Disorders In Cats Research Articles

Follow-up protein profiles in urine samples during the course of obstructive feline idiopathic cystitis

Feline idiopathic cystitis (FIC) is a common lower urinary tract disorder in cats, which often recurs. Published reports document increased urine fibronectin and thioredoxin concentrations in cats with FIC compared with healthy control cats. Therefore, these proteins might be of interest in the pathophysiology of FIC. The purpose of the present study was to evaluate variations in these urine proteins throughout the course of FIC by assessing their concentrations in urine specimens from cats with a history of obstructive FIC. Urine total protein (TP) was measured using the Bradford assay, while urine fibronectin and thioredoxin concentrations were determined by Western blot analysis.Urine TP was significantly higher in cats with obstructive FIC at presentation (day 0) than in healthy control cats (P<0.01). There were significant decreases in urine TP in cats with obstructive FIC after 3months (P<0.01). Significantly higher urine fibronectin (P<0.01) and thioredoxin (P<0.05) concentrations were demonstrated in cats with FIC at day 0 compared to control cats, but there was no significant change over time (P>0.05). Increased concentrations of these proteins over time might reflect ongoing structural and pathological alterations to functional processes in the urinary bladders of cats with obstructive FIC.

Feline CKD: Pathophysiology and risk factors--what do we know?

Chronic kidney disease (CKD) is one of the most frequently encountered disorders in cats, having increased in prevalence in recent decades. Although the underlying cause is rarely identified, the common final outcome of feline CKD is tubulointerstitial fibrosis. Knowledge of CKD pathophysiology is necessary for optimal individualised patient management, especially with regard to diagnosis and treatment of extrarenal complications. CKD is most common in senior and geriatric cats, but should be considered in any feline patient with ureterolithiasis, hyperthyroidism, retrovirus infection, systemic hypertension, cardiovascular disease or urinary tract infection. Most of our knowledge of the pathogenesis of CKD is extrapolated from human nephrology and experimental animal studies. There is, therefore, a need for further studies in cats. The prevalence of clinical signs in feline CKD is well documented. Several concurrent diseases associated with CKD have also been reported in cats, especially in the geriatric population, but there is no or only limited published evidence demonstrating a cause-and-effect relationship between most of these conditions and CKD. Studies performed over the past 15 years have nevertheless allowed identification of major risk factors (proteinuria, plasma phosphate and plasma creatinine) influencing the progression of feline CKD. Clinical signs occur in the late stages of renal disease, so populations at higher risk of CKD should be screened routinely. CKD-associated complications (systemic hypertension, secondary renal hyperparathyroidism, hypokalaemia, anaemia, metabolic acidosis) must not be overlooked as they may affect the progression of disease. Disease progression is itself unpredictable and renal function may remain stable for extended periods. Most cats with early CKD do not progress to end-stage CKD before they die. General practitioners play a major role in screening feline patients at risk of development or progression of CKD.

Spinal dural ossification causing neurological signs in a cat

A six-year-old Ragdoll cat underwent examination due to a six-month history of slowly progressive gait abnormalities. The cat presented with an ambulatory tetraparesis with a neurological examination indicating a C1-T2 myelopathy. Radiographs of the spine showed a radiopaque irregular line ventrally in the vertebral canal dorsal to vertebral bodies C3-C5. In this area, magnetic resonance imaging revealed an intradural extramedullary/extradural lesion compressing the spinal cord. The spinal cord was surgically decompressed. The cause of the spinal cord compression was dural ossification, a diagnosis confirmed by histopathological examination of the surgically dissected sample of dura mater. The cat gradually improved after the procedure and was ambulating better than prior to the surgery. The cat’s locomotion later worsened again due to ossified plaques in the dura causing spinal cord compression on the same cervical area as before. Oral prednisolone treatment provided temporary remission. Ten months after surgery, the cat was euthanized due to severe worsening of gait abnormalities, non-ambulatory tetraparesis. Necropsy confirmed spinal cord compression and secondary degenerative changes in the spinal cord on cervical and lumbar areas caused by dural ossification. To our knowledge, this is the first report of spinal dural ossification in a cat. The reported cat showed neurological signs associated with these dural changes. Dural ossification should be considered in the differential diagnosis of compressive spinal cord disorders in cats.

