Anti-cancer effects of DHP107 on canine mammary gland cancer examined through in-vitro and in-vivo mouse xenograft models.

BACKGROUND: Canine mammary gland cancer (CMGC) is a common neoplasm in intact bitches. However, the benefit of adjuvant chemotherapy is unclear. The aim of this study was to investigate the anti-proliferative effects of paclitaxel on CMGC in in-vitro and in-vivo settings. RESULTS: Paclitaxel dose-dependently inhibited viability and induced G2/M phase cell cycle arrest and apoptosis in both primary and metastatic CMGC cell lines (CIPp and CIPm). In animal experiments, the average tumour volume decreased significantly in proportion to the administered oral paclitaxel dose. By examining tumour tissue using a TUNEL assay and immunohistochemical staining with anti-CD31 as a marker of endothelial differentiation, respectively, it was confirmed that oral paclitaxel induced apoptosis and exerted an anti-angiogenetic effect in tumour tissues. Further, downregulation of cyclin D1 in tumour tissues suggested that oral paclitaxel induced cell cycle arrest in tumour tissues in-vivo. CONCLUSIONS: Our results suggest that paclitaxel may have anti-cancer effects on CMGC through cell cycle arrest, induction of apoptosis, and anti-angiogenesis. This study could provide a novel approach to treat CMGC.

Anticancer effect of superoxide dismutase on canine mammary gland tumour in vitro.

BACKGROUND: Reactive oxygen species (ROS) have been shown to promote tumour growth and metastasis in human cell lines. The superoxide anion (•O2 - ) is produced during ROS formation and is involved in tumour cell signalling. OBJECTIVES: Superoxide dismutase (SOD) has been applied to canine mammary gland tumours to investigate its antitumour effects in vitro. METHODS: Cell proliferation, cell cycle cell migration assays, reverse transcription-quantitative polymerase chain reaction, and western blot analysis were performed to determine the effects of SOD on canine mammary tumour cell line. RESULTS: SOD treatment resulted in anti-proliferative effects and mediated cell cycle arrest in the canine mammary gland tumour cell lines (CIPp and CIPm). It also downregulated the expression of N-cadherin and Vimentin. CONCLUSIONS: The results confirmed that SOD inhibits tumour cell proliferation and migration, thus supporting the potential applications of SOD as a chemotherapeutic agent for canine mammary gland tumours.

Clinical Outcomes in Dogs Undergoing Cholecystectomy via a Transverse Incision: A Meta-Analysis of 121 Animals Treated between 2011 and 2021.

Although many studies have been conducted on the use of median and transverse incisions in various surgeries in the field of human medicine, related studies in veterinary medicine are lacking. This study aimed to present treatment options for dogs requiring cholecystectomy by reporting the pros and cons of 121 cholecystectomies performed via transverse incision at our hospital over 10 years. In most included cases, nonelective cholecystectomy was performed in an unstable emergency situation. The perioperative mortality rate was 23.14%, which was not significantly different from that of cholecystectomy performed via the conventional midline approach. However, the overall operation time (46.24 ± 6.13 min; range 35-65 min) was shortened by securing an adequate surgical field of view. The transverse incision approach facilitates fast and accurate surgery without increasing the fatality rate in small-breed dogs, in whom securing an adequate surgical field of view is difficult. Thus, transverse incision should be actively considered in dogs undergoing cholecystectomy due to emergency conditions, such as bile leakage or biliary tract obstruction, since prolonged anesthesia can be burdensome. This study may improve cholecystectomy outcomes in small-breed dogs with difficult-to-secure surgical fields.

Evaluation of serum interleukin 2 receptor and beta-2-microglobulin as prognostic factors for canine lymphoma: A pilot study.

Interleukin 2 receptor (IL-2R) is released from activated T cell lymphocytes and related to proliferation of B cells and T cells. Beta-2-microglobulin (B2M) is synthesized from all nucleated cells and constitutes a major histocompatibility complex class I antigen. In human medicine, high concentrations of these two factors have been found to be related to prognosis in aggressive non-Hodgkin's lymphoma. In this pilot study, we aimed to assess the correlation between the serum concentration of IL-2R and B2M and the diagnosis and prognosis of canine lymphoma. This study included 8 healthy dogs and 17 dogs with lymphoma. To measure the serum concentration of IL-2R and B2M, a commercial enzyme-linked immunosorbent assay was used. In dogs with lymphoma, IL-2R concentrations were significantly high at the time of diagnosis, but B2M concentrations were not. In relapsed dogs, both IL-2R and B2M concentrations were significantly higher than those in the control and chemotherapy response groups. When the serum concentrations of IL-2R and B2M during chemotherapy were monitored in four relapsed dogs, B2M levels were more closely related with relapse. This study demonstrated that serum IL-2R and B2M concentration can be a diagnostic or prognostic tool for canine lymphoma. Monitoring of serum B2M concentration seems to be useful for predicting relapse.

