TABLE 8.

Results of logistic regression models examining the association of serum urea nitrogen and creatinine concentrations, UCR, Hb, Hct, MCV, and MCHC and upper GIB compared to lower GIB in dogs

	n	Odds ratio	95% CI	P value
Urea nitrogen (mg/dL)	50	0.99 a	0.94‐1.04	.61
Creatinine (mg/dL)	50	0.37 a	0.05‐2.70	.33
UCR	50	1.01 a	0.95‐1.07	.79
		1.01 b	0.95‐1.06	.82
		1.02 c	0.95‐1. 09	.60
Hb (g/L)	45	1.01 a	0.99‐1.03	.26
Hct (L/L)	47	27.17 a	0.09‐8237	.26
MCV (fL)	46	1.03 a	0.95‐1.12	.44
		1.01 d	0.93‐1.09	.89
MCHC (g/L)	45	1.00 a	0.97‐1.03	.89

Note: Thirty‐seven dogs were diagnosed with upper and 13 with lower GIB. Upper GIB was defined as hemorrhage orad to the ligament of Treitz (duodenojejunal junction). Results for Hb and MCHC were available from 45 dogs (upper GIB, 32; lower GIB, 13). MCV was measured in 46 dogs (upper GIB, 33; lower, 13), and Hct in 47 dogs (upper GIB, 34; lower GIB, 13). Confounding effects of age and presence of overt GIB were assessed for all variables. Additionally, confounding effects of weight were assessed for serum creatinine concentration and UCR, and the presence of anorexia and weight loss for serum urea nitrogen and creatinine concentrations, and UCR. If the inclusion of the covariates resulted in a ≥20% change in the coefficient of the independent variable, the adjusted odds ratio was reported.

Abbreviations: CI, confidence interval; GIB, gastrointestinal bleeding; Hb, hemoglobin; Hct, hematocrit; MCHC, mean corpuscular hemoglobin concentration; MCV, mean corpuscular volume; n, sample size; UCR, urea nitrogen/creatinine ratio.

^aAdjusted odds ratio after inclusion of type of GIB (overt vs occult) as covariate.

^bAdjusted odds ratio after inclusion of weight as covariate.

^cAdjusted odds ratio after inclusion of presence of anorexia as covariate.

^dAdjusted odds ratio after inclusion of presence of age as covariate.