Possible Hemolytic Uremic Syndrome in Three Cats After Renal Transplantation and Cyclosporine Therapy

OBJECTIVE: To describe the clinical history of 3 cats with possible hemolytic uremic syndrome (HUS) after renal transplantation. STUDY DESIGN: This case series documents historical findings, physical examination findings, clinical pathologic features, necropsy and histopathologic findings of 3 cats with possible HUS. RESULTS: Two cats had chronic renal failure; 1 cat had acute renal failure secondary to ethylene glycol toxicity. A renal transplant was performed in each of the 3 cats without obvious problems. Complications that would support a diagnosis of HUS, including anemia, thrombocytopenia, and azotemia occurred within 24 hours in 1 cat, within 8 days in a second cat, and 2 months after transplantation in the third cat. In 2 cats, HUS was likely secondary to cyclosporine immunosuppression. In the third cat, HUS may have been secondary to allograft rejection. Renal biopsies from all 3 cats were suggestive of HUS. CONCLUSION AND CLINICAL RELEVANCE: In human beings, HUS in transplant recipients may occur secondary to immunosuppressive drugs, vascular rejection, or recurrence of original disease. Graft loss occurred in all 3 cats in this study and the mortality rate was 100%. Clinicians caring for these patients need to be aware of this disorder because early recognition and treatment is critical in the management of post-transplant HUS.     

Hypercalcemia in cats: a retrospective study of 71 cases (1991-1997)

A retrospective study was conducted to characterize the diseases, clinical findings, and clinicopathologic and ultrasonographic findings associated with hypercalcemia (serum calcium concentration >11 mg/dL) in 71 cats presented to North Carolina State University Veterinary Teaching Hospital. The 3 most common diagnoses were neoplasia (n = 21), renal failure (n = 18), and urolithiasis (n = 11). Primary hyperparathyroidism was diagnosed in 4 cats. Lymphoma and squamous cell carcinoma were the most frequently diagnosed tumors. Calcium oxalate uroliths were diagnosed in 8 of 11 cats with urolithiasis. Cats with neoplasia had a higher serum calcium concentration (13.5 ± 2.5 mg/dL) than cats with renal failure or urolithiasis and renal failure (11.5 ± 0.4 mg/dL; P <.03). Serum phosphorus concentration was higher in cats with renal failure than in cats with neoplasia ( P < .004). Despite the fact that the majority of cats with uroliths were azotemic, their serum urea nitrogen and creatinine concentrations and urine specific gravity differed from that of cats with renal failure. Additional studies are warranted to determine the underlying disease mechanism in the cats we identified with hypercalcemia and urolithiasis. We also identified a small number of cats with diseases that are not commonly reported with hypercalcemia. Further studies are needed to determine whether an association exists between these diseases and hypercalcemia, as well as to characterize the underlying pathophysiologic mechanism for each disease process.     

Acid-base balance of cats with chronic renal failure: effect of deterioration in renal function

In a previous cross-sectional study of feline chronic renal failure (CRF), metabolic acidosis was identified in 52.6 per cent of animals with severe renal failure (plasma creatinine concentration >400 micromol/litre). The aim of this longitudinal study was to determine whether metabolic acidosis preceded or accompanied a deterioration in renal function in cats with CRF. Data were analysed from 55 cats with CRF that had been followed longitudinally for at least four months. Twenty-one cases showed deterioration in renal function over the period of the study, as evidenced by significant rises in their plasma creatinine concentrations and decreases in bodyweight. In five of the 21 cases, acidaemia accompanied the deterioration in renal function. Only one of these cats had evidence of metabolic acidosis before renal function deterioration. One other case developed metabolic acidosis without a rise in plasma creatinine concentration. These data suggest that biochemical evidence of metabolic acidosis does not generally occur until late in the course of feline CRF.     

