Canine follicular cell and medullary thyroid carcinomas: Immunohistochemical characterization.

Research on modulation of iodine uptake by thyroid cells could help improve radioiodine treatment of dogs with thyroid tumors. The aim of this study was to characterize the immunohistochemical expression of thyroid transcription factor-1 (TTF-1), thyroglobulin, thyrotropin receptor (TSHR), sodium iodide symporter (NIS), pendrin, thyroid peroxidase (TPO), vimentin, and Ki-67 in follicular cell thyroid carcinomas (FTCs) and medullary thyroid carcinomas (MTCs), and to compare protein expression between FTC causing hyperthyroidism and FTC of euthyroid dogs. Immunohistochemistry was performed in 25 FTCs (9 follicular, 8 follicular-compact, and 8 compact) and 8 MTCs. FTCs and MTCs were positive for TTF-1, and expression was higher in FTCs of euthyroid dogs compared with FTCs of hyperthyroid dogs (P= .041). Immunolabeling for thyroglobulin was higher in follicular and follicular-compact FTCs compared with compact FTCs (P = .001), while vimentin expression was higher in follicular-compact FTCs compared with follicular FTCs (P = .011). The expression of TSHR, NIS, pendrin, and TPO was not significantly different among the different subtypes of FTCs or between FTCs causing hyperthyroidism and FTCs in euthyroid dogs. TSHR, NIS, pendrin, and TPO were also expressed in MTCs. Ki-67 labeling index was comparable between FTCs and MTCs, and between FTCs causing hyperthyroidism and FTCs in euthyroid dogs. Proteins of iodine transport were also expressed in canine MTCs, which could have implications for diagnosis and treatment. The different expression of thyroglobulin and vimentin between FTC histological subtypes could reflect variations in tumor differentiation.

Rearing of Hyalomma marginatum (Acarina: Ixodidae) under laboratory conditions in Morocco.

Hyalomma marginatum Koch is one of the main tick vectors of human and animal tick-borne diseases. The objective of this study was to establish standard procedures for rearing H. marginatum under laboratory conditions. Such laboratory tick populations are required to study acaricide resistance of Hyalomma ticks. In our rearing program, larvae and nymphs were fed on New Zealand white rabbits, whereas adults were fed on sheep. Non-parasitic stages were held at 18 and 28 °C to study the effect of temperature on development and survival. In our experiments, H. marginatum ticks have maintained the characteristics of a two-host life cycle. The engorged larvae did not detach and moulted on the rabbit, after which the emerged nymphs continued to feed on the same animal. The life cycle duration of H. marginatum was influenced by temperature, with each non-parasitic stage-i.e., larva and nymph molting-developing faster at 28 than at 18 °C; preoviposition and oviposition periods were shorter at 28 than at 18 °C. At 18 °C, no eggs hatched. The whole cycle from the collection of an engorged field tick until the emergence of second-generation larvae took 189 days. One such tick on average results in 3500 eggs which over time, taking into account the losses at each developmental stage, develop into 1200 adult ticks. Rearing these ticks a second generation therefore could result in millions of larval ticks.

Value of repeated health screening in 259 apparently healthy mature adult and senior cats followed for 2 years.

BACKGROUND: Although regular health screening is recommended, long-term follow-up data in healthy aged cats are lacking. OBJECTIVES: Determine the most common conditions in a large group of apparently healthy older cats and which diseases are manifested within 2 years in cats confirmed to be healthy based on extensive health screening. ANIMALS: Client-owned cats. METHODS: Prospective study. Thorough history, physical examination, blood tests, and urinalysis were performed in 259 apparently healthy mature adult (7-10 years) and senior (>10 years) cats. Semi-annual follow-up examinations were performed in 201 confirmed healthy cats. RESULTS: At baseline, 21% of apparently healthy cats were not considered healthy but were diagnosed with International Renal Interest Society (IRIS) ≥ stage 2 chronic kidney disease (CKD; 7.7%) or hyperthyroidism (4.6%), among other disorders. Disease occurred significantly more frequently in senior cats compared with mature adult cats. In addition, 40% cats were overweight, 35% had moderate to severe dental disease, and 22% had abnormal cardiac auscultation findings. Within 2 years, 28% of mature adult and 54% of senior cats that were confirmed healthy at inclusion developed new diseases, most commonly IRIS ≥ stage 2 CKD (cumulative incidence, 13.4%), hyperthyroidism (8.5%), chronic enteropathy, hepatopathy or pancreatitis (7.5%), or neoplasia (7%). CONCLUSIONS AND CLINICAL IMPORTANCE: The high prevalence and 2-year incidence of physical examination abnormalities and systemic diseases in apparently healthy older cats argue for regular health screening in cats ≥7 years of age. Although more common in senior cats, occult disease also occurs in mature adult cats, and owners should be informed accordingly.

