Iatrogenic adrenal atrophy following oral corticotherapy is not reliably identified ultrasonographically in cats.

Background: In dogs, corticosteroid administration is known to decrease adrenal gland height when measured ultrasonographically. However, comparable information is lacking in cats. Objectives: i) Validate that the adrenal height of our control population without corticosteroid administration was similar to previous data, ii) determine effects of dose and duration of oral corticosteroid therapy on adrenal height, and iii) determine an adrenal size threshold to differentiate cats receiving corticosteroids or not. Animals and procedures: Adult cats (N = 308) that received abdominal ultrasonographic examination(s) were retrospectively recruited and allocated into 2 groups: those with and without oral corticosteroid use. Cats receiving corticosteroids were subdivided into 6 subgroups by dose (supraphysiologic, anti-inflammatory, or immunosuppressive) and duration of therapy (≤ 1 mo or > 1 mo). Results: Adrenal height in cats without corticosteroid therapy was comparable to previous studies. An anti-inflammatory corticosteroid dose for > 1 mo caused a 21.4% decrease in adrenal height (mean difference of 0.8 mm; P = 0.009). However, no difference in adrenal height was noted in the other subgroups (P > 0.21), and no useful adrenal height threshold was established. Conclusion and clinical relevance: Feline iatrogenic adrenal atrophy may be difficult to establish with ultrasonography, as only cats receiving anti-inflammatory corticosteroid doses for > 1 mo had a modest (< 1 mm) decrease in adrenal height.

L'atrophie iatrogène des surrénales consécutive à une corticothérapie orale n'est pas identifiée de manière fiable par échographie chez le chat. Contexte: Chez le chien, l'administration de corticostéroïdes est connue pour diminuer la taille des glandes surrénales lorsqu'elle est mesurée par échographie. Cependant, des informations comparables manquent chez les chats. Objectifs: i) Valider que la taille des surrénales de notre population témoin sans administration de corticostéroïdes était similaire aux données précédentes, ii) déterminer les effets de la dose et de la durée de la corticothérapie orale sur la taille des surrénales, et iii) déterminer un seuil de taille des surrénales pour différencier les chats recevant des corticostéroïdes ou pas. Animaux et procédures: Des chats adultes (N = 308) qui ont subi un ou plusieurs examens échographiques abdominaux ont été recrutés rétrospectivement et répartis en 2 groupes : ceux avec et sans corticothérapie orale. Les chats recevant des corticostéroïdes ont été subdivisés en 6 sous-groupes selon la dose (supraphysiologique, anti-inflammatoire ou immunosuppresseur) et la durée du traitement (≤ 1 mois ou > 1 mois). Résultats: La taille des surrénales chez les chats sans corticothérapie était comparable à celle des études précédentes. Une dose de corticoïdes anti-inflammatoires pendant > 1 mois a entraîné une diminution de 21,4 % de la taille des surrénales (différence moyenne de 0,8 mm; P = 0,009). Cependant, aucune différence de taille surrénalienne n'a été notée dans les autres sous-groupes (P > 0,21) et aucun seuil de taille surrénalienne utile n'a été établi. Conclusion et pertinence clinique: L'atrophie surrénalienne iatrogène féline peut être difficile à établir par échographie, car seuls les chats recevant des doses de corticostéroïdes anti-inflammatoires pendant > 1 mois ont présenté une diminution modeste (< 1 mm) de la taille des surrénales.(Traduit par Dr Serge Messier).

No evidence of pulmonary hypertension revealed in an echographic evaluation of right-sided hemodynamics in hyperthyroid cats.

