Abstract
ISFM Congress poster session A total of 21 clinical/research abstracts were accepted for presentation at the poster session held during the 2019 ISFM Congress in Cavtat, Croatia, 26–30 June.
SERUM CONCENTRATION OF BISPHENOL A IN ELDERLY CATS
Simona Kovaříková, Petr Marsalek, Monika Habanova, Jarmila Konvalinova
Department of Animal Protection, Welfare and Behaviour, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic Email:
Bisphenol A (BPA) as an endocrine disruptor has been mentioned as one of the possible causes of feline hyperthyroidism because of its presence in epoxy resins that coat inner surfaces of metal cans and owing to its structural similarity to thyroid hormones.
The serum concentration of BPA was measured in samples obtained from 69 cats aged 7–18 years where health status was assessed. It was determined by high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry.
The concentration of BPA was 1.1 ± 0.9 ng/ml. No significant differences in BPA concentration were found between males and females, and cats with different body condition scores. The concentration of BPA significantly (P = 0.017) decreased with age (mature cats, 1.3 ± 1.0 ng/ml; senior cats, 0.8 ± 0.6 ng/ml; geriatric cats, 0.4 ± 0.2 ng/ml; the difference between mature and geriatric cats was statistically significant). A significantly higher (P = 0.001) BPA concentration was found in cats living only indoors when compared with cats with outdoor access (1.3 ± 1.0 ng/ml vs 0.7 ± 0.5 ng/ml). Cats fed with canned food had higher (P = 0.04) BPA concentrations than cats fed with dry food or non-canned meat (1.2 ± 0.9 ng/ml vs 0.8 ± 0.8 ng/ml). Nevertheless, using two-way ANOVA, only the factor of environment (indoor/ outdoor status) was found to be significant (P = 0.02).
Our results document measurable concentrations of BPA in the serum of domestic cats, with lifestyle having a more significant impact than feeding strategy.
This work was supported by IGA VFU Brno 228/2016/FVHE and 230/2018/FVHE.
OUTBREAK OF MYCOBACTERIUM BOVIS TUBERCULOSIS IN UK INDOOR-ONLY CATS ASSOCIATED WITH RAW FOOD FEEDING
Conor O’Halloran, Glynn Woods, Jayne Hope, Danièlle Gunn-Moore
Hospital for Small Animals and The Roslin Institute, The Royal (Dick) School of Veterinary Medicine, Easter Bush Campus, Midlothian, UK Email:
In recent years, feeding cats so-called biologically appropriate raw food (BARF) diets has increased exponentially. Concerns regarding BARF have predominantly included the risk of acquiring infectious diseases pathogens; for example, Escherichia coli and Salmonella species.
We report an outbreak of tuberculosis caused by Mycobacterium bovis, putatively owing to the ingestion of a contaminated BARF diet. Between July 2018 and April 2019, we identified 105 cats exposed to a single brand of commercial venison food, which was subsequently withdrawn following our investigation.
Sixty-eight cats showed clinical signs compatible with active tuberculosis including coughing, weight loss, lethargy and/or the presence of pyo/granulomatous lesions (particularly within the lungs and abdomen). A further 27 cats gave positive results on interferon-gamma release assay (IGRA) testing but showed no signs of active clinical disease, suggesting they had developed latent infections.
This outbreak indicates high penetrance of infection among cats fed the high-risk venison food. These cats have developed clinical signs of severe and rapidly progressive infection that is atypical of UK sylvatic M bovis-associated feline infections. The usual success rate of antituberculous therapy is approximately halved for these cats, with under a third achieving clinical remission. The cases are not limited to high-risk areas of the UK for M bovis; but instead are being diagnosed in indoor-housed cats across the UK, with no access to rodents, wildlife or raw milk. Of greatest concern, three in-contact humans have tested positive for latent tuberculosis. Consequently, clinicians are urged to show extreme caution when dealing with suspicious cases and to contact the authors for advice at the earliest opportunity.
INVESTIGATING THE INFLAMMATORY EFFECT OF NORADRENALINE IN A FELINE PRIMARY URINARY BLADDER CELL CULTURE
Patrícia Hatala, Andrea Lajos, Kata Orbán, Gábor Mátis, Zsuzsanna Neogrády
Department of Physiology and Biochemistry, University of Veterinary Medicine, Budapest, Hungary Email:
Feline idiopathic cystitis (FIC) is one of the most common urinary tract disorders in domestic cats. The pathogenesis of the illness is not well understood, but suggested to be multifactorial. Among other factors, the role of stress should be investigated, because an increased urine noradrenaline (norepinephrine) level has been measured in patients diagnosed with FIC.
In order to study the significance of stress and other possible factors separately in the development of the disease, an in vitro model has been prepared: we have established and characterised a feline primary uroepithelial cell culture for modelling FIC. The bladder, obtained from a euthanised cat (which did not show clinical signs of FIC), was excised followed by overnight incubation at 4°C in sterile minimal essential medium (MEM)-containing dispase. The epithelial cells were scraped from the underlying connective tissue, and then resuspended in trypsin-EDTA solution. Thereafter, cells were washed in MEM supplemented with fetal bovine serum, and were seeded on collagen-coated culture dishes and cultured for 2 weeks. The cell cultures were characterised by Giemsa and immunofluorescence staining. For proving the epithelial origin of the cultured cells, pan-cytokeratin-specific antibody binding was used; to determine the rate of differentiation the uroepithelial cells were labelled with specific uroepithelial-binding anti-uroplakin antibodies.
To investigate the influence of the inflammatory effect of stress on the cultured cells, 10, 100 and 1000 μM of noradrenaline treatment (for 1 h) were used, then the concentration of various inflammatory mediators, such as interleukin (IL)-6 and stromal cell-derived factor 1 (SDF-1), were determined by ELISA. We found that the IL-6 concentration in the culture media in the case of 1000 μM noradrenaline treatment and the SDF-1 concentration of the culture media in the case of 10, 100 and 1000 μM of noradrenaline treatment were increased compared with the non-treated control cells (P <0.05).
