Analysis of aqueous humor obtained from normal eyes of llamas and alpacas.

OBJECTIVE: To evaluate composition of aqueous humor obtained from normal eyes of llamas (Lama glama) and alpacas (Lama pacos). SAMPLE POPULATION: Aqueous humor obtained from 10 male llamas and 10 male alpacas. PROCEDURE: All animals had normal eyes, as determined by ocular examination. Aqueous humor samples were obtained via paracentesis of the anterior chamber of animals that were heavily sedated. Chemical analysis included measurement of concentrations of sodium, potassium, magnesium, chloride, bicarbonate, phosphorus, and glucose as well as osmolality and pH. RESULTS: With the exception of potassium concentrations, values for aqueous humor composition did not differ significantly between llamas and alpacas. Mean +/- SD values for llamas and alpacas, respectively, were: sodium, 154.7 +/- 2.1 and 152.7 +/- 2.1 mEq/L; potassium, 5.3 +/- 0.4 and 4.6 +/- 0.4 mEq/L; magnesium, 1.8 +/- 0.1 and 1.7 +/- 0.1 mg/dl; chloride, 130.0 +/- 1.6 and 127.0 +/- 3.3 mEq/L; bicarbonate, 19.2 +/- 1.5 and 20.2 +/- 2.3 mEq/L; phosphorous, 2.7 +/- 0.3 and 2.5 +/- 0.4 mg/dl; glucose, 80.3 +/- 3.9 and 80.8 +/- 7.3 mg/dl; total protein, 29.0 +/- 8.6 and 31.5 +/- 10.1 mg/dl; and osmolality, 305.8 +/- 11.8 and 306.2 +/- 4.9 mOsm. The pH ranged from 7.5 to 8.0 for both species. Potassium concentrations were significantly higher in llamas than alpacas. CONCLUSIONS AND CLINICAL RELEVANCE: Except for potassium, composition of aqueous humor did not differ significantly between llamas and alpacas. Aqueous humor composition of llamas and alpacas is similar to that of other species that have been examined.

Detection of lysozyme in llama, sheep, and cattle tears.

OBJECTIVE: To determine whether the tears of llamas, sheep, and cattle contain lysozyme and compare lysozyme concentrations in tears among these species. ANIMALS: 40 llamas, 5 sheep, and 36 cattle. PROCEDURE: Electrophoresis, western blot immunoassay for lysozyme, a spectrophotometric assay to detect tear lysozyme by its ability to lyse a suspension of Micrococcus lysodeiticus, and a microtiter plate colorometric assay were performed. RESULTS: A 13.6-kd protein band was detected by use of electrophoresis and western blot immunoassay in llama and sheep tears but not cattle tears. Results of spectrophotometric assay suggested that llama and sheep tears had high concentrations of lysozyme, whereas cattle tears had low concentrations. Results of the microtiter plate colorometric assay suggested that llama tears had high concentrations of lysozyme, whereas concentrations in sheep and cattle tears were lower. CONCLUSIONS AND CLINICAL RELEVANCE: Lysozyme concentrations in tears may vary among species and this variability may contribute to differing susceptibilities to ocular diseases such as infectious keratoconjunctivitis.

Comparison of tear proteins of llamas and cattle.

OBJECTIVE: To analyze and compare contents of the preocular tear films of llamas and cattle. ANIMALS: 40 llamas and 35 cattle. PROCEDURE: Tear pH was determined by use of a pH meter. Total protein concentration was determined by use of 2 microtiter methods. Tear proteins were separated by use of electrophoresis and molecular weights of bands were calculated. Western blot immunoassay was used to detect IgA, lactoferrin, transferrin, ceruloplasmin, alpha1-antitrypsin, alpha1-amylase, and alpha2-macroglobulin. Enzyme electrophoresis was used to detect proteases. RESULTS: The pH of llama and cattle tears were 8.05 +/- 0.01 and 8.10 +/- 0.01, respectively. For results of both methods, total protein concentration of llama tears was significantly greater than that of cattle tears. Molecular weights of tear protein bands were similar within and between the 2 species, although llama tears had a distinct 13.6-kd band that was not detected in cattle. Lactoferrin, IgA, transferrin, ceruloplasmin, alpha1-antitrypsin, alpha1-amylase, alpha2-macroglobulin, and proteases were detected in both species. CONCLUSIONS AND CLINICAL RELEVANCE: Llama tears have significantly greater total protein concentration than cattle tears, whereas pH is similar between species. Because little variation was detected within species for the number and molecular weight of protein bands, pooling of tears for analysis is justified. Results suggest that lactoferrin, ceruloplasmin, transferrin, alpha1-antitrypsin, alpha2-macroglobulin, alpha1-amylase, and IgA are present in the tears of llamas and cattle.

Feline systemic fungal infections.

