Leptospirosis in dogs: a review with emphasis on clinical aspects

Leptospirosis is a bacterial disease affecting several mammalian species, including human beings. In dogs, it is spread mainly by rodents that act as a maintenance host for several Leptospira serovars. Until recently, the most common signs observed in affected dogs consisted of icterus and haemorrhagic diathesis, but today the most prevalent clinical signs are attributed to acute renal failure. The current literature gives a good review of leptospirosis in dogs in the USA and Canada, but less information is available about its occurrence in Europe. This review considers the clinical signs, diagnosis, treatment and prevention of this emerging zoonotic disease.     

Canine parvovirus--a review of epidemiological and diagnostic aspects, with emphasis on type 2c

Canine parvovirus type 2 (CPV-2) emerged in late 1970s causing severe epizootics in kennels and dog shelters worldwide. Soon after its emergence, CPV-2 underwent genetic evolution giving rise consecutively to two antigenic variants, CPV-2a and CPV-2b that replaced progressively the original type. In 2000, a new antigenic variant, CPV-2c, was detected in Italy and rapidly spread to several countries. In comparison to the original type CPV-2, the antigenic variants display increased pathogenicity in dogs and extended host range, being able to infect and cause disease in cats. Epidemiological survey indicate that the newest type CPV-2c is becoming prevalent in different geographic regions and is often associated to severe disease in adult dogs and also in dogs that have completed the vaccination protocols. However, the primary cause of failure of CPV vaccination is interference by maternally derived immunity. Diagnosis of CPV infection by traditional methods has been shown to be poorly sensitive, especially in the late stages of infections. New diagnostic approaches based on molecular methods have been developed for sensitive detection of CPV in clinical samples and rapid characterisation of the viral type. Continuous surveillance will help assess whether there is a real need to update currently available vaccines and diagnostic tests.     

Equine metabolic myopathies with emphasis on the diagnostic approach. Comparison with human myopathies. A review

This review gives an overview of the presently known human and equine metabolic myopathies with emphasis on the diagnostic approach. Metabolic myopathies are muscle disorders caused by a biochemical defect of the skeletal muscle energy system, which results in inefficient muscle performance. Myopathies can arise in different levels of the metabolic system. In this review the metabolic myopathies are categorized in disorders of the carbohydrate metabolism, lipid metabolism, mitochondrial myopathies (other than those described in lipid metabolism), disorders of purine metabolism, primary disorders involving ion channels and electrolyte flux and secondary or acquired metabolic myopathies.     

Cartilage healing: A review with emphasis on the equine model

Articular cartilage is a remarkably resilient tissue capable of withstanding considerable stress and repeated loading. Since this tissue has no blood vessels, nerve elements, or lymphatics, it is not surprising that it has a limited capacity for repair when damaged. In the horse, cartilage damage occurs as an occupational hazard. Furthermore, developmental defects such as osteochondrosis can lead to osteochondritis dissecans. Resultant cartilage flaps, fissures, and poorly organized subchondral bone produce disruption of joint surfaces.

Veterinarians are often called upon to intervene when damaged cartilage has healed incompletely. Basic understanding of the physiology and repair mechanisms of cartilage is paramount to successfully managing such injuries. This literature review gives a brief overview of recently published clinical and experimental studies on the healing of cartilage. The discussion centers on the equine model.

     

Hormonal responses to acute exercise, training and overtraining. A review with emphasis on the horse

Overtraining is an imbalance between training and recovery leading to symptoms associated with a neuroendocrine dysbalance called the overtraining syndrome, a disease characterized by behavioral, emotional and physical symptoms similar with depression. Although the prevalence of overtraining is high in human and equine athletes, at present no sensitive and specific test is available to prevent or diagnose overtraining. Nowadays, it is believed that combination of different (hormonal) parameters appear to be the best indicators of overtraining. Therefore, this review provides a summary of previous literature examining the response of the hypothalamic-pituitary-adrenal (HPA) axis and the growth hormone-insulin-like growth factor-I (GH-IGF-I) axis to acute and chronic exercise as well as overtraining in humans and horses. The exercise induced hormonal responses seem to be equal for the equine as well as the human athlete, which makes comparisons possible. Repeated bouts of exercise are suggested to provide a way to detect subtle changes in hormonal responses in the individual athlete, which may make them an important tool in detecting early overtraining. This should be combined with corticotropin releasing hormone (CRH) stimulation tests and basal ACTH and GH pulsatility determination. Further research is needed to establish the correct training intensity and rest period for the exercise test in equines.     