Based on our results, it is expected that elevated production of pro-inflammatory cytokines through the action of noradrenaline plays an important role in the development of FIC. However, for a more accurate understanding of the pathomechanism of this disease, further research is needed, and this cell culture can serve as a good model for studying the molecular background of FIC.
FELINE RETROVIRUS-INFECTED HOSPITALISED CATS – AETIOLOGY, COINFECTIONS AND SURVIVAL RATES
Inês C Machado1,2, António J Carvalho1, Joana F Gomes1, Eva G Cunha1,2, Luís M Tavares2, Virgílio S Almeida2, Solange A Gil1,2
1Infectious Diseases Isolation Unit (IDIU), Veterinary Teaching Hospital, Faculty of Veterinary Medicine, University of Lisbon, Portugal
2CIISA – Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Animal Health Department, Lisbon, Portugal
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Retroviral infections are relatively frequent in the Portuguese cat population. Previous studies in stray cats found a 10.2% prevalence of feline immunodeficiency virus (FIV) and a 7.6% prevalence of feline leukaemia virus (FeLV).
The main objectives of this study were to:
(i) estimate the retroviral infection frequency among the hospitalised cat population at the Infectious Diseases Isolation Unit (IDIU) of the Veterinary Teaching Hospital at the University of Lisbon, Portugal, during a 6-year period (2013–2018); (ii) characterise concomitant infections; and (iii) calculate survival rates.
Two hundred and twenty-nine cats were hospitalised at IDIU with clinical signs and lifestyle risk factors for retrovirus infection. Of these, a retrovirus infection was confirmed by laboratory testing in 160 (69.9%). Concomitant infections were present in 47/160 (29.4%) cats, mostly feline infectious upper respiratory tract disease (40/47; 85.1%). The remaining seven concomitant infections included dermatophytosis, and panleukopenia virus, feline coronavirus and multidrug-resistant bacterial infections.
Neoplasia affected 37 (23.2%) cats, including 25 (67.6%) lymphoid/haematopoietic tumours. Severe anaemia was present in 22 (13.8%), gingivitis in 19 (11.9%) and Mycoplasma haemofelis infection in eight (5%) cats.
Of the FIV-positive cats, 73.9% were discharged at first hospitalisation (n = 69), but their survival rate dropped to 56.5% on subsequent admissions. These proportions reduced to 62.2% and 41.9%, respectively, among FeLV-positive cats (n = 76). When coinfection with FIV and FeLV was present (n = 17), a high proportion of cats was discharged at first hospitalisation (70.6%), but their survival rate went down to 35.3% on subsequent admissions.
Overall, concomitant infections were the major reason for hospitalisation of retrovirus-infected cats, and survival rates decreased over time.
This work was supported by CIISA – Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Lisboa, Portugal, Project UID/CVT/00276/2019 (funded by the Foundation for Science and Technology [FCT]) and FCT (Eva Cunha Fellowship SFRH/BD/131384/2017).
ASSESSMENT OF THE 1,2-O-DILAURYL-RAC-GLYCERO GLUTARIC ACID-(6’-METHYLRESORUFIN) ESTER (DGGR) LIPASE ASSAY FOR THE DIAGNOSTIC EFFICACY OF CONCURRENT PANCREATITIS IN CATS WITH HEART DISEASE
Nicole Van Israël, Charlotte M-C Estenbergh
Animal Cardiopulmonary Consultancy (ACAPULCO), Masta, Belgium
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The 1,2-o-dilauryl-rac-glycero glutaric acid-(6’-methylresorufin) ester (DGGR) lipase assay has been well established as a highly reliable screening test for pancreatitis in the general feline population. The objective of this study was to assess the sensitivity and specificity of this test for the diagnosis of concurrent pancreatitis in cats with heart disease.
Medical records of cats with heart disease and with serum lipase measured using the DGGR assay were retrospectively evaluated. Serum lipase levels above 26 U/l were considered indicative of pancreatitis according to the reference values provided by the referral lab (Synlab, Belgium). The diagnosis of pancreatitis was confirmed or ruled out by the presence or absence of clinical signs that could be attributed to pancreatitis and by abnormal findings on pancreatic imaging (ultrasonography).
Of 19 cats with heart disease, four cats showed elevated serum lipase activity (mean: 52 U/l [35–79 U/l]). In none of these four cats could the diagnosis of pancreatitis be confirmed by the presence of clinical signs or by typical findings on pancreatic imaging. Two cats with heart disease were diagnosed with concurrent pancreatitis based on the presence of clinical signs and findings on pancreatic imaging. Both cats tested negative for pancreatitis using the DGGR lipase assay. Based on these results, the sensitivity of the DGGR lipase assay in diagnosing pancreatitis in these cats was 0% while the specificity was 76.5%. The positive predictive value (PPV) and negative predictive value (NPV) of the test were 0% and 86.7%, respectively.
None of the four cats with a positive test result using the DGGR lipase assay appeared to suffer from concurrent pancreatitis. A negative test result could not rule out the presence of pancreatitis in two cats.
Serum lipase activity measured by the DGGR lipase assay should be interpreted with caution in cats with heart disease as false positive and false negative test results may occur. Diagnosis of pancreatitis in these cats should be confirmed by the presence of clinical signs and abnormal findings on abdominal imaging. These preliminary findings need to be confirmed in a larger scale study.
