Heart failure is common in diabetic cats: findings from a retrospective case-controlled study in first-opinion practice

OBJECTIVES: To study the prognosis and cause of death in cats with diabetes mellitus. METHODS: Twenty consecutive cases of feline diabetes mellitus diagnosed in first-opinion practice were followed. Three control cats, without diabetes, were matched to each case of diabetes; these were also followed. RESULTS: One Somali cat with diabetes could not be matched, so complete data analysis considered only 19 diabetics and 57 matched controls. Death occurred in 14 of 20 diabetics and 23 of 57 controls although one control cat was eventually lost to follow-up. Heart disease and heart failure led to death in six diabetic cats. One of these was the non-matched Somali; nevertheless, the death rate from heart disease in the diabetics was five of 19 compared with two of 57 in controls. The relative risk of heart failure in diabetic cats was 10.4 times that of the controls; this difference in rates was statistically significant. Survival amongst diabetics was significantly worse than for controls. For the control cats median survival was 718 days after the index visit, whereas for the diabetic cases median survival was 385 days after diagnosis. CLINICAL SIGNIFICANCE: Heart disease and failure are common in diabetic cats. This observation deserves further attention.     

Use of pimobendan in 170 cats (2006–2010)

Hypothesis/ObjectivesTo describe the therapeutic use of pimobendan in cats, describe the patient population to which it was administered, document potential side effects and report the clinical course following administration of pimobendan in conjunction with standard heart failure therapy. It is hypothesized that cats with advanced heart disease including congestive heart failure from a variety of causes will tolerate pimobendan with a minimum of side effects when used in treatment in conjunction with a variety of other medications.Animals, materials and methodsOne hundred and seventy client owned cats with naturally occurring heart disease, one hundred and sixty four of which had congestive heart failure. Medical records were reviewed and owners and referring veterinarians were contacted for follow-up data. Data collected included pimobendan dose, other medications administered concurrently, data collected at physical examination, presence or absence of heart failure, adverse effects, classification of heart disease, echocardiographic data and survival time. The data were analyzed for significance between the initial visit and any follow-up visits.ResultsAll cats were treated with pimobendan. The median pimobendan dose was 0.24 mg/kg q 12 h. Pimobendan was used in combination with multiple concurrent medications including angiotensin converting enzyme inhibitors, diuretics and anti-thrombotics. Five cats (3.0%) had potential side effects associated with pimobendan. One cat (0.6%) had presumed side effects severe enough to discontinue pimobendan use. Median survival time for 164 cats with congestive heart failure after initiation of pimobendan was 151 days (range 1–870).ConclusionPimobendan appears to be well tolerated in cats with advanced heart disease when used with a variety of concurrent medications. Randomized controlled studies need to be performed to accurately assess whether it is efficacious for treatment of congestive heart failure in cats.     

Transient clinical diabetes mellitus in cats: 10 cases (1989-1991)

