Congenital ureteral ectopia in continent and incontinent-related Entlebucher mountain dogs: 13 cases (2006-2009).

BACKGROUND: Ectopic ureters (EUs) associated with varying combinations of urinary incontinence, hydronephrosis, and urinary tract infection have been identified in related North American Entlebucher Mountain Dogs. OBJECTIVES: To characterize the disease phenotype in affected dogs and evaluate possible modes of inheritance. ANIMALS: Twenty client-owned Entlebucher Mountain Dogs. Nine dogs had clinical signs of urinary tract disease. METHODS: Prospective case series in which 17 dogs were evaluated with excretory urography, ultrasonography, and urethrocystoscopy. Three additional dogs were evaluated by necropsy alone. Clinical and pedigree histories from 165 North American Entlebuchers were compiled for analysis. RESULTS: Eleven female and 2 male dogs were found to have EUs. Six females and 1 male were continent. Bilateral intravesicular ectopic ureters (IVEUs) were identified in 9 dogs, bilateral extravesicular ectopic ureters (EVEUs) in 3 dogs, and 1 dog had IVEU and EVEU. Hydronephrosis was identified in 5 dogs, 3 of which had bilateral IVEUs. Two necropsied dogs had bilateral hydronephrosis with presumed ureterovesical junction obstruction associated with chronic granulation tissue or lymphoplasmacytic inflammation. Twenty-six dogs with EUs were identified in the pedigree. Because of incomplete penetrance, mode of inheritance could not be determined. CONCLUSIONS AND CLINICAL IMPORTANCE: Ureteral ectopia is common in North American Entlebucher Mountain Dogs and clinical signs alone could not reliably predict disease phenotype. EVEUs were associated with urinary incontinence and occasionally hydronephrosis. IVEUs were clinically silent or associated with hydronephrosis. Further analyses are necessary to confirm and characterize the hereditary nature of the disorder.

Optimal testing for thyroid hormone concentration after treatment with methimazole in healthy and hyperthyroid cats.

BACKGROUND: Methimazole suppresses thyroid hormone synthesis and is commonly used to treat feline hyperthyroidism. The degree of variation in thyroid hormone concentrations 24 hours after administration of methimazole and optimal time for blood sampling to monitor therapeutic efficacy have not been determined. OBJECTIVE: To assess thyroid hormone concentration variation in serum of normal and hyperthyroid cats after administration of methimazole. ANIMALS: Four healthy cats and 889 retrospectively acquired feline thyroid hormone profiles. METHODS: Crossover and retrospective studies. In the crossover study, healthy cats were treated with increasing doses of oral methimazole until steady state of thyroid suppression was achieved. Thyroid hormones and thyroid stimulating hormone (TSH) were serially and randomly monitored after methimazole. Paired t-tests and a 3-factor analysis of variance were used to determine differences between thyroid hormone concentrations in treated and untreated cats in the crossover study. Thyroid profiles from methimazole-treated hyperthyroid cats were retrieved from the Diagnostic Center for Population and Animal Health database and reviewed. Linear regression analysis evaluated relationships of dosage (mg/kg), dosing interval (q24h versus q12h), and time after methimazole to all thyroid hormone concentrations. RESULTS: All serum concentrations of thyroid hormones were significantly suppressed and TSH was significantly increased for 24 hours after administration of oral methimazole in healthy cats (P < .005). In hyperthyroid cats, there were no significant relationships between thyroid hormone concentrations and time postpill or dosing interval. CONCLUSIONS: Timing of blood sampling after oral methimazole administration does not appear to be a significant factor when assessing response to methimazole treatment.

Serum Cytokine Profiling in Cats with Acute Idiopathic Cystitis.

