Effect of administration of a phospholipid emulsion on the initial response of horses administered endotoxin

OBJECTIVE: To evaluate the effect of a phospholipid emulsion (PLE) on the initial response of horses to administration of endotoxin. ANIMALS: 12 healthy adult horses. PROCEDURES: Horses were assigned to 2 treatment groups (6 horses/group). The control group was administered 1 L of saline (0.9% NaCl) solution, and the treated group was administered PLE (200 mg/kg, IV); treatments were administered during a period of 120 minutes. An infusion of endotoxin was initiated in both groups starting 1 hour after initiation of the saline or PLE solutions. Physical examination and hemodynamic variables were recorded, and blood samples were analyzed for concentrations of tumor necrosis factor (TNF)-alpha, interleukin-6, thromboxane B2 (TxB2), 6 keto-prostaglandin F (PGF)1alpha, total leukocyte count, and PLE concentrations. An ANOVA was used to detect significant differences. RESULTS: Administration of PLE resulted in significantly lower rectal temperature, heart rate, cardiac output, right atrial pressure, and pulmonary artery pressure and higher total leukocyte counts in treated horses, compared with values for control horses. The TNF-alpha concentration was significantly less in treated horses than in control horses. The TxB2 and 6 keto-PGFF1alpha concentrations were significantly different between treated and control horses at 30 minutes (TxB2) and at 30 and 60 minutes (6 keto-PGF1alpha). CONCLUSIONS AND CLINICAL RELEVANCE: Prior infusion of PLE in horses administered a low dose of endotoxin decreased rectal temperature, heart rate, pulmonary artery pressure, and TNF-alpha concentrations. Results of this study support further evaluation of PLE for use in the treatment of horses with endotoxemia.     

Sensitivity of test strategies used in the Voluntary Johne's Disease Herd Status Program for detection of Mycobacterium paratuberculosis infection in dairy cattle herds

OBJECTIVE: To evaluate sensitivities at the herd level of test strategies used in the Voluntary Johne's Disease Herd Status Program (VJDHSP) and alternative test strategies for detecting dairy cattle herds infected with Mycobacterium paratuberculosis. DESIGN: Nonrandom cross-sectional study. SAMPLE POPULATION: 64 dairy herds from Pennsylvania, Minnesota, Colorado, Ohio, and Wisconsin. Fifty-six herds had at least 1 cow shedding M. paratuberculosis in feces; the other 8 herds were free from paratuberculosis. PROCEDURE: For all adult cows in each herd, serum samples were tested for antibodies to M. paratuberculosis with an ELISA, and fecal samples were submitted for bacterial culture for M. paratuberculosis. Sensitivities at the herd level (probability of detecting infected herd) of various testing strategies were then evaluated. RESULTS: Sensitivity at the herd level of the testing strategy used in level 1 of the VJDHSP (use of the ELISA to test samples from 30 cows followed by confirmatory bacterial culture of feces from cows with positive ELISA result) ranged from 33 to 84% for infected herds, depending on percentage of cows in the herd with positive bacterial culture results. If follow-up bacterial culture was not used to confirm positive ELISA results, sensitivity ranged from 70 to 93%, but probability of identifying uninfected herds as infected was 89%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the testing strategy used in the VJDHSP will fail to identify as infected most dairy herds with a low prevalence of paratuberculosis. A higher percentage of infected herds was detected if follow-up bacterial culture was not used, but this test strategy was associated with a high probability of misclassifying uninfected herds.     

A comparison of catecholamine and cortisol responses of young lambs and calves to painful husbandry procedures

AIM: To compare the changes in plasma concentrations of noradrenaline, adrenaline and cortisol in lambs after ring castration plus tailing and in calves after dehorning with or without prior local anaesthesia. METHODS: Male lambs were castrated and tailed with rings and calves were dehorned by amputation using a scoop with or without prior local anaesthesia. Blood samples were taken before and after treatment and plasma concentrations of noradrenaline, adrenaline and cortisol were determined. RESULTS: Castration plus tailing of lambs resulted in a rapid increase in noradrenaline concentrations, a lack of an adrenaline response and a marked increase in cortisol concentration. There were similar changes in catecholamine concentrations in calves that were dehorned both with and without local anaesthetic, with adrenaline being elevated within 5 min of treatment and noradrenaline exhibiting a more protracted response. Dehorning caused a marked cortisol increase which was reduced to control concentrations by local anaesthesia for as long as the associated nerve blockade lasted. CONCLUSIONS: The very short-lived adrenaline responses in calves were attributed to dehorning-induced nociceptor input leading to sympathetic stimulation of the adrenal medulla. The longer lasting noradrenaline responses in lambs and calves were thought be due to 'wash-out' of noradrenaline from damaged tissue associated with rings and amputation wounds, respectively.     

