Journal of Feline Medicine and Surgery

Traditional thinking views apparently non-programmed disruptions of aging, which medical science calls geriatric diseases, as separate from ‘less harmful’ morphological and physiological aging phenotypes that are more universally expected with passage of time (loss of skin elasticity, graying of hair coat, weight gain, increased sleep time, behavioral changes, etc). Late-life disease phenotypes, especially those involving chronic processes, frequently are complex and very energy-expensive. A non-programmed process of homeostatic disruption leading into a death trajectory seems inconsistent with energy intensive processes. That is, evolutionary mechanisms do not favor complex and prolonged energy investment in death. Taking a different view, the naturally occurring feline (Felis silvestris catus) renal model suggests that at least some diseases of late life represent only the point of failure in essentially survival-driven adaptive processes. In the feline renal model, individuals that succumbed to failure most frequently displayed progressive tubular deletion and peritubular interstitial fibrosis, but had longer mean life span than cats that died from other causes. Additionally, among cats that died from non-renal causes, those that had degrees of renal tubular deletion and peritubular interstitial fibrosis also had longer mean life span than those cats with no changes, even though causes of death differed minimally between these latter two groups. The data indicate that selective tubular deletion very frequently begins early in adult life, without a clear initiating phase or event. The observations support a hypothesis that this prolonged process may be intrinsic and protective prior to an ultimate point of failure. Moreover, given the genetic complexity and the interplay with associated risk factors, existing data also do not support the ideas that these changes are simple compensatory responses and that breed- or strain-based ‘default’ diseases are inevitable results of increasing individual longevity. Emerging molecular technology offers the future potential to further evaluate and refine these observations. At present, the existence of plastic and adaptive aging programming is suggested by these findings.

The well recognized cardiac effects of severe hyperkalemia include progressive rhythm and conduction disturbances such as bradycardia, spiked and narrow T waves, widening QRS complex, widening and flattening P wave, disappearance of the P wave, and cardiac arrest. Paradoxically, a heart rate greater than 200 beats/min may coexist with hyperkalemia in some cats. This report describes three cats with moderate to severe hyperkalemia and concurrent rapid heart rate. In each cat, the serum potassium (K⁺) concentration was ≥7.5 mEq/dl with a concurrent heart rate>200 beats/min. In each cat, nine-lead electrocardiograms demonstrate an absence of P waves and a wide-complex tachycardia. Hyperkalemia should be considered in the differential diagnosis when a feline electrocardiogram demonstrates a wide-complex tachycardia without identifiable P waves.

The vast majority of mammary tumors in cats are malignant with high metastatic and mortality rates. This study evaluated clinical, cytological and histopathological aspects of 20 cases of cat mammary masses deriving from the city of Rio de Janeiro. Data on history, macroscopic description, evidence of regional lymph node and distant metastases, clinical examination and treatment were collected. The cats were treated with unilateral mastectomy, unilateral mastectomy plus chemotherapy or chemotherapy alone. Tissues were submitted for cytological and histological evaluation. Histopathological analysis described one case of mammary hyperplasia and 19 cases of adenocarcinoma. Inadequate surgical margins were obtained in two cats while six showed evidence of microscopic invasion in other mammary glands. Multiple mammary involvement and greater tumor size (diameter over 7.05 cm) were correlated with increased chance of local metastases. Ulceration of tumors and metastases were common. These facts support the highly malignant nature of this neoplasia and emphasize the risks associated with delay in diagnosis and treatment of feline patients. In conclusion, mammary palpation should be performed routinely in the clinical practice.

In this study, the cytokine profiles of clinically healthy cats naturally infected with feline coronavirus (FCoV), of cats with feline infectious peritonitis (FIP) and of specific pathogen-free (SPF) cats were investigated in whole blood using a traditional reverse-transcriptase polymerase chain reaction (RT-PCR) assay and a semi-quantitative method of analysis based on computerised quantification of positive bands. The low inter-assay coefficient of variation recorded demonstrated that this method is highly repeatable. Compared with SPF cats, cytokine production was upregulated in most of the samples from FCoV-positive non-symptomatic cats. The appearance of a case of FIP in the cattery was associated with an increased expression of cytokines, in particular there was an increased production of IL-1β and IFN-γ, suggesting that these cytokines might protect infected cats from the disease. This hypothesis was also supported by the low levels of IFN-γ recorded in blood from cats with FIP.

