Serum vitamin A concentrations in captive sea otters (Enhydra lutris)

Individual dietary preferences and difficulty with animal training create challenges and nutritional concerns when evaluating a captive sea otter (Enhydra lutris) diet. The importance of vitamin A within the body reflects the necessity that it be ingested in adequate amounts to ensure optimal health. To compare levels of serum vitamin A concentrations from captive sea otters on daily oral vitamin A supplementation, serum samples from eight adult sea otters from three institutions were evaluated for serum vitamin A concentrations. The eight animals were fed a total of four different diets and received oral supplementation via three different methods. Multiple diet items were analyzed for vitamin A content and were found to have low to nondetectable levels of vitamin A. Oral vitamin A supplementation, as a slurry with dietary items, was shown to be effective and a mean serum concentration of approximately 170 +/- 51 microg/L was obtained for serum vitamin A concentrations in captive sea otters. Captive diets can be modified to increase vitamin A concentration and supplementation and, if accepted, can be used as a means to ensure adequate vitamin A intake.     

Vitamin A deficiency and hepatic retinol levels in sea otters, Enhydra lutris

Vitamin A deficiency has rarely been reported in captive or free-ranging wildlife species. Necropsy findings in two captively housed southern sea otters (Enhydra lutris nereis) included irregular thickening of the calvaria characterized by diffuse hyperostoses on the internal surface. One animal also had moderate squamous metaplasia of the seromucinous glands of the nose. There was no measurable retinol in the liver of either sea otter. For comparison, hepatic retinol concentration was determined for 23 deceased free-ranging southern and northern (Enhydra lutris kenyoni) sea otters from California and Alaska. Free-ranging otters were found to have similar hepatic retinol concentrations (316 +/- 245 mg/kg wet weight) regardless of their location and subspecies. All of these values were significantly higher than the levels in the affected animals. Consumption of a diet with very low vitamin A concentrations and noncompliance in daily supplementation are hypothesized as the causes of vitamin A deficiency in these two sea otters.     

Validation of a cell culture bioassay for detection of petroleum exposure in mink (Mustela vison) as a model for detection in sea otters (Enhydra lutris)

OBJECTIVE: To validate a luciferase bioassay, which is based on a recombinant mouse hepatoma cell line, for the detection of exposure to petroleum in mustelid species. ANIMALS: 122 American mink (Mustela vison) and 15 sea otters (Enhydra lutris). PROCEDURES: Mink were exposed to Bunker C fuel oil or Alaska North Slope crude oil externally as a single exposure or internally via low dose concentrations in their ration for 6 months. Serum samples were analyzed for cytochrome P450 1A1 induction by quantification of luciferase activity in the bioassay. Mink liver specimens were also evaluated for cytochrome P450 1A1 induction by quantification of ethoxyresorufin-o-deethylase activity. Serum collected from exposed and unexposed sea otters was also analyzed using the luciferase bioassay. RESULTS: Serum samples from mink externally exposed to petroleum had significantly increased luciferase activities at 1 week after exposure. Serum samples taken at later time points or from mink exposed to either product in the ration did not cause significant luciferase induction. Samples from otters exposed to petroleum had significantly higher luciferase induction as compared with samples from otters not exposed to petroleum at 2 and 8 years after the spill. Cytochrome P450 1A1 activity in liver specimens collected from mink that were internally exposed through diet was significantly increased at the conclusion of our study. CONCLUSION AND CLINICAL RELEVANCE: The luciferase bioassay is a sensitive and specific method for determining recent exposure to petroleum in mink. The lack of luciferase activity in serum samples collected from mink greater than 1 week after experimental exposure was likely attributable to lower overall petroleum exposure in our trial, compared with natural exposures.     

