Journal of Feline Medicine and Surgery

Estimation of the glomerular filtration rate (GFR) is a useful tool in the evaluation of kidney function in feline medicine. GFR can be determined by measuring the rate of tracer disappearance from the blood, and although these measurements are generally performed by multi-sampling techniques, simplified methods are more convenient in clinical practice. The optimal times for a simplified sampling strategy with two blood samples (2BS) for GFR measurement in cats using plasma ⁵¹chromium ethylene diamine tetra-acetic acid (⁵¹Cr-EDTA) clearance were investigated. After intravenous administration of ⁵¹Cr-EDTA, seven blood samples were obtained in 46 cats (19 euthyroid and 27 hyperthyroid cats, none with previously diagnosed chronic kidney disease (CKD)). The plasma clearance was then calculated from the seven point blood kinetics (7BS) and used for comparison to define the optimal sampling strategy by correlating different pairs of time points to the reference method. Mean GFR estimation for the reference method was 3.7±2.5 ml/min/kg (mean±standard deviation (SD)). Several pairs of sampling times were highly correlated with this reference method (r²≥0.980), with the best results when the first sample was taken 30 min after tracer injection and the second sample between 198 and 222 min after injection; or with the first sample at 36 min and the second at 234 or 240 min (r² for both combinations=0.984). Because of the similarity of GFR values obtained with the 2BS method in comparison to the values obtained with the 7BS reference method, the simplified method may offer an alternative for GFR estimation. Although a wide range of GFR values was found in the included group of cats, the applicability should be confirmed in cats suspected of renal disease and with confirmed CKD. Furthermore, although no indications of age-related effect were found in this study, a possible influence of age should be included in future studies.

Dysautonomia is caused by degeneration of the autonomic ganglia. Failure of the autonomic system affecting the gastrointestinal and urinary tracts can cause oesophageal distension and/or dysfunction, gastric and bowel distension and hypomotility, and urinary bladder distension. The aim of this retrospective study was to describe diagnostic imaging findings in cats with dysautonomia. Common findings were megaoesophagus and/or oesophageal dysfunction, gastric distension and signs of intestinal ileus. Associated aspiration pneumonia and megacolon appeared less commonly. Although diagnostic imaging findings are not specific for this disease, if findings in multiple systems are detected, along with consistent clinical signs and neurological deficits, dysautonomia should be considered among the differential diagnosis.

Despite the lack of validated methods for differentiating feral from frightened socialized cats upon intake to animal welfare agencies, these organizations must make handling and disposition decisions for millions of cats each year based on their presumed socialization status. We conducted a nationwide survey of feline welfare stakeholders to learn about methods used to evaluate and categorize incoming cats, amount of time cats are held before assessment, disposition options available, and the level of cooperation among welfare agencies to minimize euthanasia of ferals. A wide variety of assessment methods were described and only 15% of 555 respondents had written guidelines. Holding periods of 1–3 days were common, and cats deemed feral were often euthanased. About half the shelters transferred ferals to trap–neuter–return (TNR) programs at least occasionally. Results highlight the need for validated assessment methods to facilitate judicious holding and disposition decisions for unowned cats at time of intake.

The aim of this study was to use real-time polymerase chain reaction assays to determine the prevalence of three haemoplasma species in cats from Greece and to evaluate possible associations between haemoplasma infection and age, gender, feline immunodeficiency virus/feline leukaemia virus (FIV/FeLV) status and packed cell volume (PCV). Ninety-seven cats (24 ill anaemic, 55 ill non-anaemic, 18 healthy non-anaemic) were included in the study. Twenty cats (20.6%) were haemoplasma positive; seven cats were infected only with Mycoplasma haemofelis, 10 were infected only with ‘Candidatus Mycoplasma haemominutum’ and three were co-infected with M haemofelis and ‘Candidatus M haemominutum’. ‘Candidatus Mycoplasma turicensis’ was not detected. Haemoplasma infection was associated with older age (P=0.019). M haemofelis infection tended to be more common in anaemic cats (P=0.058). No association between gender and haemoplasma infection, or haemoplasma relative copy number and PCV, was detected. Retroviral infection rates were very low with only one FeLV proviral positive cat found.