BACKGROUND: Feline idiopathic cystitis (FIC) is a common lower urinary tract disorder of domestic cats that resembles interstitial cystitis/painful bladder syndrome (IC/PBS) in humans. Diagnosis of FIC is based on clinical signs and exclusion of other disorders because of a lack of specific pathologic findings or other objective biomarkers. Cytokines are potential noninvasive biomarkers to define the presence, severity, and progression of disease, and response to treatment. OBJECTIVES: The objective of this pilot study was to determine concentrations of selected cytokines in serum from healthy cats and cats with acute FIC. ANIMALS: Serum samples from 13 healthy cats and from 12 cats with nonobstructive acute FIC were utilized. METHODS: Multiplex analysis of 19 cytokines (CCL2, CCL5, CXCL1, CXCL12, CXCL8, Flt3L, GM-CSF, IFN-γ, IL-12 (p40), IL-13, IL-18, IL-1ß, IL-2, IL-4, IL-6, PDGF-BB, SCF, sFas, and TNF-α) was performed with a commercially available feline-specific multiplex bead-based assay. RESULTS: Mean serum concentrations of IL-12 (p40; P < 0.0001), CXCL12 (P = 0.002), IL-18 (P = 0.032), and Flt3L (P = 0.0024) were significantly increased in FIC cats compared to healthy cats. GM-CSF, IL-1b, IL-2, and PDGF-BB were undetectable or detected in an insufficient number of cats to allow meaningful comparisons. CONCLUSIONS AND CLINICAL IMPORTANCE: We have identified increased serum concentrations of pro-inflammatory cytokines and chemokines CXCL12, IL-12, IL-18, and Flt3L in FIC-affected cats. These findings suggest potential candidates for noninvasive biomarkers for diagnosis, staging, and therapeutic outcome monitoring of affected cats and provide additional insight into the etiopathogenesis of FIC.

Quantification of Urine Elimination Behaviors in Cats with a Video Recording System.

BACKGROUND: Urinary disorders in cats often require subjective caregiver quantification of clinical signs to establish a diagnosis and monitor therapeutic outcomes. OBJECTIVE: To investigate use of a video recording system (VRS) to better assess and quantify urination behaviors in cats. ANIMALS: Eleven healthy cats and 8 cats with disorders potentially associated with abnormal urination patterns. METHODS: Prospective study design. Litter box urination behaviors were quantified with a VRS for 14 days and compared to daily caregiver observations. Video recordings were analyzed by a behavior analysis software program. RESULTS: The mean number of urinations per day detected by VRS (2.5 ± 0.7) was significantly higher compared with caregiver observations (0.6 ± 0.6; P < .0001). Five cats were never observed in the litter box by their caregivers. The mean number of urinations per day detected by VRS was significantly higher for abnormal cats (2.9 ± 0.7) compared with healthy cats (2.1 ± 0.7; P = .02); there were no apparent differences in frequency between these groups reported by caregivers (0.7 ± 1.0 and 0.5 ± 1.0, respectively). There were no differences in mean urination time between healthy and abnormal cats as determined by VRS or caregivers. Mean cover-up time determined by VRS was significantly longer in healthy cats (22.7 ± 12.9 seconds/urination) compared with abnormal cats (8.7 ± 12.9 seconds/urination; P = .03); differences in cover-up time were not detected by caregivers. CONCLUSIONS AND CLINICAL IMPORTANCE: Caregivers commonly underestimate urination frequency in cats when compared to video-based observations. Video recording appears to facilitate objective assessment of urination behaviors and could be of value in future clinical studies of urinary disorders in cats.

Safety of Intraperitoneal Injection of Adipose Tissue-Derived Autologous Mesenchymal Stem Cells in Cats.

BACKGROUND: Chronic inflammatory diseases are common in cats and mesenchymal stem cells (MSC) are a promising therapeutic approach for management of these disorders. The purpose of this study was to evaluate the safety of intraperitoneal injection of MSC in cats. HYPOTHESIS: Intrapertioneal injection of autologous MSC in cats is safe. ANIMALS: Ten healthy adult purpose-bred cats. METHODS: Mesenchymal stem cells were isolated from subcutaneous adipose tissue collected during ovariohysterectomy and characterized for expression of CD90, CD105 and CD44 and trilineage differentiation. Three weeks postoperatively a complete blood count, serum chemistry profile, urinalysis, and abdominal ultrasound were performed. Five cats then received 1 × 10(6) of autologous MSC/kg of body weight intraperitoneally with ultrasound guidance; 5 additional cats were sham injected. Cats were monitored for 6 weeks with daily physical examinations and weekly clinicopathological evaluations. Abdominal ultrasonography was repeated at weeks 1 and 5 after injection. RESULTS: Serious adverse effects were not observed in any MSC-injected cat. Two animals developed transient lethargy and decreased activity. Jejunal lymph node size was increased in MSC-injected cats compared to controls at weeks 1 (1.38 ± 0.25 versus 0.88 ± 0.25 cm(2); P = .036) and 5 (1.75 ± 0.82 versus 0.79 ± 0.12 cm(2); P = .047). A hyperechoic renal segmental cortical lesion was observed in 1 MSC-injected cat. CONCLUSIONS AND CLINICAL RELEVANCE: Intraperitoneal MSC injection was well tolerated with only mild, self-limiting adverse effects being observed in 2 cats. This route provides a safe means of administration for cell-based treatment in cats.

