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1.
Background: Serum cobalamin concentrations below reference range are a common consequence of gastrointestinal disease in cats. Serum cobalamin ≤ 100 ng/L is associated with methylmalonic acidemia.
Objectives: To determine the prevalence of cobalamin deficiency, defined by elevated serum methylmalonic acid (MMA), in cats with serum cobalamin ≤ 290 ng/L, and the optimum serum cobalamin concentration to predict cobalamin deficiency in cats.
Sample Set: Residual serum samples (n = 206) from cats with serum cobalamin ≤ 290 ng/L.
Methods: Retrospective, observational study. Serum cobalamin and folate were measured with automated assays. Serum MMA was determined by gas chromatography-mass spectrometry. Cobalamin deficiency was defined as serum MMA > 867 nmol/L. Sensitivity and specificity of serum cobalamin concentrations ≤290 ng/L for detecting MMA > 867 nmol/L were analyzed using a receiver-operator characteristic curve.
Results: There was a negative correlation between serum cobalamin and MMA concentrations (Spearman's r =−0.74, P < 0.0001). The prevalence of MMA ≥ 867 nmol/L in cats with serum cobalamin ≤ 290 ng/L was 68.4%. Serum cobalamin ≤ 160 ng/L had a 74% sensitivity and 80% specificity for detecting MMA > 867 nmol/L. No significant difference in serum folate concentrations was detected between affected and unaffected cats.
Conclusions and Clinical Importance: Elevated MMA concentrations, suggesting cobalamin deficiency, are common in cats with serum cobalamin ≤ 290 ng/L. Cobalamin deficiency is clinically significant, and supplementation with parenteral cobalamin is recommended for cats with gastrointestinal disease and low serum cobalamin concentrations.  相似文献   

2.
Hypocobalaminemia in dogs is most commonly associated with gastrointestinal disorders leading to impaired absorption and utilization of cobalamin. The objectives of this study were to compare serum cobalamin concentrations between dogs with leishmaniosis and clinically healthy dogs, and to assess possible alterations of serum cobalamin concentrations in dogs with leishmaniosis at different timepoints during treatment. Fifty-five dogs with leishmaniosis and 129 clinically healthy dogs were prospectively enrolled. Diagnosis of leishmaniosis was based on clinical presentation, positive serology and microscopic detection of Leishmania amastigotes in lymph node aspiration smears. Twenty of the dogs with leishmaniosis were treated with a combination of meglumine antimonate and allopurinol for 28 days and serum cobalamin concentrations were measured in blood samples that were collected before initiation of treatment (timepoint 0) and on days 14 and 28. In order to estimate alterations of serum cobalamin concentrations during treatment, cobalamin concentrations were measured in blood samples from 20 out of 55 dogs with leishmaniosis at all timepoints. Serum cobalamin concentrations were significantly lower in dogs with leishmaniosis before treatment (median: 362 ng/L; IQR: 277−477 ng/L) compared to clinically healthy dogs (median: 470 ng/L; IQR: 367−632 ng/L; P = 0.0035). Serum cobalamin concentrations increased significantly in dogs with leishmaniosis on day 14 of treatment compared to timepoint 0 (P = 0.02).In the present study, serum cobalamin concentrations were significantly lower in dogs with leishmaniosis compared to clinically healthy dogs. In addition, there was an increase in serum cobalamin concentrations during treatment. The clinical significance of hypocobalaminemia in dogs with leishmaniosis remains to be determined.  相似文献   