Factors Affecting the Outcome of Medical Treatment in Cats with Obstructive Ureteral Stones Treated with Tamsulosin: 70 Cases (2018-2022).

The incidence of diseases associated with feline ureteral obstruction is increasing; however, non-surgical treatment options are limited. This study evaluated the outcome of medical treatment in cats with obstructive ureteral stones treated with tamsulosin and identified potential factors predicting spontaneous stone passage. We retrospectively reviewed 70 client-owned cats treated at the Western Referral Animal Medical Center, Seoul, Korea, from 2018 to 2022. All the cats had obstructive ureterolithiasis and were treated using tamsulosin. The baseline characteristics of the cats, stone diameter and location, and stone passage outcomes were analyzed. Stone passage occurred in 22 cats; the remaining 48 cats showed no change in stone locations. Sex, creatinine, and diameter and location of stones were potential risk factors associated with successful stone passage, but age, weight, and side of the stone were not. No serious adverse events related to tamsulosin treatment were observed. This is the first study to identify the risk factors predictive of the spontaneous stone passage of cats with obstructive ureterolithiasis after tamsulosin treatment. Tamsulosin could be an alternative treatment for ureteral obstruction in male cats with smaller distal ureteral stones and low baseline serum creatinine levels. These findings could help develop guidelines for treating feline ureterolithiasis.

Evaluation of endothelial cell-specific molecule-1 as a biomarker of glycocalyx damage in canine myxomatous mitral valve disease.

BACKGROUND: Endothelial cell-specific molecule-1 (ESM-1) has emerged as a potential biomarker for cardiovascular disease in humans. Myxomatous mitral valve disease (MMVD) is the most common heart disease in dogs, and we hypothesized that MMVD causes chronic inflammation that increases susceptibility to endothelial glycocalyx (eGCX) damage. In this study, we measured the concentration of ESM-1 in a group of dogs with MMVD and evaluated factors affecting eGCX damage. RESULTS: Sixty-four dogs (control, n = 6; MMVD, n = 58) were enrolled in this study. There was no significant difference in serum ESM-1 concentrations among the MMVD stages. The serum ESM-1 concentration was significantly higher in the death group than in the alive group in MMVD dogs. (p = 0.006). In five dogs with MMVD, serum ESM-1 concentrations tended to decrease when the cardiac drug (pimobendan, furosemide, and digoxin) dose was increased. CONCLUSIONS: In cases where MMVD progressed to decompensated heart failure with clinical symptoms and resulted in death, the concentration of serum ESM-1 increased significantly. Therefore, ESM-1 could be utilized as a new potential negative prognostic factor in patients with MMVD.

Retrospective analysis of efficacy and safety of oral paclitaxel for treatment of various cancers in dogs (2017-2021).

BACKGROUND: In humans, several safety evaluations have shown minimal adverse events with oral paclitaxel; however, its therapeutic efficacy and safety has not been well established in dogs with various cancers. OBJECTIVES: We aimed to retrospectively evaluate the efficacy and safety of oral paclitaxel in dogs with various cancers. METHODS: Twenty-one dogs diagnosed with various cancers were administered several doses of oral paclitaxel three times a month (group 1) or six times a month (group 2). RESULTS: The overall response rate was 6.25% (6.25%, complete response; 56.25%, stable disease; 37.5%, progressive disease) in dogs for which the treatment response could be evaluated. The median overall survival (OS) and progression-free survival (PFS) were 74 and 60.5 days, respectively. Regardless of the administration group, differences in OS and PFS of the two groups did not reach statistical significance. Most dogs tolerated the treatment regimen well, and although minor adverse events were observed in some dogs, they recovered after temporary drug discontinuation, dose reduction or symptomatic treatment. There was no significant difference in the prevalence of adverse events between the two groups. CONCLUSIONS: Based on the observed responses in certain types of cancers and the minimal adverse events, the study findings supported the efficacy and safety of oral paclitaxel administration in dogs. Thus, oral paclitaxel could play a role in the management of cancer in dogs.