Membranous nephropathy in the cat: a clinical and pathological study

A series of 13 cases of feline membranous nephropathy is presented. Two groups were distinguished clinically; eight cats had the nephrotic syndrome and five others were in renal failure but not nephrotic. The definitive diagnosis was based on histological, immunofluorescence and ultrastructural examinations of renal tissue obtained at renal biopsy or necropsy. Glomerular lesions were classified according to the degree of glomerular change into three distinct groups; mild, moderately severe and advanced. A relationship was established between the mild and moderately severe groups and cats with the nephrotic syndrome, and the advanced group and cats in renal failure. Diuretic therapy was satisfactory in initial control of oedema in the nephrotic cases. Monitoring of previously nephrotic cats for up to three years indicated that the disease is progressive, although in some cases it is sufficiently slow for a cat to live a relatively normal life without continuing treatment. The prognosis for cats presented in renal failure is hopeless.     

Ocular lesions associated with systemic hypertension in cats: 69 cases (1985-1998)

OBJECTIVE: To characterize clinical and clinicopathologic findings, response to treatment, and causes of systemic hypertension in cats with hypertensive retinopathy. DESIGN: Retrospective study. ANIMALS: 69 cats with hypertensive retinopathy. PROCEDURE: Medical records from cats with systemic hypertension and hypertensive retinopathy were reviewed. RESULTS: Most cats (68.1%) were referred because of vision loss; retinal detachment, hemorrhage, edema, and degeneration were common findings. Cardiac abnormalities were detected in 37 cats, and neurologic signs were detected in 20 cats. Hypertension was diagnosed concurrently with chronic renal failure (n = 22), hyperthyroidism (5), diabetes mellitus (2), and hyperaldosteronism (1). A clearly identifiable cause for hypertension was not detected in 38 cats; 26 of these cats had mild azotemia, and 12 did not have renal abnormalities. Amlodipine decreased blood pressure in 31 of 32 cats and improved ocular signs in 18 of 26 cats. CONCLUSIONS AND CLINICAL RELEVANCE: Retinal lesions, caused predominantly by choroidal injury, are common in cats with hypertension. Primary hypertension in cats may be more common than currently recognized. Hypertension should be considered in older cats with acute onset of blindness; retinal edema, hemorrhage, or detachment; cardiac disease; or neurologic abnormalities. Cats with hypertension-induced ocular disease should be evaluated for renal failure, hyperthyroidism, diabetes mellitus, and cardiac abnormalities. Blood pressure measurements and funduscopic evaluations should be performed routinely in cats at risk for hypertension (preexisting renal disease, hyperthyroidism, and age > 10 years). Amlodipine is an effective antihypertensive agent in cats.     

Assessment of melamine and cyanuric acid toxicity in cats.

The major pet food recall associated with acute renal failure in dogs and cats focused initially on melamine as the suspect toxicant. In the course of the investigation, cyanuric acid was identified in addition to melamine in the offending food. The purpose of this study was to characterize the toxicity potential of melamine, cyanuric acid, and a combination of melamine and cyanuric acid in cats. In this pilot study, melamine was added to the diet of 2 cats at 0.5% and 1%, respectively. Cyanuric acid was added to the diet of 1 cat at increasing doses of 0.2%, 0.5%, and 1% over the course of 10 days. Melamine and cyanuric acid were administered together at 0%, 0.2%, 0.5%, and 1% to 1 cat per dose group. No effect on renal function was observed in cats fed with melamine or cyanuric acid alone. Cats dosed with a combination were euthanized at 48 hours after dosing because of acute renal failure. Urine and touch impressions of kidneys from all cats dosed with the combination revealed the presence of fan-shaped, birefringent crystals. Histopathologic findings were limited to the kidneys and included crystals primarily within tubules of the distal nephron, severe renal interstitial edema, and hemorrhage at the corticomedullary junction. The kidneys contained estimated melamine concentrations of 496 to 734 mg/kg wet weight and estimated cyanuric acid concentrations of 487 to 690 mg/kg wet weight. The results demonstrate that the combination of melamine and cyanuric acid is responsible for acute renal failure in cats.     

