Pitfalls in immunofluorescence testing in dermatology. III. Pemphigus-like antibodies in the horse and direct immunofluorescence testing in equine dermatophilosis

Indirect immunofluorescence testing for pemphigus-like antibodies was performed on 79 horses: 28 horses with various nonpemphigus dermatologic diseases, 21 horses with various nondermatologic diseases, and 30 normal horses. Pemphigus-like antibodies were detected in 6 horses: 3 normal horses with titers of 1:40, 2 horses with dermatophilosis at titers of 1:10 and 1:80, and 1 horse with lymphosarcoma at a titer of 1:320. It was concluded that equine pemphigus-like antibodies are a potential source of misinterpretation and misdiagnosis in indirect immunofluorescence testing. Direct immunofluorescence testing for whole immunoglobulin, IgG, IgM, and IgA was performed on skin lesions from 2 horses with dermatophilosis. Diffuse intercellular deposition of whole immunoglobulin and IgG was found in both horses. It was concluded that equine dermatophilosis is a potential source of misinterpretation and misdiagnosis in direct immunofluorescence testing.     

Colitis in sheep due to a Campylobacter-like bacterium

Epidemic diarrhoea was observed in approximately 2,000 of 6,700 sheep on 9 farms. The disease, called weaner colitis, caused mortality of 1%, while morbidity varied from 20 to 75%. Colon contents from affected sheep were inoculated into 17 sheep, 13 of which developed diarrhoea 5 to 7 days after inoculation. Naturally and experimentally infected sheep had mild, erosive typhlitis and colitis. Microscopic examination of washed scrapings of colonic mucosa from all affected sheep revealed masses of curved bacteria that were not seen in controls. Electron microscopic examination showed similar bacteria adherent to colonic epithelium of an experimentally infected sheep. Curved, motile bacteria were isolated from 2 naturally occurring cases. One isolate was inoculated into 9 sheep, 2 of which developed diarrhoea. The other isolate was given to 4 sheep without observable effect. The curved bacteria grew only on media containing blood, in an atmosphere of approximately 10% air, 10% CO2 and 80% H2. They were Gram-negative, with a polar flagellum at one or both ends, they did not ferment glucose or give a positive catalase reaction. It is suggested that these bacteria are a new Campylobacter species and that they play a major role in the aetiology of weaner colitis.     

Prevalence of gastrointestinal parasitism in Oklahoma swine

The prevalence of swine gastrointestinal parasites was determined from all listed large swine operations (28) and a geographically representative sample (70) of the population of small hog farm operations in Oklahoma. Fecal samples (n = 975) were collected from 98 farms. From the 98 farms, parasites were recovered in pig feces as follows: Ascaris, 53.0%, strongyles, 53.1%, Trichuris, 35.7%, spirurids, 6.1%, Strongyloides, 19.4%, coccidia, 57.1%, and Balantidium, 55.1%. A higher percentage (16.5%) of hogs maintained on cement floors were positive for Ascaris than were those on either dirt lots (11.9%) or slatted floors (9.9%), but pigs on dirt lots were more often positive with a higher percentage of coccidia (21.0%) than those on either cement or slatted floors (8.5% and 6.0%, respectively). Prevalence of Trichuris was essentially the same (6.8% to 11.3%) in hogs from all 3 management practices.     

Toxic effects of selenium on growing swine fed corn-soybean meal diets

A total of 96 crossbred pigs received various levels of sodium selenite to determine the effect of dietary selenium (Se) on growing swine fed corn-soybean meal diets. Levels of supplemental Se were 0, 4, 8, 12, 16 and 20 micrograms/g. There were linear decreases (P less than .01) in both gain and feed intake with increasing levels of dietary Se. Feed/gain increased numerically as dietary Se increased. Hair Se increased quadratically (P less than .01) and blood Se increased linearly (P less than .01) with increasing level of dietary Se. Cell volume and hemoglobin were not affected by dietary treatment. Increasing dietary Se significantly increased glutathione peroxidase (GSH-Px), glutamic-oxalacetic transaminase (GOT). and glutamic-pyruvic transaminase (GPT). External signs of selenosis were noted in some pigs fed 12 or 20 micrograms/g of Se. The toxic level of Se in a corn-soybean meal diet for crossbred pigs appears to be between 4 and 8 micrograms/g. Of variables studied, growth rate was the most sensitive indicator of chronic selenosis in swine.     