Unusual case of pleural effusion caused by amlodipine in a dog with systemic hypertension.

OBJECTIVE: The aim of this report is to document the case of a dog that developed pleural effusion as a potential side-effect to the administration of a high-dose of amlodipine. CASE SUMMARY: A Yorkshire terrier dog (13-year-old, castrated male, 4.5 kg) presented with severe systemic hypertension (>200 mmHg), hyperkalaemia, and acute pancreatitis. The dog had hyperadrenocorticism, chronic valvular heart disease, chronic kidney disease, and cerebellar infarction as underlying diseases. Additionally, the dog had laboured breathing and tachypnoea during hospitalization. Screening examinations revealed a pleural effusion (pure transudate) for which hypoalbuminemia and thromboembolism were ruled out as the causes. Therefore, the adverse drug event of an anti-hypertensive drug (amlodipine) was tentatively diagnosed. CONCLUSIONS: Pleural effusion resolved within 24 h of reducing the dosage of amlodipine. Hence, the dog was diagnosed with amlodipine-induced pleural effusion. Rarely, amlodipine can cause pleural effusion after high-dose administrations in humans, but only two cases of peripheral edema have been reported in animals. If pleural effusion occurs in hypertensive patients administered amlodipine, it should be considered as the potential cause.

Gene expression of adipokines and inflammatory cytokines in peripheral blood mononuclear cells of obese dogs.

BACKGROUND: Peripheral blood mononuclear cells (PBMCs) have been identified as a possible marker of inflammation in obesity. Understanding the expression of pro- and anti-inflammatory cytokines in PBMCs in obese dogs will help control obesity-related inflammatory diseases. OBJECTIVES: The aim of this study was to evaluate the role of PBMCs in obesity-associated chronic inflammation by analyzing the expression of adipokines and inflammatory cytokines. METHODS: Blood samples were obtained from 25 subjects and real-time quantitative polymerase chain reaction determinations were performed to quantify the gene expression levels of adipokines and inflammatory cytokines, including TNF-α, IL-17, leptin, MCP-1, and adiponectin, in the PBMCs. RESULTS: The results showed that the gene expression levels of TNF-α (p < 0.001), IL-17 (p < 0.0001), and leptin (p < 0.0001) were strongly upregulated in the PBMCs of obese dogs compared to that in non-obese dogs. CONCLUSIONS: The changes in gene expression levels of inflammation-related adipokines and pro-inflammatory cytokines occur in PBMCs, which may contribute to the low-grade chronic inflammation that is present in obesity.

Transient thrombocytopenia in a cat following G-CSF treatment.

A 4-year-old, castrated male, Russian blue cat with idiopathic epilepsy was diagnosed with neutropenia. The neutropenia was classified as idiopathic after blood tests and abdominal imaging did not reveal an infectious, inflammatory or neoplastic aetiology. As a treatment trial for idiopathic neutropenia, the cat was administered granulocyte colony-stimulating factor by subcutaneous injection once daily for 3 days. Two weeks after completion of granulocyte colony-stimulating factor therapy, the cat developed severe thrombocytopenia, with the granulocyte colony-stimulating factor therapy considered to be the most likely cause. No treatment was initiated, and the thrombocytopenia had resolved spontaneously by 2 weeks after diagnosis. This is the first reported case of transient severe thrombocytopenia in a cat following granulocyte colony-stimulating factor treatment.

Canine peripheral blood mononuclear cell-derived B lymphocytes pretreated with lipopolysaccharide enhance the immunomodulatory effect through macrophage polarization.

