The morphology and behavior of feline cutaneous mastocytomas

Correlation of histopathology with the behavior of cutaneous mastocytomas in 85 cats revealed two distinct histologic subtypes which were predictive of biologic behavior. The first subtype comprised 65 cats of various breeds which had solitary, discrete, dermal tumors composed of slightly atypical mast cells. Most tumors in this group were histologically and behaviorally benign. However, seven solitary tumors with marked anisocytosis and mitotic activity recurred or spread to other sites within 2 to 3 months. The second subtype occurred in 18 cats which had discrete subcutaneous nodules composed primarily of histiocyte-like cells with equivocal cytoplasmic granularity after staining with toluidine blue. They were identified as mast cells by electron microscopy. Seventeen of the 18 affected cats were Siamese. The histiocytic mastocytomas occurred predominantly in young cats (less than 4 years) and were usually multiple. In the four cats of this group for which we have prolonged follow-up data, the tumors underwent apparently spontaneous regression within 2 years of initial tumor detection. Two other cats had tumors which contained mixtures of mast cell and histiocytic morphologies.     

Dietary effects on canine and feline behavior.

The effects of dietary deficiency, including both malnutrition and deficiency of specific vitamins, on behavior is discussed with special emphasis on the growing kitten and puppy. The effect of caloric restriction on behavior is reviewed so that owners can be advised what to expect when their dog is placed on a reducing diet. The evidence for influence of dietary protein and tryptophan on canine aggression is presented. The effect of special diets on canine cognitive dysfunction is reviewed.     

A pilot study using synthetic feline facial pheromone for the management of feline idiopathic cystitis

Synthetic feline facial pheromone (FFP) (Feliway; Ceva Animal Health) was assessed for the management of cats with recurrent feline idiopathic cystitis (FIC). Nine of 12 cats completed the randomised, double-blinded, placebo-controlled, crossover pilot study. They had their environment treated daily with either FFP or placebo for 2 months, after which time the treatment groups were reversed. Owners used visual analogue scales to define the severity of their cat's clinical signs and behavioural changes. Five (56%) of the owners stated that their cat's overall health was better when they were using FFP. Four (44%) of the owners noticed no difference between when using the FFP and when using the placebo. While there were no statistical differences between the two treatment groups there was a trend for the cats exposed to FFP to show fewer days with clinical signs of cystitis (FFP total, mean per cat+/-standard deviation, 30, 4.3+/-6.7; placebo 69, 9.9+/-19.1), a lower overall clinical score (1667, 238+/-476; 2009, 287+/-425), a reduced number of episodes of cystitis (9, 1.3+/-2.0; 10, 1.4+/-2.1) and reduced negative behavioural traits (e.g., less aggression and fear) (-128, -18.3+/-65.8; -73, -10.4+/-35.1).     

Measurement of feline intact parathyroid hormone: Assay validation and sample handling studies

A two-site intact immunoradiometric assay was validated for the measurement of parathyroid hormone (PTH) in the cat, by assessment of precision, sensitivity and specificity. The mean intra- and interassay coefficients of variation were 12·7 and 12·8 per cent, respectively. The sensitivity of the assay was 3·90 pgl/ml. The presence of carboxyl fragment interference was suspected from the non-parallel dilution of two of seven feline samples and the decreased recovery of PTH on addition of carboxyl terminal fragment PTH to samples. The plasma PTH concentration, measured using this assay, in 40 clinically healthy cats was 10·9 ± 5·3 pg/ml (mean ± SD). The assay demonstrated appropriate responses in cases of secondary renal hyperparathyroidism, hypercalcaemia of malignancy and iatrogenic hypoparathyroidism. Storage characteristics would permit posting of samples. This assay will therefore provide a useful non-invasive tool for the diagnosis of disorders of calcium metabolism in the cat.     

检测猫杯状病毒RT-qPCR方法的优化与应用

为建立一种通用性良好的SYBR GreenⅠ荧光定量RT-PCR方法,根据GenBank上猫杯状病毒(feline calicivirus, FCV) ORF1保守区域序列,设计合成1对特异性引物,用于FCV的快速检测。灵敏性试验结果显示,该方法的检测下限为4.93×10¹拷贝/μL,比普通RT-PCR检测下限高100倍;特异性试验结果显示,该检测方法与猫疱疹病毒、猫细小病毒、猫传染性腹膜炎病毒等无交叉反应;通用性试验结果显示,针对引物靶位点区间,该方法对所有已知变异位点的人工合成质粒和本实验室保存的不同变异位点的FCV毒株,均能够良好检出;重复性试验结果显示,组内的变异系数为0.09%～0.71%,组间变异系数为0.05%～0.82%,均小于1%。对23份临床样品进行检测,该方法的阳性检出率为60.9%,检出的14份阳性病料分别接种到CRFK细胞中,对细胞病变产物进行扩增并测序,BLAST对比后结果证实为FCV毒株。结果表明,本试验建立的荧光定量RT-PCR检测方法可用于FCV的快速诊断及流行病学的调查。     