3.
Objective-To determine reference ranges for serum cobalamin (Cbl), urine methylmalonic acid (uMMA), and plasma total homocysteine (tHcys) concentrations and to compare values for healthy control dogs with values for Border Collies (BCs), a breed in which hereditary cobalamin deficiency has been identified. Animals-113 BCs, 35 healthy control dogs fed a typical diet, and 12 healthy dogs fed a bone and raw food diet exclusively. Procedures-Urine and blood samples were obtained from each dog and Cbl, uMMA, and tHcys concentrations were determined. Results-Reference ranges for Cbl (261 to 1,001 ng/L), uMMA (0 to 4.2 mmol/mol of creatinine), and tHcys (4.3 to 18.4 μmol/L) concentrations were determined. Four BCs had a Cbl concentration lower than the assay detection limit (150 ng/L); median uMMA and tHcys concentrations in these dogs were 4,064 mmol/mol of creatinine and 51.5 μmol/L, respectively. Clinical abnormalities included stunted growth, lethargy, anemia, and proteinuria. Abnormalities improved after administration of cobalamin. Of the 109 healthy BCs with Cbl and tHcys concentrations within reference ranges, 41 (37.6%) had a high uMMA concentration (range, 5 to 360 mmol/mol). Results for dogs fed raw food were similar to those for control dogs. Conclusions and Clinical Relevance-Hereditary cobalamin deficiency is a rare disease with various clinical signs. The finding of methylmalonic aciduria in healthy eucobalaminemic BCs and BCs with clinical signs of Cbl deficiency was surprising and indicated these dogs may have defects in intracellular processing of Cbl or intestinal Cbl malabsorption, respectively. Studies investigating Cbl absorption and metabolic pathways are warranted.  相似文献   

4.
A total of 22,462 serum sample results from dogs being evaluated for gastrointestinal disease at the Gastrointestinal Laboratory, College of Veterinary Medicine, Texas A&M University were evaluated retrospectively. The proportion of dogs with serum cobalamin concentrations below the reference interval and median serum concentrations were compared between Shar Peis and other dog breeds. Serum samples were also obtained prospectively from 22 healthy and 32 Shar Peis with chronic gastrointestinal disease and 59 healthy dogs of other breeds, and serum concentrations of cobalamin, folate, and methylmalonic acid were determined and compared. Overall, 64.0% (89/139) of serum samples from Shar Peis showed serum cobalamin concentrations below the limit of the reference interval and 38.1% (53/139) of these were below the detectable limit for the assay. The median serum cobalamin concentration in Shar Peis was significantly lower than in other breeds. Shar Peis with gastrointestinal disease had significantly lower serum cobalamin and higher serum methylmalonic acid concentrations compared to healthy Shar Peis. Healthy Shar Peis had significantly increased serum methylmalonic acid concentrations compared to healthy dogs of other breeds. There were no meaningful differences in folate concentrations between groups. In conclusion, Shar Peis have a high prevalence of cobalamin deficiency compared to other breeds and healthy Shar Peis may have subclinical cobalamin deficiency.  相似文献   

5.
Domestic cats with small intestinal disease may develop cobalamin deficiency because of reduced small intestinal uptake of this vitamin. This study assessed the impact of cobalamin deficiency on biochemical and clinical findings in cats with intestinal disease. Nineteen pet cats, all with severe hypocobalaminemia (< or =100 ng/L) and histories of gastrointestinal signs, were studied. Cats received cobalamin, 250 microg SC once weekly, for 4 weeks. Biochemical indices of cobalamin availability (e.g., serum methylmalonic acid, homocysteine, and cysteine concentrations), serum feline trypsinlike immunoreactivity (fTLI) and serum folate concentrations, and clinical findings were recorded at the start of the study and after 4 weeks of cobalamin therapy. Serum methylmalonic acid (MMA) concentrations (median; range) decreased after cobalamin supplementation (5373.0; 708.5-29,329.0 versus 423.5; 214.0-7219.0 nmol/L, P < .0001). Serum homocysteine concentrations were not significantly altered (mean +/- SD 8.2 +/- 2.9 versus 10.3 +/- 4.5 micromol/L, P = .1198), whereas cysteine concentrations increased significantly (122.3 +/- 38.8 versus 191.5 +/- 29.4 micromol/L, P < .0001). Mean body weight increased significantly after cobalamin therapy (3.8 +/- 1.1 versus 4.1 +/- 1 kg, P < .01), and the average body weight gain was 8.2%. Significant linear relationships were observed between alterations in serum MMA and fTLI concentrations and the percentage body weight change (P < .05 for both, Pearson r2 = 0.26 and 0.245, respectively). Mean serum folate concentration decreased significantly (mean +/- SD 19 +/- 5 microg/L versus 15.4 +/- 6.2 microg/L, P < .001). Reduced vomiting and diarrhea were observed in 7 of 9 and 5 of 13 cats, respectively. These results suggest that cobalamin supplementation in cats with small intestinal disease and severe hypocobalaminemia is associated with normalization of biochemical test results and improvements in clinical findings in most affected cats.  相似文献   

