Protothecosis and Toxoplasma gondii co-infection in a dog from Nova Scotia, Canada.

A 2-year-old, neutered male mixed-breed dog from Nova Scotia, Canada was evaluated for panuveitis, polyuria, polydipsia, and hind limb ataxia. Toxoplasmosis was diagnosed ante-mortem based on markedly increased Toxoplasma gondii titers. The post-mortem examination confirmed systemic toxoplasmosis and demonstrated disseminated protothecosis. This article documents the first reported case of canine protothecosis in Atlantic Canada. Key clinical message: This case report demonstrates that protothecosis should be a clinical consideration for dogs in Canada. Co-infection with other organisms may occur, which may mask clinical signs and potentially delay diagnosis.

Protothécose et co-infection à Toxoplasma gondii chez un chien de la Nouvelle-Écosse, Canada. Un chien de race mixte mâle castré de 2 ans de la Nouvelle-Écosse, au Canada, a été évalué pour une panuvéite, une polyurie, une polydipsie et une ataxie des membres postérieurs. La toxoplasmose a été diagnostiquée antemortem sur la base d'une augmentation marquée des titres de Toxoplasma gondii. L'autopsie a confirmé la toxoplasmose systémique et mis en évidence une protothécose disséminée. Cet article documente le premier cas signalé de protothécose canine en Atlantique. Message clinique clé: Ce rapport de cas démontre que la protothécose devrait être une considération clinique pour les chiens au Canada. Une co-infection avec d'autres organismes peut survenir, ce qui peut masquer les signes cliniques et potentiellement retarder le diagnostic.(Traduit par Dr Serge Messier).

Preliminary evaluation of a gel tube agglutination major cross-match method in dogs.

BACKGROUND: A major cross-match gel tube test is available for use in dogs yet has not been clinically evaluated. OBJECTIVES: This study compared cross-match results obtained using the gel tube and the standard tube methods for canine samples. METHODS: Study 1 included 107 canine sample donor-recipient pairings cross-match tested with the RapidVet-H method gel tube test and compared results with the standard tube method. Additionally, 120 pairings using pooled sera containing anti-canine erythrocyte antibody at various concentrations were tested with leftover blood from a hospital population to assess sensitivity and specificity of the gel tube method in comparison with the standard method. RESULTS: The gel tube method had a good relative specificity of 96.1% in detecting lack of agglutination (compatibility) compared to the standard tube method. Agreement between the 2 methods was moderate. Nine of 107 pairings showed agglutination/incompatibility on either test, too few to allow reliable calculation of relative sensitivity. Fifty percent of the gel tube method results were difficult to interpret due to sample spreading in the reaction and/or negative control tubes. CONCLUSIONS: The RapidVet-H method agreed with the standard cross-match method on compatible samples, but detected incompatibility in some sample pairs that were compatible with the standard method. Evaluation using larger numbers of incompatible pairings is needed to assess diagnostic utility. The gel tube method results were difficult to categorize due to sample spreading. Weak agglutination reactions or other factors such as centrifuge model may be responsible.

Association between excess body weight and urine protein concentration in healthy dogs.

BACKGROUND: Markedly overweight people can develop progressive proteinuria and kidney failure secondary to obesity-related glomerulopathy (ORG). Glomerular lesions in dogs with experimentally induced obesity are similar to those in people with ORG. OBJECTIVES: The aim of this study was to evaluate if urine protein and albumin excretion is greater in overweight and obese dogs than in dogs of ideal body condition. METHODS: Client-owned dogs were screened for underlying health conditions. These dogs were assigned a body condition score (BCS) using a 9-point scoring system. Dogs with a BCS of ≥ 6 were classified as being overweight/obese, and dogs with a BCS of 4 or 5 were classified as being of ideal body weight. The urine protein:creatinine ratio (UPC) and urine albumin:creatinine ratio (UAC) were then determined, and compared between 20 overweight/obese dogs and 22 ideal body weight control dogs. RESULTS: Median UPC (0.04 [range, 0.01-0.14; interquartile range, 0.07]) and UAC (0.41 [0-10.39; 3.21]) of overweight/obese dogs were not significantly different from median UPC (0.04 [0.01-0.32; 0.07]) and UAC (0.18 [0-7.04; 1.75]) in ideal body weight dogs. CONCLUSIONS: Clinicopathologic abnormalities consistent with ORG were absent from overweight/obese dogs in this study.