Pretanned leather shavings in a supplement mixture for steers: II. Digesta kinetics, ruminal fermentation, and grazing behavior in steers grazing dormant wheatgrass pasture

Twelve ruminally cannulated steers (Angus x Holstein; average initial BW = 533 +/- 3.28 kg) were randomly allotted to one of three treatments (four steers/treatment) to evaluate the use of pretanned leather shavings as a component of a protein supplement for steers grazing dormant intermediate wheatgrass (Thinopyrum intermedium Host). Steers were allotted to one of three treatments: 1) no supplement (control); 2) supplementation intraruminally at 0700 with soybean meal at .2% of BW (as-fed basis); 3) supplementation intraruminally with soybean meal and pretanned leather shavings (17:8 ratio, respectively) at .16% of BW (as-fed basis). Supplements were formulated so that intakes were isonitrogenous and were placed intraruminally once daily (0700). Sampling periods were conducted February 3 to 16 and February 17 to March 5, 1995. In situ organic matter disappearance of the soybean meal supplement was greater (P > .05) than that of the leather shavings supplement at all incubation times (1, 3, 6, 9, 12, 24, and 48 h). Data suggested that pretanned leather shavings within the leather shavings supplement were only 25% degradable within the rumen. Forage OM intake (control = 12.7, soybean meal = 12.7, and leather shavings = 13.4 g/kg of BW), grazing time, and grazing efficiency were not altered (P > .10) by supplementation or type of supplement provided but did increase between the February and March samplings. Total intake was increased (P = .09) with supplementation and reflected the addition of the protein supplements. Particulate and fluid passage estimates were unaffected (P > .10) by the supplements; however, gastrointestinal fill increased (P = .01) between the February and March samplings. Ruminal pH was lower (P = .04) and ruminal NH3 N concentration was greater (P = .02) for supplemented steers than for control steers, and supplementation treatments did not differ (P > .10). Total VFA concentrations were increased (P = .01) by supplementation but were not affected by type of supplement provided (P > .10). Ruminal molar proportions of acetate and propionate and the ratio of these two VFA did not differ (P > .10) between supplementation types. Nonetheless, supplementation increased molar proportions of butyrate (P = .04), valerate (P = .02), and isovalerate (P = .05), and leather shavings supplementation increased (P = .10) isobutyrate proportions over those in steers supplemented with soybean meal. Combining pretanned leather shavings with soybean meal seemed to have no deleterious effects on forage intake, digesta passage, grazing behavior, or ruminal fermentation and seemed to provide effects similar to those of soybean meal alone.     

Effects of food withdrawal and transport on 5- to 10-day-old calves

The effects of food withdrawal for 30 hours and transport for up to 12 hours on 5- to 10-day-old calves were determined by monitoring plasma concentrations of glucose, beta-hydroxybutyrate, urea, lactate and creatine phosphokinase. In addition gamma-glutamyl transferase activity, packed cell volume, total plasma protein concentration, bodyweight and rectal temperature were recorded. Food withdrawal for 30 hours caused hypoglycemia but calves maintained normothermia and although their beta-hydroxybutyrate level increased indicating lipid mobilisation, the changes in blood urea level were minimal indicating low amino acid catabolism. When calves were transported for 12 hours in addition to having food withdrawn for 30 hours, they remained normoglycemic for six hours longer than non-transported calves, probably due to an effect of muscular activity during bracing against truck movements. Stocking calves at a lower density during transport apparently had a beneficial effect, as calves were able to lie down throughout the journey and therefore produced a similar metabolic profile to resting, non-transported animals. Transport and food withdrawal had no obvious effects on calf hydration. The results of this study suggest that food withdrawal for up to 30 hours and transport for up to 12 hours had no detrimental effects on the metabolism of healthy and clinically normal calves. With correct feeding regimes and transport protocols, welfare compromise in young, healthy calves being transported for up to 12 hours can be minimised when they are slaughtered within 30 hours of the start of transport.     

Agreement among surgical pathologists evaluating routine histologic sections of digits amputated from cats and dogs.

Agreement among pathologists interpreting histologic specimens is an area of interest within human pathology, but little work in this area has been reported in the veterinary literature. Agreement among pathologists evaluating routine histologic sections of amputated digits from cats and dogs submitted to multiple diagnostic centers was examined. Histologic sections from surgical specimens were reviewed in a blinded fashion by two pathologists, and a comparison to the original diagnosis, as stated in the diagnostic report, was recorded. A total of 513 cases were reviewed, and complete agreement was reached in 409 (79.7%). Of the 104 instances of disagreement, 77 (74.0%) were considered to be of clinical significance. The diagnosis of keratoacanthoma was disagreed with in 19 of 21 diagnoses (90.4%). No other individual diagnosis was similarly disputed. The overall level of disagreement is large and is similar to that reported in human pathology and suggests that further study of this issue would be useful in veterinary pathology.     

Oral eosinophilic granulomas in tigers (Panthera tigris)--a collection of 16 cases.

Oral eosinophilic granulomas were diagnosed in 16 tigers (Panthera tigris). All lesions were located on the hard or soft palate and typically consisted of flat or slightly raised circular ulcers. Histologic features of these lesions were essentially identical to those seen in oral eosinophilic granulomas of domestic cats and dogs. No clinical signs were noted in eight cases, though various degrees of inappetence, excessive salivation, and dysphagia were noted in the other eight tigers. Six cases were not treated. Treatment for the remaining 10 cases centered on corticosteroids and additional treatments included surgical removal, cryotherapy, antibiotics, and chlorpheniramine. Treatment with corticosteroids did appear to be effective in some cases, though lesions would worsen after cessation of therapy and no cases were cured. In addition, three cases developed complications possibly related to this corticosteroid therapy. The etiology of these lesions remains unknown, though an underlying allergic condition is likely.