Clinical availability of urinary N-acetyl-beta-D-glucosaminidase index in dogs with urinary diseases

Urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) was examined in healthy dogs and dogs with urinary diseases, and its clinical usefulness as an indicator of urinary diseases was discussed. Twenty-eight healthy dogs and 20 dogs with urinary diseases were used. Urinary NAG activity was measured using p-nitrophenyl N-acetyl-beta-D-glucosaminide as substrate, and expressed as units per gram of urinary creatinine (NAG index). Urinary NAG index in urine of healthy dogs was 3.2+/-2.4 U/g, and NAG index in the dogs with chronic renal failure or lower urinary tract infection accompanied by pyelonephritis was higher than that in healthy dogs. However, the dogs with lower urinary tract infection without pyelonephritis showed normal values of NAG index. Some dogs with diabetic mellitus showed elevated values of NAG index when control of blood sugar was not successful. Increase of NAG index was observed in some dogs with pyometra before increases of BUN and serum creatinine concentration. Therefore, NAG index in urine seems to be a good indicator for urinary diseases in dogs.     

Urinary transforming growth factor-beta1 in feline chronic renal failure

Transforming growth factor-beta1 (TGF-beta1), an inflammatory cytokine, plays a role in tissue fibrosis, such as glomerular sclerosis and tubulointerstitial fibrosis of the kidneys. In the present study, the urinary TGF-beta1 level of cats diagnosed with chronic renal failure (CRF) was measured to investigate its relationship to the pathogenesis of feline CRF. Urinary TGF-beta1 levels (TGF-beta1/creatinine ratio) were significantly increased compared with healthy controls, whereas serum levels of TGF-beta1 were not. These results indicate that TGF-beta1 is expressed in the kidneys of CRF cats, and that it was reflected in the urinary TGF-beta1 level. Therefore, TGF-beta1 may play a role in feline CRF, and urinary TGF-beta1 could be used as a clinical marker for renal fibrosis.     

Electrophoretic fractionation of creatine kinase isoenzymes and macroenzymes in clinically healthy dogs and cats and preliminary evaluation in central neurologic disease

Background: Information about the electrophoretic distribution of CK‐MM, CK‐MB, and CK‐BB, serum creatine kinase (CK) isoenzymes that are indicators of skeletal muscle, cardiac muscle, and brain lesions, respectively, and CK macroenzymes (macro‐CK1 and macro‐CK2) in dogs and cats with and without central neurologic disease is scant and equivocal. Objectives: The objectives of this study were to describe the electrophoretic distribution of CK isoenzymes and macroenzymes in healthy dogs and cats and to provide a preliminary assessment of the utility of CK enzymatic electrophoresis in dogs and cats with central neurologic disease. Methods: Electrophoretic separation of serum CK isoenzymes and macroenzymes was performed on freeze‐thawed serum samples from 20 healthy dogs and 3 dogs with central neurologic disease and from 14 healthy cats and 6 cats with neurologic feline infectious peritonitis (FIP). Electrophoretic separation was also performed on supernatants of homogenized brain, skeletal muscle, and cardiac muscle from both species, to assess the tissue distribution of isoenyzmes in dogs and cats. Results: CK‐MM was the predominant isoenzyme in the serum of healthy dogs and cats, followed by macro‐CK2 and CK‐BB in dogs and by both macroenzymes in cats. In dogs, CK‐MB was essentially absent from both serum and homogenized hearts. CK‐BB increased in dogs with neurologic disease. In cats, CK‐BB was essentially absent from serum, but was present in brain homogenates. Two of 6 cats with FIP had increased macro‐CK1 and increased CK‐BB activity. Conclusions: This study identified the electophoretic distribution of CK isoenzymes and macroenzymes of dogs and cats and provided encouraging data about the possible use of CK‐BB as a biomarker for canine neurologic disorders, but not for FIP.     