Hyperglycemic, hyperosmolar syndrome in feline diabetics: 17 cases (1995–2001)

Objective: The purposes of this study were to characterize the hyperglycemic, hyperosmolar syndrome (HHS), also known as nonketotic hyperosmolar diabetes, in cats; to determine the prevalence of HHS in the diabetic cat population in the emergency room; to document the outcome in cats with HHS; and to identify any predisposing factors or predictors of survival. Design: Retrospective study. Setting: An emergency service at a veterinary teaching hospital located in a major metropolitan area. Animals: The case records of 17 cats with hyperglycemic, hyperosmolar syndrome presenting from 1995 to 2001 were evaluated. An additional 37 cats with diabetic ketoacidosis and 80 cats with diabetes mellitus served as comparison groups. Interventions: None. Measurements and main results: Signalment, history, physical examination findings, clinico‐pathologic data, concurrent disease, and outcome were recorded. Hyperglycemic, hyperosmolar syndrome was seen in older cats that were often long‐standing diabetics receiving insulin for many months. Client concerns included polydipsia, polyuria, and lethargy. Neurologic and respiratory signs occurred frequently. Evaluation at presentation revealed profound dehydration, lactic acidosis, and azotemia. Serious concurrent diseases that likely contributed to the development of the HHS crisis were diagnosed in 88% (15/17) of the HHS cats. The most common concurrent diseases were renal failure, respiratory compromise, infection, congestive heart failure, neoplasia, and gastrointestinal tract disease. Pancreatitis and hepatic disease did not occur frequently in this diabetic cat population. Sixty‐five percent of HHS cats did not survive the initial hospitalization, with most dying or being euthanized within 10 hours of presentation. The long‐term survival rate was low (12%). Conclusions: HHS is a serious life‐threatening form of diabetic crisis and cats with HHS often have other severe systemic diseases. Cats with diabetes and concurrent disease, especially renal failure and congestive heart failure, are at increased risk of HHS and should be closely monitored for signs of crisis. The mortality rate for HHS cats is high.     

Cardiac troponin I is elevated in dogs and cats with azotaemia renal failure and in dogs with non-cardiac systemic disease

OBJECTIVE: To determine if dogs and cats with renal failure, or other severe non-cardiac disease, and no antemortem evidence of cardiac disease on basic clinical evaluation, have elevated levels of cardiac troponin I (cTnI). DESIGN: Cross-sectional study using 56 dogs and 14 cats with primary non-cardiac disease (39 dogs with azotaemic renal failure, 14 cats with azotaemic renal failure, 17 dogs with non-cardiac systemic disease); 7/25 dogs and 6/14 cats had murmurs detected on physical examination. Serum or heparinised plasma was collected and analysed for cTnI. RESULTS: Cardiac troponin I concentrations were elevated above reference intervals in 70% of dogs and 70% of cats with azotaemic renal failure and in 70% of dogs with a variety of systemic non-cardiac diseases. Cardiac troponin I concentrations did not correlate with the degree of azotaemia, presence of murmurs, hypertension or type of non-cardiac illness. CONCLUSIONS: Cardiac troponin I concentration is often elevated in dogs and cats with azotaemic renal failure and in dogs with other systemic non-cardiac illness, suggesting that these conditions often result in clinically inapparent myocardial injury or possibly altered elimination of cTnI.     

CHANGES IN RENAL FNCTION IN CATS FOLLOWING TREAMENT OF HYPERTHYROIDISM USING131I

Changes in renal fnction of twenty-two cats treated for hyperthyrodism using radioiodine were evaluated. Serum thyroxine (T₄), serum creatinine, blood urea nitrogen (BUN) and urine specificgravity were measured before treatment and 6 and 30 days after treatment. Twenty-two cats had pretreatment and 21 cats had 6 day posttreatment measurement of glomercular filtration rate (GFR) using nuclear medicine imaging techniques. there were significant declines in serum T₄ at 6 days following treatment, but the changes in GFR, serum creatinine and BUN were not significant. At 30 days following treatment, there were significant increases in BUN and serum creatinine and further significant declines in serum T₄. Nine cats were in renal failure prior to treatment and 13 cats were in renal failure 30 days following treatment. Renal failure was defined as BUN greater than 30 mg/dl and/or serum creatinine greater than 1.8 mg/dl with concurrent urine specific gravity less than 1.035. these 13 cats included eight of 9 cats in renal failure prior to treatment on 9 of these 13 cats indicated that all remained in renal failure. Based on receiver operating curve analysis of pretreatment glomerular filtration rate (GFR) in predicting posttreatment renal failure, a value of 2.25 ml/kg/min as a point of maximum sensitivity (100%) and spefificity (78%) was derived, Fifteen of 22 cats had pretratmentGFR measurements of less than 2.25 ml/kg/min. these 15 cats included all 9 cats in renal failure and 65 cats with normal renal clinicopathologic values prior to treatment. at 30 days following treatment, 13 of these 15 cats were in renal failure. The 2 cats not in renal failure had persistently increased serum T₄ values. seven of 22 cats had pretreatment GFR measurements greater than 225 ml/kg/min. None of these 7 cats was in renal failure at 30 days following treatment, all cats having normal BUN, serum creatinine, and urine specific gravity values. It was concluded that significant declines in renal function occur after treatment of hyperthyroidism and this decline is clinically important in cats with renal disease. Pretreatment measurement of GFR is valuable in detecting subclinical renal disease and in predicting which cats may have clinically important declines in renal function following treatment.     

