Canine molecular genetic testing.

Inherited diseases are common among dogs. Recent advances in molecular genetics provide the groundwork for the development of genetic tests for the diagnosis and prevention of inherited diseases. As a result of this progress, genetics should become an integral part of veterinary medicine. DNA tests are safe, easy to perform, and reliable if interpreted correctly. Genetic tests only need to be performed once in a dog's lifetime, because the results of DNA testing never change. Veterinarians should be prepared to understand genetic testing and counseling because they are becoming increasingly important to veterinary medicine.     

Ethics and Genetic Selection in Purebred Dogs

There is an ongoing revolution in medicine that is changing the way that veterinarians will be counselling clients regarding inherited disorders. Clinical applications will emerge rapidly in veterinary medicine as we obtain new information from canine and comparative genome projects ( Meyers‐Wallen 2001 : Relevance of the canine genome project to veterinary medical practice. International Veterinary Information Service, New York). The canine genome project is described by three events: mapping markers on canine chromosomes, mapping gene locations on canine chromosomes ( Breen et al. 2001 : Genome Res. 11, 1784–1795), and obtaining the nucleotide sequence of the entire canine genome. Information from such research has provided a few DNA tests for single gene mutations [ Aguirre 2000 : DNA testing for inherited canine diseases. In: Bonagura, J (ed), Current Veterinary Therapy XIII. Philadelphia WB Saunders Co, 909–913]. Eventually it will lead to testing of thousands of genes at a time and production of DNA profiles on individual animals. The DNA profile of each dog could be screened for all known genetic disease and will be useful in counselling breeders. As part of the pre‐breeding examination, DNA profiles of prospective parents could be compared, and the probability of offspring being affected with genetic disorders or inheriting desirable traits could be calculated. Once we can examine thousands of genes of individuals easily, we have powerful tools to reduce the frequency of, or eliminate, deleterious genes from a population. When we understand polygenic inheritance, we can potentially eliminate whole groups of deleterious genes from populations. The effect of such selection on a widespread basis within a breed could rapidly improve health within a few generations. However, until we have enough information on gene interaction, we will not know whether some of these genes have other functions that we wish to retain. And, other population effects should not be ignored. At least initially it may be best to use this new genetic information to avoid mating combinations that we know will produce affected animals, rather than to eliminate whole groups of genes from a population. This is particularly important for breeds with small gene pools, where it is difficult to maintain genetic diversity. Finally, we will eventually have enough information about canine gene function to select for specific genes encoding desirable traits and increase their frequencies in a population. This is similar to breeding practices that have been applied to animals for hundreds of years. The difference is that we will have a large pool of objective data that we can use rapidly on many individuals at a time. This has great potential to improve the health of the dog population as a whole. However, if we or our breeder clients make an error, we can inadvertently cause harm through massive, rapid selection. Therefore, we should probably not be advising clients on polygenic traits or recommend large scale changes in gene frequencies in populations until much more knowledge of gene interaction is obtained. By then it is likely that computer modelling will be available to predict the effect of changing one or several gene frequencies in a dog population over time. And as new mutations are likely to arise in the future, these tools will be needed indefinitely to detect, treat and eliminate genetic disorders from dog populations. Information available from genetic research will only be useful in improving canine health if veterinarians have the knowledge and skills to use it ethically and responsibly. There is not only a great potential to improve overall canine health through genetic selection, but also the potential to do harm if we fail to maintain genetic diversity. Our profession must be in a position to correctly advise clients on the application of this information to individual dogs as well as to populations of dogs, and particularly purebred dogs.     

