The economic impact of infectious bovine keratoconjunctivitis (IBK) warrants continued investigation of the mechanisms by which Moraxella bovis survives on and colonizes the corneal surface. Virulent strains of M bovis produce hemolysin and exhibit different plasmid profiles than nonvirulent strains. Interactions among host, environment, vector, season, and concurrent infection influence the prevalence of IBK. Mycoplasma sp. or infectious bovine rhinotracheitis virus may enhance or hasten the disease process. The manifestations of IBK may range from mild conjunctivitis to severe ulceration, corneal perforation, and blindness. Treatment of IBK is dictated by economic considerations, intended animal use, and feasibility of administration. Antibiotic therapy is aimed at achieving drug concentrations in tears to meet or exceed the minimum inhibitory concentration for prolonged periods. At present, IBK is not a preventable disease. Affected animals must be separated from the herd and vector control vigorously instituted. Carrier animals must be identified and removed from the herd. Vaccination trials have been unsuccessful because of pili antigen crossreactivity, variable strains, and uncontrolled environmental factors. Recent investigations have determined that M bovis may utilize host iron sources via iron-repressible outer membrane proteins and siderophores for growth. Elucidation of normal defense mechanisms of the bovine eye may lead to new strategies to enhance the immune response against M bovis.Key words: Bovine pinkeye; IBK.he first reports of infectious bovine keratoconjunctivitis EpizoologyAlthough M bovis is the pathogen most commonly isolated from IBK, various factors are involved with the pathogenesis of this disease. The environment, season, concurrent pathogens, M bovis strain, and host immune system play integral roles in the occurrence and clinical severity of IBK. IBK is a highly contagious disease that spreads rapidly within a herd.6 The yearly and seasonal prevalence of the disease in different geographic regions varies greatly.l0." The isolation rate of M bovis infection gradually increases during the spring (21.4%) and summer (29.3%) months to reach a maximum in the fall at 45%.12 Peak IBK prevalence is preceded by the highest values of ultraviolet (UV) radiation.I3J4 IBK can occur during any time of the year, but outbreaks are more common during summer months. Nonetheless, heavy snowfall and UV radiation have been individually associated with outbreaks of IBK.M. bovis is spread by direct contact, nasal and ocular discharges, and by mechanical vectors. The most important vector is considered to be the face fly (Musca a~turnnalis).~~ The house fly (Musca dornestica) and barn fly (Stomoxys calcitrans) may also transport the organism. In addition to physically irritating the eye, insects may harbor the organism on their legs for up to 3 days.Is A positive correlation exists between the number of flies per animal and M bovis infection,I8 and disease prevalence is reduced by rigorous fly control pr...

A 1-year-old Shar Pei presented for recent-onset exophthalmos and right peri-ocular facial swelling. Physical examination revealed the facial mass was of soft-tissue consistency and nonpainful to the dog. Due to inability to retropulse the globe during ophthalmologic examination, it was suspected the mass had impinged into the orbit, resulting in rostral displacement of the globe. Anatomic location suggested the lesion was probably associated with the zygomatic salivary gland. Fine-needle aspiration and subsequent cytological evaluation of fluid extracted from the facial mass was consistent with a diagnosis of zygomatic mucocele. Computed tomography imaging confirmed a single fluid-filled mass was resulting in both the facial distention and the exophthalmos. A modified, lateral orbitotomy surgical approach was selected for excision of the lesion to provide ventral exposure to the orbit, while minimizing trauma to the globe and supporting structures. Histopathology of the excised lesion confirmed a diagnosis of zygomatic mucocele. This case demonstrates utilization of a modified lateral orbitotomy for effective surgical management of a zygomatic mucocele in a dog, with preservation of vision and absence of any significant postoperative complications.

