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1.
OBJECTIVE: To evaluate the potential of excess dietary iron to cause hepatic lesions similar to those described in horses with suspected iron toxicosis or hemochromatosis. DESIGN: Prospective study. ANIMALS: 6 adult male ponies. PROCEDURE: 4 ponies received 50 mg of iron/kg (22.7 mg/lb) of body weight each day by oral administration of ferrous sulfate, which contained 20% elemental iron; 2 ponies received only the carrier (applesauce). Complete blood counts, serum biochemical analyses, and hepatic tissue biopsies were performed, and serum iron concentrations were measured. Blood and tissue samples were obtained at days 0 and 2, and at the end of weeks 1, 3, 6, and 8 after administration of iron was initiated. Treatment was discontinued after 8 weeks, and hepatic iron concentrations were measured at 28 weeks. RESULTS: Hepatic iron concentrations, serum iron concentrations, percentage saturation of transferrin, and serum ferritin concentrations were increased, compared with baseline and control concentrations, by week 8. Adverse clinical signs or histologic lesions in the liver were not detected in any ponies. At 28 weeks, hepatic iron concentrations had decreased. CONCLUSIONS AND CLINICAL RELEVANCE: Histologic lesions were not seen in the hepatic biopsy specimens obtained from the ponies treated with ferrous sulfate. It was concluded that it would be unlikely for iron toxicosis to develop in adult ponies or horses during a period of < 8 weeks when food or water contained increased amounts of iron. It is suspected that previous reports of hepatopathies in animals with hemosiderin accumulation may represent a primary hepatopathy with secondary hemosiderin accumulation, especially if the only source of iron is via oral consumption.  相似文献   

2.
Twenty calves were orally inoculated with Mycobacterium paratuberculosis at six weeks old. At six months old, 10 of these, plus four uninfected controls were maintained on limited dietary copper and supplemented iron intake for a further 27 months. During this time all these animals, together with a further four untreated controls, were bred before being killed and examined for evidence of paratuberculosis. Despite significant reduction in weight gain, attributable to both iron supplementation and infection, no significant difference was found in the numbers of iron-supplemented and unsupplemented animals that developed clinical signs nor in the extent and severity of intestinal lesions between groups. Accumulation of iron in paratuberculosis lesions was not affected by iron supplementation but was positively correlated with the frequency of shedding of M paratuberculosis in faeces (P less than 0.05). Dietary iron supplementation alone resulted in serum hyperferraemia, hepatic siderosis and slight hypocuprosis, whereas, in infected animals, this resulted in marked hypocuprosis and anaemia within groups (P less than 0.05). Infection alone resulted in serum hypoferraemia and intestinal and hepatic siderosis which was positively correlated with the severity of infection within groups (P less than 0.05). Susceptibility to paratuberculosis may result from failure ultimately to limit monokine-mediated iron sequestration in intestinal tissue.  相似文献   

3.
Background: Hepatic failure is one of the more common complications in foals requiring blood transfusion to treat neonatal isoerythrolysis. Iron intoxication is likely the cause of hepatic injury. Objectives: To determine the effects of deferoxamine on iron elimination in normal foals. Animals: Thirteen neonatal foals. Methods: Randomized‐controlled trial. At 1–3 days of age, foals received either 3 L of washed packed dam's red blood cells (RBC) or 3 L of saline IV once. Foals were treated with deferoxamine (1 g) or saline (5 mL) SC twice daily for 14 days. Foals were randomly assigned to 1 of 3 groups: RBC/deferoxamine (deferoxamine), RBC/saline (placebo), or saline/saline (control). Blood and urine samples and liver biopsy specimens were collected for measurement of hematological, biochemical, and iron metabolism variables. Results: There was a significant (P < .05) increase in hematocrit, RBC count, and hemoglobin in the groups transfused with packed RBC as compared with controls at all times. Biochemical variables and liver biopsy scores were not significantly different between groups at any time. Urine iron concentrations and fractional excretion of iron were significantly higher in deferoxamine treated foals. By 14 days after transfusion, liver iron concentrations in foals treated with deferoxamine (79.9 ± 30.9 ppm) were significantly lower than that of foals receiving placebo (145 ± 53.0 ppm) and similar to that of controls (44.8 ± 4.09 ppm). Conclusions and Clinical Importance: Deferoxamine enhances urinary iron elimination and decreases hepatic iron accumulation after blood transfusion in foals.  相似文献   

