Proteomic analysis of dog tears for potential cancer markers

The first reference map of the proteome of pooled normal dog tears was created using 2-dimensional polyacrylamide gel electrophoresis and the identity of a number of the major species determined using matrix-assisted laser desorption time of flight mass spectrometry (MALDI-TOF) and peptide mass fingerprint matching on protein sequence databases. In order to understand the changes in protein expression in the tear film of dogs with cancer, tears from such animals were similarly examined. A number of differences were found between the tears of healthy dogs and the dogs with cancer. Differences were found in levels of actin and albumin and in an unidentified protein which may be analogous to human lacryglobulin. These findings suggest that it may be possible to develop tear film analysis to provide a simple non-invasive test for the diagnosis and/or management of canine cancers.     

Analysis of tear uptake by the Schirmer tear test strip in the canine eye

OBJECTIVE: To analyze the uptake of tears in a Schirmer tear test (STT) in vitro and in vitro. MATERIALS AND METHODS: Uptake of fluid by Schirmer tear test strips was studied in vitro by examining fluid uptake over time from an unlimited fluid supply as well as with specific fluid volumes applied to the test strip. Uptake of fluid by Schirmer tear test strips was evaluated in a population of 100 ophthalmologically normal dogs together with a group of 40 dogs with tear film abnormalities such as keratoconjunctivitis sicca (KCS) or epiphora. Each animal was given a full ophthalmic examination followed by a standard Schirmer tear test extended over between 3 and 5 min with the STT reading recorded every 5 s and plotted over time. To determine the effect of ocular irritation by the test strip, uptake of tears by test strips was determined before and after topical anesthesia in 20 dogs. RESULTS: In vitro examination of fluid uptake by the STT strips showed an initial rapid uptake followed by a gradual reduction in rate of uptake. Temporal evaluation of STT in vivo showed a similar rapid initial uptake of tear fluid, followed in the majority of cases by a sudden change to a steady state uptake of fluid. The initial gradient was 29.3 +/- 16.9 mm/min followed by a steady state uptake of 5.2 +/- 2.3 mm/min in normal dogs and 1.9 +/- 1.3 mm/min in dogs with KCS. This corresponds to a steady state tear turnover of 7.8 +/- 3.4 microL/min in normal dogs and 2.8 +/- 1.9 microL/min in animals with KCS. Dogs with nasolacrimal blockage and resultant epiphora showed a high initial gradient but final gradients were not statistically different from those of normal dogs. Discussion and conclusions Temporal evaluation of tear uptake by the STT shows substantial differences in rate of tear uptake at different time-points during the period of the test. RESULTS: of this study suggest that the initial rapid rise in STT value represents uptake from the tear lake followed by a slower tear uptake of tears from steady state tear production. Temporal examination of the Schirmer tear test allows a more precise evaluation of tear production than the standard STT measuring tear uptake in 1 min, together with estimation of the contribution to the test strip tear uptake of tears from the residual tear lake volume and those from continual tear production.     

Lysozyme concentrations in the tears of cattle, goats, and sheep

Tear samples were collected from 1 eye of each of 40 cows, 27 sheep, 5 goats, and 5 human beings. Additionally, 10 bovine tear samples were pooled and concentrated. Spectrophotometric assays, using Micrococcus lysodeikticus, were performed on each sample to detect lysozyme activity expressed in hen egg lysozyme (HEL) equivalents. Lysozyme activity was not detected in tears of cows, but 158.8 +/- 159.3 mg of HEL/ml was detected in tears of sheep, 220.7 +/- 37.5 mg of HEL/ml in tears of goats, and 216.3 +/- 86.2 mg of HEL/ml in tears of human beings. In pooled bovine tear samples, lysozyme activity was not detected on plate assay and lysozyme protein was not detected on polyacrylamide gel electrophoresis, column chromatography, or immunoelectrophoresis with rabbit anti-bovine tear antibodies. On the basis of these observations, we concluded that the basic ocular protective mechanism in bovine tears is not lysozyme. Other anti-bacterial proteins such as lactoferrin, transferrin, complement, or beta-lysin may, therefore, be of primary importance in protecting the bovine eye.     

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.     