Mechanisms, causes, investigation and management of vomiting disorders in cats: a literature review.

Vomiting is a common presenting complaint in feline practice. This article differs from previous reviews in that it is an evidence-based review of the mechanisms, causes, investigation and management of vomiting in the domestic cat. Published evidence was reviewed, and then used to make recommendations for clinical assessment, diagnosis, antiemetic drug treatment, dietary management and monitoring of cats presenting with vomiting. The strength of the evidence on which recommendations are made (and areas where evidence is lacking for cats) has been highlighted throughout.

Effusion in the cat: classification of 396 fluids according to a problem-oriented scheme

An effusion is an abnormal accumulation of fluid within a body cavity (abdominal, thoracic, pericardial) and it is a common sign of several disorders in cats. Examination and classification of effusions can help to establish the cause of disease and to provide useful information for diagnosis and prognosis. The aim of this study was to classify feline effusions according to a problem-oriented approach in order to reduce the diagnostic differential. Three hundred and ninety-six thoracic and abdominal feline effusions were classified using both cytological criteria and refractometrical estimates of total protein concentration. This study revealed the high prevalence of lymphorrhagic effusions (23.2 %) and the rarity of bile peritonitis (0.3 %), mesothelial hyper- plasia (0.5 %), and eosinophilic exudates (0.8 %) in the cat. Our problem-oriented classification scheme appears to be clinically useful, providing a reduced diagnostic differential, and drives the clinician to perform additional diagnostic tests.

Computed tomographic findings in dogs and cats with temporomandibular joint disorders: 58 cases (2006–2011)

To describe CT findings in dogs and cats with temporomandibular joint (TMJ) disorders. Retrospective case series. 41 dogs and 17 cats. Medical records and CT images of the skull were reviewed for dogs and cats that were examined at a dentistry and oral surgery specialty practice between 2006 and 2011. Of 142 dogs and 42 cats evaluated, 41 dogs and 17 cats had CT findings consistent with a TMJ disorder. In dogs, the most common TMJ disorder was osteoarthritis; however, in most cases, there were other TMJ disorders present in addition to osteoarthritis. Osteoarthritis was more frequently identified at the medial aspect rather than the lateral aspect of the TMJ, whereas the frequency of osteoarthritic involvement of the dorsal and ventral compartments did not differ significantly. In cats, fractures were the most common TMJ disorder, followed by osteoarthritis. Clinical signs were observed in all dogs and cats with TMJ fractures, dysplasia, ankylosis, luxation, and tumors; however, only 4 of 15 dogs and 2 of 4 cats with osteoarthritis alone had clinical signs. Results indicated that TMJ disorders were frequently present in combination. Osteoarthritis was the most common TMJ disorder in dogs and the second most common TMJ disorder in cats. Computed tomography should be considered as a tool for the diagnosis of TMJ disorders in dogs and cats with suspected orofacial disorders and signs of pain. (J Am Vet Med Assoc 2013;242:69-75).

Assessment of owner willingness to treat or manage diseases of dogs and cats as a guide to shelter animal adoptability

To determine community approaches to medical and behavioral diseases in dogs and cats. Cross-sectional descriptive study. 97 companion animal veterinarians and 424 animal owners. Companion animal veterinarians in central Iowa ranked medical or behavioral diseases or conditions by what they thought most clients would consider healthy, treatable, manageable, or unhealthy (unmanageable or untreatable). In a parallel survey, cat- or dog-owning households in central Iowa responded to a telephone survey regarding the relationship of their animal in the household, owner willingness to provide medical or behavioral interventions, and extent of financial commitment to resolving diseases. One hundred twenty common health or behavioral disorders in cats and dogs were ranked by veterinarians as healthy, treatable, manageable, or unhealthy (unmanageable or untreatable) on the basis of their opinion of what most clients would do. Findings were in congruence with animal owners' expressed willingness to provide the type of care required to maintain animals with many acute or chronic medical and behavioral conditions. In general, owners indicated a willingness to use various treatment modalities and spend money on veterinary services when considering current or previously owned animals as well as hypothetical situations with an animal. Past experiences with veterinary care in which an animal did not recover fully did not diminish the willingness of respondents to use veterinary services again in the future. These results provide a baseline indication of community willingness to address medical or behavioral conditions in dogs and cats. These considerations can be used in conjunction with Asilomar Accords recommendations to assess adoptability of cats and dogs in animal shelters.

Evaluation of fecal α1-proteinase inhibitor concentrations in cats with idiopathic inflammatory bowel disease and cats with gastrointestinal neoplasia

Idiopathic inflammatory bowel disease (IBD) and gastrointestinal lymphoma are common disorders in cats. The aim of this study was to evaluate fecal α1-PI concentrations, a marker of gastrointestinal protein loss, in cats with histopathological evidence of gastrointestinal inflammation or gastrointestinal neoplasia.Fecal and serum samples were obtained from 20 cats with chronic gastrointestinal disease in which endoscopic biopsies were performed. Two groups of cats were assembled based on histopathology: Group A (n=8), mild to moderate IBD; Group B (n=12), severe IBD or gastrointestinal neoplasia. Fecal α1-PI concentrations and serum concentrations of total protein, albumin, globulin, cobalamin, folate, pancreatic lipase immunoreactivity, and trypsin-like immunoreactivity were determined.Nineteen of the 20 diseased cats had elevated fecal α1-PI concentrations, ranging from 1.9 to 233.6μg/g compared to 20 healthy control cats (normal range: ⩽1.6μg/g). Fecal α1-PI concentrations were statistically significantly different between healthy cats and cats of Group A (median: 3.9μg/g, range: 1.3–9.2μg/g, P<0.001) or cats of Group B (median: 20.6μg/g, 4.3–233.6μg/g; P<0.001), and between cats of Groups A and B (P<0.01). Hypoalbuminemia, hypoproteinemia, and hypocobalaminemia were detected in 88%, 83%, and 56% of the diseased cats, respectively.This study suggests that increased fecal α1-PI concentrations in association with low serum albumin and total protein concentrations may be a common finding in cats with IBD or gastrointestinal neoplasia. Furthermore, fecal α1-PI concentrations appear to be higher in cats with severe IBD or confirmed gastrointestinal neoplasia when compared to cats with mild to moderate IBD.

Medial Humeral Epicondylitis in Cats

To describe medial humeral epicondylitis in cats based on radiographic, anatomic, and histologic observations. Prospective cohort study. Feline cadavers (n = 60). Extended craniocaudal, and extended and flexed mediolateral radiographic projections were taken of both elbows of 60 consecutive European shorthair cats that died or were euthanatized. Elbows with new bone formation at the medial epicondyle were dissected and embedded in methyl-methacrylate (MMA). For comparison, both elbows of a cat with no radiographic changes were prepared in a similar manner. Sections of the MMA blocks were Giemsa stained and examined with light microscopy. Bilateral new bone formation was identified radiographically at the medial aspect of the humeral epicondyle in 6 cats (10%). All of these cats had mineral deposition in the humeral head of the flexor carpi ulnaris muscle. Other findings were cartilage damage (n = 3 cats), an additional loose medial joint body (1), and tendinosis (3). The ulnar nerve was flattened and displaced caudally, and signs of chronic epineural fibrosis were present in 2 severely affected cats. Ten percent of this feline population had radiographic evidence of medial humeral epicondylitis with chronic degeneration, mineralization, and metaplastic bone formation in damaged fibrillar matrix involving the origin of the humeral head of the flexor carpi ulnaris muscle. New bone formation caused displacement and compression of the ulnar nerve in severely affected elbows. Based on our findings, medial humeral epicondylitis appears to be a common disorder in cats with potential clinical sequelae.