4.
Acute experimentally induced aflatoxicosis in the weanling pony   总被引：1，自引：0，他引：1  
Nineteen weanling ponies and 1 adult pony were given a single oral dose of aflatoxin B1 (AFB1). Dosages were: 0, 0.5, 1, 2, 4, 5, 6, and 7.4 mg of AFB1/kg of body weight. Vital signs were monitored, and whole blood and serum collected for analysis of serum enzymes, prothrombin time, blood cell counts, and serum urea nitrogen. Ponies that died were examined for gross lesions, and tissues were collected for histopathologic examination and analysis of AFB1 and AFM1 residues. Two of the 4 ponies given the 2 mg/kg dose and all ponies given the larger dosages died within 76 hours. Clinical signs included increased rectal temperature, faster heart and respiratory rates, abdominal straining, bloody feces, and tetanic convulsions. At necropsy, ponies that died of acute aflatoxicosis showed visceral petechiae and hepatic focal lesions. Histopathologic changes included severe hepatic necrosis, vacuolation, and bile duct hyperplasia. Aflatoxins B1 and M1 were recovered from liver, kidney, skeletal muscle, and gastrointestinal contents. One other pony given the 2 mg/kg dose died 32 days after dosing, and 1 control pony died after 70 days. Continuous elevations in prothrombin time and serum aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transpeptidase levels were observed in ponies dosed at 4 mg/kg or more. Significant (P less than 0.05) elevations in these values, which peaked 2 to 3 days after dosing, were seen in ponies given the 2 mg/kg dose. This group also had significant increases over controls in PCV and hemoglobin concentration 5 days after dosing.  相似文献   

5.
Serum levels of type III procollagen peptide (P-III-P) were measured by radioimmunoassay in clinically normal adult ponies (n = 15) and horses (n = 10). The mean serum levels of P-III-P from the ponies, 10.4 +/- 2.9 (SD) ng/mL, and the horses, 12.2 +/- 2.6 (SD) ng/mL, were not significantly different. Segments of jejunum were made ischemic to induce fibrous peritoneal adhesions in two ponies, and serum P-III-P levels were measured on days 4, 5, 7, 14, and 21. An exploratory celiotomy on day 21 revealed that the ischemic injury had induced fibrosis of the mesentery and bowel, but no adhesions had formed. The fibrotic mesentery contained type III collagen. The highest mean serum level of P-III-P, 23.0 +/- 3.5 (SD) ng/mL on day 7, was more than 4 SD above the mean from the normal ponies. There was a significant difference in the serum P-III-P levels in the ponies on days 0 (7.1 +/- 1.6 ng/mL) and 7 (23.0 +/- 3.5 ng/mL). Serum levels of P-III-P may be useful to study fibrosis associated with intestinal ischemia.  相似文献   

6.
Corticosteroid preparation was administered to 7 Shetland Ponies and 10 Quarter Horses. Serum iron concentration increased dramatically for 48 to 72 hours after the steroid treatment, whereas serum iron-binding capacity and serum ferritin concentration did not. An increase in available iron may allow bacteria to proliferate when ponies or horses are stressed or treated inappropriately with corticosteroids.  相似文献   

7.
The objective of this study is to determine whether doxycycline, ceftiofur or tetracycline could be effectively used to treat equine Lyme disease. Ponies experimentally infected with Borrelia burgdorferi by tick exposure were treated with doxycycline, ceftiofur or tetracycline for 4 weeks (28 days). Doxycyline and ceftiofur treatment were inconsistent in eliminating persistent infection in this experimental model. However, tetracycline treatment seems to eliminate persistent infection. Although serum antibody levels to B. burgdorferi in all ponies declined gradually after antibiotic treatment, three out of four ponies treated with doxycline and two out of four ponies treated with ceftiofur, serum KELA titers were raised again 3 month after treatment was discontinued. Five months after antibiotic treatment, tissues aseptically collected at necropsy from ponies with increased antibody levels after antibiotic treatment also showed culture positive to B. burgdorferi in various post-mortem tissues. However, all four-tetracycline treatment ponies showed a negative antibody level and culture negative from post-mortem tissues. Untreated infected ponies maintained high KELA titers throughout the study and were tissue culture positive.  相似文献   

