Renal mass was surgically reduced in 78 dogs by uninephrectomy or by combined renal infarction and uninephrectomy. Renal clearance of inulin and renal clearance of exogenous creatinine were determined simultaneously, and the creatinine to inulin clearance (C/I) ratio was calculated. Clearance procedures were performed 2 to 3 months after reduction of renal mass, and were repeated at intervals thereafter. Overall, the C/I ratio was 1.008 +/- 0.007 for 192 determinations, with a highly significant correlation (R2 = 0.994, P < 0.0001) between creatinine clearance and inulin clearance. There was no significant effect of gender of dogs, time after partial renal ablation, or dietary protein intake on C/I ratios. Degree of renal ablation did not affect C/I ratios. The results indicated that exogenous creatinine clearance is a valid measure of glomerular filtration rate in both male and female dogs with reduced renal mass.

Excretion of creatinine, sodium sulfanilate (SS), and phenolsulfonphthalein (PSP) was studied in healthy goats. In conscious goats, mean (+/- SEM) inulin clearance was 2.26 +/- 0.08 ml/min/kg of body weight. Endogenous creatinine clearance, 1.97 +/- 0.09 ml/min/kg, underestimated inulin clearance (P < 0.01), probably because of the presence of noncreatinine chromogens in caprine plasma. The estimated renal clearance of PSP was 6.88 +/- 0.39 ml/min/kg, whereas the estimated renal clearance of SS was 3.71 +/- 0.39 ml/min/kg. Both exceeded inulin clearance (P < 0.01), confirming renal tubular secretion of both compounds. In 6 anesthetized goats, exogenous creatinine clearance and SS clearance exceeded inulin clearance (P < 0.05). Results of stop-flow experiments documented secretion of creatinine and ss by the peoximal portion of the caprine nephron. Plasma half-life of PSP in uninephrectomized goats exceeded that in intact goats (20.2 +/- 1.5 min vs 11.9 +/- 0.7 min; P < 0.01). Similarly, plasma half-life of SS was greater in goats after uninephrectomy (58.2 +/- 6.2 min vs 30.4 1.2 min; p < 0.01).

Three methods of determining glomerular filtration rate (GFR) were performed in adult ferrets, 9 months to 7 years old. Endogenous creatinine clearance was determined, using serum and urine creatinine values obtained during 24- and 48-hour collection periods from 27 ferrets housed in metabolic cages. Creatinine and radiolabeled inulin were administered to 12 female ferrets by constant IV infusion during isoflurane-induced anesthesia. Serial 20-minute urine collections, together with serum samples obtained at the midpoint of urine collection, provided measures for clearance calculations of these substances. Mean +/- SD endogenous creatinine clearance in ferrets for metabolic cage collections was 2.50 +/- 0.93 ml/min/ kg of body weight. There were no significant differences between the 24- and 48-hour clearance rates. Mean inulin clearance was 3.02 +/- 1.78, and mean exogenous creatinine clearance was 3.32 +/- 2.16 ml/ min/kg. Analysis of variance, using least-squared means adjustment, did not yield any significant differences between inulin and exogenous creatinine clearance rates. Exogenous creatinine clearance-to-inulin clearance ratio was 0.99 +/- 0.46, and there was significant correlation between the 2 methods (r = 0.82, P = 0.0001). Significant body temperature effects on inulin or exogenous creatinine clearance were not found. Infused inulin clearance, the generally preferred method for GFR calculation in mammalian species, was significantly (P = 0.0069) higher in younger (3.65 ml/min/kg) vs older ferrets (2.29 ml/min/kg). Results of this study indicate that inulin clearance is an adequate measure of GFR in ferrets as it is in other species. Compared with inulin clearance, exogenous creatinine clearance also provides a reliable estimate of GFR in ferrets.

Renal clearance procedures were performed on adult mixed-breed dogs with a wide range of renal function. Endogenous creatinine clearance was computed after analyzing plasma and urine for creatinine by use of 2 methods, PAP and kinetic Jaffe. For 20-minute clearance procedures, [14C]inulin clearance was measured simultaneously with endogenous creatinine clearance. For 111 twenty-minute clearance procedures performed on 24 dogs, [14C]inulin clearance was highly correlated with creatinine clearance for both methods of creatinine analysis (R2 = 0.979 for [14C]inulin-PAP; R2 = 0.943 for [14C]inulin-Jaffe). The absolute values for PAP and [14C]inulin clearance were nearly the same (PAP-to-[14C]inulin clearance ratio = 1.03 +/- 0.08), but those for Jaffe clearance were substantially less than those for [14C] inulin clearance Jaffe-to-[14C]inulin clearance ratio = 0.88 +/- 0.10). The Jaffe-to-[14C] inulin clearance ratio was inversely correlated with degree of renal function (R2 = 0.464), whereas the PAP-to-[14C]inulin clearance ratio was not correlated with degree of renal function (R2 = 0.060). Thus, Jaffe-determined creatinine clearance varied, in relation to [14C] inulin clearance, depending on degree of renal function. In 4 clinically normal dogs, 20-minute and 24-hour sample collections analyzed by use of the PAP method gave clearance values significantly greater, for both periods, than did Jaffe analyses. The PAP-determined creatinine clearance values were less than, but not significantly different from 20-minute exogenous creatinine clearance values determined 10 days after 24-hour collections. For 20-minute and 24-hour collections, the difference in clearance values between the PAP and Jaffe methods was attributable mostly to lower plasma creatinine values for the PAP method (mean +/- SEM, plasma PAP-to-Jaffe ratio = 0.798 +/- 0.053). However, urine creatinine values also were less by use of the PAP method.

Two diets similar in caloric density and mineral content, but markedly different in protein content, were used to study the effects of dietary protein on renal function and morphologic and histopathologic changes in dogs that had functional renal tissue reduced by seven-eighths nephrectomy. The effects of moderate protein intake (MPrI = 15% protein; dry-matter basis) and high-protein intake (HPrI = 31% protein; dry-matter basis) were studied for the initial 7 months (period 1 [P1]) after renal mass reduction. Diets were then switched between groups during the following 7 months (period 2 [P2]) to evaluate the effects of increased or decreased protein intake. The HPrI caused significantly (P < 0.05) greater glomerular filtration rate (GFR) and renal growth than did MPrI during P1. Dogs that maintained HPrI during P1 and MPrI during P2 (group 1) had significant (P < 0.05) reduction in GFR during P2. Dogs that maintained MPrI during P1 and HPrI during P2 (group 2) had significant (P < 0.05) improvement in GFR and renal growth during P2. At the end of the study, renal reserve was evaluated in both groups of dogs before and after group 1 was returned to HPrI for 2 weeks. During this 2-week feeding trial, group-1 dogs had marked improvement in renal reserve, relative to group 2, and GFR increased to the terminal P1 values. Results indicate a possible residual benefit from HPrI during the early phase of compensatory renal growth in the form of functional compensatory memory to HPrI. The severity of renal lesions was indistinguishable between dogs of dietary groups during both study phases. Plasma electrolyte concentrations rapidly returned to normal range after renal ablation, but mild azotemia and proteinuria persisted throughout most of the study. High protein intake was not associated with increased degree or progression of proteinuria.

Achyranthes japonica Nakai (A. japonica) is a medicinal herb found widely distributed throughout Korea. The biological activities of A. japonica are well-documented and include anti-fungal, anti-inflammatory, and immunity enhancement. The objective of the present study was to investigate the immune-related activities of A. japonica extract in dogs. The extract was acquired by ethanol extraction and purified by filtration. To examine the effect of A. japonica extract on immune cell viability, human lymphocytes, such as Jurkat T-cells and Ramos B-cells, were exposed to the extract. After treatment with the extract, the number of Ramos B-cells was increased, whereas Jurkat T-cells remained unaffected. Griess assay revealed decreased nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated mouse macrophage Raw 264.7 cells after exposure to A. japonica extract. To evaluate the in-vivo effect in dogs, feed containing A. japonica extract was provided to 8 dogs for 2 months. Blood samples were collected before, during, and after consumption of the feed. Peripheral blood mononuclear cells (PBMCs) were isolated from the blood samples and the number of T-cells and B-cells were assessed using flow cytometry with anti-dog fluorescein isothiocyanate (FITC)-conjugated CD3 and anti-dog phycoerythrin (PE)-conjugated CD21 antibodies, respectively. We observed a significant increase in the average number of B-cells in the PBMCs during ingestion of the feed containing A. japonica. In addition, enzyme-linked immunosorbent assay (ELISA) revealed a decrease in the levels of tumor necrosis factor-alpha (TNF-α), a pro-inflammatory cytokine, in 3 out of 8 dogs and increased levels of interleukin-10 (IL-10), an anti-inflammatory cytokine, in 4 out of 8 dogs. Taken together, we believe that these changes indicate that A. japonica extract is beneficial in improving the immunity of dogs by stimulating B-cells and inducing production of anti-inflammatory responses.