Equine viral arteritis control scheme: a brief review with emphasis on laboratory aspects of the scheme in New Zealand

AIM: To review laboratory aspects of the equine viral arteritis (EVA) control scheme in New Zealand between 1989 and 2002. METHODS: The optimisation and performance of the virus neutralisation test (VNT) for equine arteritis virus (EAV) antibody, and the cell culture test to detect EAV in semen were analysed. Laboratory data and control scheme results were reviewed. RESULTS: Using optimised tests, it has been shown that antibody prevalence in Standardbred horses has steadily declined from 54% to <20%. Prevalences in Thoroughbred horses have remained at a low level of around 3%. The number of horses shedding EAV (all Standardbreds) has steadily declined from a maximum at any one time of 20 to the current figure of three. CONCLUSION: Eradication of EVA from the horse population in New Zealand is achievable in the near future.     

Factors involved in the early pathogenesis of bovine Staphylococcus aureus mastitis with emphasis on bacterial adhesion and invasion. A review

Staphylococcus aureus is the most important and prevalent contagious mammary pathogen; it causes clinical and subclinical intramammary infection with serious economic loss and herd management problems in dairy cows. In vitro studies have shown that Staphylococcus aureus adheres to mammary epithelial cells and extracellular matrix components and invades into mammary epithelial as well as other mammary cells. Staphylococcus aureus strains from intramammary infection produce several cell surface-associated and extracellular secretory products. The exact pathogenic roles of most of the products and their effects on adhesion and invasion are not well evaluated. It is also known that mammary epithelial cell-associated molecules and extracellular matrix components interact with S. aureus during the pathogenesis of mastitis, but their roles on adhesion and invasion have not been characterized. The adhesion of S. aureus to epithelial cells may involve non-specific physicochemical interactions and/or specific interactions between bacterial cell-associated ligands and host cell surface receptors. In vitro adhesion depends on the S. aureus strain, the growth phase of the bacteria, the growth medium and the origin of the epithelial cells. Adhesion is hypothesized to be a prerequisite and crucial early step for mammary gland infection. Staphylococcus aureus invades mammary epithelial cells. It also invades other cells such as endothelial cells and fibroblasts. Bacteria are found enclosed in membrane bound vacuoles in the cytoplasm of mammary epithelial cells. Recent observations indicate that S. aureus escapes from the phagosome into the cytoplasm and induces apoptosis. The invasion into mammary epithelial cells may occur through an endocytic process that requires involvement of elements of the cytoskeleton or by direct binding of bacteria to epithelial cells through a process mediated by specific receptors that needs de novo protein synthesis by both cells. Thus, the recurrent subclinical infection may result from this intracellular existence of bacteria that are protected from host defenses and effects of antibiotics. This review emphasizes on recent findings on S. aureus adhesion to mammary epithelial cells and extracellular matrix components and invasion into mammary epithelial cells.     

A review of drug toxicity in the cat

Abstract— The toxicity of drugs and therapeutic agents commonly used in feline medicine is reviewed. Résumé— Il s'agit d'une revue de la toxicité des droguee et des agents thérapeutiques couramment utilisés en médecine féline. La résponse idiosyncrasique manifestée par le chat à l'égard de beaucoup d'agents thérapeutiques appliqués, soit par voie interne, soit par voie externe, est bien connue de la plupart des cliniciens des petits animaux. Cependant, récemment plusieurs substances autrefois considérées comme sans danger, ont été incriminées comme cause de syndromes toxiques chez le chat. I1 est souhaité que cet article constitute un rappel opportun de certain des dangers inhêrents â la prescritpion médicamentueses en médecine féline. Zusammenfassung— Die Toxizität von Medikamenten und Mitteln, die bei Katzen vielfach Anwendung finden, wird besprochen. Die besondre Empfindlichkeit der Katze gegen viele Medikamente, ob innerlich oder äußerlich angewandt, ist den meisten Klinikern in der Kleintierpraxis wohlbekannt. Vor kurzem sind aber mehrere Substanzen, die bisher als ungefährlich angesehen wurden, als die Urheber von Vergiftungssyndromen bei Katzen erkannt worden. Vielleicht kommt dieser Artikel zur rechten Zeit, umeinige der Gefahren, die das Verschreiben für Katzen mit sich bringt, vor Augen zu führen.     