8.
A main symptom of equine metabolic syndrome (EMS) in ponies is pathological obesity characterized by abnormal accumulation of fat deposits and inflammation. In this study, we analyzed the expression of two pro-inflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), in subcutaneous adipose tissue and the correlation with serum concentrations in peripheral blood of Welsh ponies. Based on clinical examination findings, the animals were divided into two groups: ponies affected with EMS (n = 8) and obese ponies (n = 8). The adipose tissue was examined using immunohistochemical analysis while concentrations IL-6 and TNF-α were measured using enzyme-linked immunosorbent assays (ELISAs). Additionally, histological characterization of the adipose tissue was performed. The results obtained showed that IL-6 expression in adipose tissue biopsies derived from animals with EMS was enhanced while TNF-α levels of both groups were comparable. Compared to the obese ponies, EMS animals also had significantly elevated levels of serum IL-6 and TNF-α. Histological analysis revealed macrophage infiltration and fibrosis in adipose tissue preparations from the EMS group. These data suggest that IL-6 may play a key role in the course of EMS in Welsh ponies. Our findings also demonstrated that analysis of pro-inflammatory cytokines levels in serum may serve as an additional tool for diagnosing EMS.  相似文献   

9.
Haematological variables and selected serum indices, particularly those affected by changes in renal and hepatic function, were examined in 6 healthy ponies following 4 intramuscular doses of 4 mg/kg imidocarb dipropionate administered every 72 hours. This treatment regime has been reported to sterilise experimental Babesia equi infections in horses and may have value in preventing the spread of this disease during exportation of possible carrier horses to non-endemic countries. Serum bile acids and serum gamma glutamyltransferase activity were measured to evaluate the effect of this treatment regime on hepatic function. Owing to the absence of any increase in these variables it was concluded that this treatment regime had no clinically detectable deleterious effect on hepatic function in healthy ponies. Urinary gamma glutamyltransferase : creatinine ratios (IU/g), serum creatinine and fractional clearance of sodium, potassium and phosphate (%) were calculated as a measure of renal function. Urinary GGT and urinary GGT : creatinine ratios were significantly elevated on Day 5 of the trial, with 2 of the trial animals also exhibiting mild azotaemia indicative of changes in renal function. The changes in urine GGT : urine creatinine ratios observed in this study also provides evidence of the value of this ratio for the early detection of renal toxicity, following exposure to nephrotoxic agents.  相似文献   

10.
The antibody response in serum and nasal secretions of groups of ponies vaccinated or infected with Myxovirus influenzae A-equi 2 was examined. Following infection by aerosol with live virus, a weak antibody response was recorded in both serum and secretions. Antibody levels were undetectable in secretions at 31 days after infection.

After primary intramuscular vaccination with killed virus, using sodium alginate as an adjuvant, antibody was detected only in the serum. However, following revaccination, a pronounced antibody response was demonstrated in both serum and secretions. Antibody was still detectable in all four ponies when tested 135 days later.

Only a serum antibody response was detected in ponies after primary intramuscular vaccination with a commercial vaccine. Upon revaccination nasal antibody occurred in all ponies but this only persisted for about 30 days.

Neither serum nor nasal antibody response occurred following intranasal vaccination and revaccination with a killed virus vaccine.

  相似文献   

11.
Dried tansy ragwort, which contains pyrrolizidine alkaloids, was fed as 10% of a complete diet to ponies, with and without a mixture of additives. The additives provided a dietary supplement equivalent to 1% cysteine, 0.75% butylated hydroxyanisole, 200 micrograms of vitamin B12/kg of feed, and 5 mg of folic acid/kg of feed. The additives did not alter tansy ragwort toxicity, as assessed by survival time, liver changes, sulfobromophthalein (BSP) clearance rate, serum gamma-glutamyl transpeptidase activity, and plasma amino acid patterns. In ponies fed tansy ragwort, BSP clearance rate was a sensitive indicator of liver damage, and decreased to about 20% of control values. gamma-Glutamyl transpeptidase activities showed considerable variability, but generally were elevated in animals fed tansy ragwort. Liver iron and copper concentrations increased, and liver zinc concentrations decreased in tansy ragwort-fed ponies. Plasma amino acid patterns in tansy ragwort-fed ponies showed changes typical of those observed in liver disease.  相似文献   

