Endoscopy is an often-underutilised tool in veterinary hospitals. We want to shine the spotlight on this imaging modality by exploring five recent research papers in small animal endoscopy. These papers demonstrate the importance of endoscopy in both diagnosis and treatment of a variety of patients, hopefully inspiring your next case work-up.
Five recent studies on small animal endoscopy
1. Diagnosis of canine idiopathic inflammatory bowel disease
In this study, Bhavani et al. (2023) wanted to assess how useful endoscopy is at diagnosing inflammatory bowel disease (IBD), as well as correlating the clinical activity index with endoscopic score. For those not familiar with it, the clinical inflammatory bowel disease activity index (CIBDAI) is a numeric index proposed to score the severity of the condition. It is based on the presence and frequency of gastrointestinal signs, such as appetite, vomiting, faecal consistency, frequency of defecation, weight loss and attitude/activity.
The authors achieved this through endoscopy of the stomach, duodenum and colon of 33 dogs. They documented the visible lesions, and histopathology was performed on biopsy samples obtained, which were used to confirm the disease.
Interestingly, however, there was no correlation between the clinical activity index and the endoscopic score
Mucosal inflammation and friability were frequently visible on endoscopy and lymphoplasmacytic infiltration was common on biopsy samples of dogs with the common diffuse form of IBD. It was therefore found that gastroduodenoscopy and colonoscopy in combination with endoscopically guided biopsy and histopathology are of value when diagnosing and assessing IBD. Interestingly, however, there was no correlation between the clinical activity index and the endoscopic score.
This study showed that, in particular, colonoscopy with ileal biopsy could act as a gold standard diagnostic technique in the confirmation of diffuse IBD in dogs. CIBDAI is a way of measuring the clinical signs of the disease, but confirmation of the diagnosis still relies on direct access to the lumen of the gastrointestinal tract, with endoscopic biopsy being the least invasive way of achieving this.
Key points
- Endoscopy allows a visual exam of the gastrointestinal tract lumen and tissue biopsy, which could be considered the gold standard for confirming diffuse IBD in dogs
- Mucosal inflammation and friability are key features of endoscopic exams in dogs with IBD
- The CIBDAI is useful for categorising clinical signs but does not correlate with endoscopic score
You can read the full paper here.
2. The use of intraoperative endoscopy in dogs and cats for the removal of gastrointestinal foreign bodies
This paper by Israeli (2024) serves as a reminder of the usefulness of small animal endoscopy in foreign body retrieval, in both cats and dogs. All five animals in the study were anaesthetised for an exploratory laparotomy. During surgery, they were found to have a foreign body (FB) on palpation or visual exam. Small, non-gastric FBs were gently massaged back into the stomach. With the abdomen still open, a flexible endoscope was passed by an endoscopist and guided by the surgeon through the cardia and into the stomach. Air was used to insufflate the stomach for visualisation and extraction of the FB. The surgeon could assist the endoscopist by stabilising the FB against the stomach wall. This allowed for faster retrieval and less air needed for insufflation.
Just because we are already in the abdomen, it doesn’t mean that we can’t reach for another tool rather than causing further surgical trauma
The use of endoscopy eliminates many of the risks associated with gastrotomy, and also shortens the patient’s anaesthetic time. Endoscopy should therefore be considered a viable and potentially preferred option to gastrotomy. The paper highlights that just because we are already in the abdomen, it doesn’t mean that we can’t reach for another tool rather than causing further surgical trauma.
Key points
- Small animal endoscopy is a useful tool for gastric foreign body removal
- Endoscopic retrieval of a foreign body is preferable to gastrotomy
- Just because the patient is already undergoing an exploratory laparotomy doesn’t mean we can’t still reach for the endoscope
You can read the full paper here.
3. Endoscopic visualisation and irrigation in management of the recalcitrant discharging canine ear
Bhutta and Kureshi (2022) discussed the management of a discharging ear canal in dogs, and how veterinary treatment is often lacking compared to human care in this field. The authors recognise that in cases of otitis, many patients only require one visit to the vet. However, in ear discharge cases that are recurrent or persistent, further action is required.
