Proksch Anna-Lena, Schaefer Sophia, Dreller Vanessa, Langenstein Judith, Fingerhut Ralph, Bauer Natali, Moritz Andreas
Clinic for Small Animals, Internal Medicine, JLU Giessen, Frankfurter Strasse 114, Giessen 35392, Germany.
Antech Lab Germany GmbH, Gubener Str. 39, Augsburg 86156, Germany.
J Vet Intern Med. 2025 Jan-Feb;39(1):e17250. doi: 10.1111/jvim.17250.
In dogs, data on reference intervals (RIs) for cobalamin, markers of metabolism (markersBmet), age and sex effects are limited.
HYPOTHESIS/OBJECTIVES: Establish RI for serum cobalamin, homocysteine, and methylmalonic acid (sMMA) concentrations, urinary methylmalonic acid-to-creatinine ratio (uMMA:crea), and determine effects of sex and age.
Prospective study using healthy dogs (1-10 years). Cobalamin and markersBmet were determined using chemiluminescence immunoassay (cobalamin) and liquid chromatography/tandem mass spectrometry (homocysteine, sMMA, uMMA:crea). In dogs with outlying data, changes in health, markersBmet, and onset of gastrointestinal signs were reevaluated after 9-15 months.
Twelve of 120 healthy dogs had abnormal uMMA:crea ratios. No other cobalamin analyte outliers were found. Outlying data re-examination (odRE) was performed in 10/12 dogs. Chronic gastrointestinal signs occurred in 64% of odRE-dogs, whereas 36% remained healthy. In total, 112 dogs (67 females, 45 males; median ages, 3.5 and 3.75 years, respectively) were included in RI analyses. Reference intervals were 178.5-851 pmol/L (cobalamin), 5.8-29.0 μmol/L (homocysteine), 45.3-159.5 μg/L (sMMA), and ≤22.4 mg/g (uMMA:crea). Only age affected cobalamin concentrations (significant decrease). Compared by sex and neuter status, intact male dogs had significantly higher uMMA:crea ratios (median, 13.5; range, 1.9-83.6 mg/g) than the other groups (median, 2.5; range, 0.7-9.7 mg/g; P < .0001). Sex-specific RI were ≤58.9 mg/g (intact male) vs ≤5.2 mg/g (females and neutered males).
Intact male dogs had significantly higher uMMA:crea ratios than the other groups. Thus, sex-specific RI are recommended for uMMA:crea. Because of the wide distribution of uMMA:crea ratios, careful interpretation in intact male dogs is advised.
关于犬钴胺素、代谢标志物、年龄和性别影响的参考区间（RI）数据有限。
假设/目的：建立血清钴胺素、同型半胱氨酸和甲基丙二酸（sMMA）浓度、尿甲基丙二酸与肌酐比值（uMMA:crea）的RI，并确定性别和年龄的影响。
对健康犬（1 - 10岁）进行前瞻性研究。使用化学发光免疫分析法（钴胺素）和液相色谱/串联质谱法（同型半胱氨酸、sMMA、uMMA:crea）测定钴胺素和代谢标志物。对数据异常的犬，在9 - 15个月后重新评估健康状况、代谢标志物和胃肠道症状的发作情况。
120只健康犬中有12只uMMA:crea比值异常。未发现其他钴胺素分析物异常值。对12只犬中的10只进行了异常数据重新检查（odRE）。odRE犬中64%出现慢性胃肠道症状，而36%保持健康。总共112只犬（67只雌性，45只雄性；中位年龄分别为3.5岁和3.75岁）纳入RI分析。参考区间为178.5 - 851 pmol/L（钴胺素）、5.8 - 29.0 μmol/L（同型半胱氨酸）、45.3 - 159.5 μg/L（sMMA）和≤22.4 mg/g（uMMA:crea）。仅年龄影响钴胺素浓度（显著降低）。按性别和去势状态比较，未去势雄性犬的uMMA:crea比值（中位数为13.5；范围为1.9 - 83.6 mg/g）显著高于其他组（中位数为2.5；范围为0.7 - 9.7 mg/g；P <.0001）。性别特异性RI为≤58.9 mg/g（未去势雄性）对≤5.2 mg/g（雌性和去势雄性）。
未去势雄性犬的uMMA:crea比值显著高于其他组。因此，建议对uMMA:crea采用性别特异性RI。由于uMMA:crea比值分布广泛，建议对未去势雄性犬进行仔细解读。