Comparison of the effects of daily and intermittent-dose calcitriol on serum parathyroid hormone and ionized calcium concentrations in normal cats and cats with chronic renal failure

BACKGROUND: Chronic renal failure is complicated by secondary hyperparathyroidism, which traditionally has been controlled by dietary restriction of phosphorus and administration of phosphorus binders. Early treatment of patients with chronic renal failure with calcitriol may be indicated because once established, parathyroid gland hyperplasia does not readily resolve with therapy. HYPOTHESIS: Daily and intermittent dosing of calcitriol will decrease plasma parathyroid hormone concentration in normal cats and cats with chronic renal failure without causing ionized hypercalcemia. ANIMALS: Ten normal cats; 10 cats with chronic renal failure. METHODS: Phase 1 was daily calcitriol administration (2.5 ng/kg PO q24h) for 14 days. Phase 2 was intermittent calcitriol administration (8.75 ng/kg PO q84h) for 14 days. A 7-day washout period separated phases 1 and 2. Before each phase, calcitriol, parathyroid hormone, and ionized calcium concentrations were measured. On days 1, 2, and 3 of both phases, serum ionized calcium concentrations were measured. On the last day of both phases, calcitriol, parathyroid hormone, and ionized calcium concentrations were measured 0, 2, 4, and 6 hours after calcitriol administration. RESULTS: Overall, serum parathyroid hormone concentrations were significantly higher in cats with chronic renal failure than in normal cats (P = .022), but serum parathyroid hormone concentrations for both normal cats and cats with chronic renal failure were not significantly different before and after 14 days of treatment with calcitriol, regardless of whether calcitriol was administered daily or intermittently. Adverse effects of calcitriol administration (specifically ionized hypercalcemia) were not seen in either feline group during either phase of the study over the 3-day evaluation after calcitriol administration was initiated. CONCLUSIONS AND CLINICAL IMPORTANCE: At the dosages used, calcitriol treatment did not result in significant differences in serum parathyroid hormone concentrations before and after treatment in both normal cats and cats with chronic renal failure. With these dosages, adverse affects of calcitriol administration were not seen. Potential reasons for lack of apparent effect include small sample size, insufficient duration of study, insufficient dosage of calcitriol, problems with formulation or administration of calcitriol, and variable gastrointestinal absorption of calcitriol.     

Renal clearance studies in cats with chronic renal disease: Dietary implications

Renal clearance studies were undertaken on 15 cats, 10 with mild chronic renal disease (CRD) and five with severe CRD. Plasma creatinine concentration and urinary specific gravity measurements in the mild and severe CRD cats were significantly different (P < 0–05) and were 131 ± 26-7 umol/litre and 1–034 ± 0–016, and 392 ± 117-3 nmol/litre and 1–015 ± 0–002, respectively. Endogenous creatinine clearance in the mild and severe CRD cats were significantly different (P < 0–01) and were 2–3 ± 0–58 and 0–62 ± 0–230 ml/min/kg bodyweight, respectively. Hypokalemia was present in one cat but it was not associated with hypercalcinuria. Two cats with mild CRD had hypophosphataemia, hypercalcaemia and hyperphosphaturia which was suggestive of primary hyperparathyroidism, while two cats with severe CRD had hyperphosphataemia and hyperphosphaturia which was indicative of renal secondary hyperparathyroidism. Eight of the 15 cats were subsequently necropsied and were found to have segmental atrophic nephropathy.     

