Effects of Angled Dynamic Compression Holes in a Tibial Plateau Levelling Osteotomy Plate on Cranially Directed Fragment Displacement.

OBJECTIVE: To compare angled dynamic compression holes in a tibial plateau levelling osteotomy (TPLO) plate to a commercially available TPLO plate in an ovine cadaveric model. STUDY DESIGN: Ovine tibias (40 bones) were mounted on a custom-made securement device and radiopaque markers were placed to aid radiographic measurements. A standard TPLO procedure was performed on each tibia with either a custom-made six-hole 3.5 mm angled compression hole plate (APlate) or a six-hole 3.5 mm standard commercial plate (SPlate). Radiographs were obtained before and after tightening of the cortical screws and evaluated by an observer blinded to the plate. Measurements of cranio-caudal displacement (CDisplacement), proximo-distal displacement (PDisplacement) in relation to the long axis of the tibia, and change in tibial plateau angle (TPA) were determined. RESULTS: CDisplacement was significantly greater in APlate (median 0.85 mm, Q1-Q3: 0.575-1.325 mm) compared to SPlate (median 0.00 mm, Q1-Q3: -0.35-0.50 mm, p < 0.0001). There were no significant differences in the PDisplacement (median 0.55 mm, Q1-Q3: 0.075-1.00 mm, p = 0.5066) or TPA change (median -0.50°, Q1-Q3: -1.225-0.25°, p = 0.1846) between the two plate types. CONCLUSION: APlate increases cranially directed displacement of the osteotomy in a TPLO procedure without causing TPA change. The reduced interfragmentary distance across the whole osteotomy could improve osteotomy healing compared to standard commercial TPLO plates.

Feline ureteral obstruction: a case-control study of risk factors (2016-2019).

OBJECTIVES: Ureteral obstruction (UO) in cats causes acute kidney injury and typically requires surgical intervention. Information is required about potentially modifiable risk factors to inform prevention strategies. METHODS: A case-control study was performed to assess risk factors associated with feline UO. Cases were defined as cats with either of the following: (1) ureteral obstruction (ureteroliths: 13/18; unknown: 5/18) confirmed with pyelography; or (2) a creatinine concentration >140 µmol/l with both UO (ureteroliths: 6/10; blood clots: 3/10; pyonephrosis: 1/10) and pyelectasia ⩾5 mm on abdominal ultra sonography. Controls were defined as cats without evidence of UO on history, physical examination and abdominal ultrasound. Age, sex, breed (domestic shorthair/longhair), diet (predominantly dry, mixed or predominantly moist food), housing (indoors or mixed) and plasma total calcium were evaluated for their association with UO using multivariable logistic regression. A receiver operator characteristic (ROC) curve was created to evaluate the predictive ability of the final model. RESULTS: In total, 168 cats (28 cases, 140 controls) were included. Age, sex, breed, housing and total calcium were not significantly associated with UO; however, diet was. Compared with cats eating a predominantly moist food diet, cats fed a predominantly dry food diet were 15.9 times more likely to develop a UO (95% confidence interval 2.9-295; P = 0.009). There was no difference in the association between diet and UO in cats fed a mixed diet vs cats fed a predominantly moist food diet (P = 0.25). The area under the ROC curve was 72%. CONCLUSIONS AND RELEVANCE: Changes in diet formulation could provide a simple and economical method to reduce the risk of UO.

Renal Crest Proliferative Lesions in Cats with Chronic Kidney Disease.