X-Chromosome Inactivation Pattern Analysis for the Assessment of Cell Clonality in Cats

X-chromosome inactivation pattern (XCIP) analysis has been widely used to assess cell clonality in various types of neoplasms in humans. In the present study, a polymerase chain reaction-based feline XCIP analysis using the feline androgen receptor gene was developed. To construct the system of the analysis, polymorphism in CAG tandem repeats within the feline androgen receptor gene was explored using somatic DNAs from 50 male and 103 female cats. CAG tandem repeats in exon 1 of the feline androgen receptor gene were found to be polymorphic, containing 15 to 22 CAG repeats. Of the 103 female cats, 70 (68%) were heterozygous for the number of CAG repeats, indicating the possible usefulness of XCIP analysis in cats. Application of the feline XCIP analysis to 3 feline mammary gland adenocarcinoma cell lines revealed distinctly skewed XCIPs in these cell lines, indicating their clonal origins. Twelve (80%) of the 15 primary tissue/cell samples obtained from cats with various neoplastic diseases showed skewed XCIPs. Moreover, bone marrow samples from 3 cats with myelodysplastic syndrome were also found to have skewed XCIPs. The polymerase chain reaction-based XCIP analysis developed in this study can provide information on cell clonality in female cats, potentially facilitating the differential diagnosis of various disorders in cats.

Comparison of oral robenacoxib and ketoprofen for the treatment of acute pain and inflammation associated with musculoskeletal disorders in cats: A randomised clinical trial

The objective of the study was to evaluate the efficacy and tolerability of robenacoxib, a selective cyclooxygenase-2 inhibitor, for the treatment of acute pain and inflammation associated with musculoskeletal disorders in cats. The study was a prospective, multi-centre, randomised, blinded, non-inferiority design clinical trial comparing robenacoxib to ketoprofen. A total of 68 cats presenting with pain and inflammation associated with acute musculoskeletal disorders were recruited and allocated randomly to receive, orally once daily for 5-6 days, either 1.0-2.4 mg/kg robenacoxib (n=47) or 1mg/kg ketoprofen (n=21). The primary efficacy endpoint was the total clinician score, which was the sum of clinician numerical rating scale scores for pain, inflammation and mobility. Assessments were made at baseline, on day 2, and day 4 or 5. For the total clinician score, non-inferior efficacy of robenacoxib was demonstrated with a relative efficacy of 1.151 (95% confidence interval 0.872-1.494). Non-inferior efficacy of robenacoxib was also demonstrated for the secondary endpoint of the total owner score. Robenacoxib was superior (P<0.05) to ketoprofen for the owner's assessment of activity and human/animal relationship. The tolerability of both treatments was good as assessed by monitoring adverse events, clinical signs and haematology and serum biochemistry variables.

Clinical evaluation of meloxicam versus ketoprofen in cats suffering from painful acute locomotor disorders

The aim of this study was to evaluate the efficacy and palatability of meloxicam 0.5mg/ml oral suspension, compared to ketoprofen tablets in cats suffering from painful acute locomotor disorders. This single blinded, positively-controlled, randomised, multicentre trial involved 121 client owned cats. Cats received either meloxicam (0.5mg/ml oral suspension) at 0.1mg/kg on day 1 followed by 0.05mg/kg q 24h on days 2-5, or ketoprofen 5mg tablets at 1.0mg/kg q 24h for 5 days. The efficacy of the two treatments was assessed subjectively by clinicians on day 6 using a clinical sum score (CSS). Palatability and accuracy of dosing were also assessed. The baseline CSS was not significantly different between the groups, and after 5 days of treatment the CSS had decreased to a similar extent, reflecting a reduction in pain. There were no significant differences between the CSS of each group at day 6. Both treatments were well tolerated. Meloxicam was significantly more palatable than ketoprofen, and allowed for more accurate dosing. Meloxicam and ketoprofen are a safe and efficacious treatment for acute locomotor disorders in cats. Meloxicam (Metacam) may be associated with superior compliance in clinical practice due to the higher palatability, which results in better ease of administration.