Comparison of fractional excretion and 24-hour urinary excretion of sodium and potassium in clinically normal cats and cats with induced chronic renal failure.

The influence of induced chronic renal failure on 24-hour urinary excretion and fractional excretion of sodium and potassium was studied in cats. Induction of chronic renal failure significantly increased fractional excretion of potassium (P less than 0.0001) and sodium (P less than 0.05); however, 24-hour urinary excretion of sodium and potassium decreased slightly following induction of chronic renal failure. Fractional excretion and 24-hour urinary excretion of sodium and potassium were compared by linear regression in clinically normal cats, cats with chronic renal failure, and clinically normal and affected cats combined. In clinically normal cats, linear regression revealed only moderate correlation between fractional excretion and 24-hour urinary excretion for sodium and potassium. Linear regression of these same relationships in cats with chronic renal failure, and in clinically normal cats and cats with chronic renal failure combined, indicated low correlation. Fractional excretions of sodium and potassium were not reliable indicators of 24-hour urinary excretion of these electrolytes in cats with chronic renal failure or unknown glomerular filtration rate. Fractional excretion of potassium and sodium correlated only moderately with 24-hour urinary excretion in clinically normal cats.     

Incidence of and risk factors for diabetes mellitus in cats that have undergone renal transplantation: 187 cases (1986-2005)

OBJECTIVE: To compare incidence of diabetes mellitus in cats that had undergone renal transplantation with incidence in cats with chronic renal failure, compare mortality rates in cats that underwent renal transplantation and did or did not develop diabetes mellitus, and identify potential risk factors for development of posttransplantation diabetes mellitus (PTDM) in cats. DESIGN: Retrospective case series. ANIMALS: 187 cats that underwent renal transplantation. PROCEDURES: Medical records were reviewed. RESULTS: 26 of the 187 (13.9%) cats developed PTDM, with the incidence of PTDM being 66 cases/1,000 cat years at risk. By contrast, the incidence of diabetes mellitus among a comparison population of 178 cats with chronic renal failure that did not undergo renal transplantation was 17.9 cases/1,000 cat years at risk, and cats that underwent renal trans-plantation were 5.45 times as likely to develop diabetes mellitus as were control cats with chronic renal failure. The mortality rate among cats with PTDM was 2.38 times the rate among cats that underwent renal transplantation but did not develop PTDM. Age, sex, body weight, and percentage change in body weight were not found to be significantly associated with development of PTDM. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cats that undergo renal transplantation have an increased risk of developing diabetes mellitus, compared with cats with chronic renal failure, and that mortality rate is higher for cats that develop PTDM than for cats that do not.     

Naturally-occurring chronic renal disease in Australian cats: a prospective study of 184 cases

OBJECTIVE: To describe cases of naturally occurring feline chronic renal disease (CRD) in a defined population of Sydney. DESIGN: Prospective case series. METHODS: The inclusion criteria were the presence of a serum creatinine concentration above the reference range with either inadequately concentrated urine (urine specific gravity < or = 1.035), necropsy findings consistent with CRD, renal proteinuria or persistent azotaemia despite rehydration. Cats were excluded if a specific aetiology was identified ante or post mortem. Patients were divided into two categories (renal insufficiency or renal failure) on the basis of history, physical findings and serum creatinine concentration. The gender and age of cats with CRD was compared to an estimated Australian urban pet cat population. The breeds of cats with CRD were compared to the breeds of cats visiting the respective veterinary hospital where possible. Breed and gender comparisons were made using Fisher's exact tests. Age comparisons were made using Mann-Whitney U tests. The age at which cats were diagnosed with CRD was compared between veterinary hospitals using a Kruskal-Wallis test. RESULTS: One hundred and eighty-four (99 female; 85 male) cats fulfilled the inclusion criteria. Amongst cats with CRD, males (median 12 years) were significantly younger than females (median 15 years; p = 0.001). The overall proportion of male and female cats with CRD was similar to that of the reference urban cat population (p = 0.41), however, between the ages of 9 and 11 years, male cats with CRD were over-represented (p = 0.038). Patients diagnosed with renal insufficiency (123 cats; median age 15 years) were significantly older than patients diagnosed with renal failure (61 cats; median age 11 years; p = 0.0001).The age at diagnosis of cats with CRD differed significantly between veterinary hospitals (p = 0.002). CONCLUSION: Male cats with CRD were significantly younger than female cats with CRD. Younger cats were more likely to be diagnosed at an advanced stage of disease than older cats. The age at which cats were diagnosed with CRD was influenced by the clinic the cats attended. Whether these differences reflect differences in the aetiology of CRD or in the rate of disease progression warrants further investigation. Breed did not appear to play a significant role in the development of CRD in this survey.     