Optimization and validation of metabolomics methods for feline urine and serum towards application in veterinary medicine.

BACKGROUND: Metabolomics is an emerging and powerful technology that offers a comprehensive view of an organism's physiological status. Although widely applied in human medicine, it is only recently making its introduction in veterinary medicine. As a result, validated metabolomics protocols in feline medicine are lacking at the moment. Since biological interpretation of metabolomics data can be misled by the extraction method used, species and matrix-specific optimized and validated metabolomic protocols are sorely needed. RESULTS: Systematic optimization was performed using fractional factorial experiments for both serum (n = 57) and urine (n = 24), evaluating dilution for both matrices, and aliquot and solvent volume, protein precipitation time and temperature for serum. For the targeted (n = 76) and untargeted (n = 1949) validation of serum respectively, excellent instrumental, intra-assay and inter-day precision were observed (CV ≤ 15% or 30%, respectively). Linearity deemed sufficient both targeted and untargeted (R2 ≥ 0.99 or 0.90, respectively). An appropriate targeted recovery between 70 and 130% was achieved. For the targeted (n = 69) and untargeted (n = 2348) validation of the urinary protocol, excellent instrumental and intra-assay precision were obtained (CV ≤ 15% or 30%, respectively). Subsequently, the discriminative ability of our metabolomics methods was confirmed for feline chronic kidney disease (CKD) by univariate statistics (n = 41 significant metabolites for serum, and n = 55 for urine, p-value<0.05) and validated OPLS-DA models (R2(Y) > 0.95, Q2(Y) > 0.65, p-value<0.001 for both matrices). SIGNIFICANCE: This study is the first to present an optimized and validated wholistic metabolomics methods for feline serum and urine using ultra-high performance liquid chromatography coupled to quadrupole-Orbitrap high-resolution mass spectrometry. This robust methodology opens avenues for biomarker panel selection and a deeper understanding of feline CKD pathophysiology and other feline applications.

Blood pressure in hyperthyroid cats before and after radioiodine treatment.

BACKGROUND: Hyperthyroid cats commonly have systemic hypertension, with a reported prevalence of 7% to 48%. Although hypertension might be expected to resolve once treatment restores euthyroidism, it can persist or only first develop after treatment. OBJECTIVES: To determine the proportion of hyperthyroid cats with hypertension (systolic blood pressure [SBP] ≥160 mm Hg), persistence or first development of hypertension after successful radioiodine treatment, and correlation of post-treatment hypertension with azotemia or hypothyroidism. ANIMALS: Four hundred one hyperthyroid nonazotemic cats were included in the study. METHODS: Prospective, cross-sectional and before-and-after studies. All hyperthyroid cats had SBP measured by Doppler; 255 had SBP rechecked 6 months after successful radioiodine (131I) treatment. RESULTS: Of untreated hyperthyroid cats, 108/401 (27%) were hypertensive. A higher proportion of hypertensive cats were nervous/excited compared with normotensive cats (47% vs 12%; P < .001). Of the initially hypertensive cats, 87/108 cats were reexamined after 131I treatment; 43/87 (49%) cats normalized SBP, whereas 44/87 (51%) remained hypertensive. Of the initially normotensive cats, 16/168 (9.5%) first developed hypertension after successful 131I treatment. 7/60 (12%) of the 131I-treated hypertensive cats were azotemic and 9/60 (15%) were hypothyroid. A higher proportion of cats remaining hypertensive had nervous/excited demeanor than did normotensive cats (50% vs 17%; P < .001). CONCLUSIONS/CLINICAL IMPORTANCE: Hypertension, when present, resolves in many hyperthyroid cats after successful treatment. Hyperthyroid cats uncommonly develop new hypertension after treatment. Persistent or newly detected hypertension was unrelated to azotemia or iatrogenic hypothyroidism. More frequently perceived nervousness/anxiety in radioiodine-treated hypertensive cats suggests that many of these cats might have "situational" hypertension, as hyperthyroid-induced hypertension should resolve after treatment.