Anesthetic management in feline renal transplantation

Objective To document perioperative and anesthetic management of 30 feline renal transplant recipients (1996–1998). Study design Retrospective clinical study. Animals Thirty adult cats in end‐stage renal failure that underwent heterotopic renal transplantation. Materials and methods The medical records were reviewed from 30 feline heterotopic renal transplant recipients. Cases were included only if they had been treated for hypertension using a beta‐adrenergic antagonist, a calcium channel blocker or hemodialysis. Data regarding signalment, preoperative management, surgical technique, type and doses of anesthetics administered, perioperative hemodynamics and intra‐ and postoperative complications, postoperative analgesia, morbidity and early mortality were recorded. Data were expressed as mean ± SD. Results Preanesthetic medication included a combination of an anticholinergic and an opioid (oxymorphone). Anesthesia induction was performed mostly with isoflurane and oxygen delivered by mask. Anesthesia maintenance was primarily achieved with isoflurane in 100% oxygen. Nitrous oxide was often used as part of the anesthetic technique. The mean duration of anesthesia was 4.6 hours ± 27 minutes. The mean renal allograft ischemic time was 60 minutes. During the anesthetic period, the majority of the recipient cats received either fresh whole blood (FWB) (N = 25, 83%), cross‐matched packed red blood cells (PRBC) (N = 3, 10%) or fresh frozen plasma (FFP) (N = 2, 7%) combined with a balanced electrolyte solution. Blood products administered averaged 63 ± 34 mL and crystalloid 94 ± 62 mL. The most common treated intraoperative complications were hypotension (N = 14, 47%), hypothermia (N = 13, 43%), metabolic acidosis (N = 11, 37%), hypocalcemia (N = 5, 17%), hypoglycemia (N = 4, 13%), hypertension (N = 2, 7%), bradycardia (N = 1, 3%), and ventricular premature contractions (N = 1, 3%). All cats received opioid analgesics postoperatively. Complications observed in the first 24 hours postoperatively were hypertension (N = 20, 67%), hematuria (N = 14, 47%), electrolyte disturbances (N = 9, 30%), temperature imbalances (N = 5, 17%), decreased PCV requiring blood transfusion (N = 5, 17%), decreased perfusion of a foot associated with external iliac anastomosis technique (N = 5, 17%), seizures associated with hypertension (N = 3, 10%), uroabdomen (N = 2, 7%), acute graft rejection (N = 1, 3%) and, corneal ulceration (N = 1, 3%). Survival rates in the perioperative period were 100, 96.7, and 93.4% intraoperatively, at 24 hours, and 7 days following surgery. Conclusion Successful anesthesia can be performed in critically ill renal transplant recipients. However, for optimal graft function and patient survival, normothermia, normovolemia, normotension, and normal acid–base and electrolyte balance should be carefully maintained. Successful anesthetic management requires understanding of the pathophysiology of end‐stage renal disease and the maintenance of homeostasis during the different stages of the perioperative period.     

Understanding feline heartworm infection: disease, diagnosis, and treatment

Feline heartworm disease is a very different clinical entity from canine heartworm disease. In cats, the arrival and death of immature heartworms in the pulmonary arteries can cause coughing and dyspnea as early as 3 months postinfection. Adult heartworms suppress the function of pulmonary intravascular macrophages and thus reduce clinical disease in chronic feline heartworm infection. Approximately 80% of asymptomatic cats self-cure. Median survival time for symptomatic cats is 1.5 years, or 4 years if only cats living beyond the day of presentation are considered. Aberrant worm migration is more frequent than it is in dogs, and sudden death can occur with no prior clinical signs. The bacterial endosymbiont Wolbachia likely contributes to the inflammatory pathology of heartworm disease, but its role is not yet fully clear. Unfortunately, the diagnosis, treatment, and management of feline heartworm disease are far from simple. Antemortem diagnosis is hampered by low worm burdens, the frequency of all-male infections, and nonspecific radiographic lesions. It is up to the veterinarian to determine the correct index of suspicion and choose the right combination of diagnostic tests to achieve an answer. Treatment is symptomatic because adulticide therapy is risky and does not increase survival time. Despite the dangers of feline heartworm disease, less than 5% of cats in the United States are on chemoprophylaxis. It is important for veterinarians to take a proactive preventive stance because heartworm infection in cats is a multisystemic disease that has no easy cure.     

Pharmacologic management of feline hyperthyroidism.

Radioiodine is considered the treatment of choice for hyperthyroidism, but in some situations, methimazole therapy is preferred, such as in cats with preexisting renal insufficiency. Unfavorable outcomes from methimazole are usually attributable to side effects, such as gastrointestinal upset, facial excoriation, thrombocytopenia, neutropenia, or liver enzyme elevations. Because restoration of euthyroidism can lead to a drop in glomerular filtration rate, all cats treated with methimazole should be monitored with blood urea nitrogen and creatinine levels in addition to serum thyroxine (T(4)) and a complete blood cell count. Transdermal methimazole is associated with fewer gastrointestinal side effects and can be used in cats with simple vomiting or inappetence from oral methimazole. Hypertension may not resolve immediately when serum T(4) is normalized, and moderate to severe hypertension should be treated concurrently with atenolol, amlodipine, or an angiotensin-converting enzyme inhibitor.     

Clinical management of the feline urological syndrome

The management of cases of the feline urological syndrome (FUS) is described with particular reference to urethral obstruction in the male cat. Treatment of the obstructive episode and in the post–obstruction period and the prevention of recurrence of blockage in the longer term are discussed and a technique for perineal urethrostomy described.     

Oral glucosamine and the management of feline idiopathic cystitis

Oral glucosamine was compared to a placebo for the management of cats with feline idiopathic cystitis (FIC) in a randomised, double-blinded, placebo-controlled, study. Forty cats with a history of recurrent cystitis due to FIC were divided into two groups and treated daily per os with either 125 mg N-acetyl glucosamine or a placebo for six months. Owners graded their cats' clinical signs at the beginning and end of the study, and kept daily diaries documenting signs of cystitis using visual analogue scales. Further episodes of cystitis were seen in 26 (65%) of the cats during the study. Affected cats experienced a mean of five recurrences (range 1-19) with each recurrence lasting a mean of four days (range 1-64 days). There were no significant differences between the two groups when considering the owners assessments of the mean health score (P>0.5), the average monthly clinical score (P=0.22) or the average number of days with clinical signs (P=0.28). Two cats suffered from such severe recurrent urethral obstruction that they were euthanased; they were both in the placebo group. Compared to the start of the study the majority of cats in both groups improved significantly (P<0.001) (mean health score of each group at the start was 0.5+/-SD 0.5, compared to glucosamine 4.4+/-0.7 and placebo 3.9+/-1.6 at the end). This is believed to have occurred because the owners of 36 of the 40 cats (90%) started feeding more canned cat food. The urine specific gravity at the start of the trial was significantly higher (mean 1.050+/-SD 1.007) than when reassessed one month later (1.036+/-1.010, P<0.01).     

Dietary management of canine and feline chronic renal failure

Nutritional therapy is the mainstay of management of chronic renal failure in dogs and cats. Diets designed for use in renal failure are typically reduced in protein, phosphorus, and sodium content. These and other dietary modifications are designed to prevent or ameliorate clinical signs of uremia, minimize disturbances associated with excesses or losses of electrolytes and minerals, arrest or retard progression of renal failure, and maintain adequate nutrition.     

Evidence for or against efficacy of beta-blockers and aspirin for management of feline cardiomyopathies.

Feline myocardial diseases today are largely represented by disorders involving LV hypertrophy. They may be attended by arrhythmias, congestive heart failure, systemic hypertension, thromboembolic complications, and sudden death. These structural myocardial disorders and their hemodynamic and electrocardiographic derangements may cause or result in variable degrees of diastolic dysfunction. Propranolol and aspirin represent two agents commonly employed to treat feline cardiomyopathies for more than 15 years. Nevertheless, clinical data describing their effect on morbidity and mortality are lacking. It is likely that propranolol administered at moderate to high doses effects favorable responses in some cats with clinical signs attributable to severe hypertrophy, outflow obstruction, or tachyarrhythmias. It is unknown whether clinical improvements are due to direct myocardial effects or (more likely) secondary responses to a beta-adrenergic blockade reduction in heart rate or contractility. Personal experience also indicates that high numbers of cats have received the drug for many years in combination with other therapies (especially furosemide) and remain in a compensated state of heart failure without untoward drug effects. On the other hand, many cardiomyopathic cats experience heart failure, arrhythmias, and death despite treatment with beta-blocking agents. Feline thromboembolism is a devastating complication of cardiomyopathic disorders. Until or unless the primary cause(s) of current diseases is elucidated to promote disease reversal, factors responsible for thrombus formation will accompany the heart diseases, protected from effective management. It appears unlikely that aspirin as currently recommended produces any obvious benefit in treating or preventing thromboembolism. Modifications of therapeutic protocols prescribing these frequently used drugs await well-constructed clinical trials evaluating their efficacy with respect to cardiovascular morbidity and mortality.