Tear urea nitrogen and creatinine levels in horse and their correlation with serum values

The objective of this paper was to determine the physiological values of urea nitrogen and creatinine in tears, and to compare the results with those obtained from serum. Thirty healthy thoroughbred horses were included in the study. Tear fluid samples were obtained using a glass capillary tube placed in lower conjunctival cul-de-sac. Blood samples were taken from the jugular vein. Tear and serum urea nitrogen and creatinine levels were quantitatively analyzed by an enzymatic colorimetric method. Urea nitrogen values were 4.22+/-1.84 mmol/l in tears and 4.44+/-1.78 mmol/l in serum, whereas creatinine values in tears were 14.14+/-7.74 micromol/l and in serum 147.63+/-12.17 micromol/l. Statistical analysis confirmed a significant correlation between serum and tear urea levels (P<0001). However, there was no significant correlation between blood and tear creatinine values. Mean value of creatinine obtained from tears was 9.6% of the mean value from serum. Urea nitrogen and creatinine levels can be measured in tears. A significant correlation was found between serum and tears urea levels. This finding may permit development of a new alternative laboratory diagnosis of uremia based on the content of urea in tears.     

A preliminary study of changes in tear film proteins in the feline eye following nictitating membrane removal

Objective To investigate the influence of nictitating membrane (third eyelid) removal on selected proteins in feline tears. Animal studied Domestic short‐haired cats (7–17 months; 2.6–5.2 kg) were used. Procedures Eye‐flush tears were collected periodically for up to 18 weeks from both eyes of animals with nictitating membranes removed, but nictitating gland left intact, (n = 4) or with nictitating membranes intact (n = 4). Tear comparisons were based on total protein content (TPC) using micro bicinchoninic acid assay, immunoglobulin A (IgA), and matrix‐metalloproteinase (MMP)‐9 measurements using sandwich enzyme‐linked immunosorbent assay (ELISA) and tear gelatinase activity using gelatin zymography. Expression of MMP‐2 and ‐9 in nictitating membranes removed at baseline (week 0) and eyes collected at 18 weeks were also investigated in histological sections using immunoperoxidase for visualization. Results Nictitating membrane removal did not significantly change TPC and MMP‐9 in tears within the first 4 weeks. MMP‐9 was not detected by ELISA in tears from eyes without nictitating membranes from week 5 onwards. IgA (%IgA of TPC) data varied between animals. Gelatin zymography showed increased MMP‐2 and ‐9 activity in tears from eyes without nictitating membranes at week 1 and a decrease following week 2 post‐surgery. MMP‐2 and ‐9 were immunolocalised to conjunctival goblet cells of removed nictitating membranes and to the conjunctival epithelium, respectively. After 18 weeks, the distribution of MMPs in tissue was comparable between eyes with and without nictitating membranes. Conclusions Based on this preliminary study, nictitating membrane removal appeared to cause long‐term changes in expression of tear proteins, including reduced MMP‐9 expression.     

Use of tears for diagnosis of feline leukemia virus infection

A comparison was made of the use of serum, tears, and saliva for the detection of feline leukemia virus (FeLV) infection in cats. Cotton swabs were used to collect saliva, and tear-test strips were used to collect tears. Specimens were analyzed by a commercially available ELISA. Using a 10- to 15-minute specimen incubation period, FeLV was detected in 70% of the saliva specimens and in 73% of the tear specimens from viremic (serum-positive) cats. Feline leukemia virus antigen was not detected in saliva and tear specimens from serum-negative cats. The sensitivity of the tear assay was improved by increasing the incubation time to 24 hours. Tear strips could be air-dried and stored at room temperature for up to 7 days without any appreciable loss of activity. Client-owned and experimentally infected laboratory cats were tested for FeLV, using air-dried tear-test strips and a 24-hour incubation period. Tears were positive (contained FeLV antigen) in 65 of 72 (90%) serum-positive cats and did not contain antigen in 46 of 46 (100%) serum-negative cats. Results of ELISA obtained from serum and tears also were compared with results obtained from indirect fluorescent antibody testing of blood smears. Results of indirect fluorescent antibody and ELISA compared favorably with each other and with the results of tear testing.     