BACKGROUND: Preconditioning with lipopolysaccharide (LPS) is used to improve the secretion of anti-inflammatory agents in B cells. However, there are only a few studies on canine B cells. OBJECTIVE: This study aimed to evaluate the immune regulatory capacity of canine peripheral blood mononuclear cell-derived B cells pretreated with LPS. METHODS: Canine B cells were isolated from canine peripheral blood mononuclear cells, which were obtained from three healthy canine donors. The B cells were preconditioned with LPS, and then cell viability and the expression of the regulatory B cell marker were assessed. Finally, RNA extraction and immunofluorescence analysis were performed. RESULTS: LPS primed B cells expressed the interleukin (IL)-10 surface marker and immunoregulatory gene expression, such as IL-10, programmed death-ligand 1, and transforming growth factor beta. Macrophages in the inflammatory condition cocultured with primed B cells were found to have significantly down-regulated pro-inflammatory cytokine, such as tumor necrosis factor-α, and up-regulated anti-inflammatory cytokines such as IL-10. Additionally, it was revealed that co-culture with primed B cells re-polarized M1 macrophages to M2 macrophages. CONCLUSIONS: This study revealed that LPS-primed B cells have an anti-inflammatory effect and can re-polarize macrophages, suggesting the possibility of using LPS-primed B cells as a therapeutic agent for its anti-inflammatory effects and immune modulation.

Role of serum high-motility group box-1 (HMGB1) concentration as a prognostic factor in canine acute pancreatitis: A pilot study.

High-mobility group box-1 (HMGB1) is an intranuclear molecule that is released extracellularly in cytotoxic conditions. In acute pancreatitis, extracellular HMGB1 acts as a stimulating factor in the mechanism associated with pancreatic injury. To evaluate the prognostic property of serum HMGB1 levels at the time of diagnosis of pancreatitis, the blood samples collected over 10 months from canine patients in Seoul National University Veterinary Medical Teaching Hospital (n = 29). The HMGB1 levels were measured with ELISA kit and results were analyzed correlation with patient's death, hospitalization cost and period. HMGB1 levels in patients with acute pancreatitis (mean = 76 ng/mL, standard deviation [SD] = 46.99 ng/mL) were higher than that of normal individuals (mean = 31.65 ng/mL, SD = 18.41 ng/mL, p = 0.0082). Similarly, non-survivors demonstrated statistically significant difference than the survivors (p = 0.008). Clinical severity of acute pancreatitis was categorized into three stages: mild, moderate, and severe based on the disease activity index (DAI). The HMGB1 levels and mortality were associated with moderate DAI (p = 0.0236). However, the correlation between serum HMGB1 and patients' hospitalization period and cost were not found to be significant (R2 = 0.01991). The evaluation of serum HMGB1 level at the time of diagnosis was identified as a potential prognostic factor to estimate the prognosis of acute pancreatitis in canines.

Extracellular vesicles derived from DFO-preconditioned canine AT-MSCs reprogram macrophages into M2 phase.

BACKGROUND: Mesenchymal stem/stromal cells (MSCs) are effective therapeutic agents that ameliorate inflammation through paracrine effect; in this regard, extracellular vesicles (EVs) have been frequently studied. To improve the secretion of anti-inflammatory factors from MSCs, preconditioning with hypoxia or hypoxia-mimetic agents has been attempted and the molecular changes in preconditioned MSC-derived EVs explored. In this study, we aimed to investigate the increase of hypoxia-inducible factor 1-alpha (HIF-1α)/cyclooxygenase-2 (COX-2) in deferoxamine (DFO)-preconditioned canine MSC (MSCDFO) and whether these molecular changes were reflected on EVs. Furthermore, we focused on MSCDFO derived EVs (EVDFO) could affect macrophage polarization via the transfer function of EVs. RESULTS: In MSCDFO, accumulation of HIF-1α were increased and production of COX-2 were activated. Also, Inside of EVDFO were enriched with COX-2 protein. To evaluate the transferring effect of EVs to macrophage, the canine macrophage cell line, DH82, was treated with EVs after lipopolysaccharide (LPS) stimulation. Polarization changes of DH82 were evaluated with quantitative real-time PCR and immunofluorescence analyses. When LPS-induced DH82 was treated with EVDFO, phosphorylation of signal transducer and transcription3 (p-STAT3), which is one of key factor of inducing M2 phase, expression was increased in DH82. Furthermore, treated with EVDFO in LPS-induced DH82, the expression of M1 markers were reduced, otherwise, M2 surface markers were enhanced. Comparing with EVDFO and EVnon. CONCLUSION: DFO preconditioning in MSCs activated the HIF-1α/COX-2 signaling pathway; Transferring COX-2 through EVDFO could effectively reprogram macrophage into M2 phase by promoting the phosphorylation of STAT3.

