Immunopathogenesis of canine aural haematoma

Platelet- Rich Plasma Treatment Supported by Ultrasound Detection of Septa in Recurrent Canine Aural Hematoma: A Case Series

Aural hematoma is a common pathological condition in veterinary practice with a high incidence rate in dogs. Drainage, corticosteroid injections, and surgical approaches represent the common treatments in these clinical cases. However, surgery leaves visible signs and is usually correlated with recurrence, scars, and deformation of the treated pinna. For this reason, more effective and less invasive methods have been proposed over the years. Platelet-Rich Plasma (PRP) is one of the most promising options due to its pro-regenerative properties and capability to modulate the inflammatory state. The present work reports 12 cases of canine aural hematoma treated with PRP. The PRP treatment was combined with an ultrasound evaluation of the pinna to detect and treat all involved septa. The results show that relatively large volumes (2 mL) of PRP associated with an ultrasound guide are safe and efficacious in the treatment of canine aural hematoma requiring a maximum of two infiltrations, both in acute and chronic conditions. All the patients recovered their normal ear thickness (compared with the controlateral one) without relapses, averaging 38.5 days from their first treatment (10-90 days; SD: 24.7). The key role of PRP combined with a tailored diagnosis process carried out by the veterinarian, which included using an ultrasound system and the proper bandage, suggests that this approach may represent a valid alternative to surgery and corticosteroids.

A Review of Recent Developments in Veterinary Otology

The knowledge gap between practical research and its implementation in veterinary practice is becoming harder to bridge, as researchers now have a plethora of journals in which to publish. This paper summarizes recent research from the latest publications related to ear disease in dogs which have implications for veterinary practitioners. The topics reviewed include 16s rRNA new-generation sequencing, the use of oclacitinib in pinnal ulceration, the etiopathogenesis of aural hematoma, contamination of the middle ear during elective myringotomy and how to avoid it, and the use of carbon dioxide lasers in chronic obstructive otitis.

Reporting the epidemiology of aural haematoma in dogs and proposing a novel aetiopathogenetic pathway

To evaluate the incidence and risk factors for aural haematoma in dogs under primary veterinary care in the UK. A cohort study design. Dogs diagnosed with aural haematoma during 2016 were identified from the VetCompass database. Univariable and multivariable logistic regression modelling were used for risk factor analysis. There were 2,249/905,554 dogs diagnosed with aural haematoma during 2016. The estimated one-year incidence risk for aural haematoma was 0.25% (95% confidence interval 0.24–0.26). After accounting for confounding factors, 14 breeds showed increased odds and 20 breeds showed reduced odds of aural haematoma compared with crossbred dogs. Breeds with the highest odds included Bull Terrier (OR 7.42, 95% confidence interval 4.39–12.54), Saint Bernard (OR 7.28, 95% confidence interval 3.58–14.81) and French Bulldog (OR 6.95, 95% confidence interval 5.55–8.70). Increasing age, increasing bodyweight and breeds with V-shaped drop and semi-erect ear carriage also showed increased odds of aural haematoma. Associations between ear carriage within breeds and the risk of aural haematoma suggest that trauma along the line of cartilage folding within V-shaped and semi-erect ears may trigger aural haematoma. New knowledge of key breed predispositions will contribute to improved breed health control strategies.

Use of Autologous Leucocyte- and Platelet-Rich Plasma (L-PRP) in the Treatment of Aural Hematoma in Dogs

Leukocyte- and platelet-rich plasma (L-PRP) can accelerate the healing process by providing increased concentrations of platelet-derived growth factors. The objective of this study was to evaluate the clinical effect of L-PRP in the treatment of canine aural hematomas associated with otitis externa. Twenty mL of citrated whole blood was collected from each of the 17 dogs included and autologous L-PRP was produced. The aural hematoma was drained and 0.5–1 mL of L-PRP was injected. The dogs were examined weekly until 7 days after complete clinical healing. A final clinical follow-up was performed 6 weeks after the first treatment with L-PRP. If there was recurrence of the aural hematoma at the first follow-up, the treatment was repeated. In total, 2/17 cases were lost after the first follow-up. In 5/17 dogs, a short-term recurrence occurred. In 12/15 cases, complete clinical resolution was achieved with a single L-PRP application (Group A1) and in 3/15 with two treatments (Group A2). The mean time to complete clinical resolution was 16 ± 8.7 days (A1) and 23.3 ± 4 days (A2), respectively. No side effects were reported. The in situ administration of autologous L-PRP resulted in a complete resolution of the aural hematoma in all dogs that completed the clinical trial.

Clinical features, treatment, and outcome of aural hematomas in horses: 7 cases (2008-2019)

OBJECTIVE

To characterize the clinical features, treatment, and outcome of aural hematomas in horses.

ANIMALS

7 horses with 1 or 2 aural hematomas (8 ears in total) treated at a veterinary teaching hospital in 2008 through 2019.

PROCEDURES

Data retrieved from medical records included signalment, pertinent historical information, clinical signs, diagnostic procedures (including dermatologic assessment), and treatments. Case outcome was determined from documentation in the medical record or via telephone communication with owners or referring veterinarians.

RESULTS

3 horses were presented after recurrence of aural hematoma following treatment by the referring veterinarian. Four horses had a history of allergic skin disease prior to aural hematoma development. Most (6/7) horses were unilaterally affected. Diagnostic assessments included otoscopic evaluation (3 horses), ultrasonography (3 horses), cytologic examination of ear canal swab samples (3 horses), and histologic examination of a pinnal biopsy specimen (1 horse). Of the 8 pinnae, 2 were treated by nonsurgical needle drainage (1 with concurrent corticosteroid injection) and the remaining 6 underwent surgical incision and placement of compressive sutures. Follow-up information was available for 6 horses, and all affected pinnae were fibrotic with 4 horses having permanent drooping of the pinna. One horse developed a hematoma in the contralateral pinna 1 year after hospital discharge.

CONCLUSIONS AND CLINICAL RELEVANCE

Equine aural hematoma is a rare condition. The main principle of treatment is drainage, and treatment options commonly used in small animal practice can be successfully applied in horses. Permanent changes in the cosmetic appearance of the pinna are likely to develop owing to secondary fibrosis.

On the nature of canine aural haematoma and its treatment with continuous vacuum drainage

OBJECTIVES

To evaluate continuous vacuum drainage from the convex side of the pinna for surgical treatment of aural haematoma in dogs. To investigate aural haematoma fluid and cartilage samples harvested during surgery in an attempt to elucidate the etiopathogenesis of the lesion.

MATERIALS AND METHODS

Ten client-owned dogs with aural haematoma were treated by convex-side vacuum drainage using different types of vacuum drains and containers and were followed-up for at least 6 months. Systemic blood samples and aural haematoma fluids were analysed for biochemical, haematologic and electrophoretic content. Cartilage samples were examined histologically.

RESULTS

Nine of the 10 dogs were successfully treated without recurrence at 6 months postoperatively and with excellent cosmetic results. In one case, infection required early drain removal and delayed healing was associated with wrinkling of the pinna. Fluid sample analysis suggested that "aural haematoma" contains a transudate that accumulates within a cartilage-lined cavity. Histologic examination of the tissue samples revealed clefts of the pinna cartilage, with the luminal surface often lined with granulation tissue. Fluids and cartilage lacked evidence of inflammation.

CLINICAL SIGNIFICANCE

This technique was characterised by patient comfort, tolerance of drains, absence of dressings and good cosmetic outcome. The results of fluid analysis suggest that the term "aural seroma" would be more appropriate for this condition.

Labrador retrievers under primary veterinary care in the UK: demography, mortality and disorders

BACKGROUND

Labrador retrievers are reportedly predisposed to many disorders but accurate prevalence information relating to the general population are lacking. This study aimed to describe demography, mortality and commonly recorded diseases in Labrador retrievers under UK veterinary care.

METHODS

The VetCompass™ programme collects electronic patient record data on dogs attending UK primary-care veterinary practices. Demographic analysis covered all33,320 Labrador retrievers in the VetCompass™ database under veterinary care during 2013 while disorder and mortality data were extracted from a random sample of 2074 (6.2%) of these dogs.