Cost-effectiveness of the arthritis self-help course.

OBJECTIVE: To evaluate the cost-effectiveness of the Arthritis Self-Help Course in reducing the pain of arthritis, the leading cause of disability in the United States and a common problem among older adults. METHODS: A decision model was used to examine the cost-effectiveness of the Arthritis Self-Help Course among individuals with arthritis over a 4-year analytic horizon from 2 perspectives, namely, society and the health care system. The Arthritis Self-Help Course was assumed to reduce pain by 20% and physician visits for arthritis by 40% among individuals receiving conventional medical therapy. Estimates for program costs, costs for physician visits, and time and transportation costs were derived from the published literature and expert opinion. Sensitivity analyses were conducted on all relevant parameters. Arthritis pain and costs (program, physician visit plus/minus time and transportation) were expressed as cost per person per unit reduction in pain. Because nearly all analyses showed the program to be cost saving, we simply report the reduction in joint pain and the cost savings, because standardizing cost savings is not a useful concept. RESULTS: From both the societal and health care system perspectives, the Arthritis Self-Help Course was cost saving in base-case analyses (reducing pain by 0.9 units while saving $320 and $267, respectively) and throughout the range of reasonable values used in univariate sensitivity analyses. Cost savings were due primarily to reduced physician visits. CONCLUSIONS: The Arthritis Self-Help Course is a cost-saving intervention that further reduces arthritis pain among individuals receiving conventional medical therapy. The benefits for both patients and health care providers warrant its more widespread use as a normal adjunct to conventional therapy.

Exercise studies in horses: 2. The cardiac response to exercise in normal horses and in horses with chronic obstructive pulmonary disease.

The relationship of velocity (v) to heart rate (HR)and of kinetic energy (KE) to heart rate, were investigated in 6 normal horses and in 6 horses with chronic obstructive pulmonary, disease (COPD). Radiotelemetry was used to determine the heart rate while subjects were ridden on a 400m track. Velocity was measured by stop-watch between 2 markers 50 m apart at the end of the track. Kinetic energy was calculated from the formula KE =1/2 Mv2, where M = mass of horse, rider, saddle and bridle (KG) and V = velocity (metres per second). In all subjects, the relationship of velocity to heart rate was a linear one at each individual pace (i.e. walk, trot and gallop). There were however significant differences between the v/HR regression curves of each pace. These differences indicated that the increase in velocity per unit increase in heart rate was greater at the trot than at the walk, and greater at the gallop than at the trot. When data for all paces were combined, the relationship log v/log HR was a linear one. The above findings were also true of the relationship of kinetic energy to the heart rate. In horses, which reached maximal heart rate at a relatively low velocity, the v/HR curve became asymptotic. At comparable submaximal velocities, the heart rate of COPD subjects was approximately 20 beats per minute higher than that of normal subjects. This was also true when the term "kinetic energy per units mass" was substituted for velocity.

Exercise studies in horses: 1. A simple telemetry system for recording excercise ECGs in horses.

A robust low cost portable radiotelemetry system is described for the horse and its method of operation and advantages briefly discussed. The equipment consisted of 2 electrodes forming a bipolar lead, a transmitter, a receiver and a writing device. The sitting, application and immobilising of the electrodes was a most important factor in obtaining good quality recordings. ECGs were recorded at all paces and also while jumping and the results proved satisfactory.