6.
OBJECTIVE: To validate an automated chemiluminescent immunoassay for measuring serum cobalamin concentration in cats, to establish and validate gas chromatography-mass spectrometry techniques for use in quantification of methylmalonic acid, homocysteine, cysteine, cystathionine, and methionine in sera from cats, and to investigate serum concentrations of methylmalonic acid, methionine, homocysteine, cystathionine, and cysteine as indicators of biochemical abnormalities accompanying severe cobalamin (vitamin B12) deficiency in cats. SAMPLE POPULATION: Serum samples of 40 cats with severe cobalamin deficiency (serum cobalamin concentration < 100 ng/L) and 24 control cats with serum cobalamin concentration within the reference range. PROCEDURE: Serum concentrations of cobalamin were measured, using a commercial automated chemiluminescent immunoassay. Serum concentrations of methylmalonic acid, methionine, homocysteine, cystathionine, and cysteine were measured, using gas chromatography-mass spectrometry, selected ion monitoring, stable-isotope dilution assays. RESULTS: Cats with cobalamin deficiency had significant increases in mean serum concentrations bf methylmalonic acid (9,607 nmol/L), compared with healthy cats (448 nmol/L). Affected cats also had substantial disturbances in amino acid metabolism, compared with healthy cats, with significantly increased serum concentrations of methionine (133.8 vs 101.1 micromol/L) and significantly decreased serum concentrations of cystathionine (449.6 vs 573.2 nmol/L) and cysteine (142.3 vs 163.9 micromol/L). There was not a significant difference in serum concentrations of homocysteine between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE: Cats with gastrointestinal tract disease may have abnormalities in amino acid metabolism consistent with cobalamin deficiency. Parenteral administration of cobalamin may be necessary to correct these biochemical abnormalities.  相似文献   

7.
Lawsonia intracellularis is the causative agent of porcine proliferative enteropathy. The clinical presentation can be acute (i.e. proliferative hemorrhagic enteropathy, PHE), chronic (i.e. porcine intestinal adenomatosis, PIA) or subclinical. In humans with chronic enteropathies, low serum folate (vitamin B9) and cobalamin (vitamin B12) concentrations have been associated with increased serum concentrations of homocysteine and methylmalonic acid (MMA), which reflect the availability of both vitamins at the cellular level. The aim of this study was to evaluate serum folate, cobalamin, homocysteine and MMA concentrations in serum samples from pigs with PHE, PIA or subclinical L. intracellularis infection, and in negative controls. Serum folate, cobalamin, homocysteine and MMA concentrations differed significantly among pigs in the PHE, PIA, subclinical and negative control groups. Serum folate concentrations in the PHE and PIA groups were lower than in the subclinical and negative control groups, while serum cobalamin concentrations were lower in the PIA group than in other groups. Serum concentrations of homocysteine were higher in the PHE, PIA and subclinical groups than in the negative control group. Serum concentrations of MMA were higher in the subclinical and PIA groups than in the control group. These data suggest that pigs infected with L. intracellularis have altered serum cobalamin, folate, homocysteine and MMA concentrations.  相似文献   