OBJECTIVES: Hyperthyroidism is a common endocrinopathy affecting middle-aged to elderly cats, with multisystemic repercussions. Hyperthyroid humans show decreased lung compliance and increased cardiac output with subsequent left heart failure leading to pulmonary capillary congestion. Prognosis worsens with the development of increased pulmonary vascular pressures (ie, pulmonary hypertension [PH]) in hyperthyroid humans. The effect of excess thyroid hormone concentration on pulmonary arterial hemodynamics is unknown in cats. Assessing pulmonary vascular pressures in veterinary medicine relies heavily on echocardiographic measurements performed at the level of the heart and pulmonary trunk. This study investigated right-sided cardiac and pulmonary arterial hemodynamics in hyperthyroid cats using echocardiography. METHODS: Echocardiographic examinations of hyperthyroid cats identified through a bi-institutional database search were reviewed for the determination of systolic pulmonary arterial pressure (PAP) and 20 other metrics. Values were compared with those of a healthy cat group using non-parametric statistical analyses. RESULTS: Systolic PAP could not be determined in 23/26 hyperthyroid and 13/14 healthy cats owing to unmeasurable tricuspid regurgitation flow velocity. Hyperthyroid cats were roughly twice as old (P <0.001) and had 2-4-fold higher respiratory rates (P <0.001) than healthy cats. Hyperthyroid cats showed an increase in acceleration time-to-ejection time ratio of pulmonary flow (1.4-fold, P = 0.001), pulmonary artery velocity time integral (1.2-1.6-fold, P = 0.001), maximal pulmonary velocity (1.3-1.7-fold, P = 0.002), stroke volume (1.5-fold, P = 0.001) and cardiac output (1.6-fold, P <0.001) vs healthy cats. None of the other echocardiographic metrics reached statistical significance. CONCLUSIONS AND RELEVANCE: Systolic PAP estimation proved unsuitable as a sole measurement for the assessment of PH in hyperthyroid cats owing to the frequent inability to interrogate tricuspid regurgitant flow velocity. Hyperthyroid cats have altered echocardiographic measures of pulmonary hemodynamics dissimilar to those reported in hyperthyroid humans. Differential effects of thyrotoxic cardiomyopathy on ventricular systolic function may underlie species differences.

Association between hyperlipidemia and calcium oxalate lower urinary tract uroliths in dogs.

BACKGROUND: Metabolic syndrome is associated with formation of calcium oxalate (CaOx) uroliths in humans. OBJECTIVES: To investigate the association between obesity and hyperlipidemia with CaOx lower urinary tract uroliths in client-owned dogs. ANIMALS: Dogs with (n = 55, U [uroliths]-dogs) and without (n = 39, UF [uroliths-free]-dogs) CaOx lower urinary tract uroliths. METHODS: Case-control study. U-dogs were retrospectively enrolled and compared to UF-dogs. Body condition score (BCS; 1-9 scoring scale), serum triglyceride (TG) and total cholesterol (CH) concentrations and glycemia (after >12-hour food withholding) were recorded in both groups. RESULTS: On univariate logistic regression, when excluding Miniature Schnauzers, odds of having uroliths increased by a factor of 3.32 (95% CI 1.38-11.12) for each mmol/L of TG (P = .027), of 39 (95% CI 9.27-293.22) for each mmol/L of glycemia (P < .0001), and of 2.43 (95% CI 1.45-4.45) per unit of BCS (P = .002). In multivariable models, the effect of TG was retained when all breeds were included for analysis and odds of having uroliths increased by a factor of 4.34 per mmol/L of TG (95% CI 1.45-19.99; P = .02). CONCLUSIONS AND CLINICAL IMPORTANCE: Serum lipid screening in dogs diagnosed with CaOx uroliths might be recommended to improve their medical staging and management.

Clinical significance of Proteus mirabilis bacteriuria in dogs, risk factors and antimicrobial susceptibility.

The objectives of this study were to describe the in vitro antimicrobial susceptibility and clinical significance of Proteus mirabilis in canine bacteriuria and to identify the risk factors associated with P. mirabilis urinary tract infections. This is a retrospective observational study of 48 P. mirabilis-positive canine urinary cultures. Only 22 of the 48 P. mirabilis isolates (45.8%) were non-susceptible to at least one tested antimicrobial. Most P. mirabilis isolates (98%) were susceptible to enrofloxacin, 93.7% to amoxicillin/clavulanic acid, and 85.4% to ampicillin, cephalothin, and trimethoprim-sulfamethoxazole. Five multidrug-resistant isolates were detected (10.4%). A significant increase in antimicrobial resistance was observed over the study period. Positive P. mirabilis cultures were associated with bacterial cystitis in 36 of 39 dogs (92.3%), pyelonephritis in 2 of 39 dogs (5.1%), and one dog had both bacterial cystitis and pyelonephritis (2.5%). There was no subclinical bacteriuria. Most urinary tract infections were complicated as risk factors were identified in 37 of 39 dogs (94.8%). The most commonly identified risk factors were the presence of a contaminated peri-vulvar area with urine/feces or a hypoplastic vulva. To conclude, P. mirabilis bacteriuria was associated with upper and lower urinary tract infections in this study and was found more frequently in complicated bacterial cystitis. Multidrug-resistant isolates and increased P. mirabilis antimicrobial resistance have been identified over the last 10 years, but most isolates remain susceptible to first-line antimicrobials such as amoxicillin and trimethoprim-sulfamethoxazole.