Dorsal lacrimal glands, superior glands of the third eyelid and Harderian glands (deep gland of the third eyelid) from 19 bison and 18 cattle free of apparent ocular disease were examined to compare the normal anatomical properties of these glands. All glands were characterized and measured (length and width). The gross anatomy of the dorsal lacrimal glands was similar, with the exception of a bipartite gland in cattle. The bison's superior gland of the third eyelid and Harderian gland was longer as compared with cattle. A subset of the bison and cattle samples (five bison and five cattle) was sectioned for histological and histochemical analysis. The histology of the dorsal lacrimal and superior gland of the third eyelid revealed tubuloalveolar cells with basophilic vacuolated cytoplasm in bison and eosinophilic granular cytoplasm in cattle. The Harderian glands consisted of a tubuloalveolar anterior part combined with large lumens acini lined with cuboidal epithelium in the posterior part; the posterior part of the bison Harderian gland was more predominant than in cattle samples. Mucosubstance histochemistry revealed acidic and neutral glycoproteins with similar staining patterns in all glands of both species.

We documented the normal conjunctival bacterial flora from 17 opossums (Didelphis virginiana) and 10 raccoons (Procyon lotor) trapped in Manhattan, Kansas (USA) from November 1999 to January 2000. Both raccoons and opossums were free of apparent ocular disease. The inferior conjunctival sacs of each animal were swabbed for aerobic bacterial and Mycoplasma culture and polymerase chain reaction (PCR) for Mycoplasma and Chlamydia detection. All conjunctival samples were positive for one or more species of aerobic bacteria. The most common isolate from opossums was Staphylococcus spp. Other isolates included Streptococcus spp., Bacillus spp., Corynebacterium spp., and Enterococcus faecalis. The most common isolate in raccoons was Bacillus spp. Other isolates included Streptococcus spp., Staphylococcus spp., non-hemolytic Escherichia coli, and Enterococcus faecalis. Mycoplasma culture was negative in samples from opossums and raccoons. Evidence of Mycoplasma and Chlamydia presence was detected by PCR.

Distribution of lactoferrin and a lack of lysozyme are similar in the lacrimal gland of cattle and bison. Differences in other tear components may be responsible for variability in the susceptibility to infectious corneal diseases that exists between bison and cattle.

In order to determine whether the rise in blood circulating committed hematopoeitic progenitor cells (CFU-GM) was sustained long enough after exercise to be a practical adjunct to increasing stem cell yields by hemapheresis, the authors evaluated two exercise protocols in 15 normal donors. Immediately after a brief period of intense exercise, there was a significant increase in the absolute number of blood CFU-GM from 164 +/- 27 to 240 +/- 46 per ml. However, all values returned to baseline within 15 minutes. Prolonging the exercise did not enhance either the circulating CFU-GM concentration or the duration of the rise. If blood hematopoietic stem cells respond to exercise similarly, such a transient increase would not appear to be of use in stem cell harvesting.

Northern bobwhite ( Colinus virginianus ) have experienced a dramatic decline in West Texas over the last 3 yr, and investigations are underway to evaluate the role of parasites in this decline. One of the key parasites being investigated is the eyeworm (Oxyspirura petrowi). Live eyeworms were extracted from both live and dead northern bobwhites, and in vitro survival was tested using 10 liquid media. Eyeworms placed in an egg white and physiological saline solution lived for at least 36 days. Live O. petrowi placed into the eyes of uninfected pen-raised bobwhites were monitored for 21 days to demonstrate successful transfer. Eyeworm behavior during feeding, mating, and development were monitored. This study is important to research that requires "banking" of live O. petrowi from wild-captured definitive hosts for life history studies and assessing the impact of O. petrowi on host individuals.

Neither once daily topical administration of 0.03% bimatoprost solution nor twice daily topical administration of 0.15% unoprostone isopropyl solution significantly affect the IOP of normal cats. Both 0.03% bimatoprost solution and 0.15% unoprostone isopropyl solution induced no significant ocular side effects in normal cats when dosed over a 10-day treatment period.