Rodolfo Oliveira Leal

Background: T lymphocytes play a central role in the intestinal immune response in dogs with immunomodulator-responsive enteropathy (IRE), but the clinical relevance of mucosal T-cell infiltration remains unclear. Hypothesis/Objectives: Compare mucosal CD3+ T-cell density between dogs with IRE and healthy comparison dogs across intestinal segments, and assess associations with clinical, biochemical, and histologic severity markers. Animals: Forty-two client-owned dogs with IRE and 12 healthy research dogs. Methods: Retrospective multicenter study. Archived endoscopic biopsy samples from the duodenum, ileum, and colon were evaluated using the Simplified Histopathological Scoring System. Immunohistochemistry for CD3 was quantified by digital image analysis (QuPath) and expressed as relative CD3+ density (RCD3). Group comparisons, receiver operating characteristic curve analyses, mixed linear models, and correlation analyses were performed. Results: Relative CD3+ density was significantly higher in dogs with IRE than in comparison dogs in the duodenum (median, 6.34% vs 1.42%; P = .03), ileum (9.79% vs 0.85%; P < .001), and colon (3.88% vs 1.32%; P = .002). The area under the curve values were 0.833, 0.896, and 0.811, respectively. The RCD3 was not correlated with clinical indices, serum albumin concentration, or histologic scores, but ileal histologic score was negatively correlated with RCD3 (ρ = −0.37; P = .04). Conclusions and clinical importance: Mucosal CD3+ T-cell density is increased in dogs with IRE but is not associated with clinical or overall histologic disease severity. Quantification of CD3+ should not be used as a solitary monitoring tool but may contribute to immunophenotyping.

Background: The role of the autonomic nervous system in the pathophysiology of chronic kidney disease (CKD) in cats is currently unknown. Hypothesis/Objectives: To describe urine and plasma metanephrines concentration in cats with CKD and their correlation with biomarkers of kidney function. Animals: Fifty-nine cats were recruited and divided into 3 groups: cats with CKD (n = 28), healthy cats (HC) (n = 21), and cats with nonadrenal, non–kidney-related chronic illness (n = 10). Methods: A cross-sectional study was performed in cats recruited from a veterinary teaching hospital. Metanephrine and normetanephrine concentrations were measured in urine (U-MN/NMN) and plasma (P-MN/NMN) by liquid chromatography tandem mass spectrometry. Data were correlated with biomarkers of kidney function measured in the same time-point sample. Results: The CKD group had significantly higher P-NMN (median, 14.20; min-max, 5.65-34.09 nmol/L) than the HC group (7.03; 5.19-13.03 nmol/L). P-MN concentrations correlated with the urinary protein-creatinine ratio (UPCR) (r = 0.528, P = .017). P-NMN correlated with symmetric dimethylarginine (SDMA) (r = 0.604, P = .006), serum creatinine (r = 0.488, P = .029) and UPCR (r = 0.445, P = .049). U-MN:urine creatinine concentration (UCreat) ratio correlated with UPCR (r = 0.683, P < .001) and urine specific gravity (r = -0.397), P < .001). U-NMN:UCreat ratio correlated with SDMA (r = 0.558, P = .007), serum phosphate (r = 0.561, P = .005) and UPCR (r = 0.494, P = .017). Conclusion and clinical importance: There is evidence of sympathetic nervous system dysfunction in cats with CKD.

