Arterial blood samples were collected from 19 anesthetized pigs before and after hemorrhage was induced. Blood gas tensions and concentrations of sodium, potassium, chloride, lactate, and total protein were measured. Results indicated that hydrogen ion (H+) concentration calculated from a specific formula was a biased and imprecise estimate of measured H+ concentration. The bias was 5.45 nEq/L, with limits of agreement from -7.92 to 18.83 nEq/L. Because albumin is the fraction of plasma protein most important in acid-base balance, the agreement between predicted and measured H+ concentration was reevaluated, using an albumin charge estimate and a reference swine albumin-to-globulin ratio. This improved the ability of the formula to predict H+ concentration; the bias decreased to 1.33 nEq/L with limits of agreement from -12.16 to 9.49 nEq/L. The formula and a simplified approach for clinical application were biased and unacceptably imprecise estimators of lactate (L-) concentration. The formula approach underestimated L- concentration by 2.8 (-12.4, 6.7) mEq/L, whereas the simplified method overestimated L- concentration by 5.0 (-3.8, 13.9) mEq/L.

Packed cell volume and plasma total protein (TP), serum albumin (Alb) and globulin (Glb), and plasma ionized calcium (PCa) concentrations, blood viscosity (BV), and plasma viscosity (PV) were measured in 42 horses at rest and after the cross country jumping phase of a horse trial competition. The BV and Pv were determined at 6 shear rates (230, 115, 46, 23, 11.5, 5.75 s 1), using a digital rotational cone and plate microviscometer. A paired t-test was used to determine differences between PCV, TP, Alb, Glb and PCa values at rest and after exercise. The PCV, TP, Alb, and Glb values increased (P < 0.05) in horses after exercise. The PCa concentration decreased (P < 0.05) in horses after exercise. Mean BV and Pv in the 42 horses at rest and after exercise were fitted to an asymptotic function. Significant (P < 0.05) correlation at aH shear rates was seen between BV at rest and PCV, TP, Alb, Glb, and PCa values at rest; and between BV after exercise and PCV, TP, Alb, Glb, and PCa values after exercise. Significant correlation was not seen between PV at rest and TP, Alb, Glb, and PCa at rest, or between PV after exercise and TP, Alb, Glb, and PCa concentrations after exercise at any shear rate.

Foremilk, residual milk, and blood samples were studied for 10 days during acute mastitis episodes induced by endotoxin infused via the teat canal. Quarter milk and blood samples were collected frequently for 3 days after the infusion and thereafter once or twice daily. Leukocyte concentration in milk and blood was determined by flow cytometry. Within 2 hours after infusion of the endotoxin, clinical mastitis was observed. Total leukocyte concentration and proportion of neutrophils increased significantly (P < 0.05) by postinfusion hour (PIH) 2 in foremilk and by PIH 4 in residual milk. From PIH 2, serum albumin content and N-acetyl-beta-D-glucosaminidase activity were significantly increased in both fractions. Neutrophils were the predominant leukocyte population in both fractions until PIH 59. From PIH 72, lymphocytes were the predominant cell population until PIH 175 in foremilk and until PIH 223 in residual milk. Serum albumin content and N-acetyl-beta-D-glucosaminidase activity in residual milk was significantly lower than in foremilk from PIH 4 to 24 and from PIH 24 to 59, respectively. Regarding total and differential leukocyte counts, values for the 2 fractions followed the same pattern throughout the course of inflammation, probably owing to frequent sample collection. Total and differential cell counts tended to differ between the fractions during some periods, although differences were not statistically significant. When samples were taken less frequently, the total leukocyte concentration in residual milk was higher than that in foremilk. Although sample collections were frequent, clustering of immature neutrophils was not observed in the cytofluorogram of blood leukocytes in this study. Residual milk seems to be the fraction that best reflects the condition in the quarter at the particular time when the milk sample is taken. Results also indicate that residual milk reflects the condition of the secretory tissue, as well as the lower regions of the gland.