Assessment of feline abdominal adipose tissue using computed tomography.

Obesity is a common nutritional disorder in cats and it increases the risk factors for various diseases. The aim of this study is to suggest a method for the evaluation of feline obesity using computed tomography. The attenuation range from -156 to -106 was determined as the range of feline abdominal adipose tissue. With this range, total (TAT), visceral (VAT) and subcutaneous (SAT) adipose tissues were measured. The best correlation between the adipose tissue in cross-sectional image and entire abdomen volume was obtained at the L3 and L5 levels. The mean VAT/SAT ratio was 1.18±0.32, which was much higher than in humans. The cats with an overweight body condition had a significantly lower VAT/SAT ratio than cats with an ideal body condition. This technique may contribute to both the clinical diagnosis and the experimental study of feline obesity.

Evaluation of orally administered robenacoxib versus ketoprofen for treatment of acute pain and inflammation associated with musculoskeletal disorders in cats

To evaluate the efficacy and tolerability of oral administration of robenacoxib for treatment of acute pain and inflammation associated with musculoskeletal disorders in cats. 155 cats requiring relief of signs of pain and inflammation associated with acute musculoskeletal disorders. The study was a multicenter, prospective, randomized, masked, noninferiority field trial. Cats were allocated randomly to 1 of 3 treatment groups: group 1 (1.0 to 2.4 mg of robenacoxib/kg, q 24 h), group 2 (1.0 to 2.4 mg of robenacoxib/kg, q 12 h [daily dosage, 2.0 to 4.8 mg/kg]), and group 3 (ketoprofen [mean dosage, 1 mg/kg, q 24 h]). All cats were administered tablets PO for 5 or 6 days. The primary efficacy endpoint was the investigator global assessment score, which was the sum of scores of signs of pain, inflammation, and mobility assessed in a masked manner by veterinary investigators at baseline, day 2, and day 4 or 5. Cat owners monitored in a nonmasked manner secondary responses by observation of cats' activity, behavior, appetite, and interactions. Safety was assessed by monitoring adverse events, clinical signs, and hematologic and plasma biochemical variables (before and after treatment). No significant differences were detected among the 3 treatment groups for any primary or secondary efficacy endpoints or for tolerability variables. Robenacoxib tablets administered once daily were significantly more palatable than ketoprofen tablets. Robenacoxib tablets administered once daily had noninferior efficacy and tolerability, and superior palatability, compared with the active control drug, ketoprofen, for the treatment of signs of acute pain and inflammation associated with musculoskeletal disorders in cats.

Evaluation of tissue factor procoagulant activity on the surface of feline leukocytes in response to treatment with lipopolysaccharide and heat-inactivated fetal bovine serum

To use a chromogenic assay to measure tissue factor (TF) activity on the cell surface and in whole cell lysates of feline monocytes in response to treatment with lipopolysaccharide (LPS) and fetal bovine serum (FBS). 14 healthy cats. Peripheral blood monocytes were isolated via density gradient centrifugation followed by adhesion to plastic. Tissue factor procoagulant activity was measured by use of an assay that detects TF-activated factor X, on the basis of cleavage of a chromogenic TF-activated factor X-dependent substrate. Activity was quantified by comparison with a serially diluted human recombinant TF-activated factor x curve. The TF procoagulant activity assay was sensitive and specific for TF. Treatment with LPS stimulated TF procoagulant activity on the surface and in whole cell lysates of isolated feline leukocytes. The LPS response in intact cells was dose dependent and cell number dependent and was inhibited by FBS. Monocyte isolation was inefficient, with monocytes comprising a mean of 22% of the isolated cells. A TF-activated factor X-dependent chromogenic assay that uses human reagents successfully measured surface-expressed and intracellular TF activity of feline monocytes. Treatment with LPS induced TF expression on feline monocytes, but this response was inhibited by FBS. The chromogenic assay was a useful method for measuring TF procoagulant activity in feline cells in vitro and can be used as a research tool to investigate the role of cell-associated TF in thrombotic disorders in cats.