Serum symmetric dimethylarginine in older dogs: Reference interval and comparison of a gold standard method with the ELISA.

BACKGROUND: Serum symmetric dimethylarginine (SDMA) is used to screen for renal dysfunction in dogs. The gold standard technique for measuring SDMA, liquid chromatography-tandem mass spectrometry (LC-MS/MS) is not widely available. Age-specific reference intervals for SDMA in older dogs are lacking. OBJECTIVES: Prospective study in older dogs to validate a commercially available LC-MS/MS method for SDMA, compare SDMA concentrations with concentrations measured using ELISA and obtain a reference interval (RI) for older dogs using both methods. ANIMALS: Client-owned older dogs undergoing health screening. METHODS: The LC-MS/MS method was analytically validated (limit of detection, precision, and linearity). Serum was sent cooled overnight for ELISA or was frozen at -80°C until batch analysis using LC-MS/MS. Results of LC-MS/MS and ELISA were compared and RIs for older dogs were calculated according to international guidelines. RESULTS: The LC-MS/MS method showed good linearity (r2 = .99) and precision (coefficient of variation <10%), with a laboratory RI between 8.0 and 14.0 µg/dL. Paired measurements were available from 118 different dogs. Median SDMA concentration were 9.4 (range, 5.0-21.2) using LC-MS/MS and 12.0 (range, 5.0-22.0) µg/dL using ELISA. Both methods significantly differed with a mean difference of 2.2 µg/dL. The RI for older dogs for LC-MS/MS was 4.4-15.0 µg/dL, and for ELISA was 6.4-17.4 µg/dL. CONCLUSIONS AND CLINICAL IMPORTANCE: The ELISA provided significantly higher SDMA concentrations compared to the validated LC-MS/MS method, indicating the need for device- or assay-specific RI. The obtained age-specific RI for SDMA is considerably higher in older dogs compared to the general laboratory RI.

Study of the behaviour of lesional and nonlesional skin of canine recurrent flank alopecia transplanted to athymic nude mice.

BACKGROUND: Recurrent flank alopecia is a clinically well-described skin disorder in dogs. The pathomechanism of the disease is difficult to study because it undergoes spontaneous regression. HYPOTHESIS/OBJECTIVES: To study the behaviour of xenografts in mice in order to assess the feasibility of a reproducible experimental model and to investigate local or systemic causes of canine recurrent flank alopecia (cRFA). METHODS: Skin biopsies were taken from lesional and nonlesional skin of two client-owned dogs with cRFA and grafted onto five athymic mice from a research facility. The lesional skin and xenografted skin were evaluated histologically on day 0 and day 30, respectively. RESULTS: Transplanted lesional and nonlesional canine skin regrew hair within 30 days, while the donor dogs were still alopecic in the lesional areas on day 30 after the skin biopsy procedure. Graft rejection was evidenced histologically in two xenografted athymic mice. Lesional hyperpigmentation disappeared in the athymic mice. CONCLUSIONS AND CLINICAL IMPORTANCE: This study showed that hair follicles from dogs with cRFA quickly regenerated and regrew hair once grafted onto the mice. Our data indicate that the pathogenesis of cRFA is likely to be mediated by systemic rather than local factors. While this xenograft approach might not be of much value for the study of cRFA, it has potential value for the study of other causes of canine alopecia due to systemic factors.

Determination of age-specific reference intervals for selected serum and urinary biomarkers in elderly cats.