Comparison of the distribution of glial fibrillary acidic protein, heat shock protein 60, and hypoxia-inducible factor-1alpha in retinas from glaucomatous and normal canine eyes

OBJECTIVE: To determine the effect of acute (clinical history of glaucoma for 相似文献   

Evaluation of cardiac lesions and risk factors associated with myocarditis and dilated cardiomyopathy in southern sea otters (Enhydra lutris nereis)

OBJECTIVE: To describe cardiac lesions and identify risk factors associated with myocarditis and dilated cardiomyopathy (DCM) in beach-cast southern sea otters. ANIMALS: Free-ranging southern sea otters. PROCEDURE: Sea otters were necropsied at the Marine Wildlife Veterinary Care and Research Center from 1998 through 2001. Microscopic and gross necropsy findings were used to classify sea otters as myocarditis or DCM case otters or control otters. Univariate, multivariate, and spatial analytical techniques were used to evaluate associations among myocarditis; DCM; common sea otter pathogens; and potential infectious, toxic, and nutritional causes. RESULTS: Clusters of sea otters with myocarditis and DCM were identified in the southern aspect of the sea otter range from May to November 2000. Risk factors for myocarditis included age, good body condition, and exposure to domoic acid and Sarcocystis neurona. Myocarditis associated with domoic acid occurred predominantly in the southern part of the range, whereas myocarditis associated with S. neurona occurred in the northern part of the range. Age and suspected previous exposure to domoic acid were identified as major risk factors for DCM. A sample of otters with DCM had significantly lower concentrations of myocardial L-carnitine than control and myocarditis case otters. CONCLUSIONS AND CLINICAL RELEVANCE: Cardiac disease is an important cause of death in southern sea otters. Domoic acid toxicosis and infection with S. neurona are likely to be 2 important causes of myocarditis in sea otters. Domoic acid-induced myocarditis appears to progress to DCM, and depletion of myocardial L-carnitine may play a key role in this pathogenesis.     

Glucosuria associated with renal calculi in Asian small-clawed otters

Urine from one female and 2 male Asian small-clawed otters (Aonyx cinerea) with bilateral renal calculi, one female with unilateral calculi, and one nonaffected male were evaluated for abnormal urinary crystalloid excretion. One otter with bilateral renal calculi had cystic calculi composed of calcium oxalate monohydrate and dihydrate. The 2 affected males were littermates, as were the 2 affected females, but the 2 litters were from different parents. At the time of the study, the otters did not have clinical signs of disease. Hematologic and serum biochemical, electrolyte, and enzyme values were normal. The urinary excretion of calcium, oxalate, uric acid, phosphate, citrate, and amino acids in otters with renal calculi was similar to that of the nonaffected otter. The 4 otters with renal calculi had glucosuria but the nonaffected otter did not have glucosuria. The glucosuria, in the absence of hyperglycemia, suggested a renal tubular transport defect for glucose. Other renal abnormalities were not found.     

Blindness and convulsions associated with vitamin A deficiency in feedlot steers

Blindness and convulsions were the predominant clinical signs in a group of feedlot steers inadvertently fed a vitamin-A deficient diet. Although vitamin A had been added to the feed at the time of preparation, it was believed that the vitamin A had been destroyed by heat, humidity, and minerals mixed in the feed. Feedlot heifers fed the same high-grain diet were clinically normal, and one heifer from which a blood sample was obtained had normal serum vitamin A content. The ingestion of sparse grasses and weeds found along the fence row of the heifers' pens was thought to have provided sufficient vitamin A to these animals. This episode demonstrated the importance of monitoring vitamin A and vitamin A precursor concentrations in stored feeds, especially those stored under adverse conditions and those fed to animals ingesting only a high-grain diet.     

The vitamin A and vitamin E status of horses raised in Alberta and Saskatchewan.

The purpose of the study was to determine normal baseline levels of vitamin A and vitamin E in clinically normal horses under typical field conditions in Saskatchewan and Alberta. Heparinized blood samples were collected from approximately 400 clinically healthy horses selected from 24 locations in Alberta and Saskatchewan during a two-year period. For each horse, historical information including feed type, vitamin supplementation, time of year, sex, and age were recorded. From each blood sample, the plasma vitamin A (all-transretinol) and vitamin E (alpha-tocopherol) levels were measured using high pressure liquid chromatography. Normal baseline plasma vitamin A and vitamin E concentrations recorded during the study were 0.70 mumol/L and 7.65 mumol/L, respectively. The plasma vitamin concentrations were lower in the younger horses. The plasma vitamin levels were higher from May to August, as compared to other times of the year. Horses grazing fresh pasture exclusively during the summer months had plasma vitamin A and vitamin E concentrations that were 27% and 63% greater than horses fed harvested or stored feeds during the same time period. Sex-related differences were not evident in the study. A number of factors may influence the baseline plasma vitamin A and vitamin E levels in horses. Consequently, it is unadvisable to use a single evaluation to assess vitamin status. Multiple sampling from individual horses or sampling from many horses within a herd may reduce the variability and improve the ability to monitor vitamin status from plasma submissions.     