Association of intestinal disorders in cats with findings of abdominal radiography

To compare the radiographic appearance of small and large intestines of cats with various medical conditions and create a quantitative index for interpretation of intestinal diameters on radiographic views of the abdomen. Retrospective cohort study. 74 cats that underwent abdominal radiography. Cats were assigned to 1 of 4 diagnosis categories: no gastrointestinal tract disease (n = 20), nonobstructive gastrointestinal tract disease (32), linear foreign body (LFB; 11), and small intestinal mechanical obstruction not caused by an LFB (11). Abdominal radiographs were evaluated without knowledge of history or diagnosis. Maximum and minimum external small intestine diameter (SID) and colon diameter (CD) were compared; dorsoventral and mediolateral measurements of the cranial end plate of L2 (VEL2) and L5 vertebrae were compared. Dorsoventral height of VEL2 from lateral radiographic views was used to determine maximum-SID:VEL2 and maximum-CD:VEL2 ratios. Gas patterns were evaluated. Nonobstructive gastrointestinal tract disease was more likely than obstruction until a maximum-SID:VEL2 ratio > 2.0. At a maximum-SID:VEL2 ratio of 2.5, probability of a disease not related to the intestinal tract was < 4%. At a maximum-SID:VEL2 ratio of 3.0, probability of a mechanical intestinal obstruction was > 70%. When the maximum-CD:VEL2 ratio was 2.0, probability of LFB was 50%; as the maximum-CD:VEL2 ratio increased beyond 2.0, likelihood of LFB decreased. Both gas pattern and CD correlated with diagnosis category. Normalizing ratios of maximum-SID:VEL2 and maximum-CD:VEL2 obtained from measurements on lateral radiographic views of the abdomen in cats were related to diagnosis category.

Presence and quantification of mast cells in the gingiva of cats with tooth resorption, periodontitis and chronic stomatitis

Objective Mast cells are tissue-dwelling granule-containing immune cells that play a pivotal role in the pathogenesis of inflammation and other processes. The three most common orodental disorders in cats are periodontitis, feline resorptive lesions (FRL), and chronic gingivostomatitis (FCGS). The presence and density of mast cells in the gingiva has been established in healthy cats but not in cats affected by FRL, FCGS or periodontitis. The aim of the present study was to document and quantify the presence of mast cells in the gingiva adjacent to teeth affected by FRL, FCGS or chronic periodontitis. Methods Samples from the gingiva of 32 cats affected by FRL, FCGS or periodontitis were obtained and compared to samples obtained from 7 specific pathogen-free (SPF) cats. Evaluation of mast cells and the inflammatory infiltrate were performed on hematoxylin and eosin, and toluidine blue stained sections. Results Mast cells densities were significantly increased in gingival tissues adjacent to teeth affected by FRL, FCGS or periodontitis in comparison to SPF samples. There were no significant differences between gingival tissues of the FRL, FCGS and periodontitis groups. However, the relative inflammatory score in the FRL group was significantly lower as compared to the FCGS or periodontitis groups, yet with similar density of mast cells. Conclusion In the gingiva of cats affected with FRL, FCGS or periodontitis, there is an increase in the number of mast cells. The high number of mast cells in the FRL group and concurrent mild inflammatory reaction suggests the notion that mast cells may potentially play role in the pathogenesis of FRL.