Effects of 2 different infusion rates of medetomidine on sedation score, cardiopulmonary parameters, and serum levels of medetomidine in healthy dogs.

The effects of 2 different continuous rate infusions (CRIs) of medetomidine over an 8-hour period on sedation score, selected cardiopulmonary parameters, and serum levels of medetomidine were evaluated in 6 healthy, conscious dogs using a crossover study design. The treatment groups were: CONTROL = saline bolus followed by saline CRI; MED1 = 2 µg/kg body weight (BW) medetomidine loading dose followed by 1 µg/kg BW per hour CRI; and MED2 = 4 µg/kg BW medetomidine loading dose followed by 2 µg/kg BW per hour CRI. Sedation score (SS), heart rate (HR), respiratory rate (RR), temperature (TEMP), systolic arterial pressure (SAP), mean arterial pressure (MAP), and diastolic arterial pressure (DAP), arterial and mixed venous blood gas analyses, lactate, and plasma levels of medetomidine were evaluated at baseline, at various intervals during the infusion, and 2 h after terminating the infusion. Statistical analysis involved a repeated measures linear model. Both infusion rates of medetomidine-induced dose-dependent increases in SS and dose-dependent decreases in HR, SAP, MAP, and DAP were measured. Respiratory rate (RR), TEMP, central venous pH, central venous oxygen tension, and oxygen extraction ratio also decreased significantly in the MED2 group at certain time points. Arterial oxygen and carbon dioxide tensions were not significantly affected by either infusion rate. In healthy dogs, both infusion rates of medetomidine-induced clinically relevant sedative effects, accompanied by typical alpha2 agonist-induced hemodynamic effects, which plateaued during the infusion and subsequently returned to baseline. While additional studies in unhealthy animals are required, the results presented here suggest that medetomidine infusions at the doses studied may be useful in canine patients requiring sedation for extended periods.

Les effets de deux taux différents d'infusion continue (CRIs) de medetomidine pendant une période de huit heures sur le score de sédation, des paramètres cardio-pulmonaires choisis, et les niveaux sériques de medetomidine ont été évalués chez six chiens en santé et conscients par un plan d'essais croisés. Les groupes de traitement étaient : TÉMOIN = bolus de saline suivi d'une CRI de saline; MED1 = 2 µg/kg de poids corporel (BW) medetomidine comme dose de charge suivi d'une CRI de 1 µg/kg BW par heure; et MED2 = 4 µg/kg BW medetomidine comme dose de charge suivi d'une CRI de 2 µg/kg BW par heure. Le score de sédation (SS), le rythme cardiaque (HR), le rythme respiratoire (RR), la température (TEMP), la pression artérielle systolique (SAP), la pression artérielle moyenne (MAP), la pression artérielle diastolique (DAP), l'analyse des gaz sanguins artériel et veineux, les niveaux de lactate, et les concentrations plasmatiques de medetomidine ont été évalués avant l'infusion, à différents intervalles durant l'infusion et 2 h après la fin de l'infusion. Les analyses statistiques ont été effectuées en utilisant un modèle linéaire de mesures répétées. Les deux taux d'infusion de medetomidine ont induit des augmentations dose-dépendante de SS, et des réductions dose-dépendante de HR, SAP, MAP, et DAP. Les valeurs de RR, TEMP, le pH veineux central, la tension veineuse centrale en oxygène, et le ratio d'extraction de l'oxygène ont également diminué de manière significative à certains moments dans le temps pour le groupe MED2. Aucun des deux taux d'infusion n'affecta de manière significative les tensions artérielles en oxygène et en dioxyde de carbone. Chez des chiens en santé, les deux taux d'infusion de medetomidine ont induit des effets sédatifs pertinents, accompagnés d'effets hémodynamiques typiques d'agoniste alpha2, qui ont atteint un plateau durant l'infusion et retournèrent subséquemment aux niveaux de base. Bien que des études supplémentaires chez des animaux malades soient requises, les résultats présentés suggèrent que des infusion de medetomidine aux doses étudiées pourraient être utiles chez des patients canins qui requièrent une sédation pour des périodes prolongées.(Traduit par Docteur Serge Messier).

Relationships among milk urea-nitrogen, dietary parameters, and fecal nitrogen in commercial dairy herds.

Our study objective was to determine the ability of milk urea-nitrogen concentrations ([MUN]) to predict fecal nitrogen concentrations ([Fecal N]) in commercial dairy herds. A total of 83 dairy herds were each visited 3 times within 48 h after a monthly herd milk test. For each farm visit, forages were sampled for nutrient analyses, which were entered into a computerized ration evaluator, and fecal samples were taken per rectum from each of 6 cows (2 early-, 2 mid-, and 2 late-lactation). Fecal samples were pooled, mixed, and analyzed for nitrogen content. Fecal nitrogen concentrations were compared with the routinely measured nutritional parameters from the ration evaluation, and the herd average [MUN] for the previous milk test date using mixed linear regression analyses. Total protein supplied in the ration was significantly positively associated with [Fecal N], but herd average [MUN] was not associated (P > 0.10) with [Fecal N].

Evaluation of ionized and total serum magnesium concentrations in hyperthyroid cats.

Hyperthyroidism can increase the renal excretion of magnesium and thus cause hypomagnesemia in various species. Anaerobically collected blood samples from 15 hyperthyroid and 40 normal, healthy cats were analyzed with an ion-selective electrode analyzer and a serum biochemical analyzer. There was no significant difference in ionized or total serum magnesium concentration between the 2 groups, but there was a significant difference (P = 0.004) in the ratio of ionized to total serum magnesium concentrations between the healthy cats and the hyperthyroid cats with thyroxine (T4) concentrations at or above the median. There was a significant correlation (r = 0.894, P = 0.000) between the ionized and total magnesium concentrations in the hyperthyroid cats. The hyperthyroid cats had a significantly lower (P = 0.003) total serum protein concentration than the healthy cats. A significant negative correlation (r = -0.670, P = 0.006) was detected between the ionized magnesium and logarithmically transformed total T4 concentrations in the hyperthyroid cats, which suggests that the severity of hyperthyroidism may contribute to a decrease in the ionized magnesium concentration.

Validation of the Nova CRT8 for the measurement of ionized magnesium in feline serum.

BACKGROUND: Evaluation of serum magnesium (Mg) concentration is becoming important in human and veterinary critical care medicine. An ion-selective electrode can measure the physiologically active ionized fraction. OBJECTIVES: The purpose of this study was to validate an ion-specific electrode analyzer and assay for measuring ionized Mg in feline serum and to determine a reference interval for this analyte in cats. METHODS: Venous blood samples were collected anaerobically from clinically healthy cats, and the serum was used to validate the analyzer and assay. This included investigating the stability of samples stored at different temperatures, intra- and interassay precision, linearity, analytical sensitivity, and potential interferences from bilirubin, lipemia, hemoglobin, or serum separator tubes. A reference interval was calculated. RESULTS: Serum samples evaluated for ionized Mg concentrations can be stored at 20 degrees C for < or =24 hours, at 4 degrees C for < or =72 hours, and at 20 degrees C for < or =4 weeks, when samples are minimally exposed to air. Intra- and interassay precisions had coefficients of variation (CVs) of 1.23% and 2.02%, respectively. There was good linearity using serum (r = .998; y = -0.0057 + 1.0256x) and manufacturer-supplied aqueous solutions and quality control materials (r = .999; y = 0.0110 + 0.9213x). Apparent analytical sensitivity was at least 0.015 mmol/L. Mean recovery was good for ionized Mg in samples with 1+ icterus (104%), 4+ lipemia (99.3%) and 1-4+ hemolysis (98.6%). There was no significant difference (P = .52) in ionized Mg concentrations in serum collected in tubes containing no additives compared with serum collected in glass separator tubes. The serum ionized Mg reference interval was 0.47-0.63 mmol/L (n = 40). CONCLUSIONS: The Nova CRT8 analyzer and assay provide a precise and reliable method of measuring ionized Mg concentration in feline serum. Strict adherence to sampling techniques, handling, and storage are necessary for reliable results.

Evaluation of an automated, homogeneous enzyme immunoassay for serum thyroxine measurement in dog and cat serum.

A homogenous enzyme immunoassay (EIA) for measurement of serum thyroxine (T4) concentration was evaluated for use with canine and feline serum. The EIA method was linear from 0 to 150 nmol T4/L for human serum, 0 to 94 nmol T4/L for feline serum and 10 to 60 nmol T4/L for canine serum. Intra- and interassay precision studies yielded coefficients of variation