Procollagen type-III aminoterminal peptide in serum and synovial fluid of dogs with hip dysplasia and coxarthrosis

Hip dysplasia is an affection of the coxofemoral joint that progresses until stabilization is caused by fibrosis and osteoarthritic changes. This stabilization process can be examined by clinical and radiographic methods. The capability of evaluating the procollagen concentrations in liquids, such as serum and synovial fluid, has further offered the basis for an objective biochemical evaluation of the stabilization process. Our study was performed to evaluate whether determination of procollagen concentrations was suitable for the use in practice. The procollagen type-III aminoterminal peptide (P-III-NP) concentration was measured in serum and in synovial fluid from coxofemoral joints in 20 dogs. Dogs were grouped on the basis of evidence of dysplasia and osteoarthritic changes of the hip: (1) a control group of 6 dogs without clinical or radiographic signs of hip dysplasia, and (2) dysplastic group of 14 dogs, which was further grouped with respect to the coxofemoral joint laxity, as determined by the Ortolani test. Synovial fluid concentration of P-III-NP was significantly (P less than 0.05) higher in fluid from dysplastic joints than in fluid from normal joints. Serum concentrations of P-III-NP were significantly (P less than 0.05) higher in dogs in which results of the Ortolani test were positive.     

Myelodysplastic syndrome in two dogs

Two cases of myelodysplastic syndrome in the dog are described. Both cases were characterized by hepatomegaly, cytopenias, macrocytosis, cellular bone marrow, and dysplastic changes in all hematopoietic cell lines. Serum vitamin B12 and folic acid concentrations were within reference ranges in one dog, but vitamin B12 was slightly decreased in the other. Vitamin B12 therapy did not result in amelioration of the hematologic disorder. The duration of illness was approximately 5 months. Necropsy of one dog revealed an acute undifferentiated leukemia.     

Incidence of canine glaucoma with goniodysplasia in Japan : a retrospective study

The incidence of primary and secondary glaucoma in dogs was investigated. A total of 1244 dogs received ophthalmologic examinations, including tonometry and gonioscopy. Goniophotographs were taken using a goniolens to evaluate the iridocorneal angle (ICA) as well as pectinate ligament (PL). The anterior width of the ciliary cleft and the total distance from the origin of the PL to the anterior corneal surface were measured from the goniophotographs. Glaucoma was diagnosed based on the cupping of the optic nerve head, clinical signs, ocular changes, and high IOP, and it was synchronized with gonioscopic grades to differentiate between primary and secondary glaucoma. We investigated 1244 dogs of 29 breeds, including the mixed breed; among these, glaucoma was diagnosed in 127 dogs (162 eyes). Of 162 eyes, primary glaucoma was diagnosed in 129 eyes and secondary glaucoma in 33 eyes. Shiba Inu dogs (42 dogs, 33%) showed the highest incidence of glaucoma, followed by Shih-Tzu (21 dogs, 16.5%). Furthermore, all the glaucomatous Shiba Inu dogs had primary glaucoma with abnormal ICA grades and dysplastic PLs. The findings of our study reveal that the Shiba Inu breed in Japan may have a hereditary predisposition to glaucoma.     

Assessment of glutamate loss from the ganglion cell layer of young DBA/2J mice with glaucoma