OBJECTIVES: Annual health screening is recommended in elderly cats to allow the early detection of conditions such as chronic kidney disease (CKD) and hyperthyroidism. Nevertheless, age-specific reference intervals (RIs) for renal and thyroid parameters in this population are lacking. The aim of this study was to determine age-specific RIs for selected serum and urine biomarkers related to CKD and hyperthyroidism, namely serum creatinine (sCr), symmetric dimethylarginine (SDMA), phosphate (P), total calcium (tCa), total thyroxine (TT4), urinary protein:creatinine ratio (UPC) and urine specific gravity (USG). These RIs were established for elderly cats (aged ⩾7 years) in general, as well as for mature adult cats (aged 7-10 years) and senior cats (aged >10 years) separately. METHODS: A prospective study was conducted on client-owned cats aged ⩾7 years and considered healthy by their owners. The cats were screened to rule out metabolic and systemic diseases by means of a thorough history, complete physical examination, blood examination and urinalysis. The data from 206 healthy elderly cats (134 mature adult and 72 senior cats) were included. Age-appropriate RIs were determined following the guidelines of the American Society of Veterinary Clinical Pathology and compared with existing laboratory RIs. RESULTS: Clinically relevant differences between the age-specific RI and the laboratory RI were found for several variables. Compared with the laboratory RI, the upper limit of the RI for cats aged ⩾7 years was lower for sCr, TT4 and P, and higher for SDMA. The lower limit of the age-appropriate RI was lower for USG. The new RI was almost identical to the existing laboratory RI for tCa and UPC. CONCLUSIONS AND RELEVANCE: Using age-specific RIs for renal and thyroid biomarkers in mature adult and senior cats has important clinical consequences for the interpretation of health screening results in elderly cats. This confirms the need to adapt laboratory RIs to the specific animal population for which the RI will be used.

Systolic blood pressure measurements with Doppler ultrasonic flow detector and high-definition oscillometry are comparable on population level but show large intra-individual differences in apparently healthy elderly dogs.

OBJECTIVE: Agreement of systolic blood pressure measurements (SBP) between noninvasive blood pressure devices in conscious dogs is poorly studied. Situational hypertension is expected in clinics, but studies are lacking. This study aimed to compare SBP measurements obtained with Doppler ultrasonic flow detector (Doppler) versus high-definition oscillometry (HDO) in clinics and at home and to estimate the prevalence of situational hypertension in conscious, apparently healthy elderly dogs. ANIMALS: 122 apparently healthy elderly or geriatric dogs were prospectively recruited. PROCEDURES: Systolic blood pressure was obtained consecutively with Doppler and HDO techniques in a randomized order per dog, following a standardized protocol. An at-home measurement was advised for in-clinic hypertensive dogs (SBP ≥ 160 mmHg), also using both devices. RESULTS: Dual measurements were available in 102 dogs. Median SBP was 147.3 mmHg (range, 105 to 239 mmHg) for Doppler and 152.3 mmHg (range, 113 to 221 mmHg) for HDO. Forty-six percent (56/122) were hypertensive, of which 9% (11/122) were hypertensive with both methods. No significant difference was found between the 2 devices in the global study population or within the group of hypertensive dogs. Repeated at-home measurements were performed in 20/56 (35.7%) hypertensive dogs, resulting in a 10 and 26 mmHg lower median SBP value for Doppler and HDO, respectively (P > .05). In-clinic situational hypertension was presumed in 8/20 (40%) dogs. CLINICAL RELEVANCE: The choice of the noninvasive blood pressure device did not significantly impact SBP results, but large interindividual differences in SBP between techniques occurred. Situational hypertension was frequently observed in clinic.

Effect of storage temperature and time on measurement of serum symmetric dimethylarginine concentration using point-of-care and commercial laboratory analyzers in cats and dogs.

BACKGROUND: Stability of serum symmetric dimethylarginine (sSDMA) during short- and long-term storage has not been assessed for the immunoassay of the Point-of-Care IDEXX Catalyst DX (POC) analyzer and the Enzyme Multiplied Immunoassay Technique of IDEXX commercial laboratory (CL). Also, the agreement between both analyzers is questioned. OBJECTIVES: To determine (a) the effect of storage time and temperature on sSDMA measured by POC and CL; (b) the agreement between sSDMA measured by POC and CL; and (c) the imprecision of the POC. ANIMALS: Serum of cats (n = 17) and dogs (n = 18) with a range of SDMA concentrations (6 to >100 µg/dL). METHODS: Based on an equivalence trial with predefined equivalence range (-3.0 to +3.0 µg/dL) and using T0 as baseline, stability was evaluated after 24 hours at 22°C and 4°C (POC); after 7 days at 4°C (POC and CL) and after 10 and 24 months at -24°C and -80°C (CL). Bland-Altman plots enabled method comparison. Imprecision of the POC was assessed by duplicate sSDMA measurements at T0. RESULTS: The POC analyzer produced equivalent sSDMA measurements if samples were stored for 24 hours at 4°C (95% confidence interval [CI]: -2.5-2.0 µg/dL), but not when stored for 24 hours at room temperature (RT; 95% CI: -4.1 to 0.5 µg/dL) or after 7 days at 4°C (95% CI: -3.6-1.0 µg/dL). The CL analyzer was less affected by preanalytical variation with clinically similar results obtained when samples were stored for 7 days at 4°C (95% CI: -2.2 to 2.4 µg/dL) and for at least 24 months at -24°C (95% CI: -1.7 to 2.9 µg/dL) and -80°C (95% CI: -1.5 to 3 µg/dL). A relevant mean difference of -2.3 µg/dL between both analyzers was found. Duplicate POC measurements were equivalent (95% CI: -2.6 to 2.0 µg/dL). CONCLUSIONS: Delayed analysis may significantly change sSDMA depending on storage and measurement conditions. Interchangeable use of assays should be done with caution because analytical variation could be interpreted as clinically relevant change.