In a histopathological study of the renal crest (RC) of kidneys of cats with chronic kidney disease (CKD), 58/90 (64%) had epithelial proliferation. Of these, 33 cats had hyperplasia of the collecting duct (CD) epithelium (CDH) alone, eight had hyperplasia of the urothelium covering the RC (RCUH), of which one had concurrent abaxial renal pelvic urothelial hyperplasia (UH), and eight had both CDH and RCUH. CDH or RCUH were present in five cats with marked dysplasia of the CD epithelium (CDD) and four cats with invasive carcinomas, which also had epithelial dysplasia. All nine cats with marked dysplasia or neoplasia of the RC also had substantially altered RC contours due to focal haemorrhage, papillary necrosis or fibrosis. Three of the carcinomas had a strong desmoplastic response. In control cats, both urothelial (RC and renal pelvis) and tubular (CD and distal tubular) cells were immunopositive for cytokeratin (CK; AE1/AE3), tubular epithelial cells were positive for vimentin (Vim) and aquaporin 2 (Aq2), while urothelial cells were positive for p63. PAX8 immunolabelling was difficult to validate. CD and UH labelling was similar to control tissue. While urothelial dysplasia had the same immunolabelling pattern as UH and control tissue, CDD was generally immunonegative for Aq2. As immunolabelling of the four carcinomas did not distinguish between tubular and urothelial origin, with three positive for both Vim and p63, all were broadly designated as RC carcinomas. Overall, proliferative epithelial lesions are common in cats with CKD and form a continuum from simple hyperplasia to neoplasia of the urothelium or CD of the RC.

Assessment of the medium- to long-term radiographically confirmed outcome for juvenile dogs with hip dysplasia treated with double pelvic osteotomy.

OBJECTIVE: To assess the medium- to long-term radiographically confirmed outcomes in juvenile dogs with hip dysplasia (HD) that did and did not undergo double pelvic osteotomy (DPO). STUDY DESIGN: Retrospective case-controlled. ANIMALS: Twenty-six dogs with HD that were candidates for DPO; 22 dogs underwent DPO (16 bilateral, six unilateral); four dogs did not. METHODS: Initial and follow-up radiographs of DPO candidates (2011-2017) that did and did not undergo surgery were reviewed, and the British Veterinary Association and Kennel Club Hip Dysplasia Scheme score (BVA-HD), osteoarthritis score (OAS) and laxity index score (LI) were determined. Baseline and follow-up BVA-HD, OAS, and change in radiographically confirmed scores were compared by using analysis of variance for correlated samples. RESULTS: There was no significant difference in BVA-HD or OAS between surgically treated and nonsurgically treated cohorts at baseline. Follow-up radiographs (median, 49 months) revealed that most (34/38) hips had a BVA-HD ≤10 after DPO, while four of eight hips from the nonsurgical cohort had BVA-HD >10. Follow-up BVA-HD and OAS were lower in hips after surgery (BVA-HD median 2.15, interquartile range [Q1-Q3] 1.3-4.1; OAS median 1.9, Q1-Q3 1.1-4.1) compared with the nonsurgically treated cohort (BVA-HD median 11.4, Q1-Q3 8.1-17.5, P < .01; OAS median 7.0, Q1-Q3 5.1-13.4, P < .01). Seven hips with an LI >1 had no radiographically confirmed progression of osteoarthritis after DPO. CONCLUSION: Double pelvic osteotomy prevented radiographically confirmed progression of osteoarthritis in the medium- to long-term. Laxity index score > 1 was not a contraindication for DPO in this study. CLINICAL SIGNIFICANCE: Double pelvic osteotomy prevents progression of radiographically confirmed features of osteoarthritis in juvenile dogs with HD.

Feline corneal sequestra: outcome of corneoconjunctival transposition in 97 cats (109 eyes).

Case series summary A retrospective study was undertaken to review outcomes of keratectomy and corneoconjunctival transposition in cats with superficial and deep corneal sequestra. Information including pertinent history, signalment, ophthalmological findings and postoperative outcome was collected from medical records. Follow-up was obtained by clinical examination, contact with the referring veterinarians and review of medical records or telephone contact with owners. Ninety-seven cats (109 eyes) were included from 2005-2015. The most commonly affected breeds included Persian, Burmese and Himalayan. The mean age at the time of surgery was 6.8 years (median 6.5 years; range 8.0 months-18.0 years). A corneal sequestrum in the contralateral eye was diagnosed in 28 cats (28.9%). Recurrent corneal sequestration was diagnosed in eight cats (nine eyes), with recurrence occurring a mean of 703 days after surgery (range 29-1750 days). Age, sex, breed, depth of sequestration and concurrent ocular disease in the contralateral eye were compared between cats with and without recurrence, with no risk factors for recurrence identified. Relevance and novel information Excellent surgical outcomes have previously been described in a series of 17 cats with superficial and mid-stromal corneal sequestra. This paper adds further information to the literature by describing a larger series of cats, with corneal sequestra affecting the full range of corneal thickness, and good long-term postoperative outcomes.

Prevalence and risk factors for parent-reported recurrent otitis media during early childhood in the Western Australian Pregnancy Cohort (Raine) Study.

AIM: To describe the prevalence and risk factors of recurrent otitis media (rOM) in an urban Australian population at 3 years of age. METHODS: Cross-sectional examination of prevalence and risk factors of rOM in 2280 participants from the Raine Study enrolled from public and private hospitals in Perth, Western Australia, between 1989 and 1991. Parental report questionnaires at 3 years of age were used for rOM identification, with secondary confirmation by otoscopic examination at 1, 2 or 3 years of age. RESULTS: The prevalence of parent-reported rOM was 26.8% (611/2280) and 5.5% (125/2280) for severe rOM in the Study. Independent associations were found between rOM and the presence of older siblings, attendance at day care and the introduction of other milk products at ≤4 months of age. Independent associations for severe rOM were the presence of allergies and attendance at day care. CONCLUSIONS: Prevalence rates of rOM within the Raine Study children are similar to a number of other known cohorts. Parity, presence of allergies, attendance at day care and introduction of other milk products at ≤4 months are highlighted as specific risk factors for rOM in this population and presence of allergies and attendance at day care being risk factors for severe rOM. Diagnosis of rOM by parent report and the delay between data collection and reporting are limitations of this study. However, as there is very limited data on OM in urban, non-Indigenous Australian children, this study improves our understanding of OM for this group.

Feline CKD: Current therapies - what is achievable?

PRACTICAL RELEVANCE: Treatment of feline chronic kidney disease (CKD) tends to focus on minimising the adverse effects of reduced renal function, rather than addressing an underlying cause. Despite this, and the progressive nature of CKD, treatment can improve quality of life and enable many cats to have long survival times. EVIDENCE BASE: Strong evidence supports the provision of renal diets, which are protein and phosphorus restricted; compliance is improved by gradual dietary transition. Additional phosphorus restriction is achieved by the use of phosphate binding agents, although it is unknown if these yield similar survival benefits to those provided by renal diets. Interventions to control hypokalaemia and hypertension in affected cats are important to prevent serious complications. Administration of benazepril to cats with proteinuric kidney disease has been shown to significantly improve their appetite but not their survival. As CKD progresses, many cats will benefit from treatment to control clinical signs of uraemic gastroenteritis and anaemia.

Urinary tract infections in cats with chronic kidney disease.

Routine urine cultures were performed in cats with chronic kidney disease (CKD) to assess the overall prevalence and clinical signs associated with a positive urine culture (PUC). An occult urinary tract infection (UTI) was defined as a PUC not associated with clinical signs of lower urinary tract disease or pyelonephritis. Multivariate logistic and Cox proportional hazard regression models were used to evaluate the risk factors for an occult UTI and its relationship with survival. There were 31 PUCs from 25 cats. Eighty-seven percent of PUCs had active urine sediments. The most common infectious agent was Escherichia coli and most bacteria were sensitive to amoxicillin-clavulanate. Eighteen of 25 cats had occult UTIs. Among cats with occult UTI, increasing age in female cats was significantly associated with PUC; no significant association between occult UTI and survival was found and serum creatinine was predictive of survival in the short term (200 days) only. In conclusion, among cats with CKD, those with occult UTI were more likely to be older and female, but there was no association with severity of azotaemia. The presence of an occult UTI, when treated, did not influence survival.

Feline chronic kidney disease: can we move from treatment to prevention?

Chronic kidney disease (CKD) is arguably the most common disease of older domestic cats. Recent research has focused on treatment options and prognostic variables. Specifically, the roles of dietary protein, hypertension and proteinuria as potential causes of a progressive decline in kidney function have been evaluated. The value of prescription kidney diets and the prognostic value of proteinuria have been confirmed. However, in contrast to dogs, rodents and people, significant proteinuria is uncommon in the cat and hypertension is not a prognostic indicator. Despite significant progress, the cause of CKD in the overwhelming majority of cats remains unknown and fundamental questions remain unanswered. Treatment of feline CKD is limited to non-specific options until some of the causes and pathophysiological mechanisms that result in chronic tubulointerstitial nephritis are identified.