Urethral obstruction is a common medical emergency in cats. Frequency of post-obstruction diuresis in cats following resolution of urethral obstruction is unknown. The objective of this study was to document frequency and associated clinical features of post-obstruction diuresis in cats. The records of 32 cats undergoing 33 admissions to the Colorado State University Veterinary Hospital for urethral obstruction were reviewed. Signalment, admission blood values, fluid therapy, and urine output were recorded. Diuresis was defined as urine output greater than 2 ml/kg/h. Post-obstructive diuresis occurred in 46% (13/28) of cats within the first 6 h of treatment. Occurrence of post-obstructive diuresis was statistically more likely in cats with venous pH<7.35 on admission. Urine production following resolution of urethral obstruction should be monitored so that fluid therapy can be adjusted to the individual patient, as many cats will have a higher fluid requirement secondary to post-obstruction diuresis.

A new inactivated and adjuvanted Chlamydophila felis vaccine was developed and its efficacy in cats was compared with that of commercially available inactivated and live vaccines. Two commercial vaccines conferred insufficient immunity on inoculated cats, as evaluated by antibody production and a challenge experiment, whereas cats administered the newly generated vaccine produced high-titre antibodies and acquired sufficient immunity. The cats immunised with the new vaccine revealed no or only mild clinical signs, and no chlamydiae were recovered from their tissue samples after exposure to a virulent C felis. However, they shed chlamydiae in their nasal and conjunctival secretions after challenge, as did those immunised with the commercial vaccines and the non-vaccinated controls. The newly developed vaccine caused no adverse reaction in the inoculated cats. These findings suggest that the new vaccine prepared here may be promising for practical use in controlling C felis infection in cats.

Osteoarthritis is the most common arthropathy of mammalian species including cats. Cartilage degradation is central to the disorder and here we present, for the first time, an in vitro model of feline cartilage degradation which will be useful for further studies in this target species. Feline articular cartilage explant cultures were maintained for 28 days and in the presence of oncostatin M with and without interleukin (IL)-17, tumour necrosis factor (TNF), IL-1α, or IL-1β. Media samples and digested cartilage explants were analysed for glycosaminoglycan (GAG) and collagen content. The combination of IL-1β and OSM, both at 20 ng/ml, was able to promote GAG release to the greatest extent at 14 days. At 28 days, all groups showed relatively high release of GAG. At 14 days, only IL-1β and OSM in combination were associated with a statistically significant increase in collagen release over and above control tissue. IL-1β dose-response studies showed that an IL-1β dose of 10 ng/ml promotes a statistically significant increase in GAG breakdown when used with OSM, and higher doses of IL-1β did not result in significantly greater response. The model demonstrated both GAG and collagen degradation and will be of use for further understanding of feline cartilage metabolism and for screening of potential structure-modifying agents to be used in cats.

A proportion of Burmese cats in Australia have an exaggerated post-prandial triglyceride (TG) response after an oral fat tolerance test (OFTT). The aim of this study was to determine (a) whether Burmese cats with presumed lipid aqueous (PLA) had exaggerated post-prandial triglyceridaemia, (b) if Burmese cats with exaggerated post-prandial triglyceridaemia (‘affected’ cats) had decreased lipoprotein lipase (LPL) activity and (c) whether affected cats were more insulin resistant than normal Burmese cats. Of cats with a history of PLA, 4/5 were shown to be lipid intolerant (4 h TG>4.5 mmol/l). Four affected Burmese cats were age, gender and body condition matched to four normal Burmese cats. Serum TG, insulin, non-esterified fatty acids (NEFA), lipoprotein and apolipoprotein concentrations were determined 2 weeks after commencing a standardised high-protein diet, with an OFTT performed 4 weeks later. Affected Burmese cats did not have significantly different fasting insulin, fructosamine, NEFA, apolipoprotein or lipoprotein concentrations compared to control cats. During the OFTT, affected cats had significantly higher 4 h and 6 h serum TG and NEFA concentrations than normal cats. There was a trend for lower LPL activity, higher insulin concentrations (at 4 and 6 h) and higher insulin area under the curve (AUC) during the OFTT in affected Burmese cats compared to controls, although these results failed to reach significance, probably due to the small number of cats studied. Further investigations using larger numbers of cats should focus on reduced LPL activity and insulin resistance as potential causes of delayed TG clearance.

This study's objective was to determine whether a relationship exists between infection or seropositivity to Bartonella species and clinical illness in cats. Blood samples were obtained for Bartonella species isolation and immunofluorescent antibody serology from 298 cats presenting to a tertiary referral hospital. Medical records were searched and the history, physical examination findings and the results of diagnostic testing relating to the visit at which Bartonella species testing was performed were recorded. Fifty-two (17%) samples were seropositive for Bartonella henselae, four (1%) for Bartonella clarridgeiae, and 57 (19%) for both organisms. Nineteen (6.4%) samples were culture positive, 17 for B henselae and two for B clarridgeiae. Gingivostomatitis was associated with Bartonella species isolation (P=0.001), but not seropositivity. There was no association with uveitis, neurologic signs, or chronic kidney disease, and a weak association between seropositivity and idiopathic lower urinary tract disease (feline interstitial cystitis) (P=0.05).