Feline adipose tissue-derived mesenchymal stem cells pretreated with IFN-γ enhance immunomodulatory effects through the PGE2 pathway.

BACKGROUND: Preconditioning with inflammatory stimuli is used to improve the secretion of anti-inflammatory agents in stem cells from variant species such as mouse, human, and dog. However, there are only few studies on feline stem cells. OBJECTIVES: This study aimed to evaluate the immune regulatory capacity of feline adipose tissue-derived (fAT) mesenchymal stem cells (MSCs) pretreated with interferon-gamma (IFN-γ). METHODS: To assess the interaction of lymphocytes and macrophages with IFN-γ-pretreated fAT-MSCs, mouse splenocytes and RAW 264.7 cells were cultured with the conditioned media from IFN-γ-pretreated MSCs. RESULTS: Pretreatment with IFN-γ increased the gene expression levels of cyclooxygenase-2, indoleamine 2,3-dioxygenase, hepatocyte growth factor, and transforming growth factor-beta 1 in the MSCs. The conditioned media from IFN-γ-pretreated MSCs increased the expression levels of M2 macrophage markers and regulatory T-cell markers compared to those in the conditioned media from naive MSCs. Further, prostaglandin E2 (PGE2) inhibitor NS-398 attenuated the immunoregulatory potential of MSCs, suggesting that the increased PGE2 levels induced by IFN-γ stimulation is a crucial factor in the immune regulatory capacity of MSCs pretreated with IFN-γ. CONCLUSIONS: IFN-γ pretreatment improves the immune regulatory profile of fAT-MSCs mainly via the secretion of PGE2, which induces macrophage polarization and increases regulatory T-cell numbers.

Efficacy and safety of allogenic canine adipose tissue-derived mesenchymal stem cell therapy for insulin-dependent diabetes mellitus in four dogs: A pilot study.

Mesenchymal stem cells (MSCs) possess regenerative and immunomodulatory properties and can control the immune dysregulation that leads to ß-cell destruction. Stem-cell transplantation could thus manage insulin-dependent diabetes mellitus (IDDM) in dogs. In this pilot study, we aimed to assess canine adipose tissue-derived MSCs (cAT-MSCs) transplantation as a treatment for canine diabetes mellitus. This study included four dogs with over a year of insulin treatment for IDDM, following diagnosis at the Veterinary Medicine Teaching Hospital of Seoul National University. Allogenic cAT-MSCs were infused intravenously three or five times monthly to dogs with IDDM. Blood and urine samples were obtained monthly. General clinical symptoms, including changes in body weight, vitality, appetite, and water intake were assessed. Three of the four owners observed improvement of vitality after stem cell treatment. Two of the four dogs showed improvement in appetite and body weight, polyuria, and polydipsia. C-peptide has increased by about 5-15% in three of the cases, and fructosamine and HbA1c levels have improved in two of the cases. Hyperlipidemia was resolved in two of the dogs, and there was no concurrent bacterial cystitis in any of the dogs. C-peptide secretion and lipid metabolism are associated with diabetic complications. Improvement in these parameters following the treatment suggests that cAT-MSC transplantation in dogs with IDDM might help to improve their insulin secretory capacity and prevent diabetic complications.

Enhanced expression of cyclooxygenase-2 related multi-drug resistance gene in melanoma and osteosarcoma cell lines by TSG-6 secreted from canine adipose-derived mesenchymal stem/stromal cells.

BACKGROUND: Multiple drug resistance (MDR) of cancer cells is the main cause of intrinsic or acquired desensitization to chemotherapy in many cancers. A number of studies have found high expression of COX-2 to be a factor for expression of MDR gene in several cancer. Furthermore, adipose tissue derived mesenchymal stem/stromal cells (ADSC) have been found to increase cyclo-oxygenase-2 (COX-2) expression in some tumour cells. The mechanism for this, however, is not yet clear and needs further study. OBJECTIVE: The purpose of this study was to determine whether tumour necrosis factor-alpha stimulated gene/protein 6 (TSG-6) secreted from ADSCs is associated with an increase in MDR genes by inducing COX-2 gene expression in melanoma and osteosarcoma cell lines. METHODS: ADSCs were transfected with TSG-6 siRNA or Control RNA respected, and cancer cell line were transfected with COX-2 siRNA or Control RNA respected. Using trans well coculture system, the interactions of ADSCs with tumour cells were investigated. RESULTS: Increased COX-2 expression was observed in cancer cell co-cultured with ADSCs. Additionally, we identified that COX-2 expression was related to drug resistance genes (P-glycoprotein, multidrug resistance-associated protein). Transfecting canine ADSCs with small interfering RNA, TSG-6 secreted from ADSCs was found to be a major factor in the regulation of COX-2 expression and drug resistance genes in osteosarcoma and melanoma cell lines. CONCLUSION: TSG-6 mediated COX-2 up-regulation is a possible mechanism of chemoresistance development induced by ADSCs. These findings provide better understanding about the mechanism associated with ADSC-induced chemoresistance in cancer.