8.
Determinations of serum folate and cobalamin concentrations in dogs have proved of considerable value for the identification and characterisation of chronic small intestinal disorders, but the microbiological assays used are time-consuming and technically demanding. Dual isotope radio-assays are more convenient and have been developed for the determination of folate and cobalamin in human beings. This study has evaluated such an assay for the determination of serum folate and cobalamin concentrations in dogs by direct comparison with microbiological assays used previously. Assays were performed on samples from 77 dogs, including controls and animals with confirmed or suspected chronic small intestinal disease. Regression analysis demonstrated a significant relationship between the two assays for serum folate concentrations (R=0–85; P=0–0001) and a definite trend for radioassay to give lower results than bioassay. There was also a significant relationship between bioassay and radioassay data for serum cobalamin (R=0–91; P=0–0001) with comparable absolute values for these two assays. Radioassay of serum samples from 31 clinically healthy dogs gave control ranges of 3–7 to 8-8 4mUg/litre for folate and 205 to 490 ng/litre for cobalamin. These ranges were similar to those calculated by comparison with the established ranges for bioassay using regression analysis, which predicted ranges of 4-4 to 8-4 μg/litre and 217 to 398 ng/litre for radioassay of serum folate and cobalamin, respectively. These data indicate that a dual isotope radioassay of serum folate and cobalamin may be used for dogs, and emphasise the need for laboratories to validate and establish their own control ranges for different assays.  相似文献   

9.
AIM: To derive reference ranges for serum methylmalonic acid (MMA) for the diagnosis of cobalt/vitamin B12-responsiveness in lambs and critique existing serum vitamin B12 reference ranges. METHODS: Individual animal data from earlier supplementation trials, involving 225 ewes, 106 suckling lambs, 301 lambs during the suckling and post-weaning periods and 414 weaned lambs, for which weight gain to supplementation was observed, were used to derive relationships between serum vitamin B12 and MMA, and liveweight gain. RESULTS: Serum MMA concentrations were rarely elevated above the norm of <2 micromol/L when serum vitamin B12 concentrations were >375 pmol/L, and not elevated into the range where a liveweight response to supplementation occurred (>10 micromol/L) unless serum vitamin B12 concentrations were below 200 pmol/L. Suckling lambs were able to maintain high growth rates despite elevated serum MMA concentrations (>20 micromol/L). CONCLUSIONS: The current reference ranges used in New Zealand for serum vitamin B12 are set conservatively high. Serum MMA concentrations appear to allow better differentiation of a responsive condition than vitamin B12 concentrations. Serum MMA concentrations >13 micromol/L indicate responsiveness to supplementation whilst concentrations <7 micromol/L indicate unresponsiveness. In the range 7-13 micromol/L, variation in response was observed and predictability of response is less certain, but supplementation is advisable. CLINICAL RELEVANCE: The current reference ranges for vitamin B12 responsiveness are conservatively high and lead to over-diagnosis of vitamin B12 deficiency in ill-thriftiness of sheep.  相似文献   

10.
The present study sought to determine the spectrum of diseases associated with subnormal concentrations of serum cobalamin in cats undergoing investigation of suspected gastrointestinal problems. The solid-phase boil radioassay (RA) for cobalamin employed in the present study was immunologically specific, precise, and accurate, with a sensitivity of 15 pg/mL. The RA yielded results that strongly correlated with those obtained by bioassay (Spearmann rho = .805; P < .0001), although the absolute values were lower for the RA. Forty-nine of 80 serum samples submitted during the period of January 1996-January 1998 had cobalamin concentrations below the reference range for healthy cats (range 900-2,800 pg/mL; mean +/- SD, 1,775 +/- 535 pg/mL; n = 33). Cats with subnormal cobalamin concentrations (mean +/- SD; 384 +/- 272 pg/mL, range 3-883 pg/mL) were middle-aged or older and were presented for weight loss. diarrhea, vomiting, anorexia, and thickened intestines. Definitive diagnoses in 22 cats included inflammatory bowel disease (IBD), intestinal lymphoma, cholangiohepatitis or cholangits, and pancreatic inflammation. Serum concentrations of cobalamin were particularly low in cats with intestinal lymphoma, three-fifths of whom also had subnormal serum concentrations of folate (< 9 ng/mL). The simultaneous presence of disease in the intestines, pancreas, or hepatobiliary system in many cats made it difficult to determine the cause of subnormal cobalamin concentrations. The circulating half-life of parenteral cyanocobalamin was shorter in 2 cats with IBD (5 days) than in 4 healthy cats (12.75 days). The presence of subnormal serum concentrations of cobalamin in 49 of 80 cats evaluated suggests that the measurement of serum cobalamin may be a useful indirect indicator of enteric or pancreatic disease in cats. The rapid depletion of circulating cobalamin in cats suggests that cats may be highly susceptible to cobalamin deficiency. However, the relationship of subnormal serum cobalamin concentrations to cobalamin deficiency and the effect of cobalamin deficiency on cats remain to be determined.  相似文献   