The objective of this retrospective study was to characterize a population of cats from a tertiary care center diagnosed with multiple endocrine disorders, including the specific disorders and time intervals between diagnosis of each disorder. Medical records of 15 cats diagnosed with more than one endocrine disorder were reviewed. The majority of cats were domestic shorthairs, and the mean age at the time of diagnosis of the first disorder was 10.3 years. The most common combination of disorders was diabetes mellitus and hyperthyroidism. Two cats had concurrent diabetes mellitus and hyperadrenocorticism, one cat had concurrent central diabetes insipidus and diabetes mellitus. A mean of 25.7 months elapsed between diagnoses of the first and second endocrine disorder, but this was variable. This study suggests the occurrence of multiple endocrine disorders is uncommon in cats.

All serum protein electrophoresis (SPE) results obtained between 2002 and 2009 from clinical cases presented to the University of Bristol Feline Centre were examined retrospectively. One hundred and fifty-five results met the inclusion criteria. Signalment and final diagnoses were obtained from the case records. Clinical cases were classified as having normal or abnormal SPE results by comparison to reference intervals for SPE created using 77 clinically normal cats. Abnormal results were then further divided according to the specific SPE abnormality. Cases were also categorised, according to the final diagnosis, using the DAMNITV classification system. Of the 155 cases, 136 (87.7%) had abnormal SPE results, most commonly due to a polyclonal increase in gamma globulins. A monoclonal gammopathy occurred in four cats; one with feline infectious peritonitis (FIP), one with lymphoma and two cases of splenic plasmacytoma (one suspected, one confirmed). The most common DAMNITV classification associated with SPE abnormalities was infectious/inflammatory disease (80/136; 58.8%), including 39 cats diagnosed with FIP.

A 12-year-old female neutered cat presented with acute onset unilateral vestibular syndrome, a spontaneous cutaneous wound, polyuria, polydipsia, and diabetes mellitus. Hyperadrenocorticism was demonstrated by means of hyper-responsiveness to adrenocorticotropic hormone stimulation, elevated urine cortisol-to-creatinine ratio, bilaterally enlarged adrenal glands on abdominal ultrasound, and pituitary enlargement on computed tomography imaging. The cat was euthanased and post-mortem histological examination revealed feline skin fragility syndrome; confirmed a pituitary cromophobe macroadenoma; and generalised toxoplasmosis with tachyzoites in the pancreas, bowel and brain. This report is the first to describe the concurrence of macroadenoma pituitary-dependent hyperadrenocorticism and generalised toxoplasmosis in a cat with central vestibular syndrome.

A male Persian cat was presented with persistent fever, anorexia, weakness, hypopyon, nystagmus, and intention tremors. The hemogram showed severe neutropenia and laboratory analysis on cerebrospinal fluid (CSF) smears revealed abundant yeast cells compatible with Paracoccidioides brasiliensis. Urinalysis demonstrated persistent funguria and an increased urine protein-to-creatinine ratio (UPC) in addition to mild azotemia. Long-term therapy with oral fluconazole was effective in controlling the nervous system signs. Funguria was resolved with subcutaneous administration of diluted amphotericin B in a large volume of saline solution for a period of 12 weeks during the second year after initial diagnosis. Throughout 5 years of treatment, no adverse effects were observed and tolerance to the drugs was normal. Due to development of progressive uremic syndrome the animal was euthanased. To the best of our knowledge, this report is the first clinical case described of a nervous and urinary system infection caused by the P brasiliensis in a cat.

A 4-year-old castrated male domestic shorthair presented for 1 week of constipation and tenesmus. A rectal stricture had been diagnosed 8 months prior at the time of adoption and the cat had been successfully managed with stool softeners until presentation. A complete diagnostic work-up failed to reveal an underlying etiology for the stricture and colonoscopy was performed. Endoscopic biopsies of the stricture revealed benign non-specific inflammatory changes. Balloon dilation of the rectal stricture was performed during the initial colonoscopy and 3 and 9 days later. Triamcinolone acetonide was injected into the stricture site with endoscopic guidance during the third dilation procedure. The patient has been monitored for over 27 months; follow-up indicates no signs of tenesmus and repeated rectal examinations reveal no stricture recurrence. This case report demonstrates that endoscopic balloon dilation with intralesional steroid injection represented a minimally invasive and effective option for the treatment of a benign rectal stricture in this cat, and deserves further prospective investigation.