Nutrition for aging cats and dogs and the importance of body condition.

Before recommending a diet for a senior pet, a thorough nutritional evaluation should be completed. Although many middle-aged and older pets are overweight, a large percentage of geriatric cats and dogs have a low BCS. Approximately one third of cats older than 12 years of age may have a decreased ability to digest fat, whereas one in five may have a compromised ability to digest protein. Thus, appropriate diets for these two age groups may differ considerably. Mature (middle-aged) cats would likely benefit from a lower calorie food, whereas geriatric cats (>12 years of age) may need a highly digestible nutrient-dense diet. More than 40% of dogs between the ages of 5 and 10 years are overweight or obese. Such dogs may benefit from diets with lower fat and calories. Senior dogs also have an increased need for dietary protein, however. Therefore, healthy older dogs may benefit from diets with an increased protein-to-calorie ratio, providing a minimum of 25% of calories from protein. Common obesity-related conditions in dogs or cats include DM and OA. Diabetes differs between dogs and cats. Type I diabetes, common in dogs, seems to respond to fiber-enriched diets, whereas type II diabetes, common in cats, seems to benefit from high-protein and low-carbohydrate diets. OA, an inflammatory condition that occurs in approximately 20% of dogs, may benefit from weight management and nutrients that reduce the inflammatory responses, such as long-chain n-3 fatty acids.     

Identification and management of cognitive decline in companion animals and the comparisons with Alzheimer disease: A review

There are a number of correlations between the pathophysiology and behavioral expression of early Alzheimer disease in humans and age-related cognitive dysfunction in dogs and cats. Changes in social interaction and the reduced ability to cope with everyday situations are difficulties experienced in human, canine, and feline age-related cognitive decline. Anxiety, distress, and confusion commonly precede diagnosis. Information obtained from family members, carers, or owners may be key to identifying early behavioral markers and allowing early management or treatment.Environment may predispose to or protect from cognitive decline over time. Neuroinflammation associated with air pollution or excessive noise can lead to oxidative damage within the cerebrum and development of β-amyloid plaques. Targeted programs promoting mental exercise may be used to delay progression once clinical signs have been presented.Pharmacological interventions in humans have focused mainly on augmenting neuronal efficacy by using agents to increase the chemical communication, whereas in veterinary medicine cerebral vasodilators are commonly used. Preclinical and mildly impaired patients have limited options in human medicine, whereas there is a trend in veterinary medicine to offer targeted nutritional supplements that include antioxidants, L-carnitine, or omega-3 fatty acids.Comparing treatment options in species provides opportunities to identify new methods of controlling age-related cognitive decline.     

ELECTRICAL SAFETY FOR THE VETERINARY SURGEON

In human medicine, protection of the patient has demanded stringent safety precautions that have not been applied in the veterinary field. There is a hazard to the operator from the increasing use of electrical equipment in veterinary medicine, often in an environment where conducting floors and other items can carry fault currents through a human or animal body. The source of these currents may be equipment that has developed faults due to disconnected earth leads and breakdown of insulation so that the case or leads from the equipment become live. Currents exceeding 10 mA passing through the body may cause death from ventricular fibrillation. Protection from accident may be provided by circuit breakers that sense fault currents and disconnect the power, and by taking precautions to correctly maintain electrical fittings.     

Pharmacology and therapeutics of non-steroidal anti-inflammatory drugs in the dog and cat: 2 Individual agents

The general pharmacology of the non-steroidal anti-inflammatory drugs (NSAIDs) used in dogs and cats has been described in part 1 of this review (Lees and others 1991). This paper outlines the properties of the individual agents as they are used in small animal practice. The NSAIDs which have been used extensively in small animals include the older agents such as Aspirin, cinchophen and phenylbutazone. These agents have previously been used empirically by extrapolation of dosages from other species and by clinical experience. Studies are now available which provide a scientific rationale for the dosage rate recommended. A number of new drugs have recently been licensed for use in the dog or may be licensed in the near future. These include flunixin, carprofen and tolfenamic acid and the data generated from these products provides very useful information for formulating I effective dosage regimens. There are also some NSAIDs such as piroxicam which have been investigated in the dog because they have particular properties which may be of use in common clinical conditions and others, such as Paracetamol and Ibuprofen, which are readily available to the public and which owners may administer to dogs or cats at toxic doses.     

An anamnestic serological test for ovine footrot

Following recovery from ovine footrot, a proportion of sheep in a flock may carry the causative organism and spread it to other sheep if environmental conditions are favourable. Footrot affected sheep have elevated levels of serum antibody against Bacteroides nodosus, but these levels decline rapidly after clinical recovery. When challenged by subcutaneous injection with 470 micrograms of protein extracted from the cell membrane of B. nodosus, without adjuvant, sheep that had recovered clinically from virulent footrot produced a marked increase in specific serum antibody within 7 d, while antibody levels in footrot-free sheep injected with the same antigen, and in saline injected controls, did not increase over a period of 25 d. Artificial stimulation and serological detection of immune memory may be useful in footrot eradication programs by identifying sheep that have had clinical footrot infection. This procedure may be applicable to other diseases where antibody responses are inconsistent or transient.     

What is Fieldwork?

Fieldwork implies the performance of veterinary procedures away from a normal workplace. In the context of exotic animals and wildlife, this often means or suggests working overseas in poorer regions of the world, but even in richer countries, field techniques may be required to diagnose disease or to carry out veterinary treatment. Equipment for such work has to be carefully selected and either transported to the location or made available on site. Standard utilities may not be available, calling for alternative sources of power such as battery or solar energy, and water may have to be carried or collected. There may be limited assistance, difficult terrain, and poor communication. As this and ensuing articles show, those involved in fieldwork, wherever it takes place, need to be adaptable and versatile. Health and safety are always important considerations.     

Nutritional management of gastrointestinal disease

The gastrointestinal (GI) tract is primarily responsible for acquiring and digesting food, absorbing nutrients and water, and expelling wastes from the body as feces. A proper diet and normally functioning GI tract are integral for the delivery of nutrients, prevention of nutrient deficiencies and malnutrition, repair of damaged intestinal epithelium, restoration of normal luminal bacterial populations, promotion of normal GI motility, and maintenance of normal immune functions (eg, both tolerance and protection from pathogens). The amount of food, its form, the frequency of feeding, and the composition of diet each have important effects on GI function and may be used to help ameliorate signs of GI disease. Although both nutrients and nonnutritional components of a diet are important to GI health, they also may cause or influence the development of GI pathology (eg, antibiotic responsive diarrhea, inflammatory bowel disease, dietary intolerance, or sensitivity and/or allergy). The appropriate diet may have a profound effect on intestinal recovery and successful management of chronic or severe GI disease.     

Effects of Mycoplasma hyopneumoniae and Actinobacillus (Haemophilus) pleuropneumoniae infections on alveolar macrophage functions in swine

Alveolar macrophages were collected at necropsy from pigs inoculated with Mycoplasma hyopneumoniae or Actinobacillus pleuropneumoniae or both and were tested for phagocytic capabilities, using in vitro techniques. Macrophages from noninoculated littermates were used as controls. Alveolar macrophages from pigs inoculated with either M hyopneumoniae or A pleuropneumoniae had significantly (P less than 0.05 to P less than 0.0025) higher phagocytic capacity than that of noninoculated controls. Macrophages from A pleuropneumoniae-inoculated pigs were comparatively more stimulated than were those from M hyopneumoniae-inoculated pigs. Pigs inoculated with M hyopneumoniae and then challenge-exposed with A pleuropneumoniae 2 and 4 weeks later had greatly reduced phagocytosis. Infection with M hyopneumoniae or A pleuropneumoniae caused stimulation of alveolar macrophage functions, and M hyopneumoniae infections may have suppressed phagocytic responses when pigs were challenge-exposed with a secondary pathogen (A pleuropneumoniae). This potential suppression may represent a prediposition of the host by M hyopneumoniae to secondary bacterial infections.     

A serological survey of minute virus of canines (MVC; canine parvovirus type-1) in dogs in the Tokai area of Japan.

A serological survey for antibodies to minute virus of canines (MVC) by use of a hemagglutination-inhibition (HI) test was performed on sera collected from dogs in the Tokai area of Japan. Forty-one of 266 (15.4%) sera had positive titers of 1:40 or higher against the MVC. Results suggest that MVC may have been present in dogs in Japan since, at least, 1990. From this serosurvey, MVC appears to be established in the dog population in Japan. MVC may have a role as a newly recognized viral pathogen of dogs in Japan.     