12.
Serum samples from 63 clinically normal captive black and white ruffed lemurs (Varecia variegata variegata) were analyzed to survey serum iron, total iron binding capacity, transferrin saturation, and serum ferritin levels. Data analysis showed no differences in these analytes attributable to sex, but significantly higher levels of serum iron, transferrin saturation, and serum ferritin in older animals. The survey data were examined in light of two black and white ruffed lemurs that were treated for iron overload with serial phlebotomies. Prior to therapy, both phlebotomized lemurs had excess hepatic iron deposition, but had serum iron, transferrin saturation, and serum ferritin below the upper limits observed in the survey animals, suggesting that some clinically normal animals included in the survey may have accumulated excess systemic iron. Serial phlebotomy therapy reduced serum iron, transferrin saturation, and serum ferritin in both animals. Three years after the conclusion of therapy in the one remaining case, serum iron and transferrin saturation have risen substantially, whereas serum ferritin has risen slightly. Serum iron, transferrin saturation, and serum ferritin may be useful predictors of systemic iron stores in this species, though the correlation between these parameters and systemic iron stores needs to be determined.  相似文献   

13.
Effects of induced cholestasis and hepatocellular necrosis and of fasting on serum biochemical constituents including bile acids, IgA, bilirubin, alkaline phosphatase, gamma-glutamyltransferase (GGT), arginase, and the clearance of sodium sulfobromophthalein were studied in 4 groups of equids. The reference value for serum bile acids, as determined by an enzymatic colorimetric procedure for horses and ponies was 5.94 +/- 2.72 mumol/L, there being no statistical difference for horses and ponies. Sample collection at time of feeding had no effect on serum bile acid concentration. Seemingly, serum bile acids, arginase, and GGT were the most sensitive indicators of cholestasis and/or hepatocellular necrosis and would form an essential minimum effective battery of tests to diagnose and prognose hepatic disease in equids. These tests provided a measure of hepatobiliary transport function (bile acids), cell necrosis (arginase), and cholestasis (GGT and bile acids).  相似文献   

14.
The concentrations of haptoglobin, immunoglobin (Ig)G(T) and IgG were measured in the serum of four previously parasite-free pony yearlings following a single dose of 700 (Group H) or 200 (Group L) stage three Strongylus vulgaris larvae (L3) and following a reinfection with the same doses 34 weeks later. The results are compared with an uninfected control pony. The haptoglobin concentration increased during Weeks 1 to 6 and 14 to 17 after infection in the serum of the ponies receiving 200 L3, but in only one pony dosed with 700 L3 (during Weeks 1 to 16). The serum haptoglobin also increased during the first seven weeks after the second infection, in three of the four ponies following the second dose of larvae. The serum IgG(T) concentration started to increase from Week 6 or 9 in the ponies given 700 L3, reaching peaks of 44 and 32 g/litre respectively, eight to nine weeks later, compared with a peak of 16 g/litre 20 to 22 weeks after infection in ponies dosed with 200 L3. The IgG(T) concentration increased to a maximum of 25 g/litre in the serum of only one of the four ponies after the reinfection. The serum IgG concentration in all ponies increased nearly twofold during the first eight weeks after both the primary and secondary dose of larvae. It is concluded that the measurement of specific proteins is more reliable and quicker than the electrophoretic separation and quantitation of protein bands, in tracing changes in serum proteins following the artificial infection of ponies with S vulgaris larvae.  相似文献   

15.
The effects of intra-articular injection of small amounts of E. coli lipopolysaccharide (LPS) into the intercarpal joint of 5 ponies were studied. The LPS induced predictable changes all of which were analogous to acute bacterial infection, except that the development of signs occurred sooner after the LPS injection, and subsided within 36 hours. Fever was monophasic and peaked at 5-7 hours. The ponies exhibited depression, reduced or absent appetite, increased pulse and respiration rates, and lameness. The lameness became evident between 1 and 2 hours after injection, at which time warmth, articular effusion, and resentment to palpation of joint flexion were evident. Hematological changes included neutrophilic leucocytosis, and changes in copper, iron and zinc serum concentrations. The synovial fluid total protein, leucocyte, and alkaline phosphatase levels increased within 2 hours. The mucin precipitation, total protein and leucocyte counts in synovial fluid remained elevated long after clinical and hematological changes had subsided. The model is useful for the study of some aspects of infectious joint disease.  相似文献   