The role of viruses in feline lower urinary tract disease.

Viruses have been implicated as causative agents in the etiopathogenesis of some forms of feline lower urinary tract disease (LUTD). This hypothesis was supported by isolation of feline calicivirus, bovine herpesvirus 4 (strain FeCAHV), and feline syncytia-forming virus from cats with naturally occurring LUTD, and by experimental studies of induced viral urinary tract infection. Results of early clinical studies yielded contradictory results concerning the role of viruses in feline LUTD. However, recent detection of bovine herpesvirus 4 antibodies in feline serum samples and discovery of calicivirus-like particles in crystalline/matrix urethral plugs obtained from cats with naturally occurring LUTD, suggests the need to reexamine the etiopathologic role of viruses using contemporary methods of virus identification and localization.

Prevalence of bovine herpesvirus-4 infection in cats in Central Michigan.

The gammaherpesvirus bovine herpesvirus-4 (BHV-4) has been isolated from a wide variety of animals, including lions and domestic cats. Although BHV-4 antibodies have been detected in normal cats and cats with urinary disorders, the epidemiology and pathogenic role of BHV-4 in cats is unknown. The purpose of this study was to determine the prevalence of BHV-4 antibodies and viral nucleic acid in a population of free-roaming cats. Plasma and peripheral blood leukocyte samples were collected from 52 male and 52 female free-roaming cats impounded at a regional animal control facility in Central Michigan. Plasma concentrations of BHV-4 antibodies were measured with an indirect fluorescent antibody test. Peripheral blood leukocyte DNA was isolated, and a 2-stage polymerase chain reaction with heminested primers delineating a conserved portion of the BHV-4 glycoprotein B gene homologue was used to amplify BHV-4-specific DNA sequences. BHV-4 antibodies were detected in 38 (73%) male and 23 (44%) female cats. Seropositive cats were significantly more likely to be male than female (odds ratio = 3.22; P = .007). Cell-associated viremia was detected in 17 (33%) male and 11 (21%) female cats. Of the 61 seropositive cats, 23 (38%) had a detectable viremia; only 5 (12%) seronegative cats had detectable viremia. Seropositive cats were significantly more likely to be viremic than seronegative cats (OR = 4.30: P = .009). Our results suggest that BHV-4 infection may be more widespread in certain cat populations than previously reported. Furthermore, many cats seropositive for BHV-4 antibodies have a concurrent cell-associated viremia.

Genetic and serologic analysis of feline cell-associated herpesvirus-induced infection of the urinary tract in conventionally reared cats.

The genetic and antigenic nature of feline cell-associated herpesvirus (FeCAHV) was characterized by use of DNA restriction endonuclease analysis, and direct and indirect fluorescent antibody (FA) techniques. Serologic responses of 6 conventionally reared cats with induced FeCAHV urinary tract infection were retrospectively evaluated, using an indirect FA test. The EcoRI, HindIII, and Pst I restriction endonuclease cleavage patterns of FeCAHV DNA were similar to those of bovid herpesvirus 4 (BHV-4; DN599 strain) DNA. Specific fluorescence was observed when FeCAHV-inoculated cell monolayers were reacted with fluorescein-conjugated BHV-4 (DN599 strain) antiserum. Conversely, specific fluorescence was also observed when feline anti-FeCAHV serum and fluorescein-conjugated caprine anti-feline IgG was reacted with BHV-4 (DN599 strain)-infected cell monolayers. At postinoculation week 10, serum antibody titer in cats with FeCAHV-induced urinary tract infection ranged from 1:2,560 to 1:10,240, as measured by use of indirect FA testing. It was concluded that FeCAHV is a member of the BHV-4 group. In addition, the FeCAHV indirect FA test provides a sensitive and specific means of evaluating FeCAHV antibody concentration in exposed cats.

Clinicopathologic and pathologic findings of herpesvirus-induced urinary tract infection in conventionally reared cats.