Acromegaly in 14 Cats

Acromegaly was diagnosed in 14 middle-aged to old cats of mixed breeding. Thirteen (93%) of the cats were male and one was female. The earliest clinical signs in the 14 cats included polyuria, polydipsia, polyphagia, all of which were associated with untreated diabetes mellitus. All developed severe insulin resistance within a few months; peak insulin dosages required to control severe hyperglycemia ranged from 20 to 130 U per day. Other clinical findings weeks to months after diagnosis included enlargement of one or more organs (e.g., liver, heart, kidneys, and tongue) (n = 14), cardiomyopathy (n = 13), increase in body size and weight gain (n = 8), nephropathy associated with azotemia and clinical signs of renal failure (n = 7), degenerative arthropathy (n = 6), and central nervous system signs (i.e., circling and seizures) caused by enlargement of the pituitary tumor (n = 2). The diagnosis of acromegaly was confirmed by demonstration of extremely high basal serum growth hormone concentrations (22 to 131 micrograms/l) in all cats. Computerized tomography disclosed a mass in the region of the pituitary gland and hypothalamus in five of the six cats in which it was performed. Two cats were treated by cobalt radiotherapy followed by administration of a somatostatin analogue (octreotide), whereas two cats were treated with octreotide alone. Treatment had little to no effect in decreasing serum GH concentrations in any of the cats. Eleven of the 14 cats were euthanized or died four to 42 months (median survival time, 20.5 months) after the onset of acromegaly because of renal failure (n = 2), congestive heart failure (n = 1), concomitant renal failure and congestive heart failure (n = 3), progressive neurologic signs (n = 2), persistent anorexia and lethargy of unknown cause (n = 1), the owner's unwillingness to treat the diabetes mellitus (n = 1), or unknown causes (n = 1). Results of necropsy examination in ten cats revealed a large pituitary acidophil adenoma (n = 10), marked left ventricular and septal hypertrophy (n = 7), dilated cardiomyopathy (n = 1), arthropathy affecting the shoulder, elbow, or stifle (n = 5), and glomerulopathy characterized by expansion of the mesangial matrix and variable periglomerular fibrosis (n = 10).     

Feline chronic renal failure: calcium homeostasis in 80 cases diagnosed between 1992 and 1995

Eighty cats with chronic renal failure (CRF) were evaluated in a prospective study to investigate the prevalence and aetiopathogenesis of renal secondary hyperparathyroidism (RHPTH), using routine plasma biochemistry and assays of parathyroid hormone (PTH), blood ionised calcium and 1,25 dihydroxycholecalciferol (1,25[OH]₂D₃). Hyperparathyroidism was a frequent sequela of CRF, affecting 84 per cent of cats with CRF, the severity and prevalence of RHPTH increasing with the degree of renal dysfunction. Compared with an age-matched control population, plasma concentrations of phosphate and PTH were significantly higher and 1,25(OH)₂D₃ concentrations were significantly lower in the two groups of cats presenting with clinical signs of CRF. Significant ionised hypocalcaemia was present only in cats with end-stage renal failure. However, a number of cats were hyperparathyroid in the absence of abnormalities in the parameters of calcium homeostasis measured in this study. There was a significant correlation between plasma phosphate and PTH concentrations.     