Tissue sources of serum alkaline phosphatase in 34 hyperthyroid cats: a qualitative and quantitative study

The concentration of serum alkaline phosphatase (SALP) is commonly elevated in hyperthyroid cats. Agarose gel electrophoresis, in tris -barbital-sodium barbital buffer, with and without the separation enhancer neuraminidase, was used to investigate the sources of the constituent isoenzymes of SALP in serum samples from 34 hyperthyroid cats, comparing them to sera from five healthy cats and to tissue homogenates from liver, kidney, bone and duodenum. Contrary to previous reports, treatment of serum with neuraminidase made differentiation of the various isoenzymes more difficult to achieve. A single band corresponding to the liver isoenzyme (LALP) was found in 100 per cent of healthy cats. Eighty-eight per cent of the hyperthyroid cats showed two bands, corresponding to the liver and bone (BALP) isoenzymes while 12 per cent showed a LALP band alone. In hyperthyroid cats, there was a significant correlation between the serum L-thyroxine concentrations and the SALP concentrations. These findings suggest pathological changes in both bone and liver in most cases of feline thyrotoxicosis.     

Assessment of acid-base status of cats with naturally occurring chronic renal failure

Metabolic acidosis is reported to be a common complication of feline chronic renal failure (CRF) but acid-base status of feline patients with this disease is rarely assessed by general practitioners. A cross-sectional study involving 59 cases of naturally occurring feline CRF was conducted to determine the prevalence of acid-base disturbances. Cases were categorised on the basis of their plasma creatinine concentrations as mild, moderate or severe. A group of 27 clinically healthy, age-matched cats was assessed for comparison. A low venous blood pH (<7.270) was found in 10 of the 19 severe cases (52.6 per cent), three of the 20 moderate cases (15 per cent) and none of the 20 mild cases. Acidaemia was associated with an increased anion gap contributed to by both low plasma bicarbonate and low chloride ion concentrations. Biochemical analysis of urine samples showed urine pH to decrease with increasing severity of renal failure. Urinary loss of bicarbonate was not associated with the occurrence of acidaemia and there was a tendency for urinary ammonium ion excretion to decrease as the severity of renal failure increased. Cats with naturally occurring CRF do not show plasma biochemical evidence of acid-base disturbances until the disease is advanced.     

Alkaline phosphatase isoenzymes in feline serum using an agarose gel alkaline phosphatase kit method.

Total serum alkaline phosphatase (ALP) activity is the product of the combined activity of isoenzymes from a number of tissue sources. In this study, a commercially available kit for electrophoretic separation of ALP isoenzymes in an agarose gel was used to separate ALP isoenzymes in feline tissue extracts and serum. Five separate bands of ALP activity were identified. These bands were numbered 1 to 5 with band 1 having the most anodal migration. The tissue of origin corresponding to the migration position of the isoenzymes are as follows: Band 3 was the liver isoenzyme, band 4 was the bone isoenzyme and ALP isoenzymes of both intestine and kidney migrate in the position labelled band 5. Band 1 appears to be related to albumin and does not represent true ALP activity. The tissue source of band 2 (a and b) was not identified. Serum ALP activity of mature, healthy cats is primarily of liver origin. Immature cats (< 1 year of age) have a greater proportion of the bone isoenzyme in the serum.     

Prevalence of the polycystic kidney disease and renal and urinary bladder ultrasonographic abnormalities in Persian and Exotic Shorthair cats in Italy

The ultrasonographic findings of kidneys, liver and urinary bladder of 288 Persian and 44 Exotic Shorthair clinically normal cats that underwent screening for polycystic kidney disease (PKD) between July 2003 and December 2005 were reviewed. Cats were divided into two groups, one including cats aged <9 months (group 1) and one cats aged >/=9 months (group 2). Cats were classified as PKD-positive when at least one renal cyst was found. One hundred and thirty-six cats (41.0%) had more than one cyst in at least one kidney. The prevalence of PKD was similar in both groups. Eight PKD-positive cats had cystic livers (5.9%). Other renal abnormalities included a pelvic calculus and a medullary rim sign (MRS). The difference in prevalence of an MRS in group 2 compared to group 1 and the difference between PKD-positive and -negative cats in group 2 were not significant. There was no difference in mean kidney length between PKD-positive and -negative cats in group 2. Urinary bladder anomalies were principally represented by urinary sediment, with prevalence significantly higher in group 2. No difference was detected in group 2 between PKD-positive and -negative cats. In conclusion feline PKD is common in Italy. The ultrasonographic findings of MRS and urinary bladder sediment did not correlate with feline PKD. Urinary bladder sediment is common in Persians and Exotic Shorthairs and more likely in adults.     

Measurement of aldosterone in feline, canine and human urine

BACKGROUND: Systemic hypertension is an important problem in older cats associated with kidney disease and hypokalaemia, suggesting that excessive activity of the renin-angiotensin-aldosterone system might contribute to the hypertensive state. Fluctuations in plasma renin activity and plasma aldosterone concentrations complicate the interpretation of these assays. OBJECTIVES: The aim of this study was to determine whether measurement of urinary aldosterone excretion in cats aided the investigation of hypertension. METHODS: Urine concentrations of free (ethyl acetate extract) and 18-glucuronidated aldosterone (acid hydrolysis before extraction) were measured by radioimmunoassay in normal, normotensive and hypertensive azotaemic cats (n=11 per group). Urine samples from 11 healthy human volunteers and eight normal dogs were also analysed for comparison. Urinary aldosterone concentration was corrected for the urinary creatinine concentration. RESULTS: Cats excreted 7.3 times less free aldosterone than human beings, and no free aldosterone was detected in dog urine. Acid hydrolysis led to large increases in aldosterone recovery from both human beings and dog but not feline urine. No significant effect of hypertension or azotaemia on feline urinary aldosterone concentration was found. CLINICAL SIGNIFICANCE: Measurement of aldosterone in feline urine using the available methodology has limited or no utility in investigating feline hypertension.     

Evaluation of renal function in cats, using quantitative urinalysis

Two consecutive 24-hour quantitative urinalyses were performed on each of 12 healthy adult cats to evaluate the technique and obtain reference values for measurements of urinary excretion of several substances. Endogenous creatinine clearance (2.31 +/- 0.47 ml/min/kg) and urinary protein excretion (17.43 +/- 9.05 mg/kg/day) were determined. Additionally, clearances and ratios to creatinine clearances were calculated for phosphate, sodium, potassium, and chloride. The endogenous creatinine clearance value was compared with another estimate of glomerular filtration rate that was based on 99mTc(Sn) diethylene-triaminepentaacetic acid clearance (2.52 +/- 0.58 ml/min/kg). Evaluation of feline renal function, using 24-hour quantitative urinalysis techniques, has potential for clinical application, but has several important limitations as well.     

N-acetyl-beta-D-glucosaminidase activity in urine of cows with renal parenchymal lesions

OBJECTIVE: To measure N-acetyl-beta-D-glucosaminidase (NAG) activity in urine of cows with renal diseases and to correlate values for NAG activity with renal lesions. ANIMALS: 8 lactating Holstein cows and a Japanese Shorthorn cow, all of which had renal disease. PROCEDURE: Urine samples were collected, and urinary NAG activity and creatinine concentration were measured. The NAG activity was expressed as units per gram of creatinine (NAG index). Cows were euthanatized, necropsy was performed, and correlations between results for urinary NAG index and histopathologic findings for the kidneys were evaluated. RESULTS: The NAG activity and NAG index in urine samples obtained from cows with interstitial nephritis were high, ranging from 4.2 to 13.6 U/L and 3.5 to 23.0 U/g, respectively. A cow with renal amyloidosis also had high values for urinary NAG activity and NAG index. Histologic examination of the kidneys revealed various kinds of parenchymal lesions. However, urinary NAG index in cows with enzootic bovine leukosis was low. CONCLUSIONS AND CLINICAL RELEVANCE: Cows with renal diseases had high urinary NAG indexes that correlated well with their renal lesions, except for cows with enzootic bovine leukosis. Therefore, measurement of NAG index in urine samples has the potential to provide new perspectives on clinical diagnosis of renal disease in cattle.     

Use of an orally administered combined sugar solution to evaluate intestinal absorption and permeability in cats

OBJECTIVE: To evaluate intestinal permeability and absorption in healthy cats in association with diet and normal intestinal microflora. ANIMALS: 6 healthy domestic shorthair cats. PROCEDURE: A sugar solution containing D-xylose, 30-methyl-D-glucose, L-rhamnose, lactulose, and 51Cr-EDTA was administered intragastrically to healthy cats, and urinary excretion of ingested sugars was determined 5 hours after administration. After the same cats had received metronidazole for 1 month, the study was repeated. A final study was performed while cats were maintained on a new diet differing in composition and processing. RESULTS: Lactulose-to-rhamnose ratios, reflecting intestinal permeability, were higher in cats, compared with values for humans or dogs, and values obtained before and after metronidazole administration (mean +/- SEM; before, 0.40 +/- 0.08; after, 0.45 +/- 0.09) were not significantly different. Intestinal absorption also was unaltered after antibiotic administration, and the xylose-to-glucose ratio was 0.70 +/- 0.03 before and 0.71 +/- 0.06 after metronidazole administration. Sugar recovery did not differ significantly while cats were maintained on canned or dry food. CONCLUSIONS AND CLINICAL RELEVANCE: Reference ranges were established for the percentage urinary recovery of orally administered D-xylose, 3-0-methyl-D-glucose, L-rhamnose, lactulose, and 51Cr-EDTA obtained after 5 hours in healthy cats. The intestines of cats appear to be more permeable than those of other species, although the normal bacterial microflora does not appear to influence the integrity or function of the feline intestine, because values obtained for the measured variables before or after antibiotic administration were not significantly different. In addition, differences were not detected when the diet was completely altered.     