Clinicopathologic manifestations of induced infection of the feline lower urinary tract with bovid herpesvirus-4 (BHV-4, strain FCAHV) were characterized in 6 conventionally reared adult cats (2 sexually intact males, 2 castrated males, and 2 females). Two additional control cats were exposed with noninfected cell culture control inoculum. Clinical and radiographic signs of lower urinary tract disease were not observed in exposed or control cats. Microscopic hematuria was detected in urine samples collected by cystocentesis from 4 to 6 exposed cats and 1 of 2 control cats. Results of culture of urine for bacteria, mycoplasmas, ureaplasmas, and viruses were consistently negative. Low titer of serum BHV-4 (strain FCAHV)-neutralizing antibodies was detected in 4 of 6 exposed cats, but not in controls. Gross abnormalities of the urinary tract were not observed in any cat. Light microscopic examination of serial sections of the lower urinary tract revealed mild focal lymphoid cystitis in 2 of 6 exposed cats, one of which also had increased amounts of connective tissue and proliferation of blood vessels in the urinary bladder lamina propria. Ninety days after initial exposure, BHV-4 (strain FCAHV) was reisolated from explanted urinary bladder tissues of 5 of 6 exposed cats. Virus was not isolated from tissues of control cats. It was concluded that BHV-4 (strain FCAHV) establishes persistent urinary tract infection in conventionally reared adult male and female cats. However, persistent BHV-4 infection in cats may remain clinically inapparent.

Clinicopathologic analysis of herpesvirus-induced urinary tract infection in specific-pathogen-free cats given methylprednisolone.

The clinicopathologic manifestations of bovid herpesvirus-4 (BHV-4; FCAHV strain)-induced infection of the lower portion of the urinary tract were characterized in 12 adult neutered male and 6 female specific-pathogen-free cats, and were compared with those in 12 neutered male control cats. Six neutered male and 6 female cats were given immunosuppressive doses of methylprednisolone acetate prior to inoculation of their urinary bladders with BHV-4. Six neutered male control cats were given immunosuppressive doses of methylprednisolone acetate prior to inoculation of their urinary bladders with uninfected tissue culture control inoculum. Six additional neutered male control cats were exposed only to uninfected tissue culture control inoculum. All cats were observed for 90 days following inoculation. Dysuria and gross hematuria were observed in only 1 BHV-4-exposed cat. Radiographic abnormalities of the lower portion of the urinary tract were not observed. Microscopic hematuria, crystalluria, and lipiduria were identified with similar frequency in BHV-4-exposed and control cats. Results of urine culturing for bacteria, mycoplasma, ureaplasma, and viruses were negative. Viruses were not isolated from blood leukocytes collected from exposed or control cats. Three to 6 weeks after inoculation, high concentrations of BHV-4 serum antibodies were detected in all exposed cats by an indirect fluorescent antibody test. Light microscopic examination of the urinary tract revealed multifocal lymphoid cystitis in 2 BHV-4-exposed cats. Except for suppurative bronchitis in 1 BHV-4-exposed cat given glucocorticoids, morphologic differences in urinary and extraurinary tissues were not observed. In urinary bladder tissue collected 90 days after inoculation, BHV-4 was reisolated from urinary bladder explants of all but 1 exposed cat. Virus was also isolated from a kidney explant of 1 exposed male cat, and spleen cell co-cultures of 1 exposed female cat given glucocorticoids.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in renal function associated with treatment of hyperthyroidism in cats.

We measured glomerular filtration rate (GFR) estimated by plasma disappearance of 99mTc-labeled diethylenetriaminepentaacetic acid, serum concentrations of thyroxine (T4), creatinine, and urea nitrogen, and urine specific gravity in 13 cats with naturally acquired hyperthyroidism before and 30 days after treatment by bilateral thyroidectomy, and in a group of 11 control cats. Mean (+/- SD) serum T4 concentration decreased from a pretreatment value of 120.46 (+/- 39.21) nmol/L to a posttreatment value of 12.15 (+/- 6.26) nmol/L (P < 0.0001; reference range, 10 to 48 nmol/L). Treatment of hyperthyroidism resulted in a decrease in mean (+/- SD) glomerular filtration rate, from 2.51 (+/- 0.69) ml/kg of body weight/min to a posttreatment value of 1.40 (+/- 0.41) ml/kg/min (P < 0.0001). Mean serum creatinine concentration increased from 1.26 (+/- 0.34) mg/dl to 2.05 (+/- 0.60) mg/dl (P < 0.01). Mean serum urea nitrogen concentration increased from 26.62 (+/- 6.83) mg/dl to a mean postthyroidectomy concentration of 34.92 (+/- 8.95) mg/dl (P < 0.01). All changes were significant. Two cats developed overt renal azotemia after treatment of hyperthyroidism. Our results provide further evidence that treatment of hyperthyroidism can result in impaired renal function. In addition, our results suggest that, in some instances, thyrotoxicosis might mask underlying chronic renal insufficiency.