16.
Iron plays a central role in bacterial infections, influencing both bacterial virulence and host cellular defense mechanisms. We investigated whether iron chelation might be of benefit in the treatment of pneumonic pasteurellosis of calves. Neutrophils obtained from calves previously treated with the iron chelator, deferoxamine, were studied for their responses to latex and opsonized zymosan by luminol-enhanced chemiluminescence and to phorbol myristate acetate and opsonized zymosan by superoxide generation. Treatment with deferoxamine in vivo failed to influence these in vitro measures of neutrophil oxidative metabolism. Furthermore, iron depletion with deferoxamine failed to modify the pathophysiological derangements that occurred in calves following experimental induction of pneumonia by intratracheal inoculation with Pasteurella haemolytica. These data indicate that iron chelation using deferoxamine cannot be recommended as an adjunct to conventional therapy in the treatment of pneumonic pasteurellosis of cattle.  相似文献   

17.
Alterations in serum lipid and lipoprotein concentrations in ponies with experimentally induced liver disease were investigated. Hepatocellular damage was induced, using a nonlethal dose of carbon tetrachloride. In a separate group of ponies, obstructive jaundice was induced by surgical ligation of the common bile duct. Over a 6-day period, blood samples were obtained from ponies after treatment with carbon tetrachloride and for 12 days in ponies subjected to surgery. Serum cholesterol and triglyceride concentrations were unaffected in both groups of ponies, except for significantly (P less than 0.01) high triglyceride concentration in ponies of the ligated group during the second postsurgical week. This increase was most likely attributable to anorexia observed during that period. Hyperbilirubinemia was observed early in ponies of the ligated group; most of the bilirubin was of the conjugated type. Using electrophoretic and ultracentrifugal methods, serum lipoprotein alterations were detected only in ponies of the ligated group. Increases of very low-density and low-density lipoprotein cholesterol concentrations and decrease in high-density lipoprotein cholesterol concentration were found. Although no changes were seen in total serum cholesterol concentration, a redistribution of lipoprotein cholesterol was observed in ponies of the ligated group. Similar alterations in lipoprotein distribution have been found in dogs, rats, and human beings with obstructive jaundice and cholestasis. The association between serum lecithin:cholesterol acyl transferase activities and these lipoprotein alterations remains to be elucidated.  相似文献   

18.
Twenty-two ponies were examined for serum-neutralizing (SN) antibody to equine herpesvirus type 1 and for in vitro lymphocyte transformation in the presence of viral antigen. Six ponies had undetectable levels of neutralizing antibody (titer less than 1:2) and had lymphocytes which did not respond in culture with viral antigen (stimulation index less than 2.0). Four ponies which had SN antibody to equine herpesvirus type 1 did not manifest lymphocyte transformation in vitro. The 12 remaining seropositive ponies had lymphocyte transformation with viral antigen in vitro (stimulation indexes from 2.0 to 23.5). Lymphocyte transformation was specifically suppressed when cells were grown in medium containing autologous serum. The temporal development of in vitro lymphocyte responsiveness and SN antibody in 3 specific-pathogenfree ponies after experimentally induced infection with equine herpesvirus type 1 is described.  相似文献   

19.
The changes in serum and urinary levels of calcium and phosphorus and serum parathyroid hormone (PTH) were studied during controlled, chemically induced, acute renal disease in 4 ponies. There was an initial rise in daily urinary calcium and hydroxyproline excretion in 2 ponies which may have indicated increased bone resorption. Mild hypercalcemia, hypophosphatemia and elevated C-terminal PTH levels were associated with oliguria. Total daily urinary excretion of calcium and phosphorus decreased as oliguria developed. The levels of C-terminal PTH were increased in all four animals. This appears to have been related to their diminished renal function in that C-terminal fragments of intact PTH (which require functioning kidneys in order to be cleared) were probably being accumulated. Although there was no evidence with regard to an actual increase in PTH secretion, prolongation of intact PTH half-life due to renal tubular damage may have contributed to the development of hypercalcemia.  相似文献   

20.
The levels of albumin, immunoglobulin G (including IgG [T]), IgA and IgM in the serum and aqueous humour of 47 horses and ponies with no ophthalmic abnormalities were determined by single radial immunodiffusion. There was a linear relationship between serum and aqueous albumin levels. No relationship of serum and aqueous IgG levels was observed. IgA was detected in only one aqueous sample. IgM was not detected in aqueous humour from any eye in this study. The factors which may influence albumin and immunoglobulin levels in normal aqueous humour are discussed.  相似文献   

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