Corneal squamous cell carcinoma in a dog

A squamous cell carcinoma in situ (corneal intraepithelial neoplasia) was diagnosed in the right eye of an 11-year-old female Golden Retriever. Papillomavirus antigen was not detected in the excised tissues, and the tumor was suspected to be a sequel to previous injury. The tumor was removed by lamellar keratectomy, and the surgical bed was subjected to double freeze-thaw cryotherapy. Tumor regrowth was not apparent approximately one year after treatment.     

A new perspective on canine keratoconjunctivitis sicca. Treatment with ophthalmic cyclosporine

Keratoconjunctivitis sicca is the major cause of chronic or recurrent conjunctivitis in dogs. The diagnosis of KCS is often delayed or mistaken for allergic or bacterial conjunctivitis and inappropriate or insufficient treatment leads to progressive corneal scarring and blindness in many dogs. The cause of KCS in dogs has not been proven, but evidence supports an immune-mediated etiology for the majority of cases. In an attempt to specifically treat the cause of KCS, a new immunosuppressant drug, cyclosporine, has been used in a topical preparation. Treatment results using ophthalmic cyclosporine are dramatic compared with historical treatments. Resolution of corneal scarring and increased lacrimation are seen in most dogs. Investigations of the mechanism of action of ophthalmic cyclosporine suggest the efficacy may have been serendipitous. A local neuroendocrine effect of cyclosporine on the lacrimal gland may actually be responsible for the increased lacrimation. Early diagnosis of KCS and treatment with ophthalmic cyclosporine may avert a major cause of blindness in dogs.     

Multiple hereditary ocular anomalies in a herd of cattle

A Brahman x Santa Gertrudis herd of cows bred to a Hereford bull was evaluated because of a 3-year history of several calves born with congenital blindness. Multiple congenital ocular anomalies in 2 calves included microphthalmos, microcornea, microcoria, heterochromia iridis, microlentia, cataracts, retinal dysplasia, retinal detachment, anterior segment dysgenesis, acorea, and proliferation of the anterior neuroectoderm. On the basis of the lack of environmental factors and persistence of an intermittent problem when breeding to a single bull, a genetic defect was diagnosed as the probable cause. Dominant inheritance with varied expressivity may have best explained the lack of obvious signs in the bull, with emergence of various anterior and posterior segment defects in offspring from unrelated cows.     

Effect of scrotal bifurcation on breeding soundness traits in Beetal bucks during summer season

Relationship of scrotal bifurcation or splitness with breeding soundness traits was investigated in 15 Beetal bucks (17–20 months of age and 48.72?±?1.57 kg mean BW). Breeding soundness traits of conjoined/unsplit (n?=?6) scrotal bucks was compared with split (n?=?9) scrotal bucks having lengthwise >?1 in. bifurcation. Two consecutive semen ejaculations per buck were collected at monthly interval during summer season (April to June 2018) using intact buck as teaser and sexual behavior was simultaneously recorded. Scrotal morphometry parameters, i.e., scrotal circumference, scrotal volume, scrotal skin thickness, testis length, width, and thickness were also recorded. Bucks with split scrotum had relatively more scrotal dimensions (scrotal circumference (P?<?0.01), scrotal volume (P?<?0.01), testis length (P?<?0.01)) than conjoined scrotal bucks. Among various semen attributes, semen volume of first ejaculate (P?<?0.01), second ejaculate (P?<?0.05), mean semen volume (P?<?0.01), total sperm count of first ejaculate, and mean sperm count of both ejaculates were more (P?<?0.01) in split scrotal bucks. However, scrotal bifurcation had no influence on sexual behavior of bucks. It is concluded that Beetal bucks with split scrotum had relatively better breeding efficiency traits than conjoined scrotal bucks.

     

Keratoconjunctivitis sicca: histopathologic study of nictitating membrane and lacrimal glands from 28 dogs

Forty nictitating membrane glands and 9 main lacrimal glands were obtained for histologic evaluation from 28 dogs with keratoconjunctivitis sicca as the result of azosulfapyridine toxicity, canine distemper, multisystemic autoimmune disease (Sj?gren's syndrome-like syndrome), congenital origin, and unilateral and bilateral idiopathic keratoconjunctivitis sicca. Similar glands from 6 control dogs were studied. The most prevalent (87%) histopathologic finding was variable degrees of multifocal chronic adenitis, characterized by acinar atrophy and replacement with increased numbers of plasma cells and lymphocytes within increased amounts of interacinar fibrous connective tissue stroma. Occasional tubular structures were dilated and filled with neutrophils and cellular debris.     

Fluorophotometric evaluation of experimental blood-aqueous barrier disruption in dogs

A protocol for performing slit-lamp fluorophotometry of the anterior chamber in dogs was established. The technique was then used to develop a model of blood-aqueous barrier disruption that can be used for comparative testing of ophthalmic anti-inflammatory drugs. It was determined that barrier disruption induced by a slow, controlled paracentesis of a small volume of aqueous humor may provide the most reliable model for drug testing. Additionally, fluorophotometry proved to be a sensitive and accurate means of detecting breakdown of the blood-aqueous barrier.     

Topically applied cyclosporin for modulation of induced immunogenic uveitis in rabbits

The experimental model of immunogenic uveitis induced by intraocular injection of human serum albumin in rabbits was inhibited by the topical application of cyclosporin A. The acute nonspecific inflammatory response that immediately follows intravitreous injection was not affected. However, the severe panuveitis that develops during the second week was markedly reduced. The safety and efficacy of topically applied cyclosporin A in this model of uveitis suggests that topical administration of this antigen-nonspecific immunosuppressor may be an effective route of therapy for certain immune-mediated forms of uveitis.     

Four cases of traumatic optic nerve blindness in the horse

Traumatic optic nerve atrophy is characterised clinically by a unilateral or bilateral sudden onset of blindness. Dilated, fixed pupils and a lack of a menace reflex are the only abnormalities noted soon after the trauma. Within three to four weeks the optic disc becomes paler and the retinal vasculature is markedly decreased. The pathological lesion is a rupture of the nerve axons from stretching forces produced by the posterior movement of the brain against the fixed canalicular portion of the optic nerves. Medical therapy has not been successful.     

Keratoconjunctivitis sicca: immunological evaluation of 62 canine cases

The etiology of keratoconjunctivitis sicca (KCS) in 62 dogs was evaluated, using immunologic techniques. Using direct fluorescent antibody testing, autoantibodies within the lacrimal, salivary, or pancreatic glands were detected in 5 of 8 dogs tested. Circulating antibodies to the nictitating membrane gland, main lacrimal gland, parotid salivary gland, or mandibular salivary gland were detected using indirect fluorescent antibodies in 9 of 31, 3 of 31, 5 of 31, and 5 of 31 sera, respectively. Using radial immunodiffusion, hyper-gamma-globulinemia was detected in 21 of 30 dogs with KCS. Antinuclear antibodies, primarily in a nucleolar pattern, were demonstrated in 20 of 50 dogs with KCS. Lymphocytic infiltrates were evident in 5 of 9 labial salivary biopsies, 2 of 4 parotid gland specimens, 2 of 4 mandibular gland specimens, and 2 of 3 thyroid gland specimens taken from dogs with KCS. Autoimmune diseases had been previously documented in 4 of 62 dogs. Twenty-five of the 62 dogs (40%) had concurrent problems indicative of an underlying immunologic disorder.