Background: Hypersomatotropism (HST) in cats has predominantly been associated with diabetes mellitus (DM) and HST in nondiabetic cats is poorly described. Hypothesis/Objectives: To describe the clinical presentation, clinicopathologic findings, and outcome of nondiabetic cats with presumed HST. Animals: Twenty-eight client-owned cats. Methods: Multi-site retrospective study based on medical records of nondiabetic cats seen at 10 institutions between 2014 and 2024 with presumed HST (elevated serum insulin-like growth factor-1 [IGF-1] ± clinical signs compatible with acromegaly ± documented pituitary enlargement). Clinical presentation, diagnostic findings, and survival times were reviewed. Results: Twenty-eight cats with HST were included. Twenty-six cats were males, and 2 cats were females; mean age was 9.5 years (±SD 3.5 years); mean body weight was 7.1 kg (±SD 2.1 kg). The median serum IGF-1 concentration was 1236 ng/mL (range 704-2455 ng/mL). Nineteen of 28 cats (68%) had clinical signs possibly related to acromegaly: prognathia inferior (13/28), weight gain (12/28), broad facial features (10/28), abdominal enlargement (10/28), respiratory stridor (9/28), polyphagia (9/28), and signs of neurological disease (3/28). The most common clinicopathological abnormalities were hyperproteinemia (12/28), serum creatinine above the reference interval (RI) (10/28), and urinary specific gravity below the RI (9/28). Hypertrophic cardiomyopathy phenotype was identified in 8/17 cases. The most common comorbidity was chronic kidney disease (10/28). The median survival time after diagnosis was 24 months (range 1-103 months). Conclusions and clinical importance: Hypersomatotropism can present without DM and should be considered in cats with signs suggestive of growth hormone excess or a pituitary tumor.

Companion animal endocrinology has benefited from international standardisation of disease terminology for diabetes mellitus, Cushing’s syndrome, and hypoadrenocorticism through Project Agreeing Language in Veterinary Endocrinology (ALIVE). A group of 14 experts and one chair convened for the third cycle of Project ALIVE, focusing on thyroid disease terminology. The cycle employed the modified Delphi approach from previous cycles, augmented by procedural refinements—such as inclusion of an off-site chair and stricter adherence to timelines —to improve efficiency and flexibility. Novel in this round was the integration of feedback from a previous cycle, which resulted in updated definitions for diabetes mellitus originally developed in ALIVE Cycle 1. Outcomes: A 100% consensus was achieved among panellists and 91.4–100% among 105 members of international veterinary endocrinology societies (32% of total memberships) over 78 thyroid-related terminology items and five revised definitions pertaining to diabetes mellitus. These standardised definitions are expected to facilitate clearer communication and education, enhance diagnostic consistency, support research comparability, and improve clinical care in feline and canine endocrine diseases.

Mirtazapine is an antidepressant used as an appetite stimulant in cats. This study aims to assess owner perspectives on the use of transdermal mirtazapine in cats. A multicentric survey-based study was conducted. A survey of 15 questions about efficacy, side effects, and overall perception was sent to owners of cats that had received the treatment between January 2021 and March 2023 in two European veterinary hospitals. From 108 contacted owners, 70 responses were obtained. Application to the ear was considered easy by 97% of respondents, and 91% followed the manufacturers’ instructions for alternating ears. Side effects were reported by 20%, most often increased vocalization, redness, or restlessness. Chronic kidney disease was the most common reason for prescription. Nine owners had previously used the oral form, and most of them found the transdermal option easier, although some preferred the oral version due to lower cost. Overall, 77% of owners considered the treatment effective in stimulating appetite. Regarding length of therapy, about half administered it for less than 14 days, while the rest followed the labeled duration, with longer use associated with more consistent appetite improvement. These findings highlight that transdermal mirtazapine is generally well accepted by owners, easy to administer, and effective in promoting appetite in cats.

Background: The survival of dogs with pheochromocytoma (PCC) treated with adrenoreceptor antagonists has not been described or compared to surgically managed cases. Hypothesis/Objectives: The objective of this study is to evaluate the survival of medically and surgically managed dogs with PCC and investigate factors associated with survival. Animals: Two hundred fifty-five dogs with PCC, treated with alpha-adrenoreceptor antagonists (AA) without adrenalectomy (Group 1, n = 75), adrenalectomy +/– AA (Group 2, n = 128), or neither treatment (Group 3, n = 52). Methods: Retrospective, multicenter review of medical records. Median overall survival time (OST) for Groups 1 and 2 combined was calculated using Kaplan–Meier estimates, and then compared between Group 1 and Group 2 using Log-Rank testing. Cox proportional hazard analysis identified factors associated with survival in Groups 1 and 2 individually and combined. Results: Median OST for all cases was 854 (95% CI: 572–1136) days. Median OST was lower in Group 1 (247 days, 95% CI: 76–418 days) than in Group 2 (927 days, 95% CI: 587–1267 days; p < 0.001). In Group 2, 88/92 dogs (97.8%) that received presurgical AA treatment survived to discharge compared to 23/27 (85.2%) that did not receive AA pretreatment (p = 0.03). Lack of clinical signs at presentation was associated with increased survival in both groups combined (HR 0.5; 95% CI 0.3–0.9; p = 0.02) and in Group 2 alone (HR 0.3; 95% CI 0.1–0.7; p = 0.01). Conclusions and Clinical Importance: Dogs with PCC treated with adrenalectomy have longer survival compared to those managed with AA without adrenalectomy.