To determine the effects of long-term dietary protein restriction in cats with chronic renal failure (CRF), 4 healthy adult cats and 7 cats with surgically induced CRF were fed a high-protein (HP, 51.7% protein) diet and 4 healthy adult cats and 7 cats with surgically induced CRF were fed a low-protein (LP, 27.6% protein) diet for 1 year. Cats with induced CRF that were fed the LP diet had reduced serum urea nitrogen concentrations, despite lower glomerular filtration rates, compared with cats with CRF fed the HP diet. Despite five-sixths reduction in renal mass, reduced glomerular filtration rate, and azotemia, 13 of the 14 cats with induced CRF retained the ability to concentrate urine and produced urine with a specific gravity > 1.035. Cats fed the HP diet consumed significantly more calories than did cats fed the Lp diet, presumably because the HP diet was more palatable. As a result of the lower caloric intake in cats fed the LP diet, these cats were protein and calorie restricted, compared with cats fed the HP diet. Cats fed the HP diet weighed significantly more than did cats fed the LP diet. Mean hematocrit and mean serum albumin concentration ere significantly lower in control cats and in cats with CRF fed the LP diet, compared with control cats and cats with CRF fed the HP diet. Hypokalemia developed in 4 of 7 cats with CRF fed the HP diet (containing 0.3% potassium); hypokalemia did not develop in control cats fed the same diet or in cats with CRF fed the LP diet containing 0.4% potassium. Excessive kaliuresis, hypomagnesemia, and metabolic acidosis did not appear to contribute to the hypokalemia. Subsequent supplementation of the HP diet with potassium gluconate prevented hypokalemia in cats with CRF.

Amino acid profiles and serum albumin and serum total protein concentrations were evaluated in dogs with renal disease. Nine dogs ranging in age from 1 to 15 years were identified as having mild to moderate chronic renal failure (CRF; exogenous creatinine clearance, 0.5 to 2.13 ml/kg of body weight/min). These dogs and a group of 10 clinically normal control dogs were fed a diet containing 31% protein for 8 weeks, at which time serum and urine amino acid assays and clearance studies were performed. All dogs then were fed a diet containing 16% protein for 8 weeks and then reevaluated. Chronic renal failure was associated with mild abnormalities in serum concentrations of amino acids. When fed the higher protein diet, dogs with CRF had lower serum concentrations of glutamine, leucine, proline, and serine and higher serum concentrations of cystathionine and 3-methylhistidine than clinically normal control dogs. When fed the low protein diet, dogs with CRF had lower serum serine concentrations and higher serum concentrations of cystathionine, phenylalanine, and 3-methylhistidine. Urine excretion of amino acids in all dogs on both diets was low, and dogs with CRF had lower renal clearances of 3-methylhistidine than control dogs. There were no significant differences in concentrations of serum albumin and total solids between either group, regardless of diet. We concluded that dogs with mild to moderately severe CRF have mild abnormalities of serum free amino acid concentrations, but renal conservation of essential amino acids is not impaired.

Hepatic abscesses were induced experimentally in 5 steers by inoculating Fusobacterium necrophorum via ultrasonography-guided, percutaneous catheterization of the portal vein. Hepatic ultrasonography was performed to determine the onset and progression of abscessation. Blood samples were collected before and after inoculation for performing leukocyte counts and hepatic function tests. Ultrasonographic evidence of liver abscesses was observed as early as 3 days after inoculation. Abscesses appeared as hyperechoic centers (cellular debris and pus) surrounded by hypoechoic or anechoic areas (fluid). Increases in rectal temperature, leukocyte counts, fibrinogen, globulin, bilirubin, gamma-glutamyltransferase, and sorbitol dehydrogenase concentrations were detected. Hepatic dysfunction was evidenced by decrease in serum albumin concentration and low sulfobromophthalein clearance. The ultrasonographic diagnosis of abscesses correlated well with necropsy findings.

Mastitis was induced in 4 lactating cows by inoculation of Klebsiella pneumoniae (10(7) organisms/ml) via the teat canal. Sterile isotonic saline solution (1 ml) was instilled into designated control quarters via the teat canal. Changes in milk leukotriene B4 and C4 (LTB4, LTC4) concentrations, milk somatic cell counts, and milk bovine serum albumin concentration were monitored over a 24-hour postinoculation period. Milk LTB4 concentration before inoculation in control quarters and quarters later to be infected was 376 +/- 45 and 326 +/- 56 pg/ml of milk, respectively. A significant (P less than 0.05) increase in milk LTB4 concentration in the infected quarters was first observed at postinoculation hour 6, and milk LTB4 concentration in infected quarters generally remained significantly high through postinoculation hour 14. Thereafter, milk LTB4 concentration in infected quarters was not significantly different from the concentration in control quarters. Measurable amounts of LTC4 were not detected in the milk of either control or infected quarters. Milk bovine serum albumin concentration in the infected quarters generally was high throughout the study, as were milk somatic cell counts. The results of this study suggested that LTB4 contributes to the pathogenesis of bovine mastitis.