Effect of laboratory and sample storage factors on urinary protein:creatinine ratios and clinical decision making in cats.

BACKGROUND: Urinary protein:creatinine ratio (UPC) results affect the diagnosis, prognosis, and therapy of chronic kidney disease in cats. OBJECTIVES: To investigate the interlaboratory and intralaboratory variability and the effect of storage on UPC and International Renal Interest Society (IRIS) proteinuria substaging in cats. ANIMALS: Healthy and diseased client-owned cats. METHODS: Prospective study. Urine of 60 cats was randomly sent to 4 (of 9) participating laboratories (to assess interlaboratory variability) and per cat, 2 laboratories each received 2 aliquots (to determine intralaboratory variability). Samples of 23 cats were analyzed in the same laboratory the day of collection, after preservation at 22°C for 1 day and at 4°C during 1-7 days (short-term storage) and at -24°C and -80°C for 6-12 months (long-term storage). Storage conditions were compared by equivalence testing. RESULTS: UPCs showed good interclass correlation (ICC-inter, 0.90) and excellent intraclass correlation (ICC-intra, 0.99). However, in 30/60 (50%) cats at least 1 of 4 laboratories assigned a different IRIS proteinuria substage. Urinary protein:creatinine ratio remained stable with short-term storage, but not after 6 months storage at -24°C and after 12 months storage at -24°C or -80°C. Long-term storage caused a change in IRIS proteinuria substage in 27% of cats, whereas a shift occurred only in 4% of cats during short-term storage. CONCLUSIONS AND CLINICAL IMPORTANCE: Laboratory choice for UPC measurement can result in different IRIS substaging for the same cat, whereas urine storage at room temperature for 1 day or in the refrigerator for up to 7 days does not clinically affect UPC.

Biological variation of urinary protein: Creatinine ratio and urine specific gravity in cats.

BACKGROUND: Laboratory results are influenced by presence and severity of disease, as well as preanalytical factors, analytical variation, and biological variation. Biological variation data for urinary protein: creatinine ratio (UPC) and urine specific gravity (USG) in cats are lacking. OBJECTIVES: Determine the biological variation of UPC and USG in cats. ANIMALS: Eighty healthy client-owned cats. METHODS: Prospective study. Urine was collected on days 0, 14, and 56 from all 80 cats to investigate the persistence of borderline or overt proteinuria or suboptimal urine concentration. In 15 of these cats, urine was collected weekly from day 0 to 42 to calculate the index of individuality (II) and reference change value (RCV), and on days 56 and 57 to evaluate day-to-day variability of UPC and USG. RESULTS: Borderline or overt proteinuria (UPC ≥0.2) was present in 18/80 (23%) cats at baseline and persisted on 3 occasions in 2 months in 8/18 (44%) cats. Urine concentration was suboptimal at inclusion (USG <1.035) in 8/80 (10%) cats and at all 3 time points during 2 months in 3/8 (38%) cats. The II of UPC and USG indicated intermediate individuality. The 1-sided RCV was 82% for UPC and 36% for USG. Proteinuria substage was identical on 2 consecutive days in 13/15 (87%) cats, and urine concentrating ability remained the same in all 15 cats. CONCLUSIONS AND CLINICAL IMPORTANCE: A >82% increase in UPC in a healthy cat is not solely attributable to physiological and analytical variation. For USG, a decrease of >36% is considered clinically relevant.

Comparison of cystocentesis versus home sampling to determine urinary protein: Creatinine ratio and urine specific gravity in cats.