OBJECTIVE: To determine whether glutamate contents are decreased in the ganglion cell layer (GCL) of retinas of DBA/2J mice with glaucoma, compared with unaffected control mice. SAMPLE POPULATION: 20 eyes from DBA/2J mice (9-week-old mice [n = 8] and 4- [4], 6- [4], and 12-month-old [4] mice) and 17 eyes from control CD-1 (7) and C57/BL6 (10) mice of similar age. PROCEDURE: After euthanasia, the eyes were rapidly dissected and fixed. Serial 0.5-microm sections were prepared from eyecups and stained with toluidine blue (to identify damaged cells) or immunogold (to localize glutamate). Microscopic images were captured digitally for comparison; immunostaining densities were assessed via special software. RESULTS: In the GCL of control mice, few cells appeared damaged; large amounts of glutamate were detected in 83 +/- 8.3% of cells. In DBA/2J mice > or = 9 weeks of age, damaged neurons were observed in retinal sections; the level of glutamate immunoreactivity was high in a few cells near areas of damage (13 +/- 3.2%) and in many cells in less-damaged regions of the same sections (82 +/- 4.2%). Many neurons with low amounts of glutamate in damaged regions did not appear damaged histologically. CONCLUSIONS AND CLINICAL RELEVANCE: In retinas of young DBA/2J mice, damaged and undamaged GCL cells had decreased levels of immunostaining for glutamate, compared with less-damaged adjacent regions or retinas from control mice. The loss of neuronal glutamate in damaged retinal regions suggests that glutamate is contributing to early retinal damage prior to changes in intraocular pressure.     

Hyperostotic bone disease in red pandas (Ailurus fulgens).

Three adult red pandas (Ailurus fulgens) developed multiple periarticular exostoses in their elbow joints. Two of these animals also had extensive periosteal new bone formation and osteosclerosis of the ulnae and radii and mild periosteal new bone deposition on the femurs. One animal also showed extensive hyperostosis of the cranium and mandibles. Dietary concentrations of calcium and phosphorus were estimated to be adequate, but dietary vitamin A and D appeared excessive when compared with recommended levels for this species. Serum vitamin A concentrations were not elevated in the two most severely affected animals, but their liver vitamin A content was higher than what is considered normal for most domestic animal species. Serum 25-hydroxy vitamin D concentrations were within normal ranges for domestic species. A definitive diagnosis for the cause of the lesions was not established, but hypervitaminosis A was suspected.     

Evaluation of the risk of motor neuron disease in horses fed a diet low in vitamin E and high in copper and iron

OBJECTIVE: To determine whether equine motor neuron disease (EMND) could be induced in adult horses fed a diet low in vitamin E and high in copper and iron. ANIMALS: 59 healthy adult horses. PROCEDURE: Horses in the experimental group (n = 8) were confined to a dirt lot and fed a concentrate low in vitamin E and high in iron and copper in addition to free-choice grass hay that had been stored for 1 year. Control horses (n = 51) were fed a concentrate containing National Research Council-recommended amounts of copper, iron, and vitamin E. The hay fed to control horses was the same as that fed to experimental horses, but it had not been subjected to prolonged storage. Control horses had seasonal access to pasture, whereas experimental horses had no access to pasture. Horses that developed clinical signs of EMND were euthanatized along with an age-matched control horse to determine differences in hepatic concentrations of vitamin E, vitamin A, copper, iron, and selenium. RESULTS: 4 experimental horses developed clinical signs of EMND. Plasma concentrations of vitamin E decreased in all 8 experimental horses. There were no significant changes in plasma concentrations of vitamin A, selenium, and copper or serum concentrations of ferritin. There were no significant differences in those analytes between experimental horses with EMND and experimental horses that did not develop EMND. No control horses developed EMND. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that lack of access to pasture, dietary deficiency of vitamin E, or excessive dietary copper are likely risk factors for EMND.     

The effectiveness of oral and parenteral vitamin A doses in growing cattle with different vitamin A supplies]

The effect of one single oral or parenterally administered dose of 1 million IU vitamin A on the vitamin A depot in the liver and on blood plasma vitamin A concentrations was investigated in 3 individual feeding experiments with involvement of 18 and 24 calves or 24 fattening bulls. 50% of all animals in each of the 3 experiments received feed without any vitamin A through 108 or 112 or 209 days, prior to vitamin A administration, or received 10.000 IU/100 kg live weight and day. Parenteral vitamin A administration in either group yielded rise in blood plasma from 0.06--0.35 to 26.2--30.2 mumol/l, after 1 or 2 days. The maximum value measured after oral administration was 1.9 mumol/l. Most of the plasma values had returned to normal (0.6--12. mumol/l) within 14 days from administration. Oral and parenteral vitamin A doses, after 14 days, caused significant rise in vitamin A concentrations in the liver (from 15.5 to 82.5), with the increase resulting from parenteral administration (from 13.7 to 99.1) being clearly higher than that resulting from oral administration (from 17.3 to 65.9 mumol/kg fresh liver tissue). