Endotracheal stent granulation stenosis resolution after colchicine therapy in a dog

[Accidental colchicine intoxication in a cross-breed dog]

A 2-year old cross-breed dog presented due to acute vomiting and progressive lethargy following ingestion of the owner's anti-gout medication (colchicine, 0.35 mg/kg) 1-3 hours prior to presentation.The dog developed signs of all 3 stages of colchicine poisoning (gastrointestinal phase, multi-organ phase, recovery phase) and the clinical course was complicated by the presence of multi-organ dysfunction syndrome (MODS) and numerous negative prognostic factors.This case report describes the clinical and laboratory effects of colchicine poisoning and represents the first successful treatment of an accidental colchicine ingestion in a dog in Europe.

The Effects of Mycophenolate on the Formation of Granulation Tissue Post-operatively in Canine Tracheal Stent Patients (2014-2020)

Objectives: To determine if mycophenolate mofetil reduces the incidence and severity of granulation tissue in-growth in canine tracheal stent patients. Study design: Randomized clinical trial. Animals: 111 dogs from the hospital population. Methods: Client-owned dogs that received an endoluminal self-expanding tracheal stent for canine tracheal collapse between 2014 and 2020 were randomly assigned into one of two treatment groups. Control group medication protocol consisted of prednisone 0.5 mg/kg PO BID/SID/EOD × 30 days, hydrocodone 0.25 mg/kg PO TID × 30 days, and cefovecin 8 mg/kg SQ post-placement. Mycophenolate group medication protocol was identical to the control group medication protocol with the addition of mycophenolate mofetil 10 mg/kg PO BID × 30 days, SID for life. Recheck tracheoscopy was performed at 1, 3, and 6 months post-stent placement. Presence and severity of granulation tissue were determined by tracheoscopy and were recorded as a percentage of tracheal lumen obstruction by blinded evaluators (none present, <25%, >25-50%, and >50%). Results: At none of the three time points was there a statistically significant difference in grade between controls and those receiving mycophenolate (p = 0.467, p = 0.330, and p = 0.410). Conclusions and Clinical Significance: Our results suggest that mycophenolate can be safely given to these patients but do not support that its administration will reduce the incidence and severity of granulation tissue. Although a difference was observed in the severity of granulation tissue between the two groups, loss to follow-up may have influenced conclusions. A larger study would be warranted to further evaluate the effect of mycophenolate on the development of granulation tissue.

Survival of a dog with accidental colchicine overdose

OBJECTIVE

To describe the treatment and clinical course of a dog accidentally prescribed 10 times the recommended dose of colchicine (0.3 mg/kg/d instead of 0.03 mg/kg/d).

CASE SUMMARY

After glaucoma surgery, a 1-year-old male neutered Pomeranian weighing 6.8 kg was prescribed 1,000 μg colchicine twice a day per os. The dog presented to the emergency department after the first dose with vomiting and was treated as an outpatient. Two colchicine doses later, the dog represented with vomiting, ocular pain, and increased intraocular pressure. The dog's vital signs were normal, and the dog was admitted for rehydration, analgesia, and revision glaucoma surgery the next day. Two hours after revision surgery, the dog developed vomiting and diarrhea. Postoperatively, the dog was hypothermic (36.3°C), persistently hypertensive (227 mm Hg), and bradycardic (60/min). Biochemistry revealed metabolic acidosis and increased hepatic enzyme activities. Mannitol was administered for presumed cerebral edema. Later, the dog developed bradycardia due to second-degree atrioventricular heart block, which responded to atropine. Total hospitalization was 9 days. Treatment included IV fluids, IV lipid emulsion, N-acetylcysteine, activated charcoal, gastroprotectants, antiemetics, opioids, antimicrobials, and barrier nursing due to transient neutropenia.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first report to describe the successful treatment of a dog with colchicine overdose. The systemic effects were presumed to be secondary to colchicine toxicosis rather than diet, infection, or other drug reaction, and may have been compounded by a second anesthetic episode. Gastrointestinal signs, symptoms of cerebral edema, cardiac arrhythmias, and neutropenia were documented. One other report of colchicine overdose in a dog exists, and that patient was euthanized. This report demonstrates that complete recovery with intensive care is possible; however, the prognosis remains guarded.

Correlations among tracheal dimensions, tracheal stent dimensions, and major complications after endoluminal stenting of tracheal collapse syndrome in dogs

Background

Endoluminal tracheal stenting can relieve signs associated with tracheal collapse syndrome (TCS) in dogs, but major complications can result.

Objective

To identify associations among tracheal dimensions, stent dimensions, and subsequent complications requiring additional stent placement after endoluminal stenting for TCS.

Animals

Fifty‐two dogs from the hospital population.

Methods

Medical records of dogs that received an endoluminal self‐expanding tracheal stent for TCS by the interventional radiology service between 2009 and 2014 were reviewed for relevant data. Signalment and clinical details, including tracheal collapse type, tracheal measurements, nominal stent dimensions, follow‐up evaluation times, and stent complications, were recorded.

Results

Fifty‐two dogs that received an endoluminal stent for TCS met the inclusion criteria. Major complications included stent fracture (13/52; 25%), obstructive tissue ingrowth (10/52; 19%), and progressive tracheal collapse (6/52; 12%). Natural tracheal taper (P = .04) and more stent diameter oversizing (P = .04) in the intrathoracic (IT) trachea were associated with caudodorsal stent fracture. Only stents with a 14‐mm nominal diameter fractured. Progressive tracheal collapse was associated with smaller maximum tracheal diameters (P = .02). The majority of dogs with obstructive tissue ingrowth (7/10; 70%; P = .30) and all dogs with thoracic inlet fractures (3/3; 100%) had tracheal malformations.

Conclusions and Clinical Importance

A higher taper in tracheal diameter may lead to increased risk of fracture in the IT location. Dogs with tracheal malformations may have higher risk for thoracic inlet fracture and development of obstructive tissue ingrowth. Clinicians should be aware of the possible risk factors for tracheal stent complications.

Effect of Variations in Stent Placement on Outcome of Endoluminal Stenting for Canine Tracheal Collapse

The study's objective was to determine effects of relative size and placement location of endoluminal stents on incidence of complications and survival for canine tracheal collapse. Measurements were obtained on lateral radiographs before and after stenting to determine percent of the trachea occupied by the stent. These values were monitored over time and compared to complication rates and survival. Overall median survival time was 502 days. Six month survival rate was 78%, 1 yr survival was 60%, and 2 yr survival was 26%. Median percent of trachea occupied by the stent at initial placement was 79% (range, 41-93%). Percent of the trachea occupied by the stent at the time of placement did not significantly correlate to complication rate (0.397) or survival time (0.853). Incidence of serious complications was 37%, including granuloma formation, pneumonia, material failure, and stent migration. For patients experiencing serious complications, median survival was shorter, at 208 days, but was not significantly different from survival without serious complications. Within the margins of the data from this study, the proportion of the trachea occupied by the stent at the time of placement does not appear to impact incidence of complications or survival time in dogs with tracheal collapse.