Evaluation of bovine embryos produced in high performance serum-free media

This review evaluates the quality of bovine embryos developed from in vitro-matured (IVM) and -fertilized (IVF) oocytes cultured in either serum-free or serum-containing media. Bovine embryos cultured in serum-supplemented medium contain numerous cytoplasmic lipid droplets and immature mitochondria compared to those cultured in serum-free medium. The accumulation of cytoplasmic lipids in embryos developed in serum-containing medium may be a result of incorporation of lipoproteins from the serum and may result in impaired function of mitochondria. The improved serum-free media (IVMD101 and IVD101) offer several advantages over culture in serum-containing medium, including increased rates of blastocyst formation and higher cell numbers. Additionally, the survival and hatching rates of embryos produced in serum-free media after post-thaw culture were superior to those of embryos produced in the serum-containing medium, suggesting that the abnormal accumulation of cytoplasmic lipids in embryos may have a negative effect on the sensitivity of embryos to chilling and freezing. These serum-free culture systems have proven to be beneficial for the production of good quality embryos from IVM-IVF bovine oocytes. Furthermore, recent studies have shown a correlation between mitochondrial function (oxygen consumption) and embryo quality. A new method using scanning electrochemical microscopy may be capable of assessing the viability and developmental potential of bovine embryos.     

Intramedullary Spinal Cord Metastasis in the Dog

Intramedullary spinal cord metastasis (ISCM) was diagnosed in three dogs with signs of myelopathy. The clinicopathologic features of ISCM in these and previously reported cases in the veterinary and human literature were compared. Myelopathic signs associated with ISCM may be the initial clinical manifestation of malignancy or may develop in the patient with known malignancy. Pain, a frequent manifestation of extradural compressive myelopathy, is not a consistent feature of ISCM. Survey spinal radiographs are usually unrewarding and cerebrospinal fluid (CSF) abnormalities nonspecific. Myelography is indicated to differentiate intramedullary lesions from more common extradural compressive lesions. Myelographic interpretation may be difficult, and intramedullary tumors must be differentiated from spinal cord edema or hemorrhage. Evidence of widely disseminated malignancy should increase suspicion for ISCM; hemangiosarcoma and lymphosarcoma should be considered the most likely histologic types. CSF cytology may be helpful in the diagnosis of patients with lymphosarcoma. Prognosis is poor due to the frequent presence of disseminated disease, although temporary response to corticosteroid therapy may be achieved. More aggressive therapeutic approaches, such as spinal irradiation and microsurgical resection of metastases, have been advocated in humans but have not been reported in the dog. Although it is an uncommon complication of systemic malignancy, ISCM should be considered in the differential diagnosis of myelopathy in the dog.     

The amended insulin to glucose ratio and diagnosis of insulinoma in dogs

Amended insulin to glucose ratios were calculated from the concentrations of serum insulin and blood glucose measured concurrently during either a glucagon tolerance test or after feeding in healthy dogs. Values greater than 30 microU/mg which are supportive of a diagnosis of insulinoma were obtained at certain times during the test period. Amended insulin to glucose ratios calculated from serum insulin and blood glucose concentrations obtained during a glucagon tolerance test and an oral glucose tolerance test on a dog with an insulinoma were less than 30 microU/mg, or equivocal, at different times during the test period. This indicates that under some circumstances healthy dogs may have elevated amended insulin to glucose ratios, and dogs with insulinoma may have a normal amended insulin to glucose ratio. Care is essential for interpretation of amended insulin to glucose ratios, and a diagnosis of insulinoma using the ratio must be made in conjunction with appropriate clinical signs of hypoglycaemia.     

Lesions of the pericardium and their significance in the aetiology of heart failure in broiler chickens

The present study focuses on lesions of the pericardium commonly observed in fast growing broilers. These lesions are examined in the context of electrophysiological and functional changes associated with cardiac performance and patho-physiology in broilers succumbing to acute or chronic heart failure. Typical lesions involving the pericardium in fast growing broiler chickens included: (1) excessive pericardial effusion, (2) locally extensive or focal adhesions between parietal and visceral components of the pericardium, (3) fibrous deposits on visceral pericardium, and (4) thickened pericardium. Echocardiographic evidence indicated that severe pericardial effusion and/or adhesions may have a restrictive effect on heart pump function, where both diastolic and systolic function of the heart may be affected. Electrocardiographic data showed a strong trend indicating that pericardial adhesions may be associated with ventricular arrhythmia and increased risk of sudden death in fast growing broilers. Relatively high levels of matrix metalloproteinase MMP-2 activity have been found in pericardial effusions from affected chickens, suggesting a possible involvement of this enzyme in the aetiology of pericardial lesions. The present results indicate that pericardial lesions may be associated with biochemical, morphological, electrophysiological, and functional changes occurring in the hearts of broilers succumbing to acute or chronic heart failure and ascites.     

Antigen specificity in canine autoimmune haemolytic anaemia.

Autoimmune haemolytic anaemia (AIHA) is the most common clinical manifestation of autoimmunity in the dog and generally presents as a profound, regenerative, Coombs' positive anaemia of acute or chronic onset. The disease pathogenesis involves formation of erythrocyte-specific autoantibodies of the IgG and IgM class that may fix complement resulting in intra- or extravascular haemolysis. Western blotting and immunoprecipitation studies using autoantibody eluted from the erythrocytes of dogs with AIHA have demonstrated specificity for erythrocyte glycophorins and the membrane anion-exchange molecule (band 3). Autoantibodies specific for the cytoskeletal molecule spectrin have been identified in serum by ELISA. The specificity of autoreactive T-cells has been examined in vitro using bulk cultures stimulated with a panel of autoantigens including intact erythrocyte membranes, purified glycophorin and spectrin fractions and a panel of overlapping 15-mer glycophorin peptides. Control responses to ConA and recall (vaccine antigens) and non-recall (KLH) antigens were measured in the same system. PBMC obtained from dogs that had recovered from AIHA consistently proliferated in response to erythrocyte membranes, with occasional responses to spectrin or glycophorin. PBMC from sone clinically normal dogs also responded to erythrocyte membranes. PBMC obtained from dogs closely related to AIHA cases gave the most consistent responses, including proliferation when stimulated by the glycophorin peptides. These data suggest that normal dogs harbour erythrocyte autoreactive lymphocytes, and that these cells may be primed in dogs recovered from AIHA or having genetic susceptibility to the disease.     

Toxicology of oil field wastes. Hazards to livestock associated with the petroleum industry

In oil-producing states, the proximity of livestock to drilling operations and production sites often results in poisoning of animals from ingestion of crude oil, condensate, salt water, heavy metals, and caustic chemicals. The heavy metals encountered most frequently are lead from pipe joint compound and arsenicals and chromates used as corrosion inhibitors. Numerous toxic and caustic chemicals are used in drilling muds and fluids. Crude oil and salt water spills are common occurrences around production sites. Pipeline breaks may result in exposure of livestock to crude oil or refined petroleum hydrocarbons. Ingestion of petroleum hydrocarbons may result in sudden death from peracute bloat. The most common cause of illness or death following exposure to petroleum hydrocarbons is aspiration pneumonia, which may cause a chronic progressive deterioration of health, with death after several days or weeks. Cases in which livestock are exposed to oil, salt water, or caustic chemicals, but do not die acutely or from aspiration pneumonia are more frustrating to diagnose. In these cases, parasitism, poor nutrition, and other debilitating diseases must be considered. Anorexia, weight loss, and decreased rumen motility may be caused by a disruption of normal rumen function. Petroleum hydrocarbons, salt water, and caustic chemicals have the potential of altering rumen flora and enzymatic processes as well as damaging the ruminal and gastrointestinal epithelium. The toxicity of petroleum hydrocarbons appears to be related more closely to the volatility and viscosity of the product than to other factors. The more volatile straight chain and aromatic petroleum hydrocarbons have a greater potential for aspiration pneumonia and may produce an anesthetic-like action if absorbed systemically. The more volatile petroleum hydrocarbons also are more irritating to skin and mucous membranes and appear to be more damaging to rumen flora. Treatment of petroleum hydrocarbon ingestion is aimed at preventing aspiration pneumonia and the animal's absorption of highly volatile components. Activated charcoal slurries and, in some instances, vegetable oil may be used to absorb the ingested petroleum or alter its viscosity to minimize absorption and aspiration. These procedures should be followed by the administration of rumenatories or saline cathartics to hasten the evacuation of the gastrointestinal tract. Chronic poor performance animals with anorexia and rumen dysfunction may respond to fresh rumen inoculant, intravenous glucose, and B-complex vitamins. Prognosis primarily hinges on whether or not aspiration pneumonia has occurred. Treatment of aspiration pneumonia rarely is effe     

Pharmacology and therapeutics in donkeys

Therapeutics are often administered to donkeys based on dosage and intervals recommended for horses because very few drugs have donkey‐specific label indications. Yet differences between donkeys and horses in drug distribution, metabolism and elimination have been noted for most therapeutic agents studied. These differences can be partially explained by the donkey's unique physiology. Since their ancestors evolved in a desert environment, the modern donkey exhibits qualities that allow them to tolerate dehydration better than the horse and recover more quickly from its effects. Fluid balance and body water compartment partitioning differ from the horse and may have implications regarding drug distribution. Since donkeys are preferential browsers, differences in diet may have influenced evolutionary differences in metabolic disposition of drugs. It is important to acknowledge these differences when designing dose regimes for donkeys based on horse protocols in order to avoid either lack of efficacy or toxicity.     