Cette étude a pour but d'évaluer la sensibilité in vitro aux antibiotiques de Proteus mirabilis lors de bactériurie chez le chien, son importance clinique et les facteurs de risques d'infection urinaire associée à Proteus mirabilis. Il s'agit d'une étude rétrospective, observationnelle reposant sur 48 cultures urinaires positives à Proteus mirabilis chez le chien. Seuls 22 des 48 isolats (45,8 %) n'étaient pas sensibles à au moins un des antibiotiques testés. La majorité des isolats (98 %) étaient sensibles à l'enrofloxacine, 93,7 % à l'amoxicilline/acide clavulanique et 85,4 % à l'ampicilline, céphalothine et trimethoprime-sulfamethoxazole. Cinq isolats multi-résistants ont été détectés (10,4 %). Une augmentation significative de la résistance a été observée sur la période étudiée. Une cystite bactérienne a été diagnostiquée chez 36 des 39 chiens inclus (92,3 %), une pyélonéphrite chez deux chiens (5,1 %) et un chien présentait des signes de cystite bactérienne et de pyélonéphrite (2,5 %). Aucune bactériurie subclinique n'a été identifiée; la plupart des infections urinaires étaient compliquées (94,8 %). Les facteurs de risque les plus rencontrés sont la contamination de la région péri-vulvaire ou la présence d'une vulve hypoplasique. En conclusion, Proteus mirabilis doit être suspecté en cas de cystite bactérienne compliquée. Des isolats multi-résistants ont été identifiés et une hausse de la résistance a été observée au cours des dix dernières années. La plupart reste sensible aux antibiotiques de premières lignes que sont l'amoxicilline et trimethoprime-sulfamethoxazole.(Traduit par les auteurs).

New findings associated with presumptive systemic lupus erythematosus in a kitten.

CASE SUMMARY: An 8-month-old neutered male domestic shorthair kitten was examined for anorexia, lethargy and palatine ulcers. Systemic lupus erythematosus (SLE) was suspected based on a positive antinuclear antibody (ANA) titer and six manifestations of autoimmunity: fever, paronychia, oral ulcers, proteinuria, thrombocytopenia and leukopenia. Mastocytemia was observed on the blood smear. Although the clinical presentation of this case meets the classification criteria for SLE in humans, tick-borne disease and histopathology evaluation of the oral and cutaneous lesions would have been necessary to support a definite diagnosis of SLE. Baseline ANA titration was performed in two laboratories with conflicting results, which may reflect substrate differences used for the titration, but a false-positive result cannot be excluded. The cat received prednisolone and all clinical and laboratory abnormalities resolved after two months of treatment. Subsequent ANA titers remained positive and were not correlated to the patient's clinical progression. RELEVANCE AND NOVEL INFORMATION: This report describes new findings associated with a presumptive diagnosis of SLE in a kitten, highlighting that SLE may not be ruled out even in young cats and may be associated with mastocytemia. ANA titration is part of the initial diagnostic work-up of SLE but is a non-specific test and discrepancies can be observed between laboratories. The titration of more specific antibodies such as those used in humans would be helpful to diagnose SLE. ANA titration may not correlate with clinical activity of SLE; hence, the interest of an ANA titer follow-up to establish disease control warrants further investigation.

Focal uterine T-cell lymphoma in an ovariectomized cat.

CASE DESCRIPTION A 14-year-old ovariectomized domestic shorthair cat was evaluated because of periuria and perineal licking of 3 days' duration. CLINICAL FINDINGS On initial examination, an abdominal mass was palpable cranial to the urinary bladder. The perineal area was soiled with a blood-tinged mucous fluid. Abdominal ultrasonography revealed a vascularized, focal, and circumferential thickening of the right uterine horn, involving particularly the muscular layer. No evidence of dissemination was noted. TREATMENT AND OUTCOME Hysterectomy was performed, revealing a localized, 2.5 × 4-cm firm mass with a smooth surface within the right uterine horn. Results of histologic examination and immunohistochemical analysis of tissue samples from the mass suggested high-grade T-cell uterine lymphoma. Owners declined medical and chemotherapeutic treatments. One year later, the cat developed diabetes mellitus, which was medically treated. Nineteen months following the uterine lymphoma diagnosis, a central corneal ulcer associated with a right retrobulbar mass was diagnosed. The cat was euthanized, and the retrobulbar mass was removed. Immunohistochemical staining revealed evidence of high-grade B-cell retrobulbar lymphoma. CLINICAL RELEVANCE The clinical outcome of this cat with uterine lymphoma was favorable for 19 months after diagnosis, with no treatment other than hysterectomy. Whether the same outcome could be expected for other cats with this rarely reported neoplasm remains to be determined. Uterine lymphoma should be considered as a possible cause of dysuria in an ovariectomized cat.