Medical records of 10 cats with transient clinical diabetes mellitus were reviewed. At the time diabetes was diagnosed, clinical signs included polyuria and polydipsia (10 cats), weight loss (8 cats), polyphagia (3 cats), lethargy (2 cats), and inappetence (1 cat). Mean (+/- SD) fasting blood glucose concentration was 454 +/- 121 mg/dL, mean blood glucose concentration during an 8-hour period (MBG/8 hours) was 378 +/- 72 mg/dL, and glycosuria and trace ketonuria were identified in 10 and 5 cats, respectively. Baseline serum insulin concentration was undetectable (6 cats) or within the reference range (4 cats) and serum insulin concentration did not increase after i.v. glucagon administration in any cat. Insulin-antagonistic drugs were being administered to 5 cats and concurrent disorders were identified in all cats. Management of diabetes included administration of glipizide (6 cats), insulin (3 cats), or both (1 cat), discontinuation of insulin-antagonistic drugs, and treatment of concurrent disorders. Insulin and glipizide treatment was discontinued 4-16 weeks (mean, 7 weeks) after the initial diagnosis of diabetes was confirmed. At the time treatment for diabetes was discontinued, clinical signs had resolved, mean fasting blood glucose concentration was 102 +/- 48 mg/dL, MBG/ 8 hours was 96 +/- 32 mg/dL, glycosuria and ketonuria were not identified in any cat, and concurrent disorders (except mild renal insufficiency in 1 cat) had resolved. Significant (P < .05) increases occurred in postglucagon serum insulin concentrations, insulin peak response, and total insulin secretion, compared with values obtained when clinical diabetes was diagnosed. Histologic abnormalities were identified in pancreatic islets of 5 cats in which pancreatic biopsies were obtained and included decreased number of islets (4 cats), islet amyloidosis (3 cats), and vacuolar degeneration of islet cells (3 cats). Mean beta cell density was significantly (P < .001) decreased in diabetic cats compared with control cats (1.4 +/- 0.7 versus 2.6 +/- 0.5%, respectively). Cells within islets stained positive for insulin, however, the number of insulin-staining cells per islet and the intensity of insulin staining were decreased in 5 and 2 cats, respectively. Clinical diabetes had not recurred in 1 cat after 6 years, in 4 cats lost to follow-up after 1.5, 1.5, 2.0, and 2.5 years, and in 2 cats that died 6 months and 5.5 years after clinical diabetes resolved. Clinical diabetes recurred in 3 cats after 6 months, 14 months, and 3.4 years, respectively. These findings suggest that cats with transient clinical diabetes have pancreatic islet pathology, including decreased beta cell density, and that treatment of diabetes and concurrent disorders results in improved beta cell function, reestablishment of euglycemia, and a transition from a clinical to subclinical diabetic state.     

Third-degree atrioventricular block in 21 cats (1997-2004)

The effect of 3rd-degree atrioventricular block on long-term outcome in cats is unknown. Clinical findings and long-term outcome of 21 cats with 3rd-degree atrioventricular block were studied retrospectively. Median age of cats studied was 14 years (range 7-19 years). Presenting signs included respiratory distress or collapse, but 6 cats had no clinical signs of disease. Eight cats had congestive heart failure (CHF) at the time that 3rd-degree atrioventricular block was detected. Heart rates ranged from 80 to 140 beats per minute (bpm; median 120 bpm) with no difference in heart rate between cats with and those without CHF. Eleven of 18 cats that had echocardiograms had structural cardiac disease, and 6 cats had cardiac changes consistent with concurrent systemic disease. No atrioventricular nodal lesions were detected by echocardiography. One cat had atrioventricular nodal lesions detected on histologic examination. Median survival of 14 cats that died or were euthanized was 386 days (range 1-2,013 days). Survival did not differ between cats with or without CHF or between cats with or without structural cardiac disease. Thirteen cats with 3rd-degree atrioventricular block survived > 1 year after diagnosis, regardless of presenting signs or underlying cardiac disease. Third-degree heart block in cats is often not immediately life threatening. Survival was not affected by the presence of underlying heart disease or congestive heart failure at the time of presentation. Even cats with collapse might survive > 1 year without pacemaker implantation.     

Beta cell and insulin antibodies in treated and untreated diabetic cats

Beta cell and insulin antibodies are involved in the pathogenesis of diabetes in human patients. Beta cell antibodies have also been found in about 50% of newly diagnosed diabetic dogs. This study's objective was to examine these antibodies' role in feline diabetes. The serum of 26 newly diagnosed untreated diabetic cats, 29 cats on insulin therapy, 30 cats with diseases other than diabetes, and 30 healthy cats was examined for beta cell and insulin antibodies. For beta cell antibody testing, purified beta cells from a radiation-induced transplantable rat insulinoma were used. Serum from cats in which anti-beta cell antibodies were induced by injecting a purified beta cell suspension subcutaneously was used as a positive control. Following incubation with test sera, fluorescein-labeled anti-cat immunoglobulins were used to visualize binding between the beta cells and cat gamma globulins. Each serum was tested on two different tumor preparations. For the detection of insulin antibodies, a charcoal separation method was used. It was found that none of the healthy cats, none of the newly diagnosed, untreated diabetic cats and none of the cats with diseases other than diabetes had antibodies against beta cells or against endogenous insulin. Four diabetic cats (14%) that had been treated with different insulin preparations had insulin antibodies.It is concluded that immune-mediated processes are not causing diabetes in the cat. Further studies are needed to evaluate if antibodies directed against exogenous insulin alter the response of diabetic cats to insulin.     

