramuscularly with Neospora caninum tachyzoites on Day 35 of pregnancy. Eight pups were born 28 days later. Five pups became ill and necropsies were performed before 20 days of age. Three pups and the bitch remained clinically normal for 7 weeks after parturition when they were intramuscularly injected with 40 mg kg-1 methylprednisolone acetate weekly to activate chronic N. caninum infection. Necropsies were performed 48, 17, 18, and 18 days respectively after administration of corticosteroids. Hepatic necrosis, pneumonia, encephalomyelitis, and myonecrosis were the main changes seen in these dogs.