Current concepts in the treatment of canine chronic hepatitis

Chronic hepatitis is a common disorder in dogs seen by general practitioners. Several new drugs have been marketed for treating this disease. Unfortunately, there are few controlled studies that examine the efficacy of these medications for the treatment of canine chronic hepatitis. A rational therapeutic approach can be implemented based on histopathologic findings of a liver biopsy. A liver biopsy is essential for establishing a definitive diagnosis and guiding the optimal therapy. The biopsy allows characterizing the inflammatory process, quantitating hepatic copper concentrations, and determining if fibrosis is present. Copper associated hepatopathy is treated with zinc and copper chelators. Idiopathic chronic hepatitis is thought to be immune mediated. The treatment of idiopathic chronic hepatitis consists of controlling inflammation (prednisone, azathioprine), reversing fibrosis (colchicine), and protecting against oxidant damage (vitamin E, ursodeoxycholic acid, S-adenosylmethionine). The prognosis for chronic hepatitis is quite variable. Dogs with end-stage disease have a poor prognosis, while dogs diagnosed earlier can have a mean survival of years. Early diagnosis and intervention are key to the successful treatment of dogs with chronic hepatitis.     

Expression of fibrosis-related genes in canine chronic hepatitis

Molecular regulation of fibrosis in chronic canine hepatitis is poorly understood. The authors employed quantitative polymerase chain reaction (PCR) to determine the expression levels of genes reported to be related to fibrosis in other species (human, mouse, and rat) and to elucidate the relationship of these genes with the degree of fibrosis and the presence or absence of ascites and/or jaundice in dogs with hepatitis. Nine fibrosis-related genes were assayed: PDGFB, PDGFD, MMP2, TIMP1, THBS1, COL1A1, COL3A1, TGFB1, and TGFB2. Liver samples of 15 dogs with chronic hepatitis and 4 healthy control dogs were obtained via laparoscopic biopsy and subjected to histologic and quantitative PCR analyses. The expression of all 9 genes showed significant positive correlation (P<.01, r>.70) with the degree of fibrosis. Furthermore, the expression levels of all genes except TGFB1 were significantly higher (P<.05) in dogs with hepatic failure-related symptoms (ascites/jaundice). Results suggest that these 9 genes are integral to the development of fibrosis in canine chronic hepatitis.     

Characterization of the inflammatory infiltrate and cytokine expression in the skin of horses with recurrent urticaria

Background – Recurrent urticaria (RU) is a common skin disease of horses, but little is known about its pathogenesis. Hypothesis/Objective – The aim of this study was to characterize the inflammatory cell infiltrate and cytokine expression pattern in the skin of horses with RU. Animals – Biopsies of lesional and nonlesional skin of horses with RU (n = 8) and of skin from healthy control horses (n = 8) were evaluated. Methods – The inflammatory cell infiltrate was analysed by routine histology. Immunohistochemistry was used to identify T cells (CD3), B cells (CD79), macrophages (MAC387) and mast cells (tryptase). Expression of T‐helper 2 cytokines (interleukins IL‐4, IL‐5 and IL‐13), a T‐helper 1 cytokine (interferon‐γ), IL‐4 receptor α and thymic stromal lymphopoietin was assessed by quantitative RT‐PCR. Results – In subepidermal lesional skin of RU‐affected horses, increased numbers of eosinophils (P ≤ 0.01), CD79‐positive (P ≤ 0.01), MAC387‐positive (P ≤ 0.01) and tryptase‐positive cells (P ≤ 0.05) were found compared with healthy horses. Subepidermal lesional skin of RU‐affected horses contained more eosinophils (P ≤ 0.05) and tryptase‐positive cells (P ≤ 0.05) compared with nonlesional skin. There was no significant difference in infiltrating cells between nonlesional skin and skin of healthy horses. Expression of IL‐4 (P ≤ 0.01), IL‐13 (P ≤ 0.05), thymic stromal lymphopoietin (P ≤ 0.05) and IL‐4 receptor α (P ≤ 0.05) was increased in lesional skin of RU‐affected horses compared with control horses. Expression of IL‐4 was higher (P ≤ 0.05) in lesional compared with nonlesional RU skin. Conclusions and clinical importance – Analysis of cytokine expression and inflammatory infiltrate suggests that T‐helper 2 cytokines, eosinophils, mast cells and presumptive macrophages play a role in the pathogenesis of equine RU.     

