Congenital branchial apparatus malformation in a Haflinger colt

Objective— To report the diagnosis and treatment of a branchial apparatus anomaly (BAA) associated with a mandibular malformation in a foal.
Design— Clinical report.
Animal— Haflinger foal.
Methods— A 6-day-old foal had a fluctuating cystic mass in the pharyngeal (throatlatch) region, which changed in appearance after ingestion of milk. Upper airway endoscopy and diagnostic imaging (ultrasonography, radiography, computed tomography) permitted identification of the anatomic location of a communicating tract between the lumen of the cystic mass and the pharynx. The mass was surgically removed and communication with the pharynx ligated. Histologic appearance of this mass was consistent with a branchial cyst or sinus. The mandibular malformation was managed conservatively.
Results— Surgical resection of a third branchial sinus resulted in an excellent functional and cosmetic outcome. There was no evidence of any mandibular deformity 2 years later.
Conclusion— BAA may induce secondary mandibular deformation in utero and may cause respiratory compromise postpartum. Careful surgical dissection and removal of BAA resulted in an excellent outcome.
Clinical Relevance— BAAs should be included in the differential diagnosis of a throatlatch region mass in equine neonates. Complete surgical excision is recommended and full recovery of any associated mandibular deformity may be anticipated without additional treatment in very young patients.     

Use of Electrocautery Probes in Arthroscopic Removal of Apical Sesamoid Fracture Fragments in 18 Standardbred Horses

OBJECTIVE: To develop a technique for arthroscopic excision of apical sesamoid fracture fragments using electrocautery probes. ANIMALS OR SAMPLE POPULATION: A total of 18 Standardbred horses. METHODS: Arthroscopic removal of apical sesamoid fracture fragments using both hook and loop electrocautery probes was performed on 18 Standardbred horses. The fracture fragments were approached using either an ipsilateral (3) or contralateral (15) arthroscopic triangulation technique. Distension of the metacarpo- (metatarso)-phalangeal joints was achieved using a 1.5% glycine solution. Under arthroscopic guidance, both the suspensory and intersesamoidean ligament attachments to the abaxial and the axial margins of the apical fragment were transected using a hook electrocautery probe. Subsequently, the palmar (plantar) soft tissue attachments to the apical fragment were transected with a loop electrocautery probe. Once freed of soft tissue attachments, the apical fragment was removed with Ferris-Smith intervertebral disc rongeur. The arthroscopic portals were closed in a routine manner. RESULTS: Horse ages ranged from 2 to 8 years (median, 2.5 years). Eighteen apical sesamoid fracture fragments were removed from the left (8) and right (8) hind limbs and the left (1) and right (1) forelimbs. Apical fragments occured in 15 lateral and 3 medial proximal sesamoid bones. No major complications occurred during or after surgery. The electrocautery probes permitted an easy and precise dissection of all soft tissue attachments to the apical sesamoid fracture fragments in all horses. Follow-up time was 7 to 44 months (median, 26 months); 10 of 14 horses returned to racing. Seven of nine horses that raced before surgery raced again and three of five that had not raced before surgery, raced afterwards. CONCLUSION: Arthroscopic excision of apical sesamoid fracture fragments can be accomplished arthroscopically using electrocautery probes. CLINICAL RELEVANCE: Arthroscopic electrosurgery is an efficient and safe alternative for intra-articular dissection in horses.     

Congenital stationary night blindness is associated with the leopard complex in the Miniature Horse

Objective To determine if congenital stationary night blindness (CSNB) exists in the miniature horse in association with leopard complex spotting patterns (LP), and to investigate if CSNB in the miniature horse is associated with three single nucleotide polymorphisms (SNPs) in the region of TRPM1 that are highly associated with CSNB and LP in Appaloosas. Animals studied Three groups of miniature horses were studied based on coat patterns suggestive of LP/LP (n = 3), LP/lp (n = 4), and lp/lp genotype (n = 4). Procedures Horses were categorized based on phenotype as well as pedigree analysis as LP/LP, LP/lp, and lp/lp. Neurophthalmic examination, slit‐lamp biomicroscopy, indirect ophthalmoscopy, and scotopic flash electroretinography were performed on all horses. Hair samples were processed for DNA analysis. Three SNPs identified and associated with LP and CSNB in the Appaloosa were investigated for association with LP and CSNB in these Miniature horses. Results All horses in the LP/LP group were affected by CSNB, while none in the LP/lp or lp/lp groups were affected. All three SNPs were completely associated with LP genotype (χ² = 22, P << 0.0005) and CSNB status (χ² = 11, P < 0.0005). Conclusions The Miniature Horse breed is affected by CSNB and it appears to be associated with LP as in the Appaloosa breed. The SNPs tested could be used as a DNA test for CSNB until the causative mutation is determined.     

Extramedullary plasmacytoma of the third eyelid gland in a dog

A case of extramedullary plasmacytoma of the third eyelid gland in a 7-year-old American Cocker Spaniel is reported. An enlargement of the third eyelid gland, abundant mucopurulent discharge, mild hyperemia and corneal pigmentation in the OD was present. Excisional biopsy of the mass revealed the gland was infiltrated and partially destroyed by a uniform population of neoplastic plasma cells. The neoplastic cells were positive for CD138, Ki-67 and λ light chain. CD20, CD3, κ light chain and cytokeratin were negative. Twelve months following surgery, no recurrence was observed. To the authors' knowledge, this is the first extramedullary plasmacytoma of the third eyelid gland reported in dogs.     

Hematoporphyrin-based photodynamic therapy for cutaneous squamous cell carcinoma in cats

Photodynamic therapy (PDT) using a haematoporphyrin derivative (Photogem®, General Physics Institute and clustes Ltda) as photosensitizer and light emitting diodes (LEDs) as the light source was evaluated in 12 cats with cutaneous squamous cell carcinoma. Lesions were illuminated with LEDs, (300 J/cm for 30 min) 24 h after the administration of the photosensitizer. Clinical responses were classified as complete disappearance of the tumour with total re-epithelialization; partial response (a reduction greater than 50%); and no response (less than 50% reduction). Tumours localized to the pinna treated with one ( n  = 3) or two ( n  = 4) applications of PDT yielded no response. Highly invasive tumours of the nose and nasal planum also showed no response, after two treatments ( n  = 2). A combination of PDT and surgery was performed in three cases. Two cats showed partial response and one complete response with one application of therapy 30 days after nasal surgery. Small and noninfiltrative lesions ( n  = 3) of the nasal planum showed a PR with one application ( n  = 2) and a CR with two applications ( n  = 1). This study shows that PDT using Photogem® and LEDs can provide local control of low-grade feline squamous cell carcinoma. The addition of PDT to surgery in more invasive cases may help prevent recurrence.     

Is the gamma interferon assay in cattle influenced by multiple tuberculin injections?

Along with other developed countries, Canada is interested in adopting the gamma interferon (IFN-γ) assay to test for bovine tuberculosis (TB). This study compared results of using the IFN-γ assay in a large number of field-tested cattle in Manitoba, some previously tested with a caudal fold test (CFT) only, and others injected with tuberculins for both a CFT and a comparative cervical test (CCT). Parallel testing further compared the IFN-γ assay and CCT results with the confirmed TB status of the animal (culture, histopathologic examination, polymerase chain reaction). Results from IFN-γ assays did not differ following the CFT versus CFT and CCT injections. Parallel testing demonstrated an apparent higher prevalence of tuberculosis for the IFN-γ assay versus CCT, which will assist in earlier removal of exposed animals and, ultimately, prevent populations from becoming infected.