BACKGROUND: Urinalysis is necessary for the diagnostic evaluation of chronic kidney disease in cats. Performing cystocentesis is not always feasible, but data comparing urine obtained by cystocentesis in the clinic with voided samples collected at home are lacking in cats. OBJECTIVES: To compare urinary protein:creatinine ratio (UPC) and urine specific gravity (USG) and to detect clinically relevant changes in proteinuria substage or urine concentration between urine collected at home and in-clinic by cystocentesis in cats. ANIMALS: Ninety-two healthy and diseased client-owned cats. METHODS: Prospective study. Owners collected voided urine at home and within 1 to 15 hours, cystocentesis was performed in the clinic. RESULTS: In a subset of motivated owners, 55% succeeded in collecting urine at home. Overall, UPC was higher (mean ±SD difference = 0.09 ±0.22; P < .001) and USG was lower (mean ±SD difference = -0.006 ±0.009; P < .001) in cystocentesis samples than in voided urine. Substantial agreement existed between sampling methods for UPC (weighted к = 0.68) and USG (к = 0.64) categories. A different proteinuria substage (UPC < 0.2, 0.2-0.4, >0.4) was present in paired urine samples from 28% of cats. In 18% of cats, urine concentrating ability (USG < or ≥1.035) differed between both samples. CONCLUSIONS AND CLINICAL IMPORTANCE: Home sampling of urine is a valid alternative to cystocentesis in cats. However, because clinically relevant differences in UPC and USG were present in 28% and 18% of cats, respectively, by the same collection method for monitoring each cat is advised.

Urinary liver-type fatty acid-binding protein in clinically healthy elderly cats: Evaluation of its potential to detect IRIS stage 1 chronic kidney disease and borderline proteinuria.

BACKGROUND: Urinary liver-type fatty acid-binding protein (uL-FABP) is a promising biomarker to detect early chronic kidney disease (CKD) in cats. Few healthy cats show increased uL-FABP for unknown reasons. OBJECTIVES: The objective of this study was to evaluate uL-FABP in a large healthy elderly cat population comparing cats with and without International Renal Interest Society (IRIS) stage 1 CKD and with and without borderline proteinuria. METHODS: This was a cross-sectional study. One hundred ninety-six clinically healthy client-owned cats of ≥7 years old were subdivided based on two criteria: (1) having either IRIS stage 1 CKD or no evidence of CKD and (2) having borderline proteinuria or no proteinuria. Urinary L-FABP was measured using a validated commercially available feline L-FABP ELISA. RESULTS: Overall, uL-FABP was detectable in 6/196 (3%) healthy elderly cats. For the first subdivision, nine (5%) cats had IRIS stage 1 CKD, 184 cats had no evidence CKD and three cats were excluded. All cats with IRIS stage 1 CKD had uL-FABP concentrations below the detection limit, whereas 6/184 (3%) cats without IRIS stage 1 CKD had detectable uL-FABP concentrations (median 1.79 ng/ml, range 0.79-3.66 ng/ml). For the second subdivision, 47 (24%) cats had borderline proteinuria, 147 cats had no proteinuria and two cats were excluded. One of the borderline proteinuric cats had a detectable uL-FABP concentration, whereas the other five cats with detectable uL-FABP concentrations were non-proteinuric. CONCLUSION: With the current assay, the screening potential of uL-FABP as an early biomarker for feline CKD is limited as uL-FABP was rarely detected in clinically healthy elderly cats independently of the presence of either IRIS stage 1 CKD or borderline proteinuria.

Radioiodine treatment in hyperthyroid cats: insights into the characteristics of owners and their cats, and owner motivation and perceptions.