RECTAL PROLAPSE AND HERNIATION OF THE URINARY BLADDER INTO THE PELVIC CANAL IN A YOUNG CAT DIAGNOSED WITH CONGENITAL HYPOTHYROIDISM
Sara Pérez Montagud, Marta Vidal-Abarca Montero, María L Ortiz Gómez, Álvaro J Gutiérrez Bautista, Leticia Tomás Marcelino
Hospital Clínico Veterinario CEU, Universidad Cardenal Herrera, Valencia, Spain
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Primary hypothyroidism was diagnosed in an 8-month-old cat examined because of rectal prolapse and herniation of the urinary bladder. Clinical examination revealed disproportionate dwarfism, retained deciduous teeth, rectal prolapse, absence of the the urinary bladder on caudal abdomen palpation and gait abnormalities.
Serum biochemistry showed severe azotemia (urea 375 mg/dl, reference interval [RI] 20–55 mg/dl, and creatinine 7.34 mg/dl, RI 0.6–2.4 mg/dl) with a urine concentration of >1050, supporting a diagnosis of acute renal failure. Radiography revealed epiphyseal dysgenesis of the vertebrae and long bones. Ultrasonography showed bilateral renal pelvic dilatation, bilateral distended ureters and abnormal extension of the urinary bladder into the pelvic canal. Initially, cystocentesis and intravenous administration of fluids were performed to decrease urea and creatinine levels. Colopexy and cystopexy were chosen to resolve rectal prolapse and herniation of the urinary bladder and the outcome was favourable. Congenital hypothyroidism was confirmed based on low serum concentration of total thyroxine (T4) with high thyroid-stimulating hormone concentration (TSH). Treatment was initiated with levothyroxine (10 μg/kg PO q24h).
Congenital hypothyroidism is a rare disease with variable clinical presentation. This represents the first case report of congenital hypothyroidism presenting with herniation of the urinary bladder into the pelvic canal and acute renal failure at the time of diagnosis. Once rectal prolapse and herniation of the urinary bladder have been resolved, the goal of treatment is normalisation of serum TSH and T4, together with an improvement in clinical signs. Further monitoring will be necessary to adjust the dose of levothyroxine supplementation.
ENVIRONMENTAL LEVELS OF FEL D1 CAN BE LINKED BACK TO A CAT’S SALIVARY LEVEL
Scott Sherrill, Berenice C Bastien, Cari Gardner, Ebenezer Satyaraj
Nestlé Purina Research, Saint Louis, USA Email:
Fel d1 is a major allergen detected in cats’ saliva and hair. Fel d1 elicits IgE responses in >90% of humans allergic to cats. As cats groom, Fel d1 is distributed to the haircoat and then shed with the cat hair and the dander. Its molecular size and structure allows it to adhere to fabrics, carpet and upholstered furniture, and to be continuously airborne, making it one of the easiest allergens to inhale. These characteristics can make it difficult to remove Fel d1 from homes. We investigated if Fel d1 levels in saliva could be related to levels measured on hair, or to environmental levels, such as in the room in which a cat is located.
Saliva and brushed hair were collected multiple times from 16 domestic shorthair cats, and Fel d1 levels were measured with an immunoassay. Hair was also collected from cat beds, and dust plates were left out for a day to collect environmental Fel d1. Spearman correlations were run between salivary and hair Fel d1.
Average levels from brushed hair ranged from 11.9–699.49 μg/g hair. Salivary Fel d1 correlated both with brushed hair (n = 16 cats, r = 0.76, P <0.001) and with hair collected from a cat bed (n = 7 cats, r = 0.79, P = 0.04). Dust plates gave 0 ng/plate in a room with no cat, 1.33 ng/plate with a cat bed and 0.14 ng/plate with the bed of a low-producer cat.
We showed a significant correlation between salivary and hair Fel d1 levels in domestic shorthair cats (Figure 1). Environmental data trended similarly, meaning a cat’s salivary/hair Fel d1 levels could indicate environmental levels. This information could be very useful in possibly matching individuals allergic to cats with cats with lower salivary/hair Fel d1.
Relationship between Fel d1 in saliva and Fel d1 on brushed hair (n = 16 cats, Spearman correlation, r = 0.76, P <0.001)
FIRST IDENTIFICATION OF FILOBACTERIUM RODENTIUM AS A CAUSATIVE AGENT OF BRONCHIAL DISEASE IN TWO CATS
Martina Načeradská1,2, Sona Pekova3
1Veterinar clinic of MVDr Martina Naceradska, Prague, Czech Republic
2The Department of Veterinary Sciences, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Czech Republic
3Tilia Laboratories, Pchery, Czech Republic
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Filobacterium rodentium was originally isolated from rats and had been named ‘cilia-associated respiratory bacillus’. It is a Gram-stain negative, microaerobic, filamentous argentophilic bacterium without flagella. It belongs to the phylum Bacteroides. According to the authors’ knowledge, this bacterium has never been isolated by bronchoalveolar lavage (BAL) in cats.
This report describes the first case demonstrating a potential pathogenic effect of this bacterium in two cats. One of the cats was a 1.5-year-old domestic shorthair (DSH) neutered male; the other was a 6.5-year-old Bengal neutered male. Both were indoor-only cats that never travelled outside of the Czech Republic, with up-to-date vaccinations and deworming. Both of them presented with clinical signs of chronic bronchial disease including intermittent coughing and typical radiographic findings (bronchial lung pattern with ‘doughnuts’ present throughout the whole lung field).
Both cats underwent complete blood work-up, which included a biochemistry profile and haematology and revealed no pathological changes. The Bengal cat had a negative N-terminal pro-B-type natriuretic peptide (NT-proBNP) SNAP test and the DSH cat was examined by a cardiologist, but no pathology of the heart was revealed. The DSH cat’s stool tested negative for lungworms and the Bengal cat underwent preventive antiparasitic therapy (emodepside and praziquantel spot-on) to exclude lungworm disease.
Full profile Mycoplasma species, Chlamydia species, feline herpesvirus-1, feline calicivirus and Bordetella bronchiseptica real-time PCR was performed on BAL fluid from both cats and came back negative. Nevertheless, direct 16S rDNA Sanger sequencing was carried out and identified Filobacterium rodentium as the major agent in the sample, suggesting a potential causative pathogen. Classic cultivation microbiology was performed in both cases, but was negative. Cytology of BAL in both cats was consistent with the clinical presentation of chronic bronchopneumonia.