RESULTS

Of the Labrador retrievers with information available, 15,427 (46.4%) were female and 15,252 (53.6%) were male. Females were more likely to be neutered than males (59.7% versus 54.8%, P <  0.001). The overall mean adult bodyweight was 33.0 kg (SD 6.1). Adult males were heavier (35.2 kg, SD 5.9 kg) than adult females (30.4 kg, SD 5.2 kg) (P <  0.001). The median longevity of Labrador retrievers overall was 12.0 years (IQR 9.9-13.8, range 0.0-16.0). The most common recorded colours were black (44.6%), yellow (27.8%) and liver/chocolate (reported from hereon as chocolate) (23.8%). The median longevity of non-chocolate coloured dogs (n = 139, 12.1 years, IQR 10.2-13.9, range 0.0-16.0) was longer than for chocolate coloured animals (n = 34, 10.7 years, IQR 9.0-12.4, range 3.8-15.5) (P = 0.028).Of a random sample of 2074 (6.2%) Labrador retrievers under care in 2013 that had full disorder data extracted, 1277 (61.6%) had at least one disorder recorded. The total number of dogs who died at any date during the study was 176. The most prevalent disorders recorded were otitis externa (n = 215, prevalence 10.4%, 95% CI: 9.1-11.8), overweight/obesity (183, 8.8%, 95% CI: 7.6-10.1) and degenerative joint disease (115, 5.5%, 95% CI: 4.6-6.6). Overweight/obesity was not statistically significantly associated with neutering in females (8.3% of entire versus 12.5% of neutered, P = 0.065) but was associated with neutering in males (4.1% of entire versus 11.4% of neutered, P < 0.001). The prevalence of otitis externa in black dogs was 12.8%, in yellow dogs it was 17.0% but, in chocolate dogs, it rose to 23.4% (P < 0.001). Similarly, the prevalence of pyo-traumatic dermatitis in black dogs was 1.1%, in yellow dogs it was 1.6% but in chocolate dogs it rose to 4.0% (P = 0.011).

CONCLUSIONS

The current study assists prioritisation of health issues within Labrador retrievers. The most common disorders were overweight/obesity, otitis externa and degenerative joint disease. Males were significantly heavier females. These results can alert prospective owners to potential health issues and inform breed-specific wellness checks.

A new operative technique for aural haematoma in dogs: A retrospective clinical study

Aural haematoma is treated either by surgical or by conservative treatment. Both techniques usually require several interventions and re-checks. A new operation technique has been evaluated that requires only a single procedure but is as effective as the techniques used previously. The haematoma is opened, cleaned surgically and the two layers of the auricular cartilage are appositioned inside with several suture lines placed on both sides of the incision, alternating the sides approaching to the sagittal cavity. None of the suture lines is stitched through the auricle completely as they all run intradermally on the side of the haematoma and to the cartilage on the other side. Twenty-three dogs with aural haematoma were treated between 2006 and 2012. In 21 (91%) of them, the haematoma healed without any auricle deformity. No secondary intervention was necessary in any of the cases. None of the 23 animals experienced a relapse during follow-up. The new method offers a minor risk of postoperative complications while accomplishing high healing rates.

Surgery of the ear and pinna

There are several disease processes of the ear and pinna that warrant surgical intervention. This article reviews surgical anatomy and common surgical procedures of the ear and pinna, including aural hematomas, lateral wall resection, vertical ear canal resection, total ear canal ablation and lateral bulla osteotomy, partial pinna resection, and feline inflammatory polyps. The clinical signs, diagnosis, and surgical treatment along with potential complications for each disease process are discussed.

Evaluation of a technique using the carbon dioxide laser for the treatment of aural hematomas

A new technique using the carbon dioxide (CO2) laser for the treatment of aural hematomas is described. The laser is used to make an incision into the hematoma to allow for evacuation of the blood, and then multiple, small incisions are made over the surface of the hematoma to stimulate adhesions between the tissue layers. The CO2 laser was used in this fashion to treat 10 aural hematomas in eight dogs. Follow-up ranged from 1 to 23 months. Owners evaluated the cosmetic results following CO2 laser surgery as excellent in three ears, good in five ears, and fair in two ears. Hematomas were resolved in all 10 cases, although two cases developed serosanguineous fluid accumulation that required percutaneous drainage in one case and a second laser procedure in the other case.

Auricular chondritis in a cat

A four-year-old male neutered domestic shorthaired cat developed bilateral thickening of the pinnae, with slight curling, intense erythema and pain. No ear canal disease was present. The cat was negative for feline immunodeficiency virus, feline leukaemia virus and feline coronavirus. Biopsy of the ear lesion revealed auricular chondritis. In humans, histologically similar lesions may involve the pinnae, nose, trachea, joints, eyes and heart, and the disease is termed relapsing polychondritis. The cat reported had a history of corneal damage, resulting in corneal vascularisation and opacity, eyelid distortion, necessitating an entropion operation, and radiological evidence of mild cardiac enlargement. The ear disease responded rapidly to treatment with prednisolone and, apart from slight thickening and curling of the pinnae, the cat remained normal and pain-free. After two years, the prednisolone was withdrawn, and there was no recurrence of the condition in a follow-up period of 14 months.