Effect of castration on the urinary protein-to-creatinine ratio of male dogs.

OBJECTIVE: To assess the urinary protein-to-creatinine ratio (UPCR) of healthy sexually intact male dogs and to compare the UPCR of these dogs before and after castration. ANIMALS: 19 client- or shelter-owned healthy adult sexually intact male dogs. PROCEDURES: Physical, hematologic, and biochemical examinations and urinalysis (including calculation of the UPCR) were performed on each dog. Dogs were then castrated, and physical examination and urinalysis (including calculation of the UPCR) were performed again at least 15 days after castration. RESULTS: A dipstick test yielded positive results for protein in the urine of 10 sexually intact male dogs, but the UPCR was < 0.5 for all sexually intact male dogs. Mean UPCR for sexually intact male dogs was 0.12 (range, 0.10 to 0.32). The UPCR was < 0.2 for all castrated dogs, except for 1. Mean UPCR for all castrated dogs was 0.08 (range, 0.05 to 0.69). There was a significant difference between mean UPCR before and after castration. CONCLUSIONS AND CLINICAL RELEVANCE: In this study, pathological proteinuria was not detected in sexually intact male dogs. Positive results for a urine dipstick test should be interpreted with caution in sexually intact male dogs and should be confirmed by assessment of the UPCR. An increased UPCR in sexually intact male dogs may be considered abnormal.

Rivaroxaban demonstrates in vitro anticoagulant effects in canine plasma.

Rivaroxaban is an oral direct factor X inhibitor used in human thrombotic disorders and its oral administration makes it an attractive potential anticoagulant for dogs. The objective of this study was to evaluate the in vitro anticoagulant effect of rivaroxaban on canine pooled platelet-poor plasma (PPP). Pooled PPP was collected from 20 healthy adult Beagle dogs. Aliquots of pooled citrated PPP were treated in vitro with DMSO solutions of rivaroxaban (98% purity) to obtain 19 final concentrations ranging from 0 to 1000 mg/L of drug. Samples were immediately submitted for the following coagulation assays: prothrombin time (PT), activated partial thromboplastin time (aPTT), tissue factor-induced thrombin generation and anti-factor Xa activity. Concentration-effect data were analyzed with various nonlinear regression models for stimulatory or inhibitory effects. Rivaroxaban caused a concentration-dependent prolongation of all coagulation parameters. Rivaroxaban concentration for 50% baseline inhibition of the propagation phase of thrombin (rate index) was 0.024 mg/L, and for 50% baseline inhibition of the optical density in the anti-factor Xa activity assay was 0.053 mg/L. At these concentrations, PT and aPTT remained within the reference range. Two-fold prolongation from baseline of PT and aPTT was achieved with higher concentrations, i.e. 1.24 and 1.69 mg/L, respectively. Thrombin generation was completely suppressed by concentrations ≥0.8 mg/L. In conclusion, rivaroxaban showed an in vitro concentration-dependent anticoagulant effect on canine plasma. Thrombin generation and anti-factor Xa activity were more sensitive and accurate than PT and aPTT in detecting the anticoagulant effect of rivaroxaban.

Comparison of gravity collection versus suction collection for transfusion purposes in dogs.

Blood donation is an essential step in transfusion medicine that must take into account the donor's welfare, collection effectiveness, and blood product quality. This prospective study enrolled 13 canine blood donors, each subjected to both gravity and suction collection methods, in a randomized order. Clinical parameters, including heart rate (HR), respiratory rate (RR), systolic blood pressure (SBP), and rectal temperature (RT), were evaluated at four time points, including when the donor was on the floor and on the collection table, and before and after blood donation. The number of times the donor and needle required repositioning, the duration of the donation, the noise created by the apparatus, and the presence of a hematoma were evaluated. The weight, index of hemolysis, and hematocrit of each unit of blood were recorded. There was no significant difference between collection methods for either the clinical parameters at each time point or the prevalence of hematoma formation, the frequency of needle repositioning, the hemolysis index, or hematocrit. Collection by suction was noisier (P < 0.0001), faster (P = 0.004), and associated with significantly less donor repositioning (P = 0.007). Suction appears to be a safe and cost-effective method that should be considered to optimize blood donation.