How to succeed as a virus: strategies for dealing with the immune system

Viruses may be viewed as genetic information whose success depends on avoiding elimination from individual hosts, or, if this is not possible, in persisting in the population of their hosts. The immune system represents the crucial defense mechanism responsible for the elimination of viruses from individual hosts and for the establishment of immunity that prevents a recurring infection by the same virus. Herd immunity, i.e., immunity of the population against infection resulting from the immunity of a certain fraction of the individuals of the population, represents an important concept in the interaction of viruses with their hosts. Thus, if the number of susceptible hosts decreases below a critical threshold, viruses may risk extinction because they literally run out of substrate. This possibility is increased due to the viruses' low resistance to inactivation outside their hosts by physical influences, such as heat and ultraviolet radiation. Some viruses have adopted a strategy of dual host tropism, i.e., they may reside in reservoir hosts that permit them to survive for extended periods of times. Examples of such viruses are the large and taxonomically diverse group of arboviruses. Moreover, although not normally discussed under this aspect, influenza viruses can also be said to have adopted this strategy, in view of water fowl representing reservoir hosts from which complete viruses may directly cross over to mammals, as was the case with the equine Jilin (Guo et al., 1995) or, more recently, the H5 subtype of influenza virus in humans (Shortridge et al., 1998). In addition, influenza viruses of birds may be transmitted, albeit only partially, through genetic reassortment (Shu et al., 1996).     

Embryo transfer in competition horses: Managing mares and expectations

Embryo transfer (ET) is an accepted and successful technique for obtaining foals from mares without interrupting their competition careers. Recent research, however, suggests that the potential of factors including heat, exercise, repeated embryo flushing and repeated manipulation of the reproductive cycle using exogenous hormones to have a negative impact on fertility may have been underestimated. This paper reviews the evidence base for involvement of these factors in repeated failures to recover embryos from nongeriatric competition mares without obvious clinical or pathological indications of reproductive abnormalities. It concludes that, for some mares at least, a cessation of exercise for the periovulatory period and the period between ovulation and embryo flushing, combined with careful management of flushing‐induced endometritis, and minimal hormonal manipulation of the reproductive cycle, may be necessary to optimise embryo recovery rates. Mare owners may have been encouraged to request ET for their mares following high‐profile examples in the media of elite mares that have produced foals by ET whilst competing. The veterinarian should educate mare owners about the multiple factors that may affect the chances of recovering an embryo from their mares, and should manage the expectations of mare owners so that they do not approach ET programmes in the expectation that there will be no disruption to their training and competition plans.     

Infectious Bovine Keratoconjunctivitis: A Review

The economic impact of infectious bovine keratoconjunctivitis (IBK) warrants continued investigation of the mechanisms by which Moraxella bovis survives on and colonizes the corneal surface. Virulent strains of M bovis produce hemolysin and exhibit different plasmid profiles than nonvirulent strains. Interactions among host, environment, vector, season, and concurrent infection influence the prevalence of IBK. Mycoplasma sp. or infectious bovine rhinotracheitis virus may enhance or hasten the disease process. The manifestations of IBK may range from mild conjunctivitis to severe ulceration, corneal perforation, and blindness. Treatment of IBK is dictated by economic considerations, intended animal use, and feasibility of administration. Antibiotic therapy is aimed at achieving drug concentrations in tears to meet or exceed the minimum inhibitory concentration for prolonged periods. At present, IBK is not a preventable disease. Affected animals must be separated from the herd and vector control vigorously instituted. Carrier animals must be identified and removed from the herd. Vaccination trials have been unsuccessful because of pili antigen crossreactivity, variable strains, and uncontrolled environmental factors. Recent investigations have determined that M bovis may utilize host iron sources via iron-repressible outer membrane proteins and siderophores for growth. Elucidation of normal defense mechanisms of the bovine eye may lead to new strategies to enhance the immune response against M bovis.