11.
AIM: To compare serum analyses of vitamin B12 and methylmalonic acid (MMA) as indices of cobalt/vitamin B12 deficiency in lambs around weaning. METHODS: Lambs on five properties, considered to be cobalt- deficient, were supplemented with either cobalt bullets, or short- or long-acting vitamin B12 preparations. Blood samples, and in some cases liver biopsies, and liveweights were obtained at monthly intervals. Serum samples were assayed for vitamin B12 and MMA and liver for vitamin B12 concentrations. Pasture cobalt concentrations were measured on three of the properties. RESULTS: Pasture cobalt concentrations were generally maintained below 0.07 microg/g dry matter (DM) on the properties sampled. Growth responses to supplementation were observed on only 2/5 properties, despite serum vitamin B12 concentrations being within the currently used 'marginal' reference range (336-499 pmol/L) for at least 3 months on all properties and in the deficient reference range (0-335 pmol/L) for at least 2 months on all farms except one. Serum MMA concentrations in supplemented lambs were <2 micromol/L, except in those animals sampled 1 month after receiving treatment with a short-acting vitamin B12 injection. Serum MMA concentrations in unsupplemented animals on properties on which no growth response to supplementation occurred generally reached peak levels of between 4 and 7 micromol/L at the nadir of serum vitamin B12 concentration. When a growth response was observed, differences in weight gain between supplemented and unsupplemented lambs occurred as mean serum MMA concentrations increased from 9 to 14 micromol/L. On one property where supplementation commenced before weaning, normal growth rates were maintained despite serum vitamin B12 concentrations of 140 pmol/L and serum MMA concentrations in excess of 40 micromol/L serum. CONCLUSIONS: The possibility that current serum vitamin B12 references ranges for diagnosis of cobalt deficiency are set too high and lead to over-diagnosis of responsiveness to cobalt/ vitamin B12 supplementation is discussed. The suggestion is made that serum MMA concentrations in excess of 9-14 micromol/L will provide a more reliable diagnostic test for cobalt deficiency. However, there was sufficient variation between properties in the relationships between cobalt concentrations of pasture and serum vitamin B12 or MMA concentrations to require more rigorous testing of the reliability of using serum MMA concentration for this purpose. The possibility that differences in rumen fermentation and therefore propionate and vitamin B12 production could be involved is discussed. The measurement of serum MMA and vitamin B12 appears to be of little value whilst the lamb is still suckling. CLINICAL SIGNIFICANCE: Serum MMA concentration may offer advantages over serum vitamin B12 concentrations in the diagnosis of a cobalt/vitamin B12 responsiveness in weaned lambs.  相似文献   

12.
AIM: To compare serum analyses of vitamin B12 and methylmalonic acid (MMA) as indices of cobalt/vitamin B12 deficiency in lambs around weaning.

METHODS: Lambs on five properties, considered to be cobalt- deficient, were supplemented with either cobalt bullets, or short- or long-acting vitamin B12 preparations. Blood samples, and in some cases liver biopsies, and liveweights were obtained at monthly intervals. Serum samples were assayed for vitamin B12 and MMA and liver for vitamin B12 concentrations. Pasture cobalt concentrations were measured on three of the properties.