Association between naturally occurring chronic kidney disease and feline immunodeficiency virus infection status in cats.

OBJECTIVE: To investigate the association between naturally occurring chronic kidney disease (CKD) and FIV infection status in cats in Australia. DESIGN: Case-control study. ANIMALS: 73 cats with CKD and 69 cats without historical, physical, or clinicopathologic evidence of CKD. PROCEDURES: Cats were tested for serum antibodies against FIV glycoprotein 40 (gp40) by use of an immunomigration assay. Information regarding age, breed (purebred or domestic), and sex was obtained from medical records. Analysis was performed on data from cats stratified into 2 age categories (< 11 years old and >or= 11 years old). Univariable and then multivariable analyses were performed to investigate the relationship between CKD and the study variable (FIV infection), the latter analysis accounting for breed (purebred or domestic), sex, and veterinary hospital of origin. RESULTS: Results of multivariable analysis revealed that younger cats with CKD (< 11 years old) were significantly more likely to have positive test results for serum antibodies against FIV gp40 than were cats without CKD. No significant associations were found between CKD and FIV infection, breed, sex, or hospital of origin among older (>or= 11 years old) cats in the multivariable analysis. CONCLUSIONS AND CLINICAL RELEVANCE: Among cats < 11 years of age, those with CKD were significantly more likely to have positive test results for serum antibodies against FIV gp40 than were cats without CKD. It cannot be definitively established from results of this study whether infection with FIV preceded the development of CKD, and the role, if any, of FIV in the establishment or progression of CKD remains to be determined.

Demographics and husbandry of pet cats living in Sydney, Australia: results of cross-sectional survey of pet ownership.

Our aim was to collect baseline data on the age, gender, breed, reproductive status and husbandry (housing, diet, vaccination, veterinary attention) of pet cats living in Sydney. Accordingly, a cross-sectional survey of 2768 households was conducted using a postal questionnaire. The 2006 Sydney residential phone book was used as the sampling frame. Non-responders were re-mailed the questionnaire on two further occasions, 2 and 4 weeks after the first posting. Completed questionnaires were received from 884 households. No pets were kept by 387 (43.8%) respondents. Dogs and cats were owned by 295 (33.4%) and 198 (22.5%) of households, respectively, with 7.8% of households having both cat(s) and dog(s). Fish and birds were the next most popular pets. Of the 198 cat-owning households, 54.0% kept only cat(s), while 46.5% kept cats with other pets. The distribution of cat ownership across Sydney was non-uniform. Each cat-owning household kept 1.3 cats on average, with the majority keeping one (75.8% households) or two (18.7%). For the 260 cats, the mean age was 7.1 years, the median 6 years, with a range of 3 months to 22 years. There were significantly more female (143; 55%) than male cats (117; 45%). Only seven cats (2.7%) were sexually entire, and these were all < or =6 years. Crossbred cats outnumbered pedigree cats by a ratio of 3.3:1. The Burmese was the most common breed, followed by the Persian. The median age of pedigree cats (5.5 years) was significantly lower than for domestic crossbred cats (7.0 years). Most cats were housed both indoors and outdoors (72.6%), with 19.7% being restricted to indoors and/or 'pet park enclosures'. Pedigree cats were significantly more likely than crossbreds to be housed indoors. Most owners fed their cats a combination of commercial dry and canned food (38.1%), although fresh meat was popular also and either fed alone (1.6%) or in combination with dry food (14.4%), tinned food (1.6%) or canned and dry food (25.8%). A diet consisting of dry food alone was fed to cats in 13.4% of households. Ninety percent of cats had been vaccinated at least once, while 72.2% received a vaccination in the last 3 years. Older cats were less likely to have been vaccinated recently than younger cats. Only 5.8% of cats had never visited a veterinarian. For the 243 cats that had received veterinary attention, the average number of years since the last visit was 1.5.

Persistent haematuria and proteinuria due to glomerular disease in related Abyssinian cats.