Characterization of the inflammatory infiltrate during IgE-mediated late phase reactions in the skin of normal and atopic dogs

In canine and human atopic patients, the intracutaneous injection of offending allergens is followed by the development of both immediate and late-phase reactions. The present study was performed to expand on the characterization and dynamics of inflammatory cell subsets during IgE-mediated late-phase reactions in canine skin. Three normal dogs and three Dermatophagoides farinae -allergic dogs were selected for this experiment. All dogs were challenged intradermally with mite allergen, purified anticanine IgE antibodies (positive control) or phosphate-buffered saline (negative control). Skin biopsies were obtained before and 6, 12 and 24 h post-injection. Sections were stained with metachromatic and eosinophil-specific histological stains. Additionally, we used an immunohistochemical method with antibodies specific for canine leukocyte antigens. This study confirmed the occurrence of a late-phase reaction in atopic skin following allergen challenge, and in normal and atopic canine skin after intradermal injection of IgE-specific antibodies. Whereas early emigrating dermal cells were composed chiefly of neutrophil and activated eosinophil granulocytes, there was an influx of αβ T-lymphocytes and dermal dendritic cells in later stages of the late-phase reactions. Because IgE-mediated late-phase reactions resemble spontaneous atopic canine skin lesions, both at macroscopic and microscopic levels, we propose the use of similar challenges to study the anti-inflammatory effects of anti-allergic drugs in a pre-clinical setting.     

The composition of the inflammatory infiltrate in three cases of polyneuritis equi

Polyneuritis equi (PNE) is a rare neurological disease in the horse. Because of the suspicion in PNE of a T-lymphocyte mediated immune response against the myelin, the objective of this study was to determine the composition of the inflammatory infiltrate in the involved nerves of 3 horses with PNE, studied retrospectively. T-lymphocytes were demonstrated in the lesions, which suggests a T-lymphocyte mediated immune response against myelin. In addition, the presence of B-lymphocytes indicated a local production of antibodies. More research, involving a prospective study, is needed to determine whether the T-lymphocytes are cytotoxic or T-helper lymphocytes.     

Noninfectious canine arthritis: the inflammatory, nonerosive arthritides.

Noninfectious, nonerosive arthritis was seen as an important manifestation of a number of chronic systemic diseases of the dog. Sixty-three dogs with this type of arthritis were seen at the Veterinary Medical Teaching Hospital during an 18-month period between 1973 and 1975. Of these dogs, 29 had systemic lupus erythematosus, 15 had arthritis in association with some chronic infectious disease process, and 19 had a similar type of arthritis, but without serologic evidence of systemic lupus erythematosus or any chronic infectious disease process.     

Role of Helicobacter felis in chronic canine gastritis.

Five gnotobiotic Beagle dogs were orally inoculated with a pure culture of Helicobacter felis. The remaining two littermates served as contact controls. Thirty days after infection, all animals were euthanatized and specimens were collected for evaluation. In infected dogs, H. felis was recovered from all areas of the stomach. Colonization was heaviest in the fundus and antrum. H. felis was not cultured from any segment of the gastrointestinal tract distal to the duodenum. Two weeks after infection, all five infected dogs had detectable IgM and IgG serum antibody to H. felis, whereas control dogs had no measurable H. felis serum antibody throughout the study. Histopathologic changes in the stomachs of infected dogs included large numbers of lymphoid nodules throughout all regions of the gastric mucosa and were most numerous in the fundus and body. A mild, diffuse lymphocytic infiltrate with small numbers of plasma cells and eosinophils was also present in the subglandular region of all portions of the gastric mucosa. Electron microscopic examination revealed large numbers of spiral-shaped H. felis in gastric mucus adjacent to or superimposed over the areas of inflammation. Occasionally, however, H. felis was observed within the canaliculi of gastric parietal cells. Histopathologic changes in the stomachs of the contact control dogs were limited to focal infiltrates of eosinophils and small aggregates of lymphocytes in the subglandular portions of the gastric mucosa in one animal. Infection with H. felis is a likely cause of naturally occurring lymphofollicular gastritis.     