Rebound hyperglycemia following overdosing of insulin in cats with diabetes mellitus

Posthypoglycemic hyperglycemia (rebound hyperglycemia) after overdosing of insulin was diagnosed in 6 cats with diabetes mellitus. Administration of excessive insulin induced hypoglycemia within 4 to 8 hours, followed by rebound hyperglycemia. Diagnosis was made by serial blood glucose determinations during a 20- to 24-hour period after insulin administration. Four cats had a history of difficulty in regulating the diabetic state. In 2 cats, rebound hyperglycemia was diagnosed on routine serial blood glucose determinations. All of the cats were hyperglycemic for most of the day. Rebound hyperglycemia was observed with both intermediate (neutral protamine hagedorn) and long-acting (protamine zinc iletin) insulins, and the range of insulin doses at which the disorder developed overlapped previously determined therapeutic doses for these insulins in the cat. Urine glucose and single afternoon blood glucose determinations were inadequate and potentially misleading in monitoring diabetic cats receiving excessive amounts of insulin.     

Transsphenoidal hypophysectomy for treatment of pituitary-dependent hyperadrenocorticism in 7 cats

OBJECTIVE: Evaluation of microsurgical transsphenoidal hypophysectomy for the treatment of pituitary-dependent hyperadrenocorticism (PDH) in cats. STUDY DESIGN: Prospective clinical study. ANIMALS OR SAMPLE POPULATION: Seven cats with PDH. METHODS: Urinary cortisol/creatinine ratios, pituitary-adrenocortical function tests, and computed tomography (CT) were performed on 7 cats that presented with a provisional diagnosis of hyperadrenocorticism. All cats underwent microsurgical transsphenoidal hypophysectomy with histologic examination of the excised specimen. Follow-up consisted of clinical evaluation, repeat adrenocortical function testing, and CT. RESULTS: Four cats had concurrent diabetes mellitus. In all cats, the urinary cortisol/creatinine (C/C) ratios were elevated. The dexamethasone screening test showed that 2 cats did not meet the criterion for hyperadrenocorticism. The response of the cats' plasma concentrations of cortisol and adrenocorticotrophic hormone to a high dose of dexamethasone varied from very sensitive to completely dexamethasone resistant. Basal plasma alpha-melanocyte-stimulating hormone concentrations were elevated in 2 cats with a pars intermedia adenoma and in 3 cats with an adenoma that originated from the anterior lobe. Preoperative CT enabled accurate assessment of pituitary size (5 nonenlarged pituitaries with a height <4 mm and 2 enlarged pituitaries with a height >5 mm) and localization relative to intraoperative anatomic landmarks. Two cats died within 4 weeks after surgery of a nonrelated disease. In the remaining 5 cats, the hyperadrenocorticism went into both clinical and biochemical remission. Hyperadrenocorticism recurred in 1 cat after 19 months, but no other therapy was given and the cat died at home 28 months after surgery. CT evaluation of this cat had identified pituitary remnants 6 weeks after surgery. The main postoperative complications were oronasal fistula (1 cat), complete dehiscence of the soft palate (1 cat), and transient reduction of tear production (1 cat). One cat died at 6 months (undefined anemia), and another cat at 8 months (recurrent nose and middle ear infection secondary to soft palate dehiscence) after surgery. In the surviving 2 cats, the remission periods at the time of writing were 46 and 15 months. In the 2 cats with sufficient follow-up time, the concurrent diabetes mellitus disappeared, ie, insulin treatment could be discontinued at 4 weeks and 5 months after hypophysectomy. In all 7 cats, the histologic diagnosis was pituitary adenoma. CONCLUSIONS: Microsurgical transsphenoidal hypophysectomy is an effective method of treatment for feline PDH in specialized veterinary institutions having access to advanced pituitary imaging techniques. Concurrent diabetes mellitus is usually reversible after hypophysectomy. Thorough presurgical screening for coexisting diseases is imperative. CLINICAL RELEVANCE: PDH in cats can be effectively treated by hypophysectomy. The neurosurgeon performing hypophysectomy must master a learning curve and must be familiar with the most frequent complications of the operation to treat them immediately and effectively. Urinary C/C ratios are sensitive indicators for the assessment of remission and recurrence of hyperadrenocorticism.     

