Effects of diet restriction on life span and age-related changes in dogs

OBJECTIVE: To evaluate the effects of 25% diet restriction on life span of dogs and on markers of aging. DESIGN: Paired feeding study. ANIMALS: 48 Labrador Retrievers. PROCEDURES: Dogs were paired, and 1 dog in each pair was fed 25% less food than its pair-mate from 8 weeks of age until death. Serum biochemical analyses were performed, body condition was scored, and body composition was measured annually until 12 years of age. Age at onset of chronic disease and median (age when 50% of the dogs were deceased) and maximum (age when 90% of the dogs were deceased) life spans were evaluated. RESULTS: Compared with control dogs, food-restricted dogs weighed less and had lower body fat content and lower serum triglycerides, triiodothyronine, insulin, and glucose concentrations. Median life span was significantly longer for dogs in which food was restricted. The onset of clinical signs of chronic disease generally was delayed for food-restricted dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that 25% restriction in food intake increased median life span and delayed the onset of signs of chronic disease in these dogs.     

Effect of background serum lithium concentrations on the accuracy of lithium dilution cardiac output determination in dogs

OBJECTIVES: To assess the effect of increasing serum lithium concentrations on lithium dilution cardiac output (LiDCO) determination and to determine the ability to predict the serum lithium concentration from the cumulative lithium chloride dosage. ANIMALS: 10 dogs (7 males, 3 females). PROCEDURE: Cardiac output (CO) was determined in anesthetized dogs by measuring LiDCO and thermodilution cardiac output (TDCO). The effect of the serum lithium concentration on LiDCO was assessed by observing the agreement between TDCO and LiDCO at various serum lithium concentrations. Also, cumulative lithium chloride dosage was compared with the corresponding serum lithium concentrations. RESULTS: 44 paired observations were used. The linear regression analysis for the effect of the serum lithium concentration on the agreement between TDCO and LiDCO revealed a slope of -1.530 (95% confidence interval [CI], -2.388 to -0.671) and a y-intercept of 0.011 (r2 = 0.235). The linear regression analysis for the effect of the cumulative lithium chloride dosage on the serum lithium concentration revealed a slope of 2.291 (95% CI, 2.153 to 2.429) and a y-intercept of 0.008 (r2 = 0.969). CONCLUSIONS AND CLINICAL RELEVANCE: The LiDCO measurement increased slightly as the serum lithium concentration increased. This error was not clinically relevant and was minimal at a serum lithium concentration of 0.1 mmol/L and modest at a concentration of 0.4 mmol/L. The serum lithium concentration can be reliably predicted from the cumulative lithium dosage if lithium chloride is administered often within a short period.     

Effects of serum vitamin E levels on skin vitamin E levels in dogs and cats

Skin problems are common in small animal practice. Oxidative stress, or the imbalance between prooxidants and the body's antioxidant defense system, likely plays a role in the development of skin disease. According to this study, increasing amounts of vitamin E in foods for dogs and cats increases serum and cutaneous concentrations of vitamin E. Based on available scientific data, these increases in vitamin E concentration are likely to be beneficial. However, the relationship between increases in serum and skin vitamin E concentrations and the prevention, development, and treatment of skin disease remains to be elucidated by intervention studies.     

Prognosis following surgical excision of canine cutaneous mast cell tumors with histopathologically tumor-free versus nontumor-free margins: a retrospective study of 31 cases

The purpose of this study was to determine if the presence of histopathologically tumor-free versus nontumor-free margins was prognostic for relapse or tumor-related death in dogs following surgical excision of single or multiple cutaneous mast cell tumors confined to the skin without evidence of metastasis to lymph nodes or other noncutaneous sites. Differences in tumor-related death or frequency of relapse between the two groups were not significant. Failure to achieve histopathological tumor-free margins frequently did not lead to local relapse. All tumor-related deaths occurred following local relapse. The lack of statistical support for an association between prognosis and histopathological tumor-free versus nontumor-free margins may be a result of small sample size.     

Detection of canine microalbuminuria using semiquantitative test strips designed for use with human urine

Background — Commercial testing for microalbuminuria in human urine is often performed with point-of-care semiquantitative test strips followed by quantitative testing when indicated. An ELISA that quantifies canine urine albumin concentration has been developed, but semiquantitative test strips for use in the dog are not available.
Objective — The purpose of this study was to prospectively determine the concordance of canine urine albumin concentrations measured by a commercial human test strip and by ELISA.
Methods — Urine samples were obtained from 67 dogs evaluated for a variety of clinical conditions. Dipstick urinalyses were performed on all samples; clinician discretion determined method of urine collection and performance of urine sediment examination and/or urine culture. Urine albumin concentration was determined using test strips (Clinitek Microalbumin, Bayer Corporation, Elkhart, Ind, USA), and results were compared with those obtained by ELISA.
Results — The Clinitek strips correctly determined albumin concentration in 42 of 67 (63%) urine samples tested. Concordance was lowest (48%) for dogs with microalbuminuria (10–300 μg/mL by ELISA). Clinitek strip sensitivity and specificity for correct identification of microalbuminuria were 48% and 75%, respectively. Concordance was lower in dogs with urinary tract infection or hematuria and in samples collected by catheterization. Sensitivity and specificity for correct identification of microalbuminuria after exclusion of dogs with urinary tract infection or hematuria were 59% and 83%, respectively.
Conclusion — These results suggest that the Clinitek strips lack sufficient concordance with results obtained by ELISA to be reliable screening tests for microalbuminuria in the dog. A reliable semiquantitative point-of-care test for canine urine albumin concentrations below those detected by standard urine dipsticks is still needed.     

Syringohydromyelia in Cavalier King Charles spaniels

Syringohydromyelia secondary to foramen magnum overcrowding is described in seven Cavalier King Charles spaniels. Clinical signs were consistent with a central spinal cord lesion. The most common signs were persistent scratching at the shoulder region with apparent neck, thoracic limb, or ear pain and thoracic limb lower motor neuron deficits. The diagnosis was made by magnetic resonance imaging. The syringohydromyelia is postulated to be a consequence of an occipital bone malformation resulting in a small caudal fossa and cerebellar herniation. Clinical signs improved but did not completely resolve when the dogs received treatment with corticosteroids or nonsteroidal anti-inflammatory drugs.     

Antioxidants in veterinary nutrition.

Nutritional antioxidants have experienced a surge in research and interest in the past 20 years. this surge may be attributed to the improved methodology for investigation as well as the focus on diseases and aging processes related to oxidative stress that lend themselves to opportunistic outcomes. As such, the field of veterinary nutritional antioxidant research is also beginning to yield some interesting results, albeit, small in number compared with laboratory animals and human beings. Nonetheless, this article updates the practitioner on recent advances in research involving nutritional antioxidant applications in companion animals.     

Performing the field necropsy examination.

This article is designed to aid the practitioner by maximizing the effectiveness of field postmortem diagnostic investigations. Contents include an outline of the procedure for field necropsy of ruminants, recommended tools and supplies, and guidelines for sample collection and submission.     

Amanita muscaria toxicosis in two dogs

Objective: To report the manifestations, history, and pathophysiologic basis of disease in 2 dogs with Amanita muscaria toxicosis. Case summaries: Two dogs were evaluated for an acute onset of gastroenteritis and seizures. A. muscaria toxicosis was suspected in each dog after confirmation of environmental exposure and visualization of ingested mushrooms in vomitus. The diagnosis was confirmed following identification of toxic Amanita metabolites in the urine and serum of each dog. Administration of supportive and symptomatic therapies resulted in the complete recovery of each animal. Unique information provided: Ingestion of the mushroom, A. muscaria, by dogs can result in acute gastrointestinal distress that precedes a potentially life‐threatening central neurologic syndrome characterized by seizures, tremors, and somnolence. Central nervous system dysfunction results primarily from the actions of ibotenic acid and its decarboxylation product, muscimol, which are analogues of the neurotransmitters glutamate and γ‐aminobutyric acid (GABA), respectively. Identification of these toxins in the urine and serum of affected dogs using high‐performance liquid chromatography (HPLC) provides a definitive diagnosis.