The DSH cat was treated with sulphonamides according to the published literature, with a complete resolution of clinical signs. The owner of the Bengal cat was not able to complete the course of sulphonamides and so the cat was switched to spiramycin and metronidazole (Stomorgyl; Merial) PO in combination with cefovecin (Convenia; Zoetis) SC and, at the time of writing 3 months later, the cat had not returned with any clinical signs. We conclude that F rodentium might be considered an under-diagnosed cause of upper respiratory tract disease that was not previously associated with chronic lung disease in cats.
STUDY COMPARING DIGITAL SLIDES VS CONVENTIONAL GLASS SLIDES FOR THE DETECTION OF ACID-FAST ORGANISMS IN ZIEHL–NEELSEN-STAINED TISSUE SECTIONS
Melanie J Dobromylskyj1, Catriona Ritchie2
1Finn Pathologists, Histopathology Department, Diss, UK
2Axiom Veterinary Laboratories, Devon, UK
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A virtual or digital slide is produced by digitally scanning histological slides in their entirety, producing a high resolution digital image for the pathologist to assess via a computer screen, rather than assessing direct from the glass slide via a conventional light microscope. Veterinary diagnostic laboratories are increasingly using digital slides for routine diagnostic purposes, including for the diagnosis of mycobacteriosis. The aim of this study was to compare the detection of acid-fast bacilli (AFB) in Ziehl–Neelsen (ZN)-stained tissue sections on digital slides and glass slides, assessing sensitivity, time efficiency, test agreement and overall detection levels for both techniques.
Fifty cases were selected, including cases with no organisms or a variable number present, within a range of tissue types. A single ZN-stained slide per case, anonymised and randomised, was assessed by one histopathologist (MJD), first using digital slides and then via conventional light microscopy of glass slides. Data recorded included whether the case was positive, negative or uncertain in terms of the presence of AFB, a subjective score as to the number of AFB (less than 10; +; ++; +++) and the approximate time taken to locate the first organism (mins).
Overall, the time spent on both methods was very similar, and there was substantial agreement between the two techniques (agreement between the two test methods was 86%; Kappa value = 0.709). There was no suggestion that conventional glass slides (sensitivity = 92%) were more sensitive than digital slides (sensitivity = 85%), especially if the time and technique used to assess them was consistent. The detection levels were very similar, with both methods detecting roughly equal numbers of AFB; differences tended to occur when there were only scant (less than 10) numbers of AFB present, occasionally resulting in false negatives using either technique.
MOTIVATION OF OWNERS TO PURCHASE PEDIGREE CATS
Liran Plitman1,2*, Petra Černá1,3*, Mark J Farnworth4, Rowena MA Packer5, Danièlle A Gunn-Moore1
1Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Easter Bush Campus, Midlothian, UK
2Animal Welfare Unit, Department of Veterinary Services, Ministry of Agriculture and Rural Affairs, Beit Dagan 5025001, Israel
3University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic
4School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Southwell, Nottinghamshire, UK
5Royal Veterinary College, Department of Clinical Science and Services (CSS), Hatfield, UK Joint first authors
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Cats are popular pets worldwide and pedigree cats are becoming increasingly widespread, with brachycephalic breeds being favoured. However, few studies have assessed owners’ motivations for obtaining a cat, their opinions and views following acquisition, and perceptions of their cat’s health and welfare.
This study used an online survey with an international convenience sample to investigate and compare owners’ motivations, perceptions and behaviours prior to, during and following acquisition of non-pedigree (NP), brachycephalic pedigree (BC; ie, Persian and Exotic Shorthair) and non-BC pedigree (P) cats.
The survey received 1367 valid responses (NP, n = 882; P, n = 400; BC, n = 85 [6.2%]). Owners of NP cats acquired their cats in a more spontaneous manner and were less influenced by the cat’s appearance, behaviour and other features than P or BC owners. In contrast, P and BC owners were highly influenced by appearance, with P owners but not BC owners also influenced by the perception of their breed as healthy.
Marked differences were identified in acquisition approaches between groups. BC owners were less likely to undertake significant research before buying their cat, and less likely to consider their cat as healthy (especially related to ocular and skin conditions). BC owners were less likely to recommend BC cats to others, which may reflect their poor health experiences and may provide an avenue for discussion about improvements in breed health. Further research is needed to determine how decisions may be altered to improve potential welfare issues raised by the choice of BC cats based on appearance over health.
COMPARISON OF IN-CLINIC FUJI V-LIP-P LIPASE AND SERUM PANCREATIC LIPASE IMMUNOREACTIVITY IN CATS
Eleanor J Mardell1, Matthew Walker2, Jason Emons2, Daniel Gregory2, Samantha Stannard2, Rand J Wilson3
1Axiom Veterinary Laboratories, Newton Abbot, UK
2MiLab Diagnostics, Harleston, UK
3Finn Pathologists, Harleston, UK
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Surplus from 63 feline serum samples submitted to a reference laboratory for 1,2-o-dilauryl-rac-glycero glutaric acid-(6’-methylresorufin) ester (DGGR) lipase measurement underwent testing as follows: pancreatic lipase qualitative assessment via SNAP fPL, quantitative measurement of pancreatic lipase via Spec fPL, and quantitative measurement of total serum lipase via an in-clinic dry chemistry slide, the Fuji v-Lip-P. Sensitivity, specificity and agreement of the total serum lipase method and the SNAP fPL test were assessed with respect to Spec fPL results.