Immune-based erosive inflammatory joint disease of the dog: canine rheumatoid arthritis.

The features of 30 cases of canine rheumatoid arthritis are described. The disease is a chronic symmetrical polyarthritis characterized by erosive, destructive changes within the joint. The latter can be identified on radiographs by loss of mineral, the presence of discrete erosions or an irregular joint margin. Increased periarticular soft tissue is common and periosteal new bone is not unusual. The most obvious clinical feature is generalized stiffness particularly after rest. Joints are often thickened and painful on manipulation. A third of cases present with pyrexia, lethargy and inappetence in addition to lameness. Synovial fluid evaluation shows an increased number of white cells, most of which are polymorphs; the mucin clot is poor. The ESR is generally increased and rheumatoid factor (an antiglobulin auto-antibody) is present in 73 per cent of cases. Treatment is often unrewarding, although many dogs can cope for considerable periods of time.     

The ocular lesions of infectious canine hepatitis. 2. Field incidence

The results of an investigation into the occurrence of corneal lesions following natural infection and after vaccination with infectious canine hepatitis virus (ICHV) are presented. They are based on case reports submitted by veterinary practices in England over a period of 1 year. An approximate figure is suggested for the incidence of reactions following vaccination with attenuated strains of ICHV and an analysis made of 113 case reports relating to both vaccinated and unvaccinated dogs.     

The ocular lesions of infectious canine hepatitis. 1. Clinical features

Corneal oedema and inflammation of the anterior uveal tract are characteristic ocular reactions associated with infectious canine hepatitis virus, and may follow either natural infection or vaccination with attenuated strains of virus. Although in most cases the ocular lesions resolve within a few days without sequelae a small proportion develop complications which in extreme instances lead to blindness. The incidence of persistent lesions is higher in the Afghan Hound than in other breeds. Résumé. L'oedème de la cornée et l'inflammation du faisceau antérieur uvéal sont des réactions oculaires caractéristiques associées avec un virus d'hépatite épidémique canine et peuvent ětre les suites, soit d'une infection naturelle, soit d'une vaccination avec des souches atténuées de virus. Bien que dans la plupart des cas les lésions oculaires résolvent en quelques jours sans séquelles, une faible proportion développe des complications qui, dans certains cas extrěmes, mènent à la cécité. L'incidence des lésions persistantes est plus élevée chez le lévrier afghane que chez les autres races. Zusammenfassung. Korneales Odem und Entzǔndung des vorderen uvealen Sehstranges sind charakteristisch fur okulǎre Reaktionen verbunden mit ansteckender Hunde Virus Hepatitis, entweder naturlicher Ansteckung oder Impfung mit vermindertem Stamm von Viren folgen kǒnnen. Obwohl sich in den meisten Fàllen die Augenschǎden innerhalb weniger Tage ohne Folgen beheben, entwickelt eine geringe Proportion Komplikationen, welche in extremen Fàllen zu Blindheit fiïhren. Das Eintreffen von anhaltenden Làsionen ist hǒher in Afghanen als in anderen Hunderassen.     

Radiological features of inflammatory conditions of the canine pancreas

The radiological signs of pancreatitis in six cases are described, and where possible, correlated with surgical and pathological findings. The use of radiography as an aid to diagnosis of pancreatic disease is discussed.
Résumé . Les signes radiologiques de malfonction du pancréas dans six cas sont déscrits, et où possible sont mis en correlation avec découvertes chirurgicales et pathologiques. L'usage da la radiographic comme une aide à la diagnose de la maladie pancréatique est discuté.
Zusammenfassung . Die radiologischen Zeichen der Bauchspeicheldrüsenentzündung werden in sechs Fällen beschrieben, und wo möglich werden mit chirurgischen und pathologischen Untersuchungsergebnissen korreliert. Der Gebrauch der Röntgenphotographie wie ein Beistand fur die Diagnose der pankreatischen Krankheit wird besprochen.