羊胎盘转移因子治疗猫急性肾衰竭的疗效研究

本试验旨在研究神元康肽羊胎盘转移因子在猫急性肾衰竭病例肾损伤中的作用。试验动物为经综合诊断确诊为急性肾衰的猫,试验分为神元康肽组和常规治疗组2组,结果常规治疗组治愈率为70%,神元康肽组治愈率为90%。本研究的结果证明,神元康肽在治疗猫急性肾衰竭中发挥了重要作用,神元康肽可以提高猫急性肾衰竭的治愈率。     

Hypertension in Cats With Chronic Renal Failure or Hyperthyroidism

The Doppler ultrasonic recording technique was used to measure systolic and diastolic blood pressures indirectly in 28 cats with naturally occurring renal failure, 39 cats with hyperthyroidism, and 33 clinically normal cats. The mean systolic and diastolic blood pressures in the normal cats were 118.4 +/- 10.6 mm Hg and 83.8 +/- 12.2 mm Hg, respectively. In the cats with chronic renal failure, both the systolic (146.6 +/- 25.4 mm Hg) and diastolic (96.6 +/- 15.2 mm Hg) blood pressures were significantly higher (P less than 0.0001 and P less than 0.01, respectively) than in the normal cats. Elevations in systolic and/or diastolic blood pressure were recorded in 17 (61%) of the 28 cats with chronic renal failure. In the 39 untreated hyperthyroid cats, both the mean systolic (167.9 +/- 28.9 mm Hg) and diastolic (111.6 +/- 21.5 mm Hg) pressures also were significantly higher (P less than 0.0001) than normal. Increased systolic and/or diastolic blood pressure was recorded in 34 (87%) of the 39 hyperthyroid cats. In seven cats with hyperthyroidism that were reevaluated two to four months after successful treatment of the hyperthyroid state, there was a significant fall in mean systolic pressure (P less than 0.05) from a pretreatment value of 159.5 +/- 15.4 mm Hg to a posttreatment value of 132.0 +/- 1.62 mm Hg. Overall, the results of this study indicate that mild to moderate hypertension is common in cats with chronic renal failure and in cats with untreated hyperthyroidism. In addition, the hypertension appears to be reversible following successful treatment of the hyperthyroid state.     

Fabellae and popliteal sesamoid bones in cats

Radiographs of the stifle joints of cats revealed a lack of mineralisation in the medial os fabella in a high percentage of domestic cats and also some exotic species of cat. In all the post mortem examinations undertaken the medial sesamoid bones were smaller. In the non-radiopaque sesamoid bones there was a solid mass which on histological examination consisted of fibrocartilage, whereas the radiodense sesamoid bones consisted of lamellar osseous tissue. The lack of mineralisation of the medial fabellae seems to be more prevalent in domestic than in pedigree cats. None of the exotic cats had mineralised tissue in the medial fabellae. Lack of mineralisation of the sesamoid bones is not significant clinically.     

Association of laboratory data and death within one month in cats with chronic renal failure

OBJECTIVES: To retrospectively compare the data taken at the first visit of 34 cats with chronic renal failure surviving more than one month (surviving group) and 16 cats dying within one month (non-surviving group). METHODS: Records were collected on cats with chronic renal failure presented to a private veterinary practice in Nagoya, Japan, from March 1996 to March 2005. All cats with chronic renal failure diagnosed on the basis of case histories, clinical signs (such as, lethargy, anorexia, loss of bodyweight and vomiting) and a high plasma creatinine (>180 micromol/l) were included in the study. RESULTS: Plasma creatinine, urea nitrogen, inorganic phosphate, packed cell volume and urine protein/creatinine ratio were significantly different between cats of the surviving and non-surviving groups. In the surviving group, survival statuses were recorded, and laboratory data was obtained within one month before death in 13 cats. In the 13 cats, plasma creatinine, packed cell volume and urine protein/creatinine ratio showed significant differences between the data taken within one month before death and that taken at first visit, and only urine protein/creatinine ratio exhibited a consistent alteration (increase) in relation to first visit data. CLINICAL SIGNIFICANCE: These results indicated that plasma creatinine, urea nitrogen, inorganic phosphate, packed cell volume and urine protein/creatinine ratio were associated with death within one month and urine protein/creatinine ratio was most likely to be associated with mortality in cats with chronic renal failure.