Feline SNAP fPL results (positive/negative) were compared with the Spec fPL at the negative/equivocal boundary of ≤3.5 μg/l. The SNAP fPL had a sensitivity of 81.58% (95% confidence interval [CI], 62.67–92.26%) and a specificity of 60.00% (95% CI, 38.67–78.88%). Feline Fuji v-Lip-P with a negative/equivocal boundary of ≤29 U/l compared with the Spec fPL ≤3.5 μg/l had a sensitivity of 94.74% (95% CI, 82.25–99.36%) and a specificity of 52.00% (95% CI, 31.31–72.20%). Feline v-Lip-P with a positive/equivocal boundary of ≤39 U/l compared with the Spec fPL ≤5.4 μg/l had a sensitivity of 71.88% (95% CI, 53.25–86.25%) and a specificity of 93.55% (95% CI, 78.58–99.21%) (Table 1).
Summary of performance of Fuji v-Lip-P and SNAP fPL compared with IDEXX Spec fPL
neg/pos = negative/positive
The in-clinic Fuji v-Lip-P lipase slide demonstrated good agreement with Spec fPL measurement and shows promise as an alternative option to the SNAP fPL test as a way to rapidly exclude or confirm pancreatic inflammation in feline patients presenting with clinical signs that suggest pancreatitis.
A MACHINE LEARNING APPROACH FOR ENHANCING FELINE INFECTIOUS PERITONITIS DIAGNOSIS
Dawn E Dunbar1, Simon A Babayan2, Diane D Addie1, Margaret J Hosie3, William Weir1
1School of Veterinary Medicine, University of Glasgow, Glasgow, UK
2Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
3MRC-University of Glasgow Centre for Virus Research, Glasgow, UK
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Cats with feline infectious peritonitis (FIP) often demonstrate non-specific clinical signs that confound diagnosis and no single test can be used to confirm a diagnosis ante mortem. Currently several tests have to be performed, with the results building a body of evidence to support or refute a diagnosis of FIP.
We hypothesise that machine learning can be used to systematically analyse laboratory data generated as part of current diagnostic work-ups, with the aim of improving accuracy and reducing subjectivity. While humans can examine laboratory data, evaluate sets of parameters and provide interpretation, computers offer the capacity to evaluate high-dimensional data sets and recognise patterns instantaneously. In this project, we are exploiting these capabilities by applying a machine learning approach to improving FIP diagnostics, based on the current tests used for FIP diagnosis.
Laboratory data and clinical interpretations for a large number of suspected FIP cases (n = 1498) were randomly sampled to create 10 smaller data sets. Seven different machine-learning algorithms were evaluated on these data sets. The models were trained according to the expert interpretations of the laboratory results and their accuracy was evaluated. A comparison of seven models revealed that the mean accuracy ranged from 95.4% (95% confidence interval [CI], 93.6–97.2%) for a logistic regression model to 99.0% (95% CI, 98.2–99.7%) for an XGBoost tree-based algorithm.
These results demonstrate that when machine learning is applied to high quality laboratory data sets, samples from cats with a high index of suspicion of FIP can be accurately and efficiently identified. This technology, therefore, offers enormous potential in terms of standardising and improving diagnostics for this important disease of cats.
CAT POISONING EPISODES REGISTERED IN NORTHEASTERN ITALY BETWEEN JANUARY 2014 AND MARCH 2019
Michela Corrò, Roberto Perin, Laura Lucchese
Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy
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Under Italian legislation (Directive 18/12/2008) the reporting of any suspected case of poisoning to the competent authorities is mandatory. The Istituto Zooprofilattico Sperimentale delle Venezie (IZSVE, Padua, northeastern Italy) is one of the official institutions performing animal necropsies and toxicological analyses on baits or organs when poisoning is suspected.
Accidental poisoning may occur, although malicious cases are also reported in domestic animals, of which cats seem to be the most frequently involved.
Our work reports the toxicological data collected between January 2014 and March 2019 at the IZSVE Padua Laboratory.
One hundred and thirty cat samples (mainly carcases) were treated as suspected cases. Necropsy excluded poisoning in 25/130 samples; in the other cases toxicological analyses were performed to detect a spectrum of main toxic substances, since no robust pathognomonic findings had emerged at necropsy.
Chemical tests included: chlorinated, phosphorus and carbamate pesticides; metaldehyde; anticoagulant rodenticides; strychnine; and zinc phosphide. Suspected poisoning by ethylene glycol was assessed on the basis of specific pathological lesions in kidneys (calcium oxalate precipitates in the renal tubules and plasma cellular nephritis).
Sixty-one cat samples (58%) tested positive after toxicology screening, with carbamate pesticides (21.9%), metaldehyde (9.5%) and anticoagulant rodenticides (4.7%) being the most frequently detected substances; phosphorus and chlorinated pesticides (3.8% and 1.9%, respectively) were found in lower percentages, while no strychnine or zinc phosphide was identified. Seventeen percent of cats showed ethylene glycol histological lesions in the kidneys. Data reveal that animal poisoning episodes are more frequent in the spring, with meaningful peaks in April, between September and November, and in January.
PNEUMONIA ASSOCIATED WITH MYCOBACTERIUM LEPRAEMURIUM IN A 4-YEAR-OLD CAT
Anna De Nitto1, Nicola Decaro2, Andrea Armenise1, Alessandra Barlaam3, Stefano Bo4, Grazia Greco2
1Santa Fara Veterinary Hospital, Bari, Italy
2Department of Veterinary Medicine, University of Bari Aldo Moro, Bari, Italy
3Department of Science of Agriculture, Food and Environment (SAFE), University of Foggia, Italy
4Bo-Ferro Veterinary Clinic Association, Turin, Italy
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A 4-year-old female spayed domestic shorthair cat was presented to Santa Fara Veterinary Hospital, Bari, Italy, for respiratory distress after a 3-month history of a chronic cough. The cat was born and lived in the UK until it was moved to Italy 4 months prior to the onset of clinical signs.