RESULTS: Pasture cobalt concentrations were generally maintained below 0.07 μg/g dry matter (DM) on the properties sampled. Growth responses to supplementation were observed on only 2/5 properties, despite serum vitamin B12 concentrations being within the currently used ’marginal‘ reference range (336–499 pmol/L) for at least 3 months on all properties and in the deficient reference range (0–335 pmol/L) for at least 2 months on all farms except one. Serum MMA concentrations in supplemented lambs were <2 μmol/L, except in those animals sampled 1 month after receiving treatment with a short-acting vitamin B12 injection. Serum MMA concentrations in unsupplemented animals on properties on which no growth response to supplementation occurred generally reached peak levels of between 4 and 7 μmol/L at the nadir of serum vitamin B12 concentration. When a growth response was observed, differences in weight gain between supplemented and unsupplemented lambs occurred as mean serum MMA concentrations increased from 9 to 14 μmol/L. On one property where supplementation commenced before weaning, normal growth rates were maintained despite serum vitamin B12 concentrations of 140 pmol/L and serum MMA concentrations in excess of 40 μmol/L serum.

CONCLUSIONS: The possibility that current serum vitamin B12 references ranges for diagnosis of cobalt deficiency are set too high and lead to over-diagnosis of responsiveness to cobalt/ vitamin B12 supplementation is discussed. The suggestion is made that serum MMA concentrations in excess of 9–14 μmol/L will provide a more reliable diagnostic test for cobalt deficiency. However, there was sufficient variation between properties in the relationships between cobalt concentrations of pasture and serum vitamin B12 or MMA concentrations to require more rigorous testing of the reliability of using serum MMA concentration for this purpose. The possibility that differences in rumen fermentation and therefore propionate and vitamin B12 production could be involved is discussed. The measurement of serum MMA and vitamin B12 appears to be of little value whilst the lamb is still suckling.

CLINICAL SIGNIFICANCE: Serum MMA concentration may offer advantages over serum vitamin B12 concentrations in the diagnosis of a cobalt/vitamin B12 responsiveness in weaned lambs.  相似文献   

13.
AIM: To derive reference ranges for serum methylmalonic acid (MMA) for the diagnosis of cobalt/vitamin B12-responsiveness in lambs and critique existing serum vitamin B12 reference ranges.

METHODS: Individual animal data from earlier supplementation trials, involving 225 ewes, 106 suckling lambs, 301 lambs during the suckling and post-weaning periods and 414 weaned lambs, for which weight gain to supplementation was observed, were used to derive relationships between serum vitamin B12 and MMA, and liveweight gain.

RESULTS: Serum MMA concentrations were rarely elevated above the norm of <2 µmol/L when serum vitamin B12 concentrations were >375 pmol/L, and not elevated into the range where a liveweight response to supplementation occurred (>10 µmol/L) unless serum vitamin B12 concentrations were below 200 pmol/L. Suckling lambs were able to maintain high growth rates despite elevated serum MMA concentrations (>20 µmol/L).

CONCLUSIONS: The current reference ranges used in New Zealand for serum vitamin B12 are set conservatively high. Serum MMA concentrations appear to allow better differentiation of a responsive condition than vitamin B12 concentrations. Serum MMA concentrations <13 µmol/L indicate responsiveness to supplementation whilst concentrations <7 µmol/L indicate unresponsiveness. In the range 7–13 µmol/L, variation in response was observed and predictability of response is less certain, but supplementation is advisable.

CLINICAL RELEVANCE: The current reference ranges for vitamin B12 responsiveness are conservatively high and lead to over-diagnosis of vitamin B12 deficiency in ill-thriftiness of sheep.  相似文献   

14.
Recent work has highlighted the importance of cobalamin deficiency in cats with a range of alimentary tract diseases. The primary aim of our study was to determine the incidence of subnormal cobalamin concentrations in sick cats with and without alimentary system disorders. Firstly, serum cobalamin concentrations were measured in a population of cats, with and without gastrointestinal (GI) disease, evaluated at a referral hospital. In the second part of the study, the incidence of cobalamin deficiency was assessed in samples submitted to a commercial laboratory specifically for cobalamin measurement. For both studies, a validated radioimmunoassay was used to measure serum cobalamin concentrations (reference range: > 150 pg/ml). In the first part of the study, 132 cats were included and none of these cats had subnormal cobalamin concentrations (median=1,172; range: 278 to >2,000). There were no differences in cobalamin concentrations between cats with alimentary system disorders, and those with diseases of other organs. In the second part, 682 samples were submitted for cobalamin assay over a period of 3 years, and only one cat had a result below the reference range (median=794; range: 147 to >2,000). Cobalamin deficiency was rare in the population tested and this may suggest that the incidence of this biochemical abnormality is less common than reported in the USA.  相似文献   

15.
Objectives : To determine the prevalence of hypocobalaminaemia in cats with moderate to severe hyperthyroidism and to investigate the relationship between cobalamin status and selected haematologic parameters. Methods : Serum cobalamin concentrations were measured in 76 spontaneously hyperthyroid cats [serum thyroxine (T4) concentration ≥100 nmol/L] and 100 geriatric euthyroid cats. Erythrocyte and neutrophil counts in hyperthyroid cats with hypocobalaminaemia were compared with those in hyperthyroid cats with adequate serum cobalamin concentrations (≥290 ng/L). Results : The median cobalamin concentration in hyperthyroid cats was lower than the control group (409 versus 672 ng/L; P=0·0040). In addition, 40·8% of hyperthyroid cats had subnormal serum cobalamin concentrations compared with 25% of controls (P=0·0336). Weak negative correlation (coefficient: –0·3281) was demonstrated between serum cobalamin and T4 concentrations in the hyperthyroid population, and the median cobalamin concentration was lower in cats with T4 above the median of 153 nmol/L compared with cats with T4 below this value (P=0·0281). Hypocobalaminaemia was not associated with neutropenia or anaemia in hyperthyroid cats. Clinical Significance : This study indicates that a substantial proportion of cats with T4≥100 nmol/L are hypocobalaminaemic and suggests that hyperthyroidism directly or indirectly affects cobalamin uptake, excretion or utilisation in this species.  相似文献   

16.
Disorders of cobalamin (vitamin B12) metabolism are increasingly recognized in small animal medicine and have a variety of causes ranging from chronic gastrointestinal disease to hereditary defects in cobalamin metabolism. Measurement of serum cobalamin concentration, often in combination with serum folate concentration, is routinely performed as a diagnostic test in clinical practice. While the detection of hypocobalaminemia has therapeutic implications, interpretation of cobalamin status in dogs can be challenging. The aim of this review is to define hypocobalaminemia and cobalamin deficiency, normocobalaminemia, and hypercobalaminemia in dogs, describe known cobalamin deficiency states, breed predispositions in dogs, discuss the different biomarkers of importance for evaluating cobalamin status in dogs, and discuss the management of dogs with hypocobalaminemia.  相似文献   

17.
OBJECTIVE: To evaluate serum 17-hydroxyprogesterone (17-OHP) concentration measurement after administration of ACTH for use in the diagnosis of hyperadrenocorticism in dogs. DESIGN: Prospective study. ANIMALS: 110 dogs. PROCEDURE: Serum 17-OHP concentrations were measured before and after ACTH stimulation in 53 healthy dogs to establish reference values for this study. Affected dogs had pituitary-dependent (n = 40) or adrenal tumor-associated (12) hyperadrenocorticism or potentially had atypical hyperadrenocorticism (5; diagnosis confirmed in 1 dog). In affected dogs, frequency interval and borderline and abnormal serum 17-OHP concentrations after ACTH stimulation were determined. Serum cortisol concentrations were assessed via low-dose dexamethasone suppression and ACTH stimulation tests. RESULTS: In healthy dogs, serum 17-OHP concentration frequency intervals were grouped by sex and reproductive status (defined as < 95th percentile). Frequency intervals of serum 17-OHP concentrations after ACTH stimulation were < 77, < 2.0, < 3.2, and < 3.4 ng/mL (< 23.3, < 6.1, < 9.7, and < 10.3 nmol/L) for sexually intact and neutered females and sexually intact and neutered males, respectively. In 53 dogs with confirmed hyperadrenocorticism, serum cortisol concentrations after ACTH stimulation and 8 hours after administration of dexamethasone and serum 17-OHP concentrations after ACTH stimulation were considered borderline or abnormal in 79%, 93%, and 69% of dogs, respectively. Two of 5 dogs considered to have atypical hyperadrenocorticism had abnormal serum 17-OHP concentrations after ACTH stimulation. CONCLUSIONS AND CLINICAL RELEVANCE: Serum 17-OHP concentration measurement after ACTH stimulation may be useful in the diagnosis of hyperadrenocorticism in dogs when other test results are equivocal.  相似文献   