Remission of Diabetes Mellitus in Cats with Diabetic Ketoacidosis

Background: Diabetic ketoacidosis (DKA) has long been considered a key clinical feature of type‐1 diabetes mellitus (DM) in humans although. An increasing number of cases of ketoacidosis have been reported in people with type‐2 DM. Hypothesis/Objectives: Cats initially diagnosed with DKA can achieve remission from diabetes. Cats with DKA and diabetic remission are more likely to have been administered glucocorticoids before diagnosis. Animals: Twelve cats with DKA and 7 cats with uncomplicated DM. Methods: Retrospective case review. Medical records of cats presenting with DKA or DM were evaluated. Diabetic remission was defined as being clinically unremarkable for at least 1 month after insulin withdrawal. The cats were assigned to 1 of 3 groups: (1) cats with DKA and diabetic remission; (2) cats with DKA without diabetic remission; and (3) cats with DM and diabetic remission. Results: Seven cats with DKA had remission from diabetes. These cats had significantly higher concentrations of leukocytes and segmented neutrophils, and significantly lower concentrations of eosinophils in blood and had pancreatic disease more often than did cats with uncomplicated DM and diabetic remission. With regard to pretreatment, 3/7 cats in group 1, 1/5 cats in group 2, and 1/7 cats in group 3 had been treated with glucocorticoids. Conclusions and Clinical Importance: Remission of DM in cats presenting with DKA is possible. Cats with DKA and remission have more components of a stress leucogram, pancreatic disease, and seemed to be treated more often with glucocorticoids than cats with uncomplicated DM and diabetic remission.     

Feline adrenal disorders

Although only recently discovered, feline adrenal disorders are becoming increasingly more recognized. Feline adrenal disorders include diseases such as hyperadrenocorticism (Cushing's syndrome) and hyperaldosteronism (Conn's syndrome). The clinical signs of feline hyperadrenocorticism, which include unregulated diabetes mellitus and severe skin atrophy, are unique to the cat. Other signs of feline hyperadrenocorticism, such as potbellied appearance, polydipsia, polyuria, and susceptibility to infections are also seen in dogs with hyperadrenocorticism. Conn's syndrome has only recently been described in the cat and is in fact more common in cats than in dogs. Characterized by severe hypokalemia, hypertension, and muscle weakness, Conn's syndrome may be misdiagnosed as renal failure. The clinician should become familiar with the clinical signs of adrenal disorders in cats and the common diagnostic tests used to diagnose these syndromes in cats as they differ from those in the dog. Treatment of feline adrenal disorders may be challenging; the clinician should become familiar with common drugs used to treat adrenal disorders in 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.     

Systolic blood pressure in cats with diabetes mellitus

OBJECTIVE: To determine the prevalence of systemic hypertension in cats with diabetes mellitus and establish ranges for echocardiographic variables in diabetic cats. DESIGN: Prospective study. ANIMALS: 14 cats with diabetes mellitus and 19 healthy control cats. PROCEDURE: Systolic blood pressure was measured indirectly with a noninvasive Doppler technique. Ophthalmic and echocardiographic examinations were performed, and urine protein concentration was measured. Cats were considered to have hypertension if they had systolic blood pressure > 180 mm Hg and at least 1 other clinical abnormality typically associated with hypertension (eg, hypertensive retinopathy, left ventricular hypertrophy, or proteinuria). RESULTS: None of the diabetic or control cats had systolic blood pressure > 180 mm Hg. One diabetic cat had left ventricular hypertrophy, but systolic blood pressure was 174 mm Hg. None of the cats had evidence of hypertensive retinopathy or proteinuria. Mean values for echocardiographic variables for the diabetic cats were not significantly different from published values for healthy cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that hypertension does not occur or occurs in only a small percentage of cats with diabetes mellitus.     

Dietary patterns of cats with cardiac disease

OBJECTIVE: To determine nutrient intake and dietary patterns in cats with cardiac disease. DESIGN: Prospective study. ANIMALS: 95 cats with congenital cardiac disease or primary cardiomyopathy. PROCEDURES: Owners completed a standardized telephone questionnaire regarding their cat's diet and a 24-hour food recall to determine daily intake of calories, fat, protein, sodium, magnesium, and potassium. RESULTS: Of the 95 cats, 18 (19%) had a history of congestive heart failure and 73 (77%) had no clinical signs of cardiac disease. Fifty-five percent (52/95) of cats had concurrent disease. Inappetance was reported in 38% (36/95) of all cats and in 72% (68/95) of cats with a history of congestive heart failure. Most (57% [54/95]) cats received treats or table scraps on a regular basis. Approximately half the cats were receiving orally administered medications, supplements, or both. Only 34% (32/68) of owners used food to administer medications to cats. Cats consumed more than the Association of American Feed Control Officials (AAFCO) minimums for protein, sodium, potassium, and magnesium, and nearly all cats consumed more than the AAFCO minimum for fat. Daily nutrient intake was variable for all of the nutrients assessed. CONCLUSIONS AND CLINICAL RELEVANCE: Dietary intake in cats with cardiac disease was variable, but results for dietary supplement use, food use for medication administration, and treat feeding were different from those found in a similar study of dogs with cardiac disease. This information may be useful for treating and designing nutritional studies for cats with cardiac disease.     

Portal Vein Thrombosis in Cats: 6 Cases (2001–2006)

Background: Portal vein thrombosis (PVT) in cats is sparsely reported.
Purpose of Study: To evaluate the clinical signs and diseases associated with PVT in cats.
Animals: 6 client-owned cats.
Methods: Medical records for cats with a portal vein thrombus diagnosed on abdominal ultrasound or at necropsy were reviewed. Signalment, historical data, underlying disorders, clinical findings, clinicopathologic and histopathologic data, diagnostic imaging findings, treatment, and outcome were recorded.
Results: All 6 cats identified with PVT also had hepatic disease. Evidence of a congenital portosystemic shunt was present in 3/6 cats. Two cats had primary or metastatic hepatic neoplasia. One cat had acute cholangitis, acute pancreatitis, and locally extensive acute centrilobular hepatic necrosis. Two cats were suspected to have acute thrombi and 4 cats had chronic thrombi.
Conclusion and Clinical Significance: PVT might be an important concurrent finding in cats with hepatic disease.     

Portal vein thrombosis in cats: 6 cases (2001-2006).

BACKGROUND: Portal vein thrombosis (PVT) in cats is sparsely reported. PURPOSE OF STUDY: To evaluate the clinical signs and diseases associated with PVT in cats. Animals: 6 client-owned cats. METHODS: Medical records for cats with a portal vein thrombus diagnosed on abdominal ultrasound or at necropsy were reviewed. Signalment, historical data, underlying disorders, clinical findings, clinicopathologic and histopathologic data, diagnostic imaging findings, treatment, and outcome were recorded. RESULTS: All 6 cats identified with PVT also had hepatic disease. Evidence of a congenital portosystemic shunt was present in 3/6 cats. Two cats had primary or metastatic hepatic neoplasia. One cat had acute cholangitis, acute pancreatitis, and locally extensive acute centrilobular hepatic necrosis. Two cats were suspected to have acute thrombi and 4 cats had chronic thrombi. CONCLUSION AND CLINICAL SIGNIFICANCE: PVT might be an important concurrent finding in cats with hepatic disease.     

Effect of nonthyroidal illness on serum thyroxine concentrations in cats: 494 cases (1988)

We reviewed the medical records of 494 cats with a variety of nonthyroidal diseases in which serum thyroxine (T4) concentration was determined as part of diagnostic evaluation. The cats were grouped by category of disease (ie, renal disease, congestive heart failure, diabetes mellitus, focal neoplasia, systemic neoplasia, hepatopathy, inflammatory bowel disease, inflammatory pulmonary disease, miscellaneous diseases, or undiagnosed disease), degree of illness (ie, mild, moderate, or severe), survival (ie, lived, died, or euthanatized), and presence or absence of a palpable thyroid gland. The mean (+/- SD) serum T4 concentrations in all 10 groups of cats, which ranged from 10.5 +/- 11.1 nmol/L in cats with diabetes mellitus to 18.7 +/- 7.8 nmol/L in cats with focal neoplasia, were significantly (P less than 0.001) lower than those of normal cats (27.0 +/- 10.4 nmol/L). The number of ill cats with low serum T4 concentrations (less than 10 nmol/L) was highest in the cats with diabetes mellitus (59%), hepatopathy (54%), renal failure (48%), and systemic neoplasia (41%). When the serum T4 concentrations in cats with mild, moderate, and severe illness were compared, mean concentrations were progressively lower (21.3 +/- 6.8, 14.8 +/- 8.1, and 6.5 +/- 5.8 nmol/L, respectively) as degree of illness increased. Severity of illness had a more significant (P less than 0.001) effect in lowering serum T4 concentrations than did disease category. Mean serum T4 concentrations in the cats that died (7.8 +/- 9.8 nmol/L) or were euthanatized (10.0 +/- 7.0 nmol/L) were also significantly (P less than 0.001) lower than those of cats that survived (15.2 +/- 8.8 nmol/L).(ABSTRACT TRUNCATED AT 250 WORDS)     