Warfarin: a review with emphasis on its use in the horse

Warfarin or dicoumarol prevents the production of functional clotting factors II, VII, IX and X. Navicular disease and thrombophlebitis are examples of equine thrombotic diseases in which warfarin has been used therapeutically. The initiation of anticoagulant therapy is relatively simple but attending veterinarians must be aware of the potential risks in order to minimize them. These risks include epistaxis, bleeding into the gastrointestinal tract and at the venipuncture site, and increased susceptibility to hematoma formation following local trauma. Vitamin K, especially vitamin K₁ is a swift and specific antidote for warfarin toxicity.     

Revised definition of Actinobacillus sensu stricto isolated from animals. A review with special emphasis on diagnosis

The taxonomy of the members of the genus Actinobacillus associated with animals has been reviewed with focus on classification and identification including molecular based characterization, typing and identification. Out of the 22 species or species like taxa reported as Actinobacillus, 19 are associated with animals. When classified on the basis of 16S rRNA sequence based phylogenetic analysis, DNA-DNA hybridizations and phenotypic analysis, Actinobacillus sensu stricto is restricted to include A. lignieresii, A. pleuropneumoniae, A. equuli subsp. equuli, A. equuli subsp. haemolyticus (taxon 11 of Bisgaard), A. hominis, A. suis, A. ureae, A. arthritidis (taxon 9 of Bisgaard), Actinobacillus genomospecies 1 and 2 and the taxa 8 and 26 of Bisgaard. The remaining 11 species of Actinobacillus are unrelated to A. sensu stricto and should consequently be grouped with other genera or be renamed as new genera depending on new data. Identification of members of Actinobacillus at species level is possible through phenotypic characterization combined with information on host of isolation. PCR tests are available for specific detection of A. pleuropneumoniae. Only A. pleuropneumoniae is presently considered as a primary pathogen. Based on different types of RTX genes it is possible to PCR type A. pleuropneumoniae to serotype level. PCR might also be used for the specific detection of A. equuli subsp. haemolyticus. Epidemiological investigations and surveillance have so far included serotyping, multilocus enzyme electrophoresis (MLEE), ribotyping and restriction fragment length profiling.     

A review of Brucella sp. infection of sea mammals with particular emphasis on isolates from Scotland

Brucellae recovered from sea mammals were first reported in 1994. In the years since both culture and serological analysis have demonstrated that the infection occurs in a wide range of species of marine mammals inhabiting a vast amount of the world’s oceans. Molecular studies have demonstrated that the isolates differ from those found amongst terrestrial animals and also distinguish between strains which have seals and cetaceans as their preferred hosts. At the phenotypic level seal and cetacean strains can also be differed with respect to their CO₂ requirement, primary growth on Farrells medium and metabolic activity on galactose. Two new species B. cetaceae and B. pinnipediae have been proposed as a result. This paper provides a review of Brucella in sea mammals and updates findings from the study of sea mammals from around the coast of Scotland.     

Retrobulbar thrombus in a cat with systemic hypertension

This report describes a 14-year-old neutered male Norwegian Forest cat that was evaluated for a complaint of inappetence, lethargy, and ocular protrusion with third eyelid prolapse. The systemic blood pressure was elevated at 205/129 mmHg. Fundic examination revealed severe retinal hemorrhage in both eyes. Based on an ultrasound study of the retrobulbar area, a thrombus caudal to the right globe was suspected. Over 18 days, the cat exhibited significant clinical improvement as well as good blood pressure control. To our knowledge this is the first report of a retrobulbar thrombus in a cat with systemic hypertension.     

A report on the clinical investigation of a paraplegic cat

From a study of approximately 1000 New Zealand Romney ewes from different areas of New Zealand it was found that the mean packed cell volume of sheep of haemoglobin type B Hb B was significantly lower than for haemoglobin type A (Hb A) sheep. The mean Hb A gene frequency was 0.60.

The concentrations of reduced glutathione (GSH) in the erythrocytes of these Romneys followed a normal distribution, the mean being 67.1 ± 12.4 mg GSH per 100 ml erythrocytes. The concentration of GSH in selenium deficient sheep was significantly higher than for selenium adequate sheep. The concentrations of the selenium-containing enzyme, glutathione peroxidase in the erythrocytes and of copper in the plasma of Hb B sheep were significantly higher than for Hb A sheep.

When different breeds of sheep on Mana Island were compared, the Finnish Landrace had significantly less ferroxidase in their plasma than did other breeds.