Feline ophthalmomyiasis externa caused by Cuterebra larvae: four cases (2005–2020)

Case series summary Described are four cats diagnosed with ophthalmomyiasis externa caused by Cuterebra larvae. Medical records were retrospectively reviewed to identify cats with ophthalmomyiasis externa between 2005 and 2020 at Cornell University Hospital for Animals. Signalment, history, clinical and diagnostic findings, treatment and outcome were recorded. All cats were young (< 3 years of age), had outdoor access and were initially examined during the summer months. All cases had unilateral disease with the right eye affected. Two cases had nictitating membrane lesions and two had orbital disease. Concurrent superficial corneal ulceration was present in three cats. Two cats suffered from pyrexia, suspected secondary to inflammation from the larval infestation. Successful larval removal was performed in all cats, which resulted in improvement of discomfort and clinical signs. A corneal ulcer persisted in one cat, which was lost to follow-up prior to ulcer resolution. Parasite identification confirmed Cuterebra species infestation in all cases. Relevance and novel information To the authors’ knowledge, this is the first report of feline ophthalmomyiasis externa caused by Cuterebra species. Parasite removal was successful in restoring comfort and resolving clinical signs in all cats with adequate follow-up information.

The ultrastructure of the nictitating membrane of the little penguin (Eudyptula minor, Aves)

The ultrastructure of the nictitating membrane in the little penguin Eudyptula minor was studied using both scanning and transmission electron microscopy to improve our understanding of the function of ocular adnexa in diving birds. Following euthanasia, eyes were enucleated and immersion fixed in Karnovsky's fixative. The nictitating membrane and conjunctiva were embedded in araldite and semi- or ultra-thin sections were stained and photographed using compound and transmission electron microscopes, respectively. Ultrastructural dimensions were measured directly from digital photographs. Surface ultrastructure was examined using scanning electron microscopy. The transparent nictitating membrane consists of a dense stroma surrounded by epithelia on both the external (conjunctival) and internal (bulbar) surfaces. The conjunctival surface of the membrane near the leading edge is covered by microvilli, which transition to microplicae and finally to microridges in the periphery. Beneath the epithelial cells, there is a well-developed basement membrane. Scattered throughout this epithelium are a few goblet cells. The surface of the bulbar epithelium is covered by microvilli near the leading edge, which become denser peripherally. The stroma consists of densely-packed collagen fibrils, which are randomly oriented in bundles near the leading edge but are aligned in the same direction parallel with the epithelial and corneal surfaces and with the leading edge, when the membrane is extended. The ultrastructure of the nictitating membrane in the little penguin differs from other birds and its function is predominantly protective, while preserving clear vision in both water and air.

Marsupialization for the treatment of nictitating membrane cyst in a dog: case report

ABSTRACT This study aims to describe the first Brazilian report of a nictitating membrane cyst’s surgical treatment in a dog. A 6-month-old female French Bulldog presented at HOSVET-UNIME with a reddish mass-like structure in the medial canthus of both eyes, with a history of recurrent third eyelid gland prolapse previously treated with two surgeries performed at another clinic. Physical examination revealed a third eyelid gland prolapse in the right eye and a cyst in the left eye’s third eyelid. The animal was submitted to surgical correction of the right eye’s third eyelid prolapse using pocket technique and of the left eye’s third eyelid using marsupialization technique for the cyst’s treatment. 180 days after th1e surgical procedure no recurrence was observed. The marsupialization technique for the treatment of a third eyelid’s lacrimal cyst in a dog allowed the maintenance of its gland and prevented the formation of a new cystic cavity.

Pathophysiology of Concussive Non-Penetrative Captive Bolt Stunning of Turkeys

The non-penetrative captive bolt (NPCB) has been proposed as a more humane and practical alternative to constant voltage electrical stunning for small-scale seasonal turkey producers. This study evaluated the effectiveness of the CASH® Small Animal Tool (SAT) (formerly known as the CASH® Poultry Killer, CPK) and three configurations of the Turkey Euthanasia Device (TED), assessing behavioural, cranial/spinal responses and brain pathology. Immediately after stunning all birds showed cessation of rhythmic breathing and loss of neck and beak tension. One bird shot with the TED/hen configuration showed a positive nictitating membrane reflex in one eye with no other positive reflexes. All birds had moderate/severe gross damage to the hyperpallium layer over the cerebrums. For almost all other cerebrum structures, thalamus, and hindbrain, the TED/poult configuration and SAT produced the most extensive damage. The frequency of petechial haemorrhage in the pons and medulla was less in SAT shot birds (76% and 71% respectively) compared to those shot with the different configurations of the TED (ranging from 81% to 100%), however this difference was not significant. In conclusion, both NPCB guns were effective in inducing unconsciousness in turkeys, regardless of the variations in shot position and the different configurations of the TED.