Eight cases of glomerular disease in young, related Abyssinian cats are described. Haematuria was the most consistent feature. Six cats developed the nephrotic syndrome. The short-term prognosis was good for cats with haematuria and fair for cats with the nephrotic syndrome as oedema resolved in three of the six cats. Light microscopic examination of renal biopsies from three cats was considered normal or revealed only mild abnormalities. In the three cases subjected to necropsy, histological abnormalities included mild mesangial hypercellularity and adhesions between the glomerular tuft and Bowman's capsule consistent with a focal proliferative glomerulopathy. Further investigation into this glomerulopathy will require ultrastructural and immunohistochemical studies to characterise the glomerular abnormality and genetic analyses to investigate its potential to be an inherited disease. Glomerular disease, potentially a familial one, should be considered in the investigation of persistent haematuria or proteinuria in Abyssinian and related cats.

Prevalence of feline immunodeficiency virus infection in domesticated and feral cats in eastern Australia.

Serum samples from 340 pet cats presented to three inner city clinics in Sydney Australia, 68 feral cats from two separate colonies in Sydney, and 329 cattery-confined pedigree and domestic cats in eastern Australia, were collected over a 2-year period and tested for antibodies directed against feline immunodeficiency virus (FIV) using immunomigration (Agen FIV Rapid Immunomigration test) and enzyme-linked immunosorbent assay methods (Snap Combo feline leukaemia virus antigen/FIV antibody test kit, IDEXX Laboratories). Western blot analysis was performed on samples in which there was discrepancy between the results. Information regarding breed, age, gender, housing arrangement and health status were recorded for all pet and cattery-confined cats, while the estimated age and current physical condition were recorded for feral cats. The FIV prevalence in the two feral cat populations was 21% and 25%. The majority of FIV-positive cats were male (60-80%). The FIV prevalence in cattery-confined cats was nil. The prevalence of FIV in the pet cat sample population was 8% (27/340) with almost equal prevalence in 'healthy' (13/170) and 'systemically unwell' (14/170) cats. The age of FIV-positive pet cats ranged from 3 to 19 years; all FIV-positive cats were domestic shorthairs with outside access. The median age of FIV-positive pet cats (11 years) was significantly greater than the median age of FIV-negative pet cats (7.5 years: P<0.05). The prevalence of FIV infection in male pet cats (21/172; 12%) was three times that in female pet cats (6/168; 4%; P<0.05). With over 80% of this pet cat population given outside access and continued FIV infection present in the feral population, this study highlights the need to develop rapid, accurate and cost-effective diagnostic methods that are not subject to false positives created by concurrent vaccination against FIV. This is especially important in re-homing stray cats within animal shelters and monitoring the efficacy of the new vaccine, which has not been challenged against Australian strains. The absence of FIV within cattery-confined cats highlights the value in routine screening and indoor lifestyles. This study provides cogent baseline FIV prevalences in three cat subpopulations which can be used for appraising potential disease associations with FIV in Australia.

Feline cholecystitis and acute neutrophilic cholangitis: clinical findings, bacterial isolates and response to treatment in six cases.

Clinicopathological findings from six cats with confirmed cholecystitis or acute neutrophilic cholangitis are presented. Historical findings included lethargy and anorexia or inappetence of up to five days duration. On physical examination all cats were pyrexic and four out of six were jaundiced and had cranial abdominal pain. Bile samples were obtained by cholecystocentesis at exploratory coeliotomy (two cases) or by percutaneous, ultrasound-guided cholecystocentesis (four cases). Gall bladder rupture and bile peritonitis occurred subsequent to ultrasound-guided cholecystocentesis in one case. The most common bacterial isolate was Escherichia coli (four cases); E coli was isolated alone in two cases, in combination with a Streptococcus species (one case) and in combination with a Clostridium species (one case). Streptococcus species alone was isolated from one case, as was Salmonella enterica serovar Typhimurium. The latter is the first reported case of Salmonella-associated cholecystitis in a cat. Concurrent pancreatic or intestinal disease was detected histologically in three cases. All cases were treated with antimicrobials based on in vitro susceptibility results. Treatment was successful in five cases. One cat with concurrent diffuse epitheliotropic intestinal lymphoma was euthanased. Percutaneous ultrasound-guided cholecystocentesis is an effective, minimally-invasive technique enabling identification of bacterial isolates in cats with inflammatory hepatobiliary disease.