OBJECTIVE To evaluate canine erythrocyte concentrates (ECs) for the presence of procoagulant phospholipid (PPL), determine whether PPL concentration changes during the course of storage of ECs, and ascertain whether prestorage leukoreduction (removal of leukocytes via gravity filtration) reduces the development of PPL. SAMPLE 10 whole blood units (420 g each) collected from 10 random-source, clinically normal dogs (1 U/dog). PROCEDURES The dogs were randomized to 1 of 2 groups. Of the 10 whole blood units collected, 5 were processed through a standard method, and 5 underwent leukoreduction. Whole blood units were processed to generate ECs, from which aliquots were aseptically collected from each unit weekly for 5 weeks. Supernatants from the concentrates were evaluated for procoagulant activity, which was converted to PPL concentration, by use of an automated assay and by measurement of real-time thrombin generation. RESULTS Supernatants from stored canine ECs contained procoagulant activity as measured by both assays. In general, the PPL concentration gradually increased during the storage period, but leukoreduction reduced the development of increased procoagulant activity over time. CONCLUSIONS AND CLINICAL RELEVANCE The presence of PPL in canine ECs may be associated with procoagulant and proinflammatory effects in vivo, which could have adverse consequences for dogs treated with ECs.

Objective-To compare the recovery rates of Campylobacter fetus subsp venerealis (Cfv) from preputial scrapings of infected bulls with passive filtration on selective medium versus nonselective medium, with and without transport medium. Samples-217 preputial scrapings from 12 bulls (4 naturally and 8 artificially infected with Cfv). Procedures-Preputial scrapings were collected in 2 mL of PBS solution and bacteriologically cultured directly on Skirrow medium or passively filtered through 0.65-μm filters onto blood agar, with or without 24 hour preincubation in modified Weybridge transport enrichment medium (TEM). After 72 hours, plates were examined for Cfv and bacterial and fungal contamination or overgrowth. Results-Passive filtration of fresh preputial scrapings onto blood agar yielded significantly higher recovery rates of Cfv (86%) than direct plating on Skirrow medium (32%), whereas recovery from TEM was poor for both media (35% and 40%, respectively). Skirrow cultures without TEM were significantly more likely to have fungal contamination than were cultures performed with any other technique, and fungal contamination was virtually eliminated by passive filtration onto blood agar. Bacterial contamination by Pseudomonas spp was significantly more common with Skirrow medium versus passive filtration on blood agar, regardless of TEM use. Conclusions and Clinical Relevance-The use of transport medium and the choice of culture medium had significant effects on Cfv recovery and culture contamination rates from clinical samples. Both factors should be considered when animals are tested for this pathogen.

Microvascular permeability characteristics were evaluated in digits of 7 adult horses. After capillaries were isolated and an extracorpeal perfusion circuit for the digit was established, a lymphatic vessel draining the distal portion of the phalangeal region was cannulated at the level of the coronary band. Venous pressure was increased in a stepwise manner, and lymph flow, lymph protein concentration (Cl), and plasma protein concentration (Cp) were determined after measured variables were allowed to reach steady state. Lymph-to-plasma protein concentration ratios (Cl/Cp) and lymph and plasma oncotic pressures were determined from samples collected during steady state. The osmotic reflection coefficient was determined after Cl/Cp became constant, regardless of increasing lymph flow, and was expressed as 1 - Cl/Cp. The osmotic reflection coefficient for the digit was 0.67. Seemingly, the microvasculature bed of the digit was relatively permeable and could maintain only 67% of the endogenous macromolecules within the vasculature.