OBJECTIVE To investigate effects of exercise on hematologic and biochemical values (especially markers of inflammation and muscle damage) in Spanish Greyhounds used for hunting without previous training. ANIMALS 32 Spanish Greyhounds and 31 dogs of other breeds. PROCEDURES Hematologic variables and concentrations of C-reactive protein (CRP) and other biochemical markers were compared in samples obtained from Spanish Greyhounds 24 hours after exercise (eg, a hunting race) and 2 months after exercise (ie, at rest) and from non–Spanish Greyhounds at rest. All dogs were healthy. Hematologic and biochemical analyses were performed within 24 hours after samples were obtained, and results were compared by means of a Student t test. RESULTS CRP concentration and muscle enzyme (creatine kinase, lactate dehydrogenase, and aspartate aminotransferase) activities were significantly higher and serum iron concentration was significantly lower for Spanish Greyhounds after exercise than at rest. The WBC and neutrophil counts were significantly higher after exercise then at rest. Plasma alanine transaminase activity and total protein, calcium, and phosphorus concentrations were significantly higher after exercise than at rest. Spanish Greyhounds at rest had higher RBC counts, PCVs, and hemoglobin concentrations and lower WBC, neutrophil, and lymphocyte counts, compared with values for non–Spanish Greyhounds at rest. CONCLUSIONS AND CLINICAL RELEVANCE Exercise of Spanish Greyhounds without prior training activated an acute-phase response represented by an increase in serum CRP concentration and decrease in serum albumin and iron concentrations. These changes, along with leukocytosis and neutrophilia, were indicative of a subclinical inflammatory state in Spanish Greyhounds.

Objective-To investigate effects of intramammary administration of prednisolone on the immune response of mammary glands in cows. Animals- 5 lactating Red Holsteins. Procedures- Cows received a different intramammary infusion in each mammary gland (10 mg of prednisolone, 100 μg of lipopolysaccharide [LPS], 100 μg of LPS and 10 mg of prednisolone, or saline [0.9% NaCl] solution). Milk samples were collected before (time 0) and 3, 6, 9, 12, 24, and 36 hours after treatment. Somatic cell count (SCC), lactate dehydrogenase (LDH) activity, and concentrations of serum albumin (SA) and tumor necrosis factor (TNF)-α in milk and mRNA expression of TNF-α, interleukin (IL)-8, and IL-1β in milk somatic cells were analyzed. Results-Saline solution or prednisolone did not change SCC, LDH activity, and SA and TNF-α concentrations in milk and mRNA expression of TNF-α, IL-1β, and IL-8 in milk somatic cells. The SCC and TNF-α concentration in milk increased similarly in glands infused with LPS, independent of prednisolone administration. However, the increase of LDH activity and SA concentration in milk after LPS infusion was diminished by prednisolone administration. The mRNA expression of TNF-α, IL-8, and IL-1β in milk somatic cells increased after LPS infusion and was unaffected by prednisolone. Conclusions and Clinical Relevance- Intramammary administration of prednisolone did not induce an immune response and did not change mRNA expression of TNF-α, IL-8, and L-1β during the response to intramammary administration of LPS. However, prednisolone reduced disruption of the blood-milk barrier. This could influence the severity and cure rate of mastitis.

Objective-To characterize systemic immune responses in Cytauxzoon felis-infected cats. Sample-Blood and lung samples obtained from 27 cats. Procedures-Cats were allocated into 4 groups: cats that died of cytauxzoonosis, acutely ill C felis-infected cats, healthy survivors of C felis infection, and healthy uninfected cats. Serum concentrations of tumor necrosis factor-α and interleukin-1 β were measured and serum proteins characterized. Blood smears were stained immunocytochemically and used to assess immunoglobulin deposition. Immunohistochemical expression of CD18 and tumor necrosis factor-α were compared in lung tissues obtained from cats that died and healthy uninfected cats. A real-time reverse-transcription PCR assay for CD18 expression was performed on selected blood samples from all groups. Results-Concentrations of both cytokines were greater and serum albumin concentrations were significantly lower in cats that died of cytauxzoonosis, compared with results for all other groups. Erythrocytes from acutely ill cats and survivors of C felis infection had staining for plasmalemmal IgM, whereas erythrocytes from the other groups did not. Increased staining of C felis-infected monocytes and interstitial neutrophils for CD18 was detected. The real-time reverse-transcription PCR assay confirmed a relative increase in CD18 expression in cats that died of cytauxzoonosis and acutely ill cats, compared with expression in other groups. Immunostaining for TNF-α in lung samples confirmed a local proinflammatory response. Conclusions and Clinical Relevance-Results indicated immunopathologic responses were greater in cats that died of C felis infection than in cats that survived C felis infection.