OBJECTIVES: Radioiodine (131I) therapy is the most appropriate treatment option for many hyperthyroid cats, as it is minimally invasive and often curative. Nevertheless, 131I treatment is not always pursued by owners. Hence, it is important to obtain more insight into owner satisfaction during and after 131I treatment, and their decision-making process. In this study, we describe the characteristics of owners and their hyperthyroid cats referred for 131I therapy, and determine owners' motivation and how they experienced the 131I treatment of their cat. METHODS: A survey was sent to owners whose cats underwent 131I therapy (n = 1071) between 2010 and 2017 at Ghent University. The survey contained 35 questions with tick-box or free-text answer options concerning family situation, pet insurance, previous therapy, comorbidities, motivation for 131I therapy and owner perception of this treatment. RESULTS: In total, 438 owners completed 94% or more of the questionnaire. Over half of the cats (55%) had received previous medical, dietary or surgical treatment. Motivations for changing the initial therapy to 131I therapy included difficulties in administering medication (31%), insufficient improvement in clinical signs (23%), side effects (16%) and following the referring veterinarian's advice (16%). Almost a fifth of owners (18%) were not informed about the existence of 131I therapy by their veterinarian and found information on 131I treatment online or through friends. Hospitalising their cat was very distressing for 17% of owners. Most owners (92%) were satisfied with the treatment. Reasons for dissatisfaction were insufficient communication, iatrogenic hypothyroidism, persistent hyperthyroidism and comorbidities post-treatment. CONCLUSIONS AND RELEVANCE: Our study stresses the importance of communication regarding the possible outcome of 131I treatment, the importance of managing underlying comorbidities before treatment and anticipating the stress of owners during their cat's hospitalisation period. The results of this study could help in improving client communication when advising on 131I treatment.

Ultrasound-guided core needle biopsy in dogs with thyroid carcinoma.

Currently, a histological diagnosis of highly vascularized canine (c) thyroid carcinoma (TC) is primarily obtained following excisional biopsy (EB) through thyroidectomy. Non-EBs are contraindicated in unresectable invasive cTCs due to their highly vascularized nature, which subsequently, lack histological diagnosis. We hypothesised ultrasound-guided core needle biopsy (UGCNB) to be a safe biopsy technique to obtain an accurate histological diagnosis in unresectable TCs. Nine client-owned dogs with suspected naturally occurring TC, presented for surgical excision, were included. First, a UGCNB was taken from the cervical tumour, followed by EB. Haemorrhage following UGCNB was evaluated preoperatively and once the tumour was surgically exposed by visual inspection and ultrasonography. Histological analysis, including cell organisation, tumour capsular and vascular invasion, and immunohistochemistry were performed and compared between both biopsy specimens (i.e., UGCNB and EB) of the same dog. Pre- and peroperative visual inspection revealed minor, localised haemorrhage, subsequent to the UGCNB, in 7/9 dogs. Histology of the EBs confirmed TC in 8/9 dogs and was inconclusive in 1/9 dogs. Histology of the UGCNBs revealed neoplastic thyroid tissue in 7/9 UGCNBs and was inconclusive in 1/9 UGCNBs. The remaining UGCNB contained no mass related tissue and was, therefore, excluded. Histological parameters (i.e., cell organisation, tumour capsular and vascular invasion) were not concordant between 6/8 included UGCNBs and their respective EB. Immunolabelling for thyroglobulin and calcitonin was concordant between all eight included UGCNBs and their respective EB. The remaining evaluated immunohistochemical markers (i.e., cyclooxygenase-2 [COX-2], P-glycoprotein and vascular endothelial growth factor [VEGF]) were concordant between the included UGCNBs and the EBs in 6/8 dogs. To conclude, UGCNBs can be safely obtained in suspected cTCs and enable a reliable diagnosis of the thyroid origin, thyroid cell origin and potential therapeutic markers such as COX-2, P-glycoprotein and VEGF. Subsequently, UGCNB enables clinicians to establish an individually tailored treatment plan in dogs with unresectable TC.

Reference interval, longitudinal variability and reliability of activated clotting time in healthy dogs using a point-of-care analyser.

BACKGROUND: Activated clotting times (ACTs) are used to screen for coagulopathies and monitor heparin therapy. OBJECTIVES: To determine a reference interval (RI) for ACT in dogs using a point-of-care analyser, to quantify intra-subject within- and between-day variability, to quantify analyser reliability and inter-analyser agreement and to study the influence of a delay in measurement. METHODS: Forty-two healthy dogs were included. Measurements were performed on fresh venous blood using the i-STAT 1 analyser. The RI was determined using the Robust method. Intra-subject within-day variability and between-day variability were quantified between baseline and 2 h (n = 8) or 48 h (n = 10) later. Analyser reliability and inter-analyser agreement were studied by duplicate measurements (n = 8) on identical analysers. The influence of measurement delay was studied before and after a delay of one analytical run (n = 6). RESULTS: Mean, lower and upper reference limits for ACT were 92.9 ± 9.1, 74.4 and 111.2 s, respectively. Coefficients of variation of intra-subject within- and between-day variability were 8.1% and 10.4%, respectively, resulting in a significant between-day measurement difference. Analyser reliability assessed by the intraclass correlation coefficient and coefficient of variation were 0.87% and 3.3%, respectively. Significantly lower ACT values were observed after a measurement delay compared to direct analysis. CONCLUSIONS: Our study provides an RI for ACT in healthy dogs using the i-STAT 1 and suggests low intra-subject within- and between-day variability. Analyser reliability and inter-analyser agreement were good; however, analysis delay and between-day differences could significantly influence ACT results.