Successful treatment of a dog with phenobarbital-responsive sialadenosis and an oesophageal stricture.

BACKGROUND: Phenobarbital-responsive sialadenosis (PRS) can cause nausea and vomiting, and is rarely reported in dogs. OBJECTIVES: An 8-year-old neutered, male Pomeranian dog was presented to our teaching hospital with vomiting that began 2 years ago. The clinical signs repeatedly improved and deteriorated despite treatment. METHODS: The only abnormality found on physical examination was salivary gland enlargement, and no specific findings were observed on blood analysis and imaging tests. The results of the fine needle aspirate cytology from the salivary glands revealed possible sialadenosis. Phenobarbital was prescribed, and the patient's symptoms resolved. However, upon discontinuing drug, the patient's clinical signs recurred and did not improve even after re-introduction of phenobarbital and the addition of other anticonvulsant drugs. An oesophageal stricture was observed on an oesophagram, and fibrosis was confirmed endoscopically. A balloon dilation was performed to expand the stenosis. RESULTS: After the first procedure, the patient's clinical signs initially improved, but relapsed 2 weeks later. A total of three oesophageal dilation procedures were performed using a sequentially larger diameter balloon. After the third procedure, the patient's clinical signs were managed without recurrence. The cause of recurrent gastrointestinal signs following the initial successful treatment of phenobarbital-responsive sialadenosis was due to oesophageal stricture formation. CONCLUSIONS: This case report demonstrates the successful management of PRS with subsequent oesophageal stricture formation in a dog.

Influence of Canine Macrophage-derived Extracellular Vesicles on Apoptosis in Canine Melanoma and Osteosarcoma Cell Lines.

BACKGROUND/AIM: The purpose of this study was to evaluate the effect of extracellular vesicles derived from canine M1-polarized macrophages (M1EVs) on canine tumor cells, such as D17 (osteosarcoma cells) and LMeC (melanoma cells). MATERIALS AND METHODS: Protein expression was determined by western blot analysis. Gene expression was determined by RT-qPCR. In addition, cell apoptosis was analyzed by Annexin V/PI staining. RESULTS: In the case of M1EV, the levels of pro-inflammatory cytokines such as TNF-α, IL-6 and IL-1ß were increased, and nitrate/nitrite levels were also increased. M1EV induced apoptosis of tumor cells by increasing caspase-3 and caspase-7 activation. In addition, M1EVs decreased expression of CCR4, Foxp3 and CTLA-4 in canine peripheral mononuclear cells cocultured with tumor cells. CONCLUSION: M1EV could be an effective anti-cancer therapeutic approach in melanoma and osteosarcoma and M1EVs can be used as immunomodulators in the tumor microenvironment for cancer treatment.

Use of oral paclitaxel for the treatment of bladder tumors in dogs.

An oral paclitaxel formulation that overcomes the hypersensitivity reaction of paclitaxel has been evaluated for safety and efficacy in humans, but not in dogs. We present the first case report on the use of oral paclitaxel in dogs. In this study, oral paclitaxel was well-tolerated in four dogs with either transitional cell carcinoma or prostate cancer; adverse effects were limited to mild neutropenia. Each of the dogs had progressive disease at the end, but clinical responses, including changes in mass size and improvement of clinical symptoms, were confirmed in some of the animals following oral paclitaxel chemotherapy. Although this study is somewhat limited by a small sample size, it suggests that oral paclitaxel may be a chemotherapeutic option for malignant tumors in dogs.

Erratum: A retrospective study of theophylline-based therapy with tracheal collapse in small-breed dogs: 47 cases (2013-2017).

This corrects the article on e57 in vol. 20, PMID: 31565900.