Alveolar–interstitial patterns with air bronchogram in the left cranial and right middle lung lobes were revealed by radiographic and ultrasonographic thoracic evaluations. Subpleural lung consolidations were also observed. A CT scan confirmed these findings, also revealing the presence of multiple non-defined nodules in both hemithoraces. Bronchoscopy and bronchoalveolar lavage were performed and the cytologic examination showed a neutrophilic inflammation with many activated macrophages (dust cells).
Ultrasound-guided fine-needle aspiration (FNA) biopsies from the left subpleural consolidations were subjected to analysis for aerobic/anaerobic bacteria, mycoplasmas and fungal infections, using standard culture methods. FNA biopsies and blood samples were also screened for Chlamydia species, Mycobacterium species, feline calicivirus, feline herpesvirus, feline immunodeficiency virus and feline leukaemia virus using molecular methods.
Mycobacterium lepraemurium infection was diagnosed in FNA samples based on positive results of the Mycobacterium species PCR and sequence analysis of a 550-base pair (bp) fragment encompassing the V2V3 hypervariable region of the 16S rRNA gene. Samples tested negative for other targets.
After 3 months of therapy with doxycycline, pradofloxacin and clarithromycin at 10 mg/kg q24h, 4.5 mg/kg q24h and 9 mg/kg q12h, respectively, prednisolone was added at 0.5 mg/kg q12h to reduce clinical signs. After 1 month, clinical and radiographic signs improved. At the time of writing, the cat is still being monitored.
This report describes the atypical pulmonary localisation of M lepraemurium in a cat, in the absence of skin lesions.
INVESTIGATION OF PATHOLOGICAL HAEMORRHAGE IN MAINE COON CATS
Conor O’Halloran1*, Petra Černá1,2*, Craig Breheny1, Nicky Reed3, Kerry Simpson4, Sue Cade5, Jaime Jones5, Richard Brown6, Suzy Slade7, Kostas Papasouliotis8, Danièlle A Gunn-Moore1
1Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Easter Bush Campus, Midlothian, UK
2University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic
3Wear Referrals Veterinary Hospital, Stockton-On-Tees, UK
4Highcroft Veterinary Referrals, Bristol, UK
5Animal Health Trust, Diagnostic Laboratory Services, UK
6Bardsea (Strathbogie Veterinary Centre), Aberdeenshire, UK
7Brilthor Maine Coons, Aberdeenshire, UK
8IDEXX Laboratories, Grange House, Sandbeck Way, Wetherby, UK
*Joint first authors
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Afibrinogenaemic haemorrhage has been previously reported in a Maine Coon cat. Two littermates subsequently died from surgical non-haemostasis, suggesting a heritable coagulopathy.
We prospectively recruited cats that were: (i) Maine Coons with pathological haemorrhage (group 1, n = 8); (ii) healthy familial relatives of group 1 (group 2, n = 13); and (iii) healthy Maine Coons unrelated to groups 1 and 2 (group 3, n = 12). Cats were convenience blood sampled and coagulation tests – prothrombin time, activated partial thromboplastin time and thrombin clotting time (TCT) – were performed on citrated plasma, along with quantification of fibrinogen. Routine haematological examination was performed on EDTA-anticoagulated blood collected contemporaneously.
Thirty-three blood samples were analysed. Fibrinogen concentrations were significantly reduced in groups 1 (P <0.01) and 2 (P <0.01) compared with group 3. Similarly, TCT was found to be significantly extended in group 1 (P <0.01) and group 2 (P = 0.02) with respect to group 3.
Dysfibrinogenaemia was identified in clinical cases and their healthy relatives, supporting the hypothesis that this is a hereditary condition of Maine Coon cats. Clinicians should be aware of the increased potential for non-haemostasis in this cat breed and consider assessing clotting function prior to (elective) surgery.
LOWER URINARY TRACT FOREIGN BODY IN A CAT
Julien Cheylan, Julien Dahan, Brice S Reynolds, Olivier Dossin
Université de Toulouse, ENVT, Toulouse, France Email:
A 6-year-old female domestic shorthair cat presented with a 1-year history of stranguria, pollakiuria and haematuria.
During previous consultations, bacterial cystitis and struvite crystalluria were suspected. The response to different courses of antibiotics was incomplete and transient. Six months before our consultation, idiopathic cystitis was suspected after normal abdominal radiography and ultrasonography. The cat’s environment was then modified and a specific diet prescribed (Royal Canin H-Dilution). The owners reported no improvement.
Abdominal palpation revealed a small, tense and painful urinary bladder. Abdominal radiography revealed a slightly radiopaque, 4 cm long element in the bladder lumen. Abdominal ultrasonography showed a hyperechoic structure with acoustic shadowing in the lumen of an empty bladder. Serum creatinine was within the reference interval. Pneumocystography revealed a well-structured linear radiopaque element in the bladder lumen, partially engaged in the urethra. This element seemed to be a mineral concretion or a foreign body. Maximal bladder distension was limited to 10 ml. Cystoscopy revealed a vegetal foreign body covered with crystals. Granular cells and bacteria were observed on sediment examination.
Cystotomy was performed to retrieve the foreign body (Figure 1). Amoxicillin–clavulanate and meloxicam were prescribed for 10 days. Fourteen days postoperatively, the cat was more comfortable during micturition, urine specific gravity was 1.037 and a mild leukocyturia was present at sediment examination. Urine culture and susceptibility testing were negative. After 2 years of follow-up, the cat remained stable with normal micturition.
Lower urinary tract diseases are frequent in feline medicine. Idiopathic cystitis is the most common diagnosis followed by urolithiasis. Urinary bladder foreign bodies are very rare, with only three cases reported in the literature. A foreign body can migrate into the bladder either from the digestive tract or via a natural anatomical route through the urethra. The duration of clinical signs at presentation varied from 2 days to 6 months. Abdominal ultrasonography is an important means of investigation for vegetal foreign bodies because they are not radiopaque. In the reported case, the foreign body was covered by crystals, explaining why it eventually became visible on the radiographs. Urinary bladder foreign bodies are rare in feline medicine but should be included in the differential diagnosis for chronic recurrent cystitis.
The authors would like to thank VPLUS -French Veterinary Network, for part funding Julien Cheylan’s attendance at the ISFM Congress in order to present the poster.
The foreign body retrieved following cystotomy
REVERSE GENETICS FOR TYPE I FELINE CORONAVIRUS FIELD ISOLATE TO STUDY THE MOLECULAR PATHOGENESIS OF FELINE INFECTIOUS PERITONITIS
Rosina Ehmann1*, Claudia Kristen-Burmann1, Barbara Bank-Wolf1, Matthias König1, Christiane Herden2, Torsten Hain3, Heinz-Jürgen Thiel1, John Ziebuhr4, Gergely Tekes1†
11nstitute of Virology, Justus Liebig University Giessen, Giessen, Germany
2Institute of Veterinary Pathology, Justus Liebig University Giessen, Giessen, Germany
3Institute of Medical Microbiology, Justus Liebig University Giessen, Giessen, Germany
4Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany
*Current address: Bundeswehr Institute of Microbiology, Munich, Germany
†Current address: Elanco Animal Health, Germany
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Feline infectious peritonitis (FIP) is one of the most important lethal infections in cats. To date, there is no approved therapeutic option available and the only vaccine has limited protective qualities. The causative agent of FIP, feline infectious peritonitis virus (FIPV), is the high-virulence biotype of feline coronaviruses (FCoVs). It is suggested that lethal FIPVs emerge from the highly prevalent and benign feline enteric coronaviruses (FECVs) by acquiring mutations in specific genes in the course of persistent infections (internal mutation theory). Although several studies identified mutations predicted to be responsible for the FECV–FIPV biotype switch, the presumed roles of specific genetic changes in FIP pathogenesis have not been confirmed experimentally. Reverse genetics systems established previously for serotype I and the less common serotype II FCoVs were based on cell culture-adapted laboratory FIPV strains; these, however, were shown to be unsuitable for FIP pathogenesis studies in vivo due to the mutations caused by the cell culture adaptation process.
To date, systems for producing and manipulating recombinant serotype I field viruses have not been developed, mainly because these viruses cannot be grown in vitro. We report the first reverse genetics system based on a serotype I FECV field isolate that is suitable for producing high-titer stocks of recombinant FECVs. We demonstrate that these recombinant viruses cause productive persistent infections in cats that are similar to those observed in natural infections, including the establishment of a persistent infection with a weak humoral immune response of the host.
The system provides an excellent tool for studying FCoVs that do not grow in standard cell culture systems. It allows the production of high-quality stocks of authentic recombinant serotype I FECVs, differing only in the specific mutations of interest, to study their effect on target cell tropism and virulence, which will vitally contribute to tracking down the essential mutations responsible for the FECV–FIPV biotype switch.
Importantly, the system could also be adapted for studies of other RNA viruses with large genomes, the production and characterisation in vivo of which is currently hampered by the lack of in vitro propagation systems.
This abstract was submitted as part of the ABCD–Boehringer Ingelheim Young Scientist Award (see page 857 of this issue) and the full paper was published in the journal mBio in July 2018 under a CC BY 4.0 license.
MYCOBACTERIUM BOVIS TUBERCULOSIS IN AN INDOOR CAT WITHIN SCOTLAND ASSOCIATED WITH COMMERCIAL RAW FOOD
Glynn Woods, Conor O’Halloran, Danièlle Gunn-Moore
Hospital for Small Animals, The Royal (Dick) School of Veterinary Medicine, Easter Bush Campus, Midlothian, UK
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A 4-year-old female neutered indoor-only Bengal cat was presented to the Hospital for Small Animals in severe respiratory distress. Radiographs obtained by referring veterinary surgeons revealed bilateral caudodorsal cavitated lung lesions with a pleural effusion, which therapeutic thoracocentesis revealed to be a modified transudate. The cat was exclusively fed a commercial raw venison meat diet.
After initial stabilisation, interferon-gamma release assay (IGRA), mycobacterial culture and PCR confirmed infection with Mycobacterium bovis spoligotype 10.
Treatment with azithromycin (Zithromax; Pfizer) at 15 mg/kg and pradofloxacin (Veraflox; Bayer) at 10 mg/kg, both PO q24h, was administered empirically alongside intensive supportive therapy while the above results were pending.
The cat deteriorated and was euthanased on welfare grounds. Post-mortem examination revealed multifocal, bilateral, firm, approximately circular pulmonary lesions containing caseous material when incised. Histopathology revealed pyogranulomatous inflammation dominated by epithelioid macrophages, and special stains identified acid-fast bacilli morphologically consistent with mycobacteria.
The indoor-only lifestyle of this patient led to concerns that the raw diet may have been the source of the infection, particularly given that M bovis spoligotype 10 is geographically limited to England.
The manufacturer and Food Standards Agency investigated the diet, which was subsequently recalled from sale.
This case demonstrates an acute presentation of M bovis infection that was likely contracted by ingestion of a commercial raw diet.
The case raises health concerns for cats, owners and raw pet food production/consumption as a whole. More broadly, this and similar cases put Scotland’s ‘officially tuberculosis-free’ status at risk
INCORPORATION OF RETICULOCYTE HAEMOGLOBIN IN COMPLETE BLOOD COUNT INTERPRETATION
Aline Barry1, Julia Chase2, Peter Hendrickson2, Jeremy Hammond2, Dennis B DeNicola2
1IDEXX Europe BV, Hoofddorp, Netherlands
2IDEXX Laboratories, Westbrook, ME, USA
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Reticulocyte haemoglobin (RETIC-HGB) is a sensitive and specific indicator of iron availability for red blood cell (RBC) production. Values below the reference interval are most commonly associated with either inflammation (INFL; iron-limited RBC production) in response to a hepcidin-mediated pathway or chronic blood loss (ID; iron-deficient RBC production). Very little information is available for RETIC-HGB changes in the cat. Recently, RETIC-HGB was incorporated in the complete blood count (CBC) of all dogs and cats with the ProCyte Dx Hematology Analyzer (PDx; IDEXX Laboratories). The objective of this study was to evaluate the frequency of changes in RETIC-HGB in the cat and preliminarily describe the clinical scenarios where this analyte will provide additional important clinical information.