18.
Objectives: Evaluation of dogs with elevated plasma thyroxine concentration fed raw food before and after changing the diet. Method: Between 2006 and 2011 all dogs presented with an elevated plasma thyroxine concentration and a dietary history of feeding raw food were included. Thyroxine (reference interval: 19·3 to 51·5 nmol/L) and in many cases also thyroid-stimulating hormone concentrations (reference interval: <0·30 ng/mL) were measured initially and after changing the diet. Results: Twelve dogs were presented with a median age of five years. The median plasma thyroxine concentration was 156·1 (range of 79·7 to 391·9) nmol/L; in six dogs, thyroid-stimulating hormone concentration was measured and was <0·03 ng/mL in five dogs and 0·05 ng/mL in one dog. Six dogs showed clinical signs such as weight loss, aggressiveness, tachycardia, panting and restlessness while six dogs had no clinical signs. After changing the diet eight dogs were examined: thyroxine concentration normalised in all dogs and clinical signs resolved. Clinical Significance: Dietary hyperthyroidism can be seen in dogs on a raw meat diet or fed fresh or dried gullets. Increased plasma thyroxine concentration in a dog, either with or without signs of hyperthyroidism, should prompt the veterinarian to obtain a thorough dietary history.  相似文献   

19.
Eighty-nine healthy dogs (44 males, 45 females) of different breeds, 1-12 years of age, living under varied feeding and environmental conditions, were sampled to evaluate a reference interval for serum fructosamine using a nitroblue tetrazolium photocolorimetric method. The analytical assay was evaluated by calculation of within-run and between-day variations. The results were approximately normally distributed and the calculated reference interval was 192.6-357.4 µmol/L (mean 275.0 µmol/L, standard deviation 41.2 µmol/L). No significant differences attributable to sex or age were observed. This reference interval is wider than those previously reported in less heterogeneous groups of dogs and in those from other geographical zones. The fructosamine values in serum from 3 diabetic dogs all exceeded the upper limit of the reference interval.  相似文献   

20.
Background: C‐reactive protein (CRP) and cardiac troponin I (cTnI) are biomarkers of systemic inflammation and cardiac damage, respectively. Objective: To investigate the effects of short‐duration high‐intensity exercise on plasma cTnI and serum CRP concentrations in sprint racing sled dogs. Animals: Twenty‐two Alaskan sled dogs of 2 different teams participating in a 2‐day racing event. Methods: In this prospective field study, cephalic venipuncture was performed on all dogs before racing and immediately after racing on 2 consecutive days. Plasma cTnI and serum CRP concentrations were evaluated at each time point. Results: There was a mild, significant rise (P < .01) in median cTnI concentrations from resting (0.02 ng/mL; 0.0–0.12 ng/mL) on both days after racing (day 1 = 0.06, 0.02–0.2 ng/mL; day 2 = 0.07, 0.02–0.21 ng/mL). Serum CRP concentrations showed a mild significant increase (P < .01) on day 2 after racing mean (9.2 ± 4.6 μg/mL) as compared with resting (6.5 + 4.3 μg/mL) and day 1 after racing (5.0 + 2.9 μg/mL). Neither cTnI or CRP concentrations exceeded the upper reference range for healthy dogs. Conclusions and Clinical Relevance: Strenuous exercise of short duration did not result in cTnI concentrations above the reference range for healthy dogs. Although increased after 2 days of short‐duration strenuous exercise, CRP did not reach concentrations suggestive of inflammation, as reported previously in the endurance sled dogs. Therefore, we surmise that moderate exercise does not present a confounding variable in the interpretation of cTnI and CRP concentrations in normal dogs.  相似文献   

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