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 Staphyloccus 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.

Eighteen dogs with naturally acquired helminth infections were used to evaluate the efficacy of nitroscanate against Ancylostoma caninum, Dipylidium caninum, and Trichuris vulpis. Approximately 15 minutes before treatment, the dogs were given 100 to 200 g of canned dog food. Ten dogs were treated with nitroscanate (50 mg/kg of body weight, PO), and 8 dogs were given placebo tablets PO. The dogs were euthanatized and necropsied 10 days after treatment and helminths were recovered from the small intestine and cecum. On the basis of the number of worms recovered from treated dogs vs the number recovered from control dogs, we determined the efficacy of nitroscanate to be 99.6% against A caninum, 99.8% against D caninum, and 0% against T vulpis.

Proteins in sporulated and unsporulated oocysts of Eimeria maxima were characterized, using monoclonal antibodies (MAB), ELISA, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and protein (western) immunoblotting techniques. Three MAB (EM1, EM2, and EM4) were produced against proteins of sporulated oocysts. The ELISA results indicated that EM1 was reactive with sporulated oocyst proteins, EM2 was reactive with sporulated and unsporulated oocyst proteins, and EM4 was reactive with unsporulated oocysts and proteins. Separation of proteins in E maxima sporulated and unsporulated oocysts by SDS-PAGE indicated that sporulated oocysts had proteins of approximately 200 kilodaltons (kD) and distinct protein bands at 21.5 and 45 kD. Using SDS-PAGE, unsporulated oocysts had less-distinct high molecular weight protein bands (> 200 kD), compared with sporulated oocysts, and a distinct protein band at 31 kD. Use of all 3 MAB yielded negative results in western blot analysis of fractions obtained by SDS-PAGE.

Cardiopulmonary function values were determined before and after surgical removal of adult heartworms in 25 dogs with spontaneous and 4 dogs with drug-induced caval syndrome (CS). Fifteen dogs with spontaneous CS (recovery group) and 4 dogs with drug-induced CS (drug-induced CS group) recovered after removal, and 10 dogs with spontaneous cs were euthanatized or died (nonsurviving group). Before heartworm removal, injected radiographic contrast medium was regurgitated from the right ventricle to the right atrium. Mean pulmonary arterial pressure and total pulmonary resistance were not statistically different between the recovery and nonsurviving groups of dogs, but the end-diastolic right ventricular pressure (mean +/- SD, 6.9 +/- 9.1 mm of Hg) and the a (8.7 +/- 9.2 mm of Hg)- and v (6.3 +/- 8.5 mm of Hg)-waves of the right atrial pressure curve in the recovery group were less, respectively, than the end-diastolic right ventricular pressure (17.3 +/- 6.0 mm of Hg) and the a (15.8 +/- 6.1 mm of Hg)- and v (21.4 +/- 6.9 mm of Hg)-waves in dogs of the nonsurviving group. After heartworm removal, contrast medium regurgitation disappeared, and cardiac output of the right ventricle increased in dogs of the recovery (from 2.08 +/- 0.72 to 2.38 +/- 0.68 L/min; P < 0.05) and drug-induced CS (from 1.42 +/- 0.19 to 1.88 +/- 0.26 L/min, P < 0.05) groups. However, regurgitation remained, and cardiac output did not increase in some dogs of the nonsurviving group. Mean pulmonary arterial pressure decreased significantly (from 37.7 +/- 18.3 mm of Hg to 32.0 +/- 16.1 mm of Hg; P < 0.01) at 1 week after heartworm removal in dogs of the recovery group, but not in those of the nonsurviving group. Total pulmonary resistance (from 12,612 +/- 7,670 dynes.sec.cm-5.kg of body weight to 9,776 +/- 6,089 dynes.sec.cm-5.kg; P < 0.01) and right atrial pressure (a-wave: from 8.7 +/- 9.2 mm of Hg to 4.1 +/- 5.6 mm of Hg; v-wave: from 6.3 +/- 8.5 mm of Hg to 2.1 +/- 4.6 mm of Hg) decreased after heartworm removal in dogs of the recovery group. Total pulmonary resistance (from 20,309 +/- 9,682 dynes.sec.cm-5.kg to 15,970 +/- 6,798 dynes.sec.cm.5.kg; P < 0.05) and right atrial pressure (a-wave: from 15.8 +/- 6.1 mm of Hg to 10.1 +/- 6.3 mm of Hg; v-wave: from 21.4 +/- 6.9 mm of Hg to 11.1 +/- 3.7 mm of Hg) also decreased in dogs of the nonsurviving group. However, pressures in the right side of the heart and total pulmonary resistance after heartworm removal were greater in dogs of the nonsurviving group than in dogs of the recovery group. At necropsy pulmonary arterial emboli containing dead heartworms were found in almost all dogs with spontaneous CS, but not in dogs with drug-induced CS. The severity of pulmonary arterial embolism correlated significantly with mean pulmonary arterial pressure before (r = 0.710; P < 0.01) and 1 week after (r = 0.728; P < 0.01) heartworm removal.

We compared the frequency and severity of osteochondrosis lesions in young Thoroughbred horses with cervical stenotic myelopathy (CSM) vs that in clinically normal Thoroughbreds of the same age. All lesions of the cervical vertebrae and appendicular skeleton were classifiedhistologically as osteochondrosis or nonosteochondrosis and were measured for severity. Minimal sagittal diameter was significantly smaller in horses with CSM from C2 through C6; no difference was detected at C7. Severity of cervical vertebral osteochondrosis was greater in the horses with CSM, however frequency was not different. Frequency and severity of nonosteochondrosis lesions were not different in cervical vertebrae or appendicular skeleton. Frequency and severity of appendicular skeleton osteochondrosis lesions were both greater in horses with CSM. Osteochondrosis and nonosteochondrosis lesions were more severe on facets at sites of compression than on facets at noncompressed sites in horses with CSM. However, compression was also observed at sites with no articular facet lesions. The association of widespread osteochondrosis and spinal canal narrowing with CSM suggests CSM may represent a systemic failure in the development or maturation of cartilage and bone.

Specimens of the uterine tube epithelium (ampulla) were obtained from 20 healthy, prepubertal, ovariohysterectomized gilts. A 2 to 3% proportion of atypical cilia was observed. Of 6,600 transversely sectioned cilia, 122 (1.8%) had microtubular disorganization, whereas 444 of 48,080 totally examined cilia (0.9%) were compound, 104 (0.2%) were swollen, and 44 (0.09%) were intracytoplasmic.

Praziquantel was used successfully for treatment of a small number of dogs and 1 cat infected with Paragonimus kellicotti. To further evaluate the usefulness of this drug in treating such infections, 7 cats and 7 dogs were inoculated orally with metacercariae (12 and 20 to 22, respectively) obtained from crayfish, then were treated after the infections became patent; 2 cats and 2 dogs served as noninfected controls. Beginning 1 week before infection, and continuing weekly thereafter, physical, hematologic, and fecal examinations were performed on each animal; thoracic radiography was performed every other week. By postinoculation week 6, all dogs given metacercariae had patent infection diagnosed on the basis of positive results of fecal examination. By postinoculation week 7, 5 cats had confirmed patent infection, but 2 cats given metacercariae never had patent infection or had signs of infection. Clinical signs of infection were minor and included increased respiratory tract noise, slight inducible cough, or mild dyspnea. Transient eosinophilia was detected in dogs around postinoculation week 3. Pretreatment radiography revealed cavitated lesions in cats only; pleural lines and patchy infiltrates in cats and dogs; or pneumothorax in dogs only. The treatment regimen consisted of 23 mg of praziquantel/kg of body weight given every 8 hours for 3 days; 1 infected cat and dog were not treated. By 11 days after treatment, eggs had disappeared from the feces of infected animals, and marked resolution of lung lesions was evident radiographically. The 2 untreated animals and 1 treated dog were euthanatized and necropsied to verify lesions and their resolution. All treated animals were considered cured of infection by use of this treatment regimen.

Comparisons of the MacKay-Marg and Tono-Pen applanation tonometers in open and closed in vitro systems were made for the eyes of cats. Both instruments significantly underestimated intraocular pressure (IOP) vs direct manometry (P < 0.001), but in readily predictable manner, with high coefficients of determination (r2 = 0.99). For tonometer 1 (MacKay-Marg), calculated actual IOP = 1.36 X (MacKay-Marg measurement) - 1.67 mm of Hg; and for tonometer 2 (Tono-Pen), calculated actual IOP = 1.37 X (Tono-Pen measurement) + 0.8 mm of Hg, using measurements from 11 enucleated eyes. In vivo comparisons were initially made in 81 clinically normal eyes (n = 41 cats) by applying the Tono-Pen first followed by the MacKay-Marg. Compared with the MacKay-Marg, the Tono-Pen significantly (P < 0.001) underestimated IOP in these cats. When the order of tonometer applanation was subsequently reversed in 73 clinically normal eyes (n = 37 cats) the Tono-pen again significantly (P < 0.001) underestimated IOP, compared with the MacKay-Marg. Alterations in tonometer order did not result in significant differences in measured IOP for the MacKay-Marg when compared with itself, but Tono-Pen measurements were significantly (P < 0.05) less when its use followed rather than preceded, that of the MacKay-Marg. Mean (+/- SD) IOP in clinically normal cats when each tonometer was used first was 22.6 +/- 4.0 mm of Hg (range, 14 to 32 mm of Hg) for the MacKay-Marg and 19.7 +/- 5.6 mm of Hg (9 to 31 mm of Hg) for the Tono-Pen. The mean (+/- SD) absolute value of the differences between MacKay-Marg measurements and those obtained by use of the Tono-Pen was 3.2 +/- 3.1 (range, 0 to 13 mm of Hg difference).

Progressive changes in serum enzyme activity and liver histologic features were monitored in calves fed tansy ragwort (Senecio jacobaea)-contaminated pellets. The experiments were designed to simulate natural intoxicant ingestion conditions in relationship to the dose and duration of exposure to the toxic plant to correlate early laboratory diagnostic changes with the natural progression of the disease, thereby facilitating early diagnosis and intervention by veterinary clinicians. Eight calves were fed tansy ragwort and 4 additional calves served as controls. In group 1, 4 calves were continuously fed dried tansy ragwort mixed in a pelleted feed at a 5% concentration by dry weight until terminal liver disease developed. Serum liver enzyme (alkaline phosphatase, glutamate dehydrogenase, and gamma-glutamyltransferase) activities were monitored at weekly intervals in these calves and in the 2 controls. In group 2, 4 calves were fed the same contaminated feed for only 60 days, with return to normal feed for the duration of the trial. Two additional calves served as controls. Their liver enzyme activities were monitored every other week in conjunction with percutaneous liver biopsies. All 8 calves fed tansy ragwort-contaminated pellets developed terminal hepatopathy in either a chronic pattern (n = 6) or a chronic-delayed pattern (n = 2), with the onset of a moribund state or sudden death at 11 to 17 weeks and 27 to 51 weeks, respectively. The calves were euthanatized when classic terminal signs of hepatic encephalopathy first became evident. The clinicopathologic patterns of chronic and chronic-delayed toxicoses were typical of over 5,000 cases of field tansy toxicosis diagnosed at the diagnostic laboratory. Serum glutamate dehydrogenase was the first enzyme to increase in most animals, with a short-term increase to peak values followed by a rapid return to normal. This enzyme change was followed by increases in alkaline phosphatase and gamma-glutamyltransferase. Serum enzyme changes preceded development of recognizable histologic lesions. Vacuolar changes in hepatocyte nuclei, biliary hyperplasia, and fibrosis sequentially developed in liver biopsy specimens from each animal, whereas megalocytosis was not a predominant feature until necropsy. On the basis of our finding we suggest that the optimal tests for diagnosis of pyrrolizidine alkaloid intoxication should consist of liver biopsy and determination of concurrent serum liver-enzyme activities.

Conjunctiva-associated lymphoid tissue (CALT) in the eyelids of chickens was studied by gross, histologic, and electron microscopic techniques. Structural features were characterized at 1 day of age and at posthatching week (PHW) 1, 2, 3, 4, 6, 8, 12, and 16. Beginning at PHW 1, prominent lymphoid nodules containing a heterogenous population of lymphocytes, lymphoblasts, and macrophages were first observed within conjunctival folds and fissures of the lower eyelid. Nodules contained germinal centers by PHW 2 and plasma cells by PHW 4. The epithelium associated with these nodules was flat, had short, irregular microvilli, contained intraepithelial lymphocytes, and lacked goblet cells. High endothelial venules were located at the base of lymphoid nodules and contained lymphocytes within and below the cuboidal endothelium. In the upper eyelid, CALT was morphologically similar to lymphoid tissue in the lower eyelid, but nodules were smaller and more random, lacked association with epithelial folds and fissures, and were clustered around the opening of the nasolacrimal duct. By PHW 12, CALT was characterized by basal germinal centers outlined by collagenous stroma, suprafollicular plasma cells, columnar epithelium with goblet cells, and fewer intraepithelial lymphocytes. On the basis of these features, CALT in chickens has morphologic characteristics similar to other components of the mucosal immune system and, therefore, may have a role in mucosal immunity.