Primary pulmonic infundibular stenosis in 12 cats: Natural history and the effects of balloon valvuloplasty

ObjectivesTo evaluate the natural history of primary pulmonic infundibular stenosis in cats and the effects of balloon valvuloplasty.BackgroundPrimary pulmonic infundibular stenosis is an uncommon congenital defect in cats. The natural history of the disease has not been described. Information regarding balloon valvuloplasty in the cat is limited.AnimalsRecords between January 1, 1999 and December 31, 2005 were reviewed and cats with a confirmed echocardiographic diagnosis of primary pulmonic infundibular stenosis, a complete medical history, and no evidence of significant systemic disease were identified.MethodsEchocardiographic, electrocardiographic, and radiographic findings are described. The natural history of those with severe disease was compared to those with mild to moderate disease. Balloon valvuloplasty was performed in six of the cats. The technique used is described.ResultsA stenotic gradient ≥70 mmHg and a right ventricular outflow tract (measured at the level of the stenosis) to pulmonary valve annulus ratio of ≤0.25 were consistent with clinical and echocardiographic severe disease. Cats with severe disease had a very guarded prognosis with a high incidence of congestive heart failure (CHF). Balloon valvuloplasty was successfully performed in 4 of the cats and appeared to improve prognosis, especially if performed prior to the development of CHF. Concurrent hypertrophic cardiomyopathy complicated the outcome in some cats.ConclusionsSevere primary pulmonic infundibular stenosis carries a very guarded prognosis in the cat. Balloon valvuloplasty should be considered in the presence of severe disease and should be performed prior to the development of CHF if possible. The presence of concurrent hypertrophic cardiomyopathy may complicate the prognosis.     

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.     

Investigation of serum IGF-I levels amongst diabetic and non-diabetic cats

Since insulin-like growth factor-I (IGF-I) was first discovered as a mediator of glucose homeostasis, it has been extensively investigated in diabetes research in humans, rodents and primates. To date, however, relatively little work has been carried out on this hormone in the cat, despite the pathophysiological similarities between human and feline diabetes mellitus, as well as the relatively common nature of the disease in cats. This study reports on the IGF-I concentrations of 42 insulin treated diabetic cats and 25 normal cats. Diabetic subjects were grouped according to length of insulin treatment as either short, medium or long term. Analysis of variance (ANOVA) and Fischer's pair-wise comparisons revealed that mean IGF-I levels in short-term diabetic cats were significantly lower than those in normal cats whilst mean levels in long-term diabetics were significantly higher. The direction and extent of these alterations may have implications for our understanding of the pathophysiology of feline diabetes mellitus and for the use of this hormone in the diagnosis of acromegaly in diabetic cats.     

Weight loss in cats which eat well

Four cats were investigated because they lost weight while eating well. One cat was found to have hypoinsulinaemic diabetes mellitus, and another had maldigestion caused by exocrine pancreatic atrophy. An enteropathy with presumed intestinal malabsorption was diagnosed in the third case. The fourth cat had hyperthyroidism and disseminated amyloidosis. The diabetic animal has been maintained satisfactorily on daily insulin injections for 2 ½ years, but treatment in the other three cases was either unsuccessful or not attempted. Weight loss is uncommon in cats which are eating well. In investigating this syndrome, it is suggested that initially urine should be tested for glucose and faeces examined for maldigestion or malabsorption. More specific tests for diabetes mellitus, pancreatic maldigestion, intestinal malabsorption or hyperthyroidism might then be indicated.