Effect of meniscal release on rate of subsequent meniscal tears and owner-assessed outcome in dogs with cruciate disease treated with tibial plateau leveling osteotomy

OBJECTIVE: To determine and compare rates of meniscal tears after tibial plateau leveling osteotomy (TPLO) among 3 groups of dogs based on treatment method: arthrotomy with meniscal release (openR), arthrotomy without meniscal release (openNR), arthroscopy without meniscal release (scopeNR), and compare long term owner-assessed outcomes for the same groups. STUDY DESIGN: Retrospective cohort study. SAMPLE POPULATION: Stifles (n=254) of dogs that had TPLO. METHODS: The three groups were compared for significant (P<.05) differences in rate of subsequent tears using a chi(2) test. Odds ratios for likelihood of subsequent meniscal tears were determined. Data for signalment, outcome, time to peak function, and time to subsequent tear were compared for significant differences using ANOVA, t-test, or rank sum test. RESULTS: Subsequent meniscal tears were diagnosed in 16 cases (6.3%). Of dogs with subsequent meniscal tears, 9 had openNR, 4 had openR, and 3 had scopeNR; the proportion of subsequent meniscal tears was significantly different (P=.035) among groups. Odds ratio indicated that subsequent meniscal tear was 3.8 times more likely to occur for openNR than openR or scopeNR. No significant differences among groups were noted for measures of outcome. CONCLUSIONS: Meniscal release did not reduce the rate of subsequent meniscal tears when compared with cases treated arthroscopically or when compared with all cases combined, but may be advantageous when meniscal pathology cannot be comprehensively assessed in the cranial cruciate deficient stifle. Meniscal release had no effects on owner-assessed outcome as determined in this study. CLINICAL RELEVANCE: The low rates of subsequent meniscal tears in conjunction with the relatively high and equivocal levels of owner-assessed outcome and time to peak function for all 3 treatment groups suggest that any of these surgical management strategies can be considered acceptable. We suggest that a meniscal release be performed when complete and thorough exploration of the joint and meniscus cannot be, or are not, performed.     

Rectal tears in the horse: an analysis of 35 cases

The records of 35 horses with Grade 3 or 4 rectal tears, presented to the Veterinary Medical Center at Texas A & M University over a five year period, were reviewed. Grade 3 tears were sub-classified according to whether the remaining tissue was serosa (Grade 3a) or mesorectum (Grade 3b). Five horses were destroyed on presentation and 30 were treated by primary suture closure (8 horses), faecal diversion alone (9 horses) or in combination with suture closure (11 horses) and packing of the tear with medicated gauze sponges (two horses). Faecal diversion was achieved with a temporary indwelling rectal liner (TIRL) in 19 horses and colostomy in one. Survival was related to classification of the tear, efficacy of first aid measures administered at time of injury and method of treatment. Seventy-four per cent of horses with Grade 3a tears and 44 per cent of those with Grade 3b tears survived. Grade 4 tears had a grave prognosis. Horses given adequate first aid before admission had a better survival rate. With proper patient selection, primary closure of the tear with sutures yielded excellent results. In horses which were not candidates for suture closure alone, a combination of faecal diversion and suturing gave better results than faecal diversion only. In addition, selected horses were treated successfully by packing the rectal tear with gauze sponges. The results demonstrate the value of a TIRL to divert faeces and appropriate first aid measures in treating rectal tears.     

Pharmacokinetics of topically applied ciprofloxacin in equine tears

OBJECTIVE: To evaluate the pharmacokinetics of topically applied ciprofloxacin 0.3% ophthalmic solution in tears of healthy horses. ANIMAL STUDIED: Twenty healthy, adult, mixed-breed horses. PROCEDURES: Twenty study horses were confirmed free of ophthalmic disease by complete ophthalmic examination. Seventy microliters of 0.3% ciprofloxacin (Ciloxan) was placed in the ventral cul-de-sac of each eye using a microliter syringe and 19-g cannula. Population kinetics were carried out by sampling the tear film from the lower cul-de-sac of each eye with tear test strips at 5, 10, 15 and 30 min and 1, 2, 4 and 6 h post administration for a total of five samples at each time-point. Sample collection time was 15 s. Concentrations of ciprofloxacin were determined using high performance liquid chromatography. RESULTS: Mean (+/-SD) of the Schirmer tear test results from all eyes was 23.4 +/- 4.8 mm wetting in 1 min. Mean concentration of ciprofloxacin in the tears at 5 min post administration was 498.4 +/- 266.8 microg/g. Mean concentration rapidly declined and began to plateau at 30 min. The mean tear concentrations of ciprofloxacin at 30 min and at 1, 2, 4 and 6 h were 66.6 +/- 56.0, 60.25 +/- 55.7, 42.25 +/- 30.9, 36.25 +/- 32.0, and 45.5 +/- 46.5 microg/g, respectively. CONCLUSIONS: The pharmacokinetics of ciprofloxacin in normal horses are similar to those in rabbits and humans. Topical application of ciprofloxacin resulted in a mean tear concentration of ciprofloxacin that remained above the MIC(90) levels for most pathogenic bacteria for 6 h post administration.     

Surgical technique to repair grade IV rectal tears in post-parturient mares

Objective— To describe a surgical technique for repair of grade IV rectal tears after parturition in mares and to report outcome.
Study Design— Clinical report.
Animals— Horses (n=6) with grade IV rectal tears.
Methods— Mares were sedated and restrained in standing stocks. After caudal anesthesia and evacuation of feces from the rectum, the perineal region was aseptically prepared. Four stay sutures were placed through the external anal sphincter before vertical transection (12 o'clock). Caudal retraction of the tear was performed using Allis tissue forceps (5 mares) or stay sutures before accurate apposition of the tear margins with steel staples below the tissue forceps. The mucosal edges were then sharply dissected leaving ∼5 mm edges which were apposed in a single layer (2-0 poliglecaprone 25) before stapler release. In 1 mare, the rectal tear was identified and apposed using a 2-layer hand-sutured closure. Systemic antibiotics and anti-inflammatory agents were administered postoperatively (5 mares) and standing abdominal lavage performed (3 mares).
Results— Four mares survived long term and subsequently became pregnant. Immediately after surgical repair, 1 mare was anesthetized for exploratory celiotomy and abdominal lavage but fractured her pelvis during recovery from anesthesia and was euthanatized. A 2nd mare was euthanatized after 72 h because of severe diffuse peritonitis; however, the repair was still intact.
Conclusion— In standing mares, rectal tears can be exteriorized by prolapse through the anal sphincter after sphincterotomy and repaired in 2 layers with staples oversewn with a continuous suture pattern.
Clinical Relevance— Rectal tears occurring as a result of parturition can potentially be repaired efficiently using an oversewn stapled primary closure technique.     

Standing surgical repair of cystorrhexis in two mares

Two surgical techniques were used to evert the bladder into the vagina for observation and repair of bladder tears that were associated with parturition. One technique involved an incision through the vaginal floor into the peritoneal cavity just caudal to the cervix, and prolapse of the bladder into the vagina. The second technique involved a 3-cm incision through the urethra, 5 cm cranial to the urethral orifice, and digital exploration of the tear and finger traction to evert the bladder through the urethral incision. In both mares, the bladder defects were repaired in two layers, with use of 2-0 polyglycolic acid in a simple continuous pattern. After repositioning, the vaginal and urethral incisions were closed in single layers using absorbable suture material. A standing vaginal approach eliminates the need for general anesthesia and allows excellent observation and repair of bladder tears in adult mares.     

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.     

The effect of Harderian adenectomy on the antibody response in chickens

Intact chicks and those that had their glands of Harder (GH) removed (GHx) at 1 day of age were studied for their response to optically or intraperitoneally (IP) applied antigens. Following exposure of the chicks to sheep red blood cells (SRBCs), killed Brucella abortus, or bovine serum albumin (BSA), serum and tear samples were collected and assayed for antibodies. Of the two sources of antibodies, the serum generally had higher levels than did the tears. The only exception to this occurred in the intact chicks inoculated by the eye, in which serum and tear levels were equivalent. With SRBCs, no difference could be detected between the two routes of inoculation. However, IP inoculation produced higher levels of antibody in the serum of intact and GHx chicks inoculated with B. abortus or BSA and in the tears of the GHx chicks exposed to B. abortus. Removal of the GH resulted in a consistent decrease in antibody levels in the tears, regardless of the route of exposure. Although this effect was noted with all three antigens, it was more pronounced in the trials using B. abortus and BSA. This finding is discussed in terms of describing the importance of the GH as a source of antibodies to optically applied antigens, and its importance as a route of circulating antibody egress. Furthermore, the feasibility of using the antibody response in tears to a test antigen is discussed as a means of measuring the immune status of a functioning GH.     

Tear production in canine neonates – evaluation using a modified Schirmer tear test

Purpose The ability of human newborns to produce tears has been a subject of controversy in the literature since the mid‐20th century, and there has been considerable debate as to whether they are able to produce tears. Recently, it was established that total tear secretion (reflex + basal) in full‐term infants is similar to those of adults whereas both reflex and basal tear production is reduced in premature babies. The objectives of this study were to assess whether newborn dogs have measurable aqueous tear production at the fourth week of life and to evaluate a modified Schirmer tear test (mSTT) as a useful method for measuring neonatal tear production in dogs. Methods Thirty four‐week‐old healthy puppies from six litters were evaluated. A control group was composed of 10 normal adult dogs. The mSTT strips were obtained by cutting a 5 mm‐wide strip in half (making two 2.5 mm‐wide strips). The mSTT1 was performed in puppies and adult dogs. Values were compared using t‐tests. Results In neonates, the average value for the mSTT1 was 13.6 ± 3.07 (range = 7–19 mm/min), which was significantly lower in neonates than in adult dogs (23.25 ± 3.5, range = 17–30 mm/min, P < 0.0001). Conclusions Canine neonates do produce tears by the fourth week of life, which can be successfully measured with the mSTT. This report established for the first time that canine neonates have significantly reduced total (reflex + basal) tear secretion compared to adults.     

A review of equine rectal tears and current methods of treatment

Rectal tears are a risk of rectal palpation during equine clinical examination and can be life‐threatening; prompt medical and surgical intervention is required to improve patient outcome. Depending on the degree of the tear, conservative treatment or surgical management may be warranted. Surgical management involves either direct suturing or faecal diversion techniques, such as colostomy or a temporary indwelling rectal liner. The prognosis for a horse with a rectal tear depends on size of the tear, grade and location of the tear, and time between occurrence and first aid measures.     

Pharmacokinetics of famciclovir and penciclovir in tears following oral administration of famciclovir to cats: a pilot study

Objective To validate a means of collecting tears from cats, develop an assay for quantifying famciclovir and penciclovir in tears, and to assess famciclovir and penciclovir concentrations and pharmacokinetics in the tears of cats being treated orally with famciclovir for suspected herpetic disease. Animals Seven client‐owned cats. Procedures Cats were treated orally with a median (range) dose of 40 (39–72) mg of famciclovir/kg three times daily for at least 24 h. At various time points following famciclovir administration, tear samples were collected using Schirmer tear test strips. Tear famciclovir and penciclovir concentrations were measured using liquid chromatography‐mass spectrometry, and concentration‐time profiles were analyzed noncompartmentally. The relationship between famciclovir dose and tear penciclovir concentration near its maximum was evaluated using least squares linear regression. Results Maximum tear famciclovir concentration of 0.305 μg/mL occurred at 2.64 h; elimination half‐life was 2.28 h. Maximum tear penciclovir concentration (0.981 μg/mL) occurred 2.25 h following oral administration of famciclovir; elimination half‐life was 2.77 h. A significant positive correlation was noted between famciclovir dose and tear penciclovir concentration at various time points between 0.5 and 3.75 h following drug administration (P = 0.025). Tear penciclovir concentration exceeded the concentration shown to have in vitro efficacy against feline herpesvirus (FHV‐1) (0.304 μg/mL) in about half of samples collected. Conclusions Oral administration of 40 mg of famciclovir/kg to cats resulted in a tear penciclovir concentration‐time profile that approximated the plasma penciclovir concentration‐time profile and frequently achieved a penciclovir concentration at the ocular surface likely to be effective against FHV‐1.     

Characterization of ocular gland morphology and tear composition of pinnipeds

Objective The importance of tear film integrity to ocular health in terrestrial mammals is well established, however, in marine mammals, the role of the tear film in protection of the ocular surface is not known. In an effort to better understand the function of tears in maintaining health of the marine mammal eye surface, we examined ocular glands of the California sea lion and began to characterize the biochemical nature of the tear film of pinnipeds. Procedures Glands dissected from California sea lion eyelids and adnexa were examined for gross morphology, sectioned for microscopic analysis, and stained with hematoxylin and eosin. The tear film was examined using interferometry. Tears were collected from humans and pinnipeds for the analysis of protein and carbohydrate content. Results The sea lion has sebaceous glands in the lid, but these glands are different in size and orientation compared with typical meibomian glands of terrestrial mammals. Two other accessory ocular glands located dorsotemporally and medially appeared to be identical in morphology, with tubulo‐acinar morphology. An outer lipid layer on the ocular surface of the sea lion was not detected using interferometry, consistent with the absence of typical meibomian glands. Similar to human tears, the tears of pinnipeds contain several proteins but the ratio of carbohydrate to protein was greater than that in human tears. Conclusions Our findings indicate that the ocular gland architecture and biochemical nature of the tear film of pinnipeds have evolved to adapt to the challenges of an aquatic environment.     

Immunoglobulin levels in tears and aqueous humor of horses before and after diethylcarbamazine (DEC) therapy

A quantitative investigation of equine tear and aqueous humor immunoglobulins was done using normal horses and ponies as well as horses and ponies infected with Onchocerca cervicalis. The equine immunoglobulin isotypes IgGa, IgM, IgA and IgG(T) were quantitated by either single radial immunodiffusion (SRID) or radioimmunoassay (RIA). Tear immunoglobulin levels for IgGa (128 +/- 151 micrograms/ml), IgA (1,664 +/- 1,038 micrograms/ml) and IgM (106 +/- 74 micrograms/ml) were measured, while IgG(T) was not detectable. In horses with ocular inflammation the IgGa was 18-fold higher in the tears, 2,269 +/- 3,077 micrograms/ml. Aqueous humor obtained by paracentesis of the normal equine eye under anaesthesia, resulted in values for IgGa (45.2 +/- 20.0 micrograms/ml), IgG(T) (5.2 +/- 2.0 micrograms/ml), IgM (1.3 +/- 4.8 micrograms/ml) and IgA (0.8 +/- 1.0 micrograms/ml). A pooled sample of normal aqueous fluid obtained from over 100 horses at an equine abbatoir in Indiana gave values of 1,150 micrograms/ml for IgGa, 65 micrograms/ml for IgG(T), 2.5 micrograms/ml for IgA and 3.0 micrograms/ml for IgM. In animals infected with 0. cervicalis and treated with Diethylcarbamazine (DEC), there was a marked elevation of IgGa and IgG(T) in the tears and aqueous humor while IgA and IgG(T) were also elevated slightly in the aqueous. The findings of elevated immunoglobulin isotypes in the aqueous humor may not be related to the DEC treatment and 0. cervicalis infections but rather to repeated paracentesis and the development of acute inflammation of the equine eye as a result of the trauma of paracentesis. The elevations in equine immunoglobulin isotypes in the tears after DEC treatment are not subject to the same caveat. The preferential elevation in IgGa and IgG(T) in the tears precedes the development of corneal opacities observed in the same horses. The concentration of specific antimicrofilarial antibody in these tears remains to be determined but may well account for a major share of the total immunoglobulins detected.     

Diagnostic accuracy of magnetic resonance imaging for meniscal tears in dogs affected with naturally occuring cranial cruciate ligament rupture

A stifle magnetic resonance (MR) imaging protocol was developed based on the appearance of the cruciate ligaments and menisci in normal dogs. Proton density images were subjectively considered to have the highest likelihood of detecting a meniscal lesion. Following this initial evaluation, the accuracy of high-field MR imaging to detect meniscal tears in dogs was evaluated in 11 dogs suffering from naturally occurring cranial cruciate ligament rupture. Dogs underwent MR imaging of the affected stifle before surgery. MR imaging and surgical findings were assessed independently, and then compared. Five tears of the medial meniscus were correctly diagnosed with MR imaging and 19 normal menisci were accurately characterized as such, based on MR images. In one medial meniscus, changes consistent with meniscal degeneration were seen on MR images but this was not seen at surgery. With regard to the lateral meniscus, one false positive diagnosis of a tear was made and this likely represented a normal variation. One other lateral meniscus had changes consistent with meniscal degeneration but, as with the similar lesion seen in the medial meniscus, this was not confirmed surgically. The global sensitivity of MR imaging for the diagnosis of a meniscal tear was 100% and the specificity was 94%. High-field MR imaging is a reliable method to diagnose meniscal tears preoperatively and this may be useful in selecting the surgical approach to clinically abnormal joints and may decrease the need for arthrotomy.