Organoids of patient-derived medullary thyroid carcinoma: The first milestone towards a new in vitro model in dogs.

Organoid cultures could constitute a valuable in vitro model to explore new treatments for canine (c) medullary thyroid carcinoma (MTC). The study's objectives were to establish and characterize 3D organoid cultures of cMTC using histology and immunohistochemistry (IHC) and to evaluate the effect of antitumor drugs on organoids' viability. Five cMTC tissue samples were used to develop organoid cultures of which one organoid line, named cMTC N°2, could be passaged for an extended period. This cMTC N°2 organoid line was further compared to the primary tumour regarding morphology and IHC expression of thyroid transcription factor-1 (TTF-1), thyroglobulin, calcitonin, synaptophysin, vimentin, Ki-67, cyclooxygenase-2 (COX-2), P-glycoprotein and vascular endothelial growth factor (VEGF). Quality control of the cMTC N°2 organoid line was achieved by a single nucleotide polymorphism (SNP) array of the organoids, primary tumour and healthy blood cells of the same dog. The effect of carboplatin, meloxicam and toceranib phosphate (TOC) on cMTC N°2 organoids' viability was evaluated. The cMTC N°2 organoid line was cultured for 94 days and showed similar histological features with the primary tumour. Immunolabelling for TTF-1, thyroglobulin, calcitonin and VEGF was similar between the primary tumour and cMTC N°2 organoids. Compared to the primary tumour, organoids showed higher immunolabelling for vimentin and Ki-67, and lower immunolabelling for synaptophysin, COX-2 and P-glycoprotein. The SNP genotype was similar for each chromosome between healthy blood cells, primary tumour and cMTC N°2 organoids. Carboplatin, meloxicam and TOC had no effect on cMTC N°2 organoid cell viability within achievable in vivo concentration range. In conclusion, the cMTC N°2 organoid line is a promising first milestone towards an established in vitro organoid model to explore pathophysiology and new treatment modalities in cMTC.

Nutritional modulation of insulin resistance in the true carnivorous cat: a review.

Cats are strict carnivores that rely on nutrients in animal tissues to meet their specific and unique nutritional requirements. In their natural habitat, cats consume prey high in protein with moderate amounts of fat and minimal carbohydrates in contrast to commercial diets, which are sometimes moderate to high in carbohydrates. This change in diet has been accompanied by a shift from an outdoor environment to an indoor lifestyle and decreased physical activity, because cats no longer need to hunt to obtain food. This transformation of the lifestyle of cats is thought to be responsible for the recent increase in incidence of obesity, insulin resistance, and diabetes mellitus in domestic cats. At first, an overview of the evolutionary physiological adaptations of carbohydrate digestion in the feline digestive tract and of the hepatic carbohydrate and protein metabolism reflecting the true carnivorous nature of cats is given. Secondly, this literature review deals with nutritional modulation of insulin sensitivity, focusing on dietary macronutrients, carbohydrate sources, and dietary fiber for prevention and treatment of insulin resistance.

Renal biomarkers in cats: A review of the current status in chronic kidney disease.

Serum creatinine concentration, the classical biomarker of chronic kidney disease (CKD) in cats, has important limitations that decrease its value as a biomarker of early CKD. Recently, serum symmetric dimethylarginine concentration was introduced as a novel glomerular filtration rate biomarker for the early detection of CKD in cats. However, data on its specificity are still limited. The limitations of conventional biomarkers and the desire for early therapeutic intervention in cats with CKD to improve outcomes have prompted the discovery and validation of novel renal biomarkers to detect glomerular or tubular dysfunction. Changes in the serum or urinary concentrations of these biomarkers may indicate early kidney damage or predict the progression of kidney before changes in conventional biomarkers are detectable. This review summarizes current knowledge on renal biomarkers in CKD in cats, a field that has progressed substantially over the last 5 years.