Feline genetics: clinical applications and genetic testing

DNA testing for domestic cat diseases and appearance traits is a rapidly growing asset for veterinary medicine. Approximately 33 genes contain 50 mutations that cause feline health problems or alterations in the cat's appearance. A variety of commercial laboratories can now perform cat genetic diagnostics, allowing both the veterinary clinician and the private owner to obtain DNA test results. DNA is easily obtained from a cat via a buccal swab with a standard cotton bud or cytological brush, allowing DNA samples to be easily sent to any laboratory in the world. The DNA test results identify carriers of the traits, predict the incidence of traits from breeding programs, and influence medical prognoses and treatments. An overall goal of identifying these genetic mutations is the correction of the defect via gene therapies and designer drug therapies. Thus, genetic testing is an effective preventative medicine and a potential ultimate cure. However, genetic diagnostic tests may still be novel for many veterinary practitioners and their application in the clinical setting needs to have the same scrutiny as any other diagnostic procedure. This article will review the genetic tests for the domestic cat, potential sources of error for genetic testing, and the pros and cons of DNA results in veterinary medicine. Highlighted are genetic tests specific to the individual cat, which are a part of the cat's internal genome.     

Future applications of biotechnology in poultry

The major biotechnological advances that can be applied in the poultry industry will include molecular genetics, molecular immunology, and solid-state reactions. The elucidation of the genetic code and the development of techniques to manipulate genes offer new opportunities for changing pathogenic agents and changing chickens to reduce the effect of disease and improve productivity. The monoclonal antibody technique and the discovery that cells of the immune response communicate with one another through peptide factors will permit improved diagnostic techniques and enhanced immune responses to vaccines. Immunologic and biochemical reactions that occur on a solid substrate can be used to simplify and accelerate diagnostic tests and to purify antigens and antibodies. These advances will lead to improvements in diagnosis, disease resistance, and productivity of poultry.     

Physical examination and preventive care of rabbits.

As rabbits gain increasing popularity as house pets, more rabbit owners are seeking basic preventive veterinary care. Although a knowledge of the unique anatomic and physiologic characteristics of pet rabbits is essential, annual examination and review of diet and husbandry are as important as with any other species. Many disease states can be detected or prevented with routine veterinary care. Despite all the advances in diagnostic testing in veterinary medicine, there will never be a substitute for a complete physical examination.     

Stem cells and veterinary medicine: tools to understand diseases and enable tissue regeneration and drug discovery

New sophisticated laboratory techniques, as well as established interactions between basic science, researchers and veterinarians, have led to an exponential increase in our understanding of the animal body in health and disease. The advent of animal cloning, the identification and characterization of stem cells, and publication of the various mammalian genomes has afforded the opportunity to exploit these technologies to better understand disease and develop new therapies. In human medicine, these medical advances are already being translated into clinical practice, the promise being that previously untreatable or incurable chronic diseases will become a thing of the past. In parallel, the veterinary profession is looking to these technologies to explore novel therapies for chronic diseases, such as osteoarthritis in companion animals, and is applying these technologies to enhance food animal production. This review focuses on the emerging area of stem cell biology and explores the potential applications of stem cell technologies to veterinary medicine.     

What's new in muscle and peripheral nerve diseases?

It is likely that most neuromuscular diseases that are described in humans will have a counterpart in our companion animals. With the advent of molecular genetics and the completion of the canine and feline genomes, an ever expanding number of DNA-based tests should become available for the diagnosis of muscle and peripheral nerve diseases. Molecular testing procedures should enable us to continue to unravel the molecular basis of neuromuscular diseases for which the cause is still unknown. It is important that accurate clinical evaluations and diagnostic testing, including muscle and peripheral nerve biopsies, are performed in order to reach these goals. This review focuses on recently identified inherited neuromuscular diseases in companion animals.     

Comparative clinical science: The medicine of the future

This review explores the emergence of Comparative Medicine in the late 19th Century as 'the medicine of the future', its failure to realise these expectations during the 20th century as it became increasingly equated with laboratory animal models of human disease, and explains why there is now an unprecedented opportunity for this latent potential to be fully realised. Comparative medicine no longer rests on apparent similarities between disease mechanisms in different species but on the rapidly maturing ability to relate these similarities to a remarkably rich shared genetic heritage. In the United Kingdom, the creation of the new Medical Research Council Comparative Clinical Science Panel, once securely funded, will provide the infrastructure and strategic focus to foster comparative clinical research, encouraging collaboration between veterinary and human medicine and between investigators in institutes and in practice. This will generate the necessary evidence base for veterinary practice, raise the standard of veterinary research, broaden the horizons of human medicine and create real opportunities for veterinary surgeons to reconcile research with practice. The review explores the broad scope of the science which will flourish in this new environment and examines specific areas in greater depth as examples, notably multifactorial disease such as hypertension and diarrhoea, also aspects of comparative endocrinology and oncology, with emphasis on the growing power conferred by comparative molecular genetics.     

Pharmacological treatment in behavioural medicine: the importance of neurochemistry, molecular biology and mechanistic hypotheses.

Psychopharmacology has become a popular, and sometimes mandatory addition to treatment regimes for canine and feline patients with behavioural problems; however, clients and practitioners should be dissuaded that behavioural drugs are 'quick fixes'. Veterinarians should only prescribe psychotropic medication when they have a specific idea of how the mechanism of action of the drug will affect the target behaviours associated with a specific diagnosis. The diagnosis must be treated rather than non-specific signs. Newer psychotropic medications demonstrate the extent to which truly abnormal behaviours are dysfunctions of neurochemistry; synaptic or cellular metabolism; or genetic encoding and 'learning', or LTP, hence there is a clear role for the interaction of neuropharmacology and behavioural and environmental modification.Future advances in treatment in behavioural medicine will be pharmacological and neurophysiological. As the field of behavioural medicine expands, its paradigm will enlarge to include combination therapy and the implementation of neuropharmacological intervention as a diagnostic tool. At present, the veterinary practitioner can effectively aid many common behavioural problems using extant drugs to treat animals with true behavioural pathology.Rational pharmacological therapy requires complete medical and behavioural histories, requisite laboratory work, complete client understanding and compliance, and an honest and ongoing dialogue between the client and veterinarian that includes frequent follow-ups and re-examinations. Copyright Harcourt Publishers Ltd.     

Response evaluation criteria for solid tumours in dogs (v1.0): a Veterinary Cooperative Oncology Group (VCOG) consensus document

In veterinary medical oncology, there is currently no standardized protocol for assessing response to therapy in solid tumours. The lack of such a formalized guideline makes it challenging to critically compare outcome measures across various treatment protocols. The Veterinary Cooperative Oncology Group (VCOG) membership consensus document presented here is based on the recommendations of a subcommittee of American College of Veterinary Internal Medicine (ACVIM) board‐certified veterinary oncologists. This consensus paper has used the human response evaluation criteria in solid tumours (RECIST v1.1) as a framework to establish standard procedures for response assessment in canine solid tumours that is meant to be easy to use, repeatable and applicable across a variety of clinical trial structures in veterinary oncology. It is hoped that this new canine RECIST (cRECIST v1.0) will be adopted within the veterinary oncology community and thereby facilitate the comparison of current and future treatment protocols used for companion animals with cancer.     

Arthroscopy.

Canine arthroscopy has made significant technological and scientific advancements in the last 10 years. The history of canine arthroscopy and currently available equipment required for performing diagnostic and therapeutic arthroscopy are discussed. Basic arthroscopic techniques are described in detail. Specific approaches to the major joints and associated disease processes treatable by arthroscopic methods are reviewed. The future of canine arthroscopy is bright and specific procedures for treating the joint diseases of dogs will undoubtedly be described as the collective arthroscopic expertise of veterinary surgeons increases.     

Recombinant vaccine technology in veterinary medicine.

Recombinant technology is relatively new to veterinary medicine. It combines safety, purity, potency, and efficacy in the vaccine. Its positive features include not exposing the vaccinate to the pathogen, the lack of need for adjuvants, and stability that allows some vaccine to remain viable at ambient temperatures. These recombinants can receive multiple genetic inserts and present an opportunity to have multiple combination vaccines for use in animals. Licensed recombinant vaccines in veterinary medicine include those protecting against Lyme disease, pseudorabies, rabies, canine distemper, Newcastle disease, and a strain of avian influenza.     

Feline Physiotherapy and Rehabilitation: 1. Principles and potential

Practical relevance: Physiotherapy is highly valued within human medicine and relatively well established for canine patients. Despite a popular misconception that feline patients will not cooperate with such treatment, physiotherapy is now increasingly being performed with cats. With cat ownership increasing in many countries, and an emergence of specialist physiotherapy practitioners, there is demand for effective postoperative and post-injury rehabilitation for any cat with compromised physical function due to injury, surgery or disease. Clinical challenges: While physiotherapy and rehabilitation are potentially beneficial for cats, due to their independent nature feline patients certainly present a greater challenge in the pursuit of effective therapy than their canine counterparts. Audience: This two-part review article is directed at the primary care veterinary team. The benefits of physiotherapy and the various treatment modalities available to the qualified veterinary physiotherapist, as well as the non-specialist veterinarian and veterinary nurse or technician, are examined in this first part. Evidence base: The benefits of human physiotherapeutic intervention are well documented, and there is good evidence for the effectiveness of most treatment modalities. Animal studies are still in their infancy, although some preliminary studies in dogs have shown good results.     

Infection and blood transfusion: a guide to donor screening

In recent years, blood-component therapy has become more accessible in veterinary practice. As with human medicine, care must be taken to minimize the risk of disease transmission from donor to recipient. Determining the appropriate diseases to screen for is complicated by regional variations in disease incidence, the existence of chronic carrier states for some diseases, the difficulty in screening-test selection, and testing cost. The feline diseases considered include retroviral infections, feline coronaviruses, ehrlichiosis (Ehrlichia canis-like), anaplasmosis (Anaplasma phagocytophilum), neorickettsiosis (Neorickettsia risticii), hemoplasmosis (Mycoplasma hemofelis and M. hemominutum, previously feline hemobartonellosis), and cytauxzoonosis (Cytauxzoon felis). The canine diseases considered in this paper include babesiosis (Babesia canis and B. gibsonii,) ehrlichiosis (E. canis and E. ewingii), anaplasmosis (A. phagocytophilum), neorickettsiosis (N. risticii var. atypicalis), leishmaniasis (Leishmania donovani complex), brucellosis (Brucella canis), hemoplasmosis (M. hemocanis, previously canine hemobartonellosis), and bartonellosis (Bartonella vinsonii).     

Congenital heart diseases in small animals: part II. Potential genetic aetiologies based on human genetic studies

Comparative genetics provides veterinary researchers and clinicians with invaluable information for the understanding the possible genetic aetiologies and the disease process in congenital heart defects (CHDs) of dogs and cats. Although, the demand on this type of research has increased in the veterinary field, to date no fundamental genetic studies have been reported in the veterinary literature. In this second part of a two-part review, the general features and pathogenesis of major CHDs in humans and small animals are discussed. In addition, the known genetic aetiologies in human CHDs have been considered in parallel to CHDs in small animals.     

Harnessing the genetic toolbox for the benefit of the racing Thoroughbred

The understanding and application of genetics have grown extremely quickly since it has become possible to sequence the whole genome of an organism. The human genome sequence was completed in 2001 and that of the horse in 2007. The significance of this is that it makes it more feasible to explain how both genetically simple and complex traits are transmitted from one generation to the next and, therefore, to make informed breeding decisions, modify how horses are managed and trained to minimise the risk of disease and injury, and improve methods of prevention, diagnosis and treatment of many conditions. The science of genetics/genomics will continue to grow internationally, limited only by the funds available. The application of the science to man, horses and other species raises very complex moral and commercial issues. Thoroughbred breeders are perceived by some as resistant to change, but their apparent intransigence is often based on a genuine concern for the integrity of the breed. By taking control of the application of the advances in genetics, the Thoroughbred industry potentially has the opportunity to improve both the health and performance of Thoroughbreds. If, however, the science is applied in an uncoordinated manner, driven by commercial interests with no underlying concern for the horses themselves, there is a very real risk that breeders, the Thoroughbred breed and individual horses will all suffer as a consequence.     

Complementary and alternative medicine for neurologic disorders

The use of complementary and alternative veterinary medicine in treating neurologic disorders has increased in popularity in response to advances in human alternative and integrative therapies. Neurolocalization of lesions to the brain, spinal cord, and neuromuscular systems is discussed, as well as the diagnostics and therapeutics used to treat such disorders. Emphasis is placed on integrative and alternative treatments for such neurologic diseases as seizures, cerebrovascular accidents, canine cognitive disorder, meningitis, intervertebral disc disease, fibrocartilagenous embolism, degenerative myelopathy, and myopathies. Thorough physical and neurologic examinations, establishment of a correct diagnosis, and integrative therapeutics are aimed at improving the overall quality of life of the veterinary patient.     

Food animal veterinary medicine: leading a changing profession

The veterinary profession has gone through periods of profound change in response to economic and social changes. We are currently in another such period: profound change is required in order for the profession to remain relevant in a marketplace where a rapidly expanding knowledge base and new technologies demand an ever-increasing level of expertise in a greater variety of areas. However, the veterinary profession is perceived both internally and by the public as possessing a narrow set of skills that supports a narrow group of careers focused on salvaging ill or injured companion animals. It will be necessary to dramatically change the way veterinary students are recruited and trained, as well as how graduate veterinarians are licensed and provided continuing education, in order for the veterinary profession to capitalize on our historical strengths and provide service and leadership in a greater diversity of career paths. Even though the number of veterinarians needed to provide primary care for livestock is decreasing, both the level of expertise demanded by livestock owners and the value of veterinary involvement on livestock farms are increasing. Colleges of veterinary medicine appear challenged to meet the changing needs for veterinary services in animal agriculture because of the declining percentage of veterinary students interested in food animal careers. Fortunately for animal agriculture, the skill set needed by food animal veterinarians is also needed by several emerging segments of the veterinary profession that have tremendous potential for rapid growth, including employment in all segments of food production systems, environmental monitoring and management, bio-security and disease eradication, laboratory diagnostics, and federal regulatory and bio-defense roles. Like previous periods of profound change, this moment in history will require creative thought, open discussion, and a willingness to step into the unknown.     

Thrombolytic Therapy in Dogs and Cats

Objective: To review the thrombolytic agents most commonly used in humans, their mechanisms of action, potential uses, adverse effects, and reports of their use in dogs and cats.
Human data synthesis: Thrombolytic agents avaliable in human medicine include streptokinase, urokinase, tissueplasminogen activator (t-PA), single-chain urokinase plasma activator (scu-PA) and anisoylated plasminogen-strep-tokinase activator complex (APSAC). These agents were originally used for the management of proximal deep vein thrombosis and severe pulmonary embolism but more recently, use of these drugs has been extended to include the treatment of acute peripheral arterial disease, cerebrovascular disease (stroke) and acute coronary thrombosis. The most predictable side effect associated with the use of thrombolytic therapy is hemorrhage.
Veterinary data synthesis: Clinical experience with thrombolytic agents in small animals is limited to streptokinase and t-PA. It is possible, that as in humans, canine and feline patients with PTE and right ventricular dysfunction may benefit from thrombolytic therapy but there are no veterinary studies to support this theory to date. Successful use of streptokinase has been documented in a small number of canine patients with systemic thromboembolism. ⁶³ Thrombolytic therapy is relatively efficacious in cats with aortic thromboemboli but is associated with a high mortality rate. ^59,60,64 With regard to use of t-PA in veterinary medicine, the small number of animals treated with varying protocols makes it impossible to provide safe and effective dose recommendations at this time.
Conclusions: Future goals for thrombolytic therapy in veterinary medicine include determination of more specific clinical indications, as well as design of effective protocols that minimize mortality and morbidity.     

Bronchoscopy in small animal medicine: indications, instrumentation, and techniques

Bronchoscopy is a useful tool in the evaluation and management of canine and feline respiratory diseases. Diagnostic indications include the evaluation of structural diseases (tracheobronchial collapse, stricture, intraluminal mass); inflammatory conditions (chronic bronchitis, pneumonia); and traumatic injuries. Several airway-sampling techniques are available with bronchoscopy; bronchoalveolar lavage has proved to be the most satisfactory specimen-collection technique. Therapeutic indications of bronchoscopy at this time in veterinary medicine are mainly limited to foreign body removal. As advances are made in veterinary bronchopulmonary medicine, other therapeutic applications of the bronchoscope may be realized.