Alkaline phosphatase bone isoenzyme and osteocalcin in the serum of hyperthyroid cats.

The effect of hyperthyroidism on serum markers for increased bone metabolism and turnover was evaluated in 36 cats with elevated serum levels of thyroxine and alkaline phosphatase. Serum was analyzed for total and ionized calcium and phosphorous. Alkaline phosphatase isoenzymes were separated by agarose gel electrophoresis and osteocalcin was measured by radioimmunoassay. Values for hyperthyroid cats were compared with those for healthy cats. Alkaline phosphatase bone isoenzyme was markedly increased in all 36 hyperthyroid cats. Osteocalcin was increased in 44% of the cats. There was no correlation among the magnitude of increase in alkaline phosphatase bone isoenzyme, osteocalcin, and serum thyroxine concentrations. Increased serum phosphorus was found in 35% of the cats. Total calcium was within the reference range in all cats, while 50% of the cats had reduced levels of serum ionized calcium. We conclude that hyperthyroid cats do have altered bone metabolism, although it is usually clinically insignificant.     

EFFECT OF REPRODUCTIVE STATUS ON FELINE RENAL SIZE

Renal length and width dimensions were determined from survey radiography and excretory urography in 28 cats of various sex and reproductive status. Renal dimensions were expressed as a ratio to the length of the second lumbar vertebra. Renal dimensions were not significantly different when males were compared to females. However, significant differences in renal dimensions between intact and neutered cats were identified. Renal length ratios for neutered cats were: left kidney 2.22 +/- 0.14 (mean +/- standard deviation), right kidney 2.29 +/- 0.14. In intact cats, renal length ratios were: left kidney 2.60 +/- 0.19, right kidney 2.65 +/- 0.24. The mean renal length ratios for neutered cats was smaller than previously reported normal values. Thus, reproductive status should be considered when evaluating feline kidneys for alterations in size. Based on this study, normal feline renal length ratios range from 1.9 to 2.6 for neutered cats and 2.1 to 3.2 for intact cats.     

Evaluation of Predictors of the Development of Azotemia in Cats

Background: Chronic kidney disease (CKD) is a common condition in geriatric cats. Diagnosis is based on the development of persistent azotemia with inadequate urine concentrating ability. Biomarkers are sought for early identification.
Hypothesis: Clinical variables, urine concentrating ability, proteinuria, and N -acetyl-β- d -glucosaminidase (NAG) index will be predictive of cats at risk of developing azotemia within 12 months.
Animals: Client-owned nonazotemic geriatric (≥9 years) cats.
Methods: Prospective longitudinal cohort study monitoring a population of healthy nonazotemic geriatric cats every 6 months until development of azotemia, death, or the study end point (September 30, 2007). Multivariable logistic regression analysis was used to assess baseline clinical, biochemical, and urinalysis variables, urine protein to creatinine ratio (UP/C), urine albumin to creatinine (UA/C) ratio, and urinary NAG index as predictors of development of azotemia.
Results: One hundred and eighteen cats were recruited with a median age of 13 years. Ninety-five cats (80.5%) had been followed or reached the study end point by 12 months of which 30.5% (29/95) developed azotemia. Age, systolic blood pressure, plasma creatinine concentration, urine specific gravity, UP/C, UA/C, and NAG index were significantly associated with development of azotemia in the univariable analysis ( P ≤ .05). However, in the multivariable analysis, only plasma creatinine concentration with either UP/C (Model 1) or UA/C (Model 2) remained significant.
Conclusions and Clinical Importance: This study demonstrates a high incidence of azotemia in a population of previously healthy geriatric cats. Proteinuria at presentation was significantly associated with development of azotemia although causal association cannot be inferred. Evaluation of NAG index offered no additional benefit.     