It is critical to clean the ear canal of debris thoroughly and perform a visual examination of the deep ear canal and tympanic membrane. The authors propose that this is “best undertaken using an irrigation pump and endoscope because the optics on a modern endoscope are far superior to an otoscope and naked eye”. Endoscopic exam also allows for easier removal of foreign bodies in the ear canal such as grass awns.
An endoscopic approach can also be used to treat middle ear tympanokeratoma (cholesteatoma). This was traditionally treated by a surgical approach, accessing the bulla to remove or debulk disease, but a less invasive endoscopic approach has been described.
Key points
- Endoscopy has uses for the treatment and diagnosis of ear disease
- Endoscopy can provide less invasive methods of treating certain ear diseases
- Recurrent or persistent discharging ears can be challenging to treat, and endoscopy may be a better way forward
You can read the full paper here.
4. Management of polyethylene glycol solution aspiration using bronchoscopic lavage in a dog
This paper describes the case of a dog that aspirated a small amount of polyethylene glycol (PEG) lavage solution, which may be used for colonic preparation in dogs ahead of colonoscopy (Aguayo Santaella et al., 2020). It is relatively safe when administered appropriately, but if accidentally inhaled it can cause pulmonary oedema, acute respiratory distress syndrome (ARDS), multiple organ failure and death. Care must be taken if administering this product to patients via nasogastric or orogastric routes to ensure correct tube placement. However, in this case, the patient regurgitated and aspirated a small amount of fluid.
While the patient seemed initially unaffected, it quickly became hypoxaemic. Treatment using bronchoscopic suction and airway lavage is crucial in these cases, and this dog was quickly treated accordingly. Bronchoscopy allowed visual examination of this dog’s airways and accurate suction of the clear foamy fluid that was partially obstructing the trachea and other airway passages, as well as accurate and thorough lavage.
This paper highlights not only the need to be extremely careful when using PEG in our patients, but also the usefulness of small animal endoscopy in treating an adverse event or toxicity.
Key points
- PEG solution can cause severe respiratory distress and death, so use carefully in patients
- This paper highlights the usefulness of endoscopy in adverse events such as this
- Most of us think about bronchoscopy as a purely diagnostic tool whereas this paper highlights its alternative uses
You can read the full paper here.
5. ACVIM consensus statement on diagnosis and management of urinary incontinence in dogs
This consensus statement provides up-to-date guidelines on the diagnosis and management of urinary incontinence in dogs. A panel of experts assess and summarise all the latest advice from recent literature so that general practitioners are clear on the recommended course of action for their patients (Kendall et al., 2024).
Cystoscopy is heavily featured in the consensus statement. This form of small animal endoscopy uses entry via the urethra to directly examine the inside of the bladder.
The panel assessed the use of computed tomography (CT) and cystoscopy when compared to radiography in the diagnosis of ectopic ureters (EU). It found that CT outperformed radiography and fluoroscopy, providing a detailed overview of urogenital anatomy. But the paper then goes on to state, “However, CT is less sensitive than cystoscopy in diagnosing EU and certain important features of EU (eg intra vs extramural course, ureteral troughs, ureteral fenestrations, branched ureters), that are evident by cystoscopy and cannot be identified by any imaging modality.” It concludes that cystoscopy is the preferred technique for diagnosing EU. Additionally, it has the advantage that laser cautery ablation can also be performed at the same time as diagnosis.
The consensus statement also covered the use of cystoscopy in cases of mechanical outflow obstruction (MOO). Interventional treatment with cystoscopy is recommended to decrease morbidity and the risk of subsequent urethral stricture associated with urethral surgery. For example, cystoscopy can allow for cystoscopic basket retrieval of uroliths and placement of stents in cases of urethral urothelial carcinoma.
Key points
- Cystoscopy is the most accurate diagnostic technique for EU cases
- Cystoscopic EU ablation is the treatment of choice for patients with EU
- Cystoscopy is also recommended in the treatment of MOO patients
You can read the full paper here.
Summary
Endoscopy can lead to a more accurate diagnosis and better clinical outcomes than other modalities might provide
Hopefully, we have shown you just how extensively endoscopy can be used in small animal practice. In the right pair of hands, a variety of body systems can be scoped. Endoscopy can lead to a more accurate diagnosis and better clinical outcomes than other modalities might provide.