Use of pamidronate disodium to reduce cholecalciferol-induced toxicosis in dogs.

OBJECTIVE: To determine whether pamidronate disodium can reduce cholecalciferol-induced toxicosis in a dose-related manner. ANIMALS: 20 clinically normal, 8- to 12-month-old male Beagles. PROCEDURE: All dogs were given 8 mg of cholecalciferol (CCF)/kg of body weight once orally, then were randomly assigned to 4 groups of 5 dogs each. Dogs were treated with IV administration of 0.9% NaCl solution (SC group), 0.65 mg of pamidronate/kg in 0.9% NaCl solution (LP group), 1.3 mg of pamidronate/kg in 0.9% NaCl solution (MP group), or 2.0 mg of pamidronate/kg in 0.9% NaCl solution (HP group) on days 1 and 4 after administration of CCF. Dogs were observed for 14 days, and serial blood samples were collected for serum biochemical, electrolyte, and 25-hydroxyvitamin D3 analyses. Urine samples were collected for determination of specific gravity. Glomerular filtration rate (GFR) was determined by plasma iohexol clearance. Histologic examination of renal tissue was performed. RESULTS: One dog in the SC group was euthanatized 3 days after administration of CCF because of severe clinical signs of toxicosis. Dogs in the HP group had significantly higher mean GFR (day 3), serum potassium concentrations (day 14), and urine specific gravity (days 7 and 14) and significantly lower mean serum creatinine concentrations and total calcium X phosphorus concentration product (days 4 and 7) than dogs in the SC group. Dogs in the HP group had no abnormal findings on histologic examination of renal tissue, dogs in the LP and MP groups had trace to mild mineralization of renal tissue, and dogs in the SC group had moderate mineralization and cellular necrosis of proximal renal tubules. CONCLUSIONS AND CLINICAL RELEVANCE: Pamidronate disodium is a potentially useful drug to reduce CCF-induced toxicosis and other causes of hypercalcemia associated with increased bone resorption in dogs.

Use of pamidronate to reverse vitamin D3-induced toxicosis in dogs.

OBJECTIVES: To determine whether pamidronate disodium can reduce vitamin D3-induced hypercalcemia in dogs and whether combination treatment with calcitonin is more effective than treatment with pamidronate alone. ANIMALS: 20 clinically normal male Beagles. PROCEDURE: All dogs were given 8 mg of cholecalciferol (CCF)/kg of body weight once orally, then were assigned randomly to 4 groups of 5 dogs each. Dogs were given 0.9% NaCl solution IV (group 1), calcitonin SC and 0.9% NaCl solution IV (group 2), pamidronate and 0.9% NaCl solution IV (group 3), or a combination of all 3 agents (group 4). Dogs were observed for 28 days, and serial blood and urine samples were collected for determination of serum biochemical, electrolyte, and 25(OH)D3 values, CBC, and urine mineral excretion. Samples of kidney, stomach, lung, aorta, liver, duodenum, and brain were evaluated by light microscopy and quantitative mineral analysis. RESULTS: Two dogs in group 1 were euthanatized 4 days after CCF administration because of severe clinical signs of disease. Dogs in group 3 lost less weight and had significantly lower serum phosphorus, total and ionized calcium, and urinary zinc concentrations, compared with dogs in group 1. On day 4, serum urea nitrogen concentration was significantly lower in dogs of groups 3 and 4, compared with dogs in group 1. Mild to moderate mineralization of kidneys and stomach were observed in the 2 group-1 dogs euthanatized on day 4. CONCLUSIONS: Pamidronate administration effectively prevents CCF-induced hypercalcemia and mineralization of soft tissues. CLINICAL RELEVANCE: Pamidronate is a potentially useful antidote against CCF toxicosis in dogs.

Lymphocytic/plasmacytic gastroenteritis in cats: 14 cases (1985-1990).

Over a 5-year period, lymphocytic/plasmacytic gastroenteritis was diagnosed in 14 cats. Purebred cats were affected significantly (P less than 0.025) more often than nonpurebred cats. Mean age at onset of clinical signs was 6.8 years (range, 1 to 13 years); 11 cats were male. Vomiting and weight loss, each reported in 10 of 14 cats, were the most common clinical signs. Diarrhea was reported in 7 of 14 cats. Alopecia was found in 4 of 14 cats. High hepatic enzyme activities and low plasma protein concentrations were frequent biochemical findings. Hyperemia, hemorrhage, and a roughened or "cobblestone" mucosa were visualized by endoscopy in only 2 of 8 cats with duodenal disease and in 2 of 5 cats with gastric disease. Lymphocytic/plasmacytic inflammation was detected in biopsy specimens from the stomach or duodenum or both in all cats; the duodenum was affected most commonly. Degree of inflammation frequently varied among gastric, duodenal, and colonic specimens from the same cat. Glucocorticoid treatment and dietary management adequately controlled clinical signs in 7 cats, but treatment was ineffective in 6 cats, 5 of which were euthanatized because of severity of clinical signs.

Lymphocytic/plasmacytic colitis in cats: 14 cases (1985-1990).

Lymphocytic/plasmacytic colitis was diagnosed in 14 cats during a 5-year period. Purebred cats were affected significantly (P < 0.001) more often than were nonpurebred cats. Six cats were male and 8 were female. Mean age at onset of clinical signs was 5.1 years (range, 0.5 to 9 years). Hematochezia, observed in 13 cats, was the most commonly reported sign; diarrhea was reported in 11 cats. Mildly high serum alanine transaminase activity and hypokalemia were frequent biochemical abnormalities. Campylobacter sp was cultured from the feces of 1 cat. On endoscopic examination, petechia and hyperemia of the colonic mucosa were detected in 7 of 8 cats. Cats were initially treated with dietary management alone or with a combination of dietary and pharmacologic management. Clinical signs in 7 of 11 treated cats completely resolved, whereas signs in 3 cats were considered improved. One cat was euthanatized when an inadequate response to treatment was observed. Most cats were eventually maintained on dietary management alone.

Acute onset of hypokalemia and muscular weakness in four hyperthyroid cats.

Sudden onset of muscular weakness and ventroflexion of the neck were identified in 4 hyperthyroid cats. In each cat, the onset of clinical signs was associated with an acute decrease in serum potassium concentration. The cause for hypokalemia was undetermined, but could have resulted from deficits in total body potassium content or shifts of potassium from the extracellular space into the intracellular space. The 4 cats responded to administration of potassium. Hyperthyroid cats may be prone to disturbances in potassium homeostasis. Clinicians should be aware of potential changes in potassium homeostasis during the treatment of cats with hyperthyroidism.

Medical dissolution of feline struvite urocystoliths.

The efficacy of a diet designed to facilitate dissolution of feline magnesium ammonium phosphate (struvite) uroliths was evaluated in 30 cases of urolithiasis, sterile struvite uroliths dissolved in a mean of 36 days after initiation of dietary treatment. In 5 cases of urolithiasis, struvite urocystoliths associated with urease-negative bacterial urinary tract infection dissolved in a mean of 23 days after initiation of dietary and antimicrobial treatment. In 3 cases of urolithiasis, struvite urocystoliths associated with urease-positive staphylococcal urinary tract infection dissolved in a mean of 79 days after initiation of dietary and antimicrobial treatment. Dissolution of uroliths in cats fed the treatment diet was associated with concomitant remission of dysuria, hematuria, and pyuria, and reduction in urine pH and struvite crystalluria. In one case, a urocystolith composed of 100% ammonium urate, and in another case, a urolith composed of 60% calcium phosphate, 20% calcium oxalate, and 20% magnesium ammonium phosphate did not dissolve.