Ventricular Tachyarrhythmias in 106 Cats: Associated Structural Cardiac Disorders

Ventricular tachyarrhythmias occur in association with cardiac and extracardiac disorders in many species of animals, but information identifying concurrent disorders in cats with such arrhythmias is scarce. We investigated coexisting diseases by retrospectively evaluating medical records of cats with ventricular tachyarrhythmias seen during a 51-month period at 1 institution. For comparative purposes, we evaluated records of dogs with similar arrhythmias during the same time period. All cats and dogs had premature ventricular complexes, accelerated idioventricular rhythm, ventricular tachycardia, or some combination of these arrhythmias, and all had undergone echocardiography during the same visit that led to the diagnosis of ventricular tachyarrhythmia. Most (102/106; 96%) cats had at least 1 echocardiographically apparent abnormality concurrent with ventricular tachyarrhythmias. Ventricular tachyarrhythmias in cats were most commonly associated with myocardial disease (eg, left ventricular concentric hypertrophy [n = 66], restrictive or unclassified cardiomyopathy [n = 17], and dilated cardiomyopathy [n = 6]). When comparing dogs and cats that had ventricular tachyarrhythmias and were diagnosed on the same clinical service of the same institution, an echocardiographically apparent cardiac lesion was seen more often in cats (102/106, 96%) than in dogs (95/138, 69%) (P < .001).

Recombinant Human Thyrotropin Administration Enhances Thyroid Uptake of Radioactive Iodine in Hyperthyroid Cats

Hyperthyroidism is the most diagnosed endocrine disorder in cats and radioiodine (131I) is the treatment of choice. The dose emission rate and radioactivity in urine, saliva, and on hair and paws are determined by the dose of administered 131I. A dose reduction of therapeutic 131I could possibly be achieved after recombinant human thyrotropin (rhTSH) administration as in humans with nodular goiter. rhTSH will increase radioiodine uptake in hyperthyroid cats. Five hyperthyroid cats. Twenty-five micrograms rhTSH (day 1) or 2 mL 0.9% sodium chloride (NaCl) (day 9) was injected IV. One hour later, 11.4 +/- 4.1 (mean +/- SD) MBq 123I was injected IV. Radioactive iodine uptake (RAIU) was measured 6, 12, and 24 hours after rhTSH (RAIU-rhTSH) or NaCl (RAIU-blanco) injection. Blood samples for measurement of TT4 were taken before injection of rhTSH or NaCl (TT4(0)) and at the time of imaging. Percentages of RAIU-rhTSH (and RAIU-blanco) at 6, 12, and 24 hours after administration of rhTSH were 34 +/- 18 (31 +/- 21), 46 +/- 20 (38 +/- 18), and 47 +/- 15 (36 +/- 14). There was a statistically significant effect of rhTSH administration on RAIU (P = .043) but not on serum TT4 concentration. Baseline serum TT4(0) concentration influenced RAIU-rhTSH significantly at 6 hours (P = .037). The increased RAIU observed after rhTSH administration in hyperthyroid cats could lead to a lower therapeutic dose of 131I after rhTSH administration in hyperthyroid cats and decreased risk of environmental and owner contamination during and after hospitalization.

Dyslipidemia in obese cats

Obesity is an important endocrine disorder in cats and is a risk factor for diabetes similar to humans. The goal of this study was to examine the effect of long-term obesity and different diets (high protein, and high carbohydrate supplemented with saturated fatty acids or n-3 polyunsaturated fatty acids) on plasma lipids in the fasted and fed states in 12 lean (LEAN) and 12 obese (OBESE) cats with ultracentrifugation, and nuclear magnetic resonance spectroscopy. OBESE had higher plasma non-esterified fatty acids and triglycerides, as well as very-low-density-lipoproteins (VLDL) consisting primarily of medium-sized particles. The concentration of low-density-lipoproteins (LDL) was comparable between the groups, although OBESE had mostly very small, whereas LEAN had mostly large particles. The concentration of high-density-lipoproteins (HDL) was lower in OBESE and consisted primarily of small particles. Plasma triglycerides, and triglycerides and cholesterol in all lipoproteins increased postprandially. Different diets had little effect on lipids. Our results show that long-term obese cats develop similar lipoprotein changes to humans, yet, hypertension and atherosclerosis have not been described in obese cats. This suggests that dyslipidemia alone is not sufficient to induce hypertension and atherosclerosis. Other anti-atherogenic factors may be present in the obese, dyslipidemic cat.