Results of 1 million CBCs from domestic cats were randomly collected from the global fleet of PDx analyzers in 2018. Statistical analyses were performed using JMP and Microsoft Excel.
Low feline RETIC-HGB (<13.2 pg) was observed in 4.98% (49,826/1,000,000) and high feline RETIC-HGB (>20.8 pg) was observed in 1.84% (18,414/1,000,000), of CBCs. Dot plot and blood film review were not available to confirm the presence of INFL in this study. Most (98.68%, 986,708/1,000,000) of the CBCs had leukogram data, and using the PDx immature neutrophil flag to support INFL, 15.30% (152,965/986,706) had a flag and 7.37% (11,281/152,965) of these had a low RETIC-HGB. Low RETIC-HGB was present in 4.55% (38,545/847,035) of non-flagged CBCs. Additionally, related to erythrogram changes, a slightly higher rate of low RETIC-HGB was seen in non-anemic (2.97%, 29,677/744,848) compared with anemic (2.01%, 20,149/255,152) cats.
In conclusion, preliminary findings document low RETIC-HGB in significant numbers of cat CBCs. Low RETIC-HGB has the potential to provide valuable clinical insight, especially in cats presenting with no obvious clinical signs. When available, evaluation of RETIC-HGB should be included in the interpretation of CBCs. Further investigation into underlying INFL and ID in the cat and their relationship to changes in RETIC-HGB is needed.
CAT LEPTOSPIROSIS: PREVALENCE, INVESTIGATION AND EVALUATION OF SERUM AMYLOID A AS A MARKER OF INFECTION
Laura Lucchese1, Laura Gagliazzo1, Silvia Marchione1, Letizia Ceglie1, Eulalia Guerrini1, Tommaso Furlanello2, Carmelo Furnari3, Alda Natale1
1Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro (PD), Italy
2San Marco, Veterinary Clinic and Laboratory, Veggiano (PD), Italy
3Aulss 9 Scaligera, Verona, Italy
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Cats are considered resistant to Leptospira species but there is scant information in the literature on the prevalence and clinical presentation of the infection.
Ninety-nine outdoor cats from northeastern Italy, where leptospirosis is often diagnosed in dogs, were tested by means of a microscopic agglutination test (MAT) on serum for antibody detection and RT-PCR on urine for identification of pathogenic Leptospira species. MAT antigens were serovars Icterohaemorrhagiae, Copenhageni, Canicola, Pomona, Hardjo, Bratislava, Tarassovi, Grippotyphosa and Ballum. The study included 48 ill cats affected by inflammatory conditions and 51 healthy cats as distinguished by their serum amyloid A (SAA) levels.
No significant difference was observed between ill and healthy cats (Fisher’s exact test = 0.08) in terms of seroprevalence. MAT was positive for 14 cats (14%); nine of them revealed antibodies against Grippotyphosa, and one or two against other serovars, except Hardjo and Tarassovi to which no positivity was observed. Three ill cats showed high titres (>1:400) for Grippotyphosa (n = 2) or Bratislava (n = 1) and these cats were immunocompromised by other pathologies (feline immunodeficiency virus infection and feline leukaemia virus infection; feline herpesvirus infection and lymphoma; hyperthyroidism). One cat was confirmed as infected by PCR. No more PCR-positive samples were recorded.
Overall, SAA showed no significant association with seropositivity, while agreement with PCR on urine could not be evaluated. The confirmation or strong suspicion of infection in immunocompromised cats only and the moderate seroprevalence observed supported the hypothesis of a feline resistance to clinical leptospirosis. Nevertheless, outdoor cats are commonly exposed to Leptospira species and this leads to the necessity for further investigation, always considering the potential zoonotic threat of this infection.
COMPARISON OF HISTOPATHOLOGICAL FEATURES IN FELINE CUTANEOUS TUBERCULOSIS LESIONS
Jordan L Mitchell, Jayne C Hope, Danièlle A Gunn-Moore
The Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Midlothian, UK
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Histopathology is often the first step when diagnosing feline mycobacterial infections; however, it is unable to discriminate between diseases caused by different organisms. There is a need to rapidly identify cases of tuberculosis (TB) and subsequently differentiate between Mycobacterium bovis and Mycobacterium microti infections.
Twenty-five formalin-fixed paraffin-embedded biopsy samples from 18 individual cats diagnosed with cutaneous TB were selected, with 5 μm sections cut for routine haematoxylin and eosin and Ziehl–Neelsen staining. They were assessed for the type of inflammatory cells present, the amount of necrosis and numbers of acid-fast bacilli (AFB).
There was a statistically significant difference between the type of inflammation in cutaneous TB lesions (P <0.02), with M microti infections more likely to result in granulomatous histopathological changes (Table 1). The median amount of necrosis present was greater in M bovis-infected tissues than in those from cats with M microti infections (19.7% compared with 12.3%); however, this was not statistically significant (P = 0.16). There was a moderate positive correlation between the amount of necrosis present and the average number of AFB per high power field in M bovis lesions (rs = +0.406), whereas for M microti lesions there was a very weak positive correlation (rs = +0.142). Neither of these relationships were statistically significant (P <0.25 and P <0.54, respectively).
Comparison of inflammatory infiltrate present in feline tuberculous lesions
These results suggest potential variation in the immune response to infection with different mycobacteria, and that the presence of a pyogranulomatous response should raise suspicion of M bovis involvement and therefore a greater zoonotic risk.