Background: Hydrolyzed protein diets are commonly used in the first-line approach to the treatment of dogs with naïve-chronic enteropathy (naïve-CE). Objectives: To characterize the responses of naïve-CE dogs transitioned to a hydrolyzed diet and to assess the efficacy of an additional dietary trial in dogs with NRE. Animals: Eighty-one dogs with naïve-CE and 23 dogs with NRE. Methods: Retrospective multicenter cohort study including dogs with CE presented to three referral centers from April 2018 to December 2021. Naïve-CE and NRE cases transitioned to hydrolyzed and alternative diets, respectively, were selected, and medical records were reviewed. Clinical response before and 4 weeks after dietary transitions (with or without concurrent therapeutic adjustments) was assessed based on stool-consistency score or Canine Inflammatory Bowel Disease Activity Index (CIBDAI) total score in naïve and NRE cases, respectively. Results: The transition into a hydrolyzed diet was the only therapeutic change in 20% (16/81). Of these, 88% (14/16) had a decreased stool-consistency score (p < 0.001). From the 23 NRE cases, the transition to an alternative diet was the sole therapeutic adjustment in 70% (16/23). Of these, the total CIBDAI score declined in 69% (11/23; p < 0.001). Conclusions and Clinical Importance: This study supports the need to feed a hydrolyzed diet in naïve CE cases. In cases classified as NRE, an additional transition into an alternative dietary trial seems beneficial.

Background: Allopurinol, one of the drugs routinely used to treat canine leishmaniosis (CanL), is an inhibitor of the enzyme xanthine oxidase, which plays a fundamental role in purine metabolism. Its inhibitory action on this enzyme leads to a state of hyperxanthinuria, favouring the development of xanthine crystals and/or uroliths. However, not all dogs with CanL treated with allopurinol develop xanthinuria and/or xanthine uroliths, and there is not much information on the possible risk factors that contribute to this event. This study aims to evaluate potential predisposing factors associated with the development of xanthinuria in dogs with a previous diagnosis of CanL that were treated with allopurinol. Methods: A multicentric, retrospective, observational study was conducted and included dogs with CanL undergoing allopurinol therapy. Dogs that developed xanthinuria (Xgroup) and those without xanthinuria (NXgroup) were selected from cases admitted to three referral hospitals between 2011 and 2022. Medical records were reviewed, and clinical and laboratorial variables were compared between groups. Descriptive statistics, contingency tables and non-parametric tests were used (P < 0.05). Results: In total, 90 dogs were selected, 45 for each group. Only age and serum alpha-1 globulin concentration were significantly different between groups at day 0. Dogs from Xgroup were younger (median 4 years; interquartile range (IQR) 2–7) than those from NXgroup (median 6 years; IQR 4–9; P = 0.002). At the time of CanL diagnosis, a higher percentage of dogs from NXgroup had decreased serum alpha-1 globulin concentrations (38.9% versus 13.3% in Xgroup, respectively; P = 0.020). In Xgroup, the median time to xanthinuria development after starting allopurinol was 150 days (IQR 31–455). Conclusions: These results suggest that closer monitoring of young dogs (< 4 years) and those with normal alpha-1 globulin levels at diagnosis is recommended to ascertain the possible development of xanthinuria at an early stage, allowing for early application of measures to reduce the likelihood of its development. Graphical