Systemic fungal diseases are important diagnostic considerations in all sick cats, particularly in cats with ocular symptoms. The most common ocular manifestation of these diseases is posterior uveitis (choroiditis); however, anterior uveitis is sometimes present and is usually secondary to the inflammation in the posterior segment. Occasionally, adnexal diseases such as blepharitis, inflammation of the nictitating membrane, and ocular discharge may be present in cats with systemic mycoses. The prognosis for cats with systemic fungal diseases has changed with the advent of the triazole antifungal drugs. In the past, the prognosis was guarded to poor for survival of the cat. Today, with prolonged antifungal therapy, many cats recover completely from their disease. The prognosis for return of vision for eyes affected with systemic fungal disease is still guarded. Often, even if the infection is controlled systemically, the retina is severely damaged and may remain nonfunctional.

Intraocular pressure in normal llamas (Lama glama) and alpacas (Lama pacos).

OBJECTIVE: To determine the mean intraocular pressure in llamas (Lama glama) and alpacas (Lama pacos) using applanation tonometry.Animals studied: Ten llamas and 10 alpacas.Procedures: Intraocular pressure (IOP) was measured with a Tono-Pentrade mark XL (Mentor Ophthalmics, Inc., Norwell, MA, USA). Three values, with 5% variance, were recorded for each eye. Least-squares means were determined for IOP for each eye of llamas and alpacas. Controlling for age, differences between left and right eye were analyzed using ANOVA. Two age groups were established, less than 5 years and greater than 5 years. The effect of age on IOP within each group was analyzed by linear regression. Probability values of less than 0.05 were considered significant. RESULTS: Comparison of mean IOP between right (n = 20) and left eyes (n = 20), independent of species type, showed no differences in IOPs for llamas and alpacas. Mean IOP declined with increasing age in llamas and alpacas. Mean IOPs for 20 eyes in 10 llamas was 16.96 +/- 3.51 mmHg. Mean IOP for 20 eyes in 10 alpacas was 16.14 +/- 3.74 mmHg. Mean IOP for all eyes (n = 40), independent of species, was 16.55 +/- 3.55 mmHg. The range of IOP in normal llamas and alpacas within 2 SD (95% of the population) was 14.89+/-18.21 mmHg. CONCLUSIONS: There was no significant difference in IOP between alpacas and llamas. Mean IOP in both species decreased with increased age.

Subconjunctivally implanted micro-osmotic pumps for continuous ocular treatment in horses.

OBJECTIVE: To evaluate the feasibility of using a subconjunctivally implanted micro-osmotic pump for continuous delivery of medication to the eyes of horses- during a 7-day period. ANIMALS: 4 healthy adult horses. PROCEDURE: With horses restrained in a standing position, micro-osmotic pumps were implanted subconjunctivally in each eye for 7 days. The treatment eye received an atropine-loaded micro-osmotic pump (100 microl of 1.5% atropine), and the contralateral eye received a sterile saline-loaded pump (100 microl of 0.9% NaCl) as a control treatment. Pupil size was measured at 12-hour intervals until values returned to baseline. RESULTS: The micro-osmotic pumps were tolerated and did not migrate or become dislodged. During the 7-day treatment period, pupils were significantly larger in the eyes implanted with atropine-loaded pumps, compared with saline-implanted control eyes. CONCLUSIONS AND CLINICAL RELEVANCE: Micro-osmotic pumps were implanted and removed easily from standing horses and were not associated with complications during the 7-day treatment period. Therefore, subconjunctivally implanted micro-osmotic pumps can potentially be used when treating ophthalmic disease in horses.

Carprofen inhibition of flare in the dog measured by laser flare photometry.

The purpose of this study was to determine whether oral carprofen (Rimadyl(R)) treatment in dogs could prevent or decrease the breakdown of the blood-aqueous barrier. The topical pilocarpine irritative model was used to induce breakdown and cause flare. Pilocarpine was instilled in both eyes of seven dogs at time zero and again 5 h later. At 7 h, laser flare photometry was used to measure the flare concentration in each eye using the Kowa FC-1000 laser flare cell meter. All treatments were then discontinued. Two days later, carprofen was administered to the same dogs for a total of three doses. After the last dose of carprofen, pilocarpine treatments and flare measurements were repeated. Carprofen pretreatment resulted in a 68% inhibition of flare, which was highly significant (P < 0.01). The pilocarpine group had a mean of 16.1 photon counts per millisecond (PC ms-1) +/- 2.2 SE, and the carprofen group had a mean of 7.0 PC/ms +/- 1.2 SE. These results compare favorably with previous studies measuring increased protein or fluorescein concentrations in the aqueous humor after blood-aqueous barrier breakdown in the dog. These results suggest that carprofen may be effectively used as a systemically administered ocular anti-inflammatory drug. Carprofen has the added benefit of fewer reported side effects.

Ocular diseases of llamas: 194 cases (1980-1993)

OBJECTIVE: To identify ocular and adnexal diseases to which llamas in North America are susceptible, to determine prevalence of these diseases in llamas, and to compare prevalences of the major ocular diseases of llamas, cattle, and horses. DESIGN: Retrospective study. ANIMALS: 194 llamas, 4,937 cows, and 11,950 horses with ocular disease. PROCEDURE: Medical records of all llamas entered into the Veterinary Medical Database between 1980 and 1993 were reviewed. Data on ocular structures affected and types of ocular disease were compiled. Prevalences of uveitis, corneal ulcers, and ocular squamous cell carcinoma in llamas were compared with prevalences in cattle and horses. RESULTS: 194 of 3,243 (6%) llamas had at least 1 ocular disease. The proportion of llamas that had ocular disease was significantly higher than the proportions of cattle or horses. The most frequently affected ocular structure in llamas was the cornea, and ulcerative keratitis was the most common corneal disease. The second most commonly affected structure was the uveal tract. Cataracts were reported in 20 (10%) of the llamas with ocular problems. Eyelid disorders, retinal diseases, glaucoma, and ocular or adnexal neoplasia were reported infrequently in llamas. CLINICAL IMPLICATIONS: Results suggest that corneal disease is common in llamas and is usually secondary to trauma. Uveitis may also be common in llamas, but llamas do not appear to be highly susceptible to glaucoma, ocular neoplasia, or to direct corneal invasion by bacteria such as Moraxella sp.

Update on llama medicine. Ophthalmology.

Review of the limited literature on camelid eyes suggests they are anatomically similar to those of domestic livestock species, except they lack meibomian glands and have iridial folds (rather than corpora nigra). The microbial flora of the healthy camelid conjunctival sac also appears to be similar to those of domestic livestock and pets, except that no Mycoplasma have been isolated from camelids. Ocular diseases for which camelids are presented to veterinarians are numerous and varied. The most frequently presented conditions are ocular trauma and congenital abnormalities. Trauma to cornea, conjunctiva, eyelids, and sclera has been reported. Therapies for these injuries are the same as for other animals. Most congenital abnormalities are cataracts and optic nerve colobomas, but congenital eyelid defects, conjunctival cysts, and multiple ocular defects have been reported. Although these conditions are not demonstrably hereditary, breeding of animals with congenital ocular defects is strongly discouraged. Intraocular inflammatory diseases are seen commonly in camelids. Uveitis and chorioretinitis may cause permanent visual loss, usually with no indication of cause. Equine herpesvirus 1 has been isolated from camelids with severe ocular inflammation and is a known cause of chorioretinitis and neurologic abnormalities. Systemic aspergillosis causes severe chorioretinitis in alpacas. More research is needed to improve our understanding of ocular physiology and pathology in camelids. Genetic studies also are needed to establish hereditary patterns of ocular maldevelopment. Additional information from researchers and practitioners should improve our ability to recognize and treat ocular disease in camelids.

Fungal flora of the healthy camelid conjunctival sac.

Swab specimens for fungal isolation were collected from the healthy conjunctival sacs of 3 species of captive camelids (Lama glama, L guanicoe, L pacos) and llama-guanaco hybrids. Fungi were collected from over half the animals in winter (53%) and summer (56%). Fungal species of 10 genera were isolated. In both seasons, Aspergillus was the most commonly isolated genus; at least 9 species of Aspergillus were found. The fungal organisms isolated were similar to those found in healthy eyes of other domestic animals and may represent a random seeding from the environment where they are ubiquitous.

Bacterial and mycoplasmal flora of the healthy camelid conjunctival sac.

Healthy conjunctival sacs of 88 animals of 3 species of captive camelids (Lama glama, Lama guanicoe, Lama pacos) and llama-guanaco hybrids were sampled for bacterial and mycoplasmal flora. Mycoplasmas were not isolated from any animal. Eleven genera of bacteria were isolated. The most frequent isolates were Staphylococcus epidermidis and Pseudomonas spp. Nine varieties of Pseudomonas were found, which represented at least 3 Pseudomonas species. Many of the bacterial isolates (especially the pseudomonads) are potential pathogens in the eyes of these camelids.

Ocular manifestations of a metastatic pulmonary adenocarcinoma in a cat.

A primary pulmonary bronchogenic adenocarcinoma originating from an intramediastinal accessory lung was diagnosed in a 14.5-year-old cat. The cat had been admitted because of a cloudy right eye. Physical examination revealed a thin cat with severe iritis, aqueous flare, and a fibrin clot in the anterior chamber of the right eye. Right fundic examination revealed bullous retinal detachment superior to the optic disc. Euthanasia and necropsy were requested when FeLV test results were positive. Metastatic neoplastic cells similar to those of the primary tumor were detected in the choroid, ciliary body, and ciliary processes of the right eye. Ciliary and iridic stromal necrosis attributable to neoplastic embolization of uveal vessels had led to severe uveitis. Foci of metastasis were also in the heart, kidney, and cerebral meninges.