Lack of evidence for the occurrence of Pasteurella ureae in rodents

The taxonomy of five typical human isolates of Pasteurella ureae, one strain of Actinobacillus hominis, and three murine isolates which had been designated as Pasteurella ureae in published reports were re-examined. Their taxonomic relationships were investigated by both conventional phenotypic characterization and by DNA/DNA hybridization using the renaturation method. The human Pasteurella urea strains were highly homogeneous in their phenotypes and in their DNA reassociation. The strain of Actinobacillus hominis studied was genetically distinct from Pasteurella ureae, but was located, like Pasteurella ureae, in the Actinobacillus group. The remaining strains exhibited only low DNA relatedness with Pasteurella ureae and each other; this agreed with their phenotypic divergence. Two of the murine isolates were identified as indole-negative variant strains of Pasteurella pneumotropica sensu stricto (i.e., type Jawetz), or of the type Heyl of Pasteurella pneumotropica, respectively. The remaining murine isolate appears to represent a hitherto unrecognized species of Pasteurellaceae. So far, there is no evidence for the occurrence of Pasteurella ureae outside the human host.     

Behaviour of amitraz in cattle dipping baths

The settling rates of 0.025% w/v amitraz (used as a 50% w/w active ingredient wettable powder) and lime stabiliser (0.7% Ca(OH)2) were studied in cattle dipping baths in the Tick Quarantine Area of northern New South Wales. Although lime settled more rapidly than amitraz, the rate for both decreased as the number of cattle dipped increased. After a total of 1,200 head had been dipped the settling rate during the hour following stirring was negligible, and re-stirring was not necessary within the hour following use. Baths could also be cleaned of heavy sediment by scooping without significant loss of chemicals. When the bath volume was allowed to decrease to 2,100 liters below working volume no significant changes in amitraz and Ca(OH)2 concentrations occurred. Data collected from 796 baths showed a significant concentration change of +0.00066% amitraz and -0.017% Ca (OH)2 per 1,000 head of cattle. Replenishment per 700 liters of water with 254 g amitraz was found to be in good agreement with 250 g recommended by the manufacturer, while 12.53 kg for lime was substantially more than the 10 kg recommended.     

Modification of humoral immune response in chickens following treatment with carrageenan

Carrageenan treatment of chickens resulted in splenomegaly and enlargement of bursa but had no effect on the thymus. The dose and route of administration had a profound effect on humoral immune response to Brucella abortus and sheep red blood cells. Antibody response to B. abortus was either unaffected or significantly enhanced, whereas response to red blood cells was severely suppressed. Furthermore, delineation of the class of antibody response affected by the treatment, using 2-mercaptoethanol, suggested that there was a selective inhibition of IgG response to the T dependent antigen.     

SILVER IMPREGNATION IN SITU

In evaluating radiographs of the limb joints and head, students encounter difficulty where superimposition occurs. By replacing calcium with silver salts in the bone, enhanced radiopacity can be produced. In this study, silver impregnation was used to increase the radiopacity of individual carpal and tarsal bones, selected bones of the skull and the sinuses, and guttural pouch of the horse. This provides an interpretation aid for teaching radiographic anatomy of these regions.     

Idiopathic pericarditis and cardiac tamponade in two cows

Idiopathic pericarditis is an uncommon diagnosis in cattle with cardiac tamponade. Two cows were examined for clinical signs of right-sided congestive heart failure, including tachycardia, venous distention, and peripheral edema. Muffled heart sounds were detected in one of the cows. Echocardiography in both cows revealed voluminous anechoic pericardial effusion and compression of the right atrium and right ventricle. Cytologic analysis of the pericardial fluid revealed hemorrhagic inflammation but no evidence of a septic or neoplastic condition such as traumatic reticulopericarditis or lymphoma, respectively. Pericardial drainage and lavage accompanied by treatment with anti-inflammatory drugs were curative in both cows. It is important to differentiate cows with idiopathic pericarditis from cows with more common septic pericarditis because the prognosis for the former disease appears to be good with appropriate treatment.     

Spinal cord granuloma due to Coccidioides immitis in a cat

A6-year-old 5.5-kg female spayed domestic short-haired cat from Tucson, AZ, presented with an ˜5-day history of progressive pelvic limb weakness. The owners had returned from a weekend away to find the cat unable to use her left pelvic limb. Approximately 2 months previously, the cat had a cough and was treated for presumptive asthma with 5 mg prednisone PO q24h. The cat had a similar cough 1 year previously and seasonal allergy was suspected. The cough resolved and prednisone treatment was discontinued. Other past pertinent history included a skin problem ˜4 years previously that was described as alopecia, erythema, and pruritus of a pelvic limb. This problem had been diagnosed as an allergy and had since resolved. The cat was housed exclusively indoors and had been adopted as a kitten from a local retail store. Viral titers (FeLV and FIV) were negative, and regular vaccinations and veterinary examinations had been completed