The pathogenesis of chronic rhinitis in cats is poorly understood and consistently effective therapies are not currently available. Therefore, randomized clinical trials were conducted to evaluate a novel immunotherapy for treatment of chronic rhinitis in adult (n=12) and young cats (n=28). In addition, cytokine profiles in cats with chronic rhinitis were compared to those of healthy cats. Cats were treated with a potent stimulator of innate immunity (liposome–IL-2 DNA complexes) and the effects of treatment on clinical signs and immune function were assessed. In adult cats with chronic rhinitis, immunotherapy led to significant improvement in frequency of sneezing but not in other clinical signs when compared to the placebo group, whereas immunotherapy failed to improve clinical signs in younger cats. Analysis of cytokine expression in cats with rhinitis did not reveal evidence of a Th2 cytokine bias in cats with rhinitis. We conclude that chronic rhinitis in cats is not a Th2-biased disease and that immunotherapy may lead to clinical improvement in adult cats with the disease.

The clinical findings, treatment and outcome of suspected clindamycin-associated oesophageal injury in five cats are reported. All cats were treated with one 75 mg clindamycin capsule twice daily (dose range 12–19 mg/kg). Capsules were administered without food or a water bolus. Dysphagia, regurgitation, choking or gagging were seen 3–9 days after starting clindamycin. On oesophagoscopy, three cats had oesophagitis, one of which progressed to stricture formation. Two cats had an oesophageal stricture at first presentation. This is the first report of suspected clindamycin-associated oesophageal injury in cats. It serves to further alert practitioners to the potential for drug-induced oesophageal disorders (DIOD) in cats treated with oral medications and to urge prevention by promoting a change in dosing practices.

A 2-month-old, female cat was presented for abdomen dilation. The patient was undernourished, and severe left hydronephrosis was diagnosed after clinical, ultrasonographical and radiographical examination. Although pyelography was performed in order to visualise the ureteral course, surgery was necessary to reach a final aetiological diagnosis and treatment. At gross examination, the left ureter crossed the renal capsula at the level of the caudal renal pole, and the subcapsular ureteral segment was markedly dilated. Distal to the renal capsula, the left ureter was very thin when compared to the right. The parenchyma of the left kidney, as suggested by ultrasonographical evaluation, was extremely reduced in thickness. An ureteronephrectomy was performed. Histopathological evaluation revealed glomerular sclerosis and diffuse parenchymal fibrosis. Severe hydronephrosis derived from an altered renal pelvic anatomy and abnormal ureteral course determining functional stenosis. Diagnosis of congenital anomaly before development of complications such as hydronephrosis could have allowed a surgical renal capsulectomy and obstruction relief. To the author's knowledge, this is the first report of severe hydronephrosis associated to altered renal pelvic anatomy and proximal ureteral ectopia in cat.

Cerebellar degeneration (abiotrophy) (CD) is a spontaneous and accelerated degeneration of one or several mature cerebellar neuronal cell populations and has been described in many domestic animals, especially in dogs, with numerous breed-related cases. In cats, CD is mentioned as a rare sporadic entity. Late onset CDs are exceptionally uncommon and only two cases are reported in young adults, both aged 18 months. This report describes clinical and pathological findings of a late onset feline CD in a 9-year-old male Persian cat. The cat was presented with a history of progressive ataxia lasting 2 years. Neurological examination revealed severe neurological deficits such as generalised and severe ataxia, hypermetria in all four limbs, and bilateral absence of menace response. The lesion was diffusely localised in cerebellum. On gross pathology, the cerebellum appeared of normal size and shape and kidneys were characterised by mild hyperaemia. Histologically, lesions were limited to the cerebellum and kidneys. In the cerebellum, all cerebellar folia of both hemispheres and the vermis were affected. Changes were characterised by severe and diffuse loss of Purkinje cells, loss of cellularity in the granular layer, mild astrogliosis associated with moderate hypertrophy of Bergmann's glia. Immunohistochemistry for feline parvovirus antigen revealed a negative result. Renal lesions consisted of chronic fibrosis associated with chronic interstitial nephritis. CD is a rare disease and occurs commonly in puppies or young animals, who are clinically normal at birth and usually develop neurological signs within a few weeks or months after birth. This report represents the first case of CD in a middle-aged cat.