Association of urinary cadmium excretion with feline hypertension

Fifty client-owned senior cats (32 normotensive and 18 hypertensive) with renal function ranging from normal to moderately reduced were recruited into a prospective cross-sectional study exploring the association of urinary cadmium excretion and hypertension in cats. Heparinised plasma samples were collected and analysed for routine biochemical parameters. Urine samples were collected via cystocentesis and were analysed for cadmium concentrations using inductively coupled plasma mass spectrometry (ICP-MS). Blood pressure was measured using the Doppler method. Urinary cadmium concentrations were indexed to urinary creatinineconcentration. Comparison of urinary cadmium excretion was made between hypertensive and normotensive cats.The median (range) urinary cadmium concentration standardised to urinary creatinine concentration (UCdCr) in the normotensive and hypertensive cats was 0.08 (0.02 to 0.37) and 0.12 (0.02 to 1.38) nmol/mmol creatinine. The UCdCr was significantly higher in hypertensive compared with normotensive cats (P=0.016). UCdCr and plasma creatinine concentration remained independent predictors of hypertensive status in a logistic regression model. UCdCr and plasma creatinine concentration were not correlated (r=-0.01, P=0.956). These data suggest cadmium exposure and accumulation in cats may play a role in the development of feline hypertension.     

Susceptibility of bacteria from feline and canine urinary tract infections to doxycycline and tetracycline concentrations attained in urine four hours after oral dosage

OBJECTIVES: To measure urinary concentrations of doxycycline in cats and dogs and tetracycline in dogs 4 h after conventional oral dosing and determine whether these antibiotics were present in sufficient concentrations to be effective against common feline and canine urinary tract pathogens as assessed in vitro by Epsilometer and disc diffusion antimicrobial susceptibility methods. DESIGN: A prospective study involving oral administration to clinically normal cats and dogs of doxycycline or tetracycline (dogs only) and culture of bacteria from dogs and cats with urinary tract infections to determine their susceptibility to both doxycycline and tetracycline in vitro. PROCEDURE: In the first study, nine cats and eight dogs were administered doxycycline monohydrate (5 mg/kg every 12 h) and a further eight dogs were administered tetracycline hydrochloride (20 mg/kg every 8 h) for 72 h. Blood was collected at 2 and 4 h, and urine at 4 h, after the last dose. The concentration of each agent in serum and urine was determined by modified agar diffusion. In the second study, 45 urine samples from cats and dogs with urinary tract infections were cultured. Every bacterial isolate was tested in vitro using both Epsilometer (doxycycline and tetracycline) and disc diffusion (doxycycline, tetracycline or amoxycillin-clavulanate) tests. RESULTS: Serum doxycycline concentrations in sera of cats and dogs at 2 h were 4.2 +/- 1.0 mg/mL and 3.4 +/- 1.1 mg/mL, respectively. The corresponding concentrations at 4 h were 3.5 +/- 0.7 mg/mL and 2.8 +/- 0.6 mg/mL. Urinary doxycycline concentrations at 4 h (53.8 +/- 24.4 mg/mL for cats and 52.4 +/- 24.1 mg/mL for dogs) were substantially higher than corresponding serum values. Serum tetracycline concentrations in dogs at 2 and 4 h, and in urine at 4 h, were 6.8 +/- 2.8, 5.4 +/- 0.8, 144.8 +/- 39.4 mg/mL, respectively. Most of the urinary tract pathogens (35/45) were susceptible to urinary concentrations of doxycycline and 38/45 were susceptible to tetracycline. In contrast 41/45 of all isolates were susceptible to amoxycillin-clavulanate. CONCLUSION: This is the first report of urinary concentrations of doxycycline after conventional oral administration. Concentrations attained in the urine of normal cats and dogs were sufficient to inhibit the growth of a significant number of urinary tract pathogens and thus doxycycline may be a useful antimicrobial agent for some urinary tract infections.     

Expression of alpha-smooth muscle actin and fibronectin in tubulointerstitial lesions of cats with chronic renal failure

OBJECTIVE: To examine renal expression of alpha-smooth muscle actin (alpha-SMA) and fibronectin in cats with tubulointerstitial nephritis (TIN) for use in predicting progression to renal fibrosis. ANIMALS: 19 cats with TIN and 9 cats without nephritis. PROCEDURE: Serum creatinine and BUN concentrations were measured. Indices for glomerular extra-cellular matrix (ECM), tubular injury (TI), and fibronectin were determined in renal specimens to quantify the extent of injury and fibrotic lesions. Expression of alpha-SMA in renal tissue was immunohistochemically detected, and correlations were evaluated between the alpha-SMA index and other histologic and clinical variables. RESULTS: The alpha-SMA index in tubulointerstitial areas (1.63 +/- 0.78) was significantly higher in cats with TIN, especially in the periglomerular and peritubular areas, than in cats without nephritis (0.20 +/- 0.14). The alpha-SMA index was significantly associated with the TI index (r2 = 0.70), fibronectin index (r2 = 0.95), BUN concentration (r = 0.64), and serum creatinine concentration () = 0.66). Of special interest was that interstitial alpha-SMA expression appeared evident in the kidneys at an early stage of TIN, prior to the onset of ECM deposition. CONCLUSION AND CLINICAL RELEVANCE: Analysis of results of histologic and clinical examinations revealed that interstitial alpha-SMA expression may have clinical importance and may be a useful early histologic marker for development of chronic renal failure in cats. An immunohistochemical examination for fibrogenic molecules (such as alpha-SMA expression) may provide fundamental information on the pathogenesis of early-stage renal disease and aid clinical management of cats with chronic renal failure, including TIN.     

Urinary orotic acid-to-creatinine ratios in cats with hepatic lipidosis.

OBJECTIVE: To determine urinary orotic acid (OA) concentration and evaluate the urinary OA-to-creatinine ratio (OACR) in cats with hepatic lipidosis (HL). ANIMALS: 20 cats with HL and 20 clinically normal cats. PROCEDURE: Hepatic lipidosis was diagnosed on the basis of clinical signs, results of serum biochemical analyses, exclusion of other concurrent illness, and cytologic or histologic evaluation of liver biopsy specimens. Urine samples were collected from each cat and frozen at -20 C until assayed. Urine creatinine concentrations were determined, using an alkaline picrate method followed by spectrophotometric assay. Urine OA concentration was determined, using high-performance liquid chromatography. Minimum amount of detectable OA in feline urine was 1 microg/ml. Because of small interfering peaks near the base of the OA peak, the minimum quantifiable concentration of OA was determined to be 5 microg/ml. Urinary OACR was compared in both groups of cats. RESULTS: Differences in urinary OACR were not detected between clinically normal cats and cats with HL. Peaks were not detected for urinary OA in any of the 20 clinically normal cats. Of the 20 HL cats, 14 did not have detectable peaks for urinary OA. Of the 6 HL cats that had detectable urinary OA peaks, 3 had values of <5 microg/ml. CONCLUSIONS: Apparently, OACR does not increase significantly in cats with HL. CLINICAL RELEVANCE: Urinary OACR is not a useful diagnostic test for HL in cats.     

Relationship of Lower Urinary Tract Signs to Seropositivity for Feline Immunodeficiency Virus in Cats

A group of 41 cats with signs of lower urinary tract disease was compared to a group of 41 cats without any history of disease for prevalence of seropositivity for feline immunodeficiency virus (FIV). The group of healthy cats was similar in age and gender to the group of cats with signs of lower urinary tract disease. Three of the cats with lower urinary tract disease and one control cat were seropositive for FIV.
This difference was not statistically significant. The most common cause of lower urinary tract signs was idiopathic. Only 7 cats had urinary tract infection, most associated with perineal urethrostomy or catheterization. Six of the cats with bacterial urinary tract infections were FIV negative. J Vet Intern Med 1996;10:34–38. Copyright © 1996 by the American College of Veterinary Internal Medicine .     

Evaluation of feline serum amyloid A (SAA) as an inflammatory marker

The concentration of feline serum amyloid A (fSAA) was determined by a direct enzyme-linked immunosorbent assay (ELISA) by using fSAA specific monoclonal antibodies, to evaluate the fSAA as an inflammatory marker in cats. The mean concentration +/- standard deviation of fSAA was found to be 0.60 +/- 1.06 microg/m l and 33.65 +/- 67.59 microg/ml in serum samples from normal cats (n=45) and cats (n=312) with various diseases and disorders, respectively. A significant difference (p<0.001) was found between the two groups. It was also found that the concentration of fSAA begins to increase rapidly at approximately 3-6 hr after spay, and increases up to significantly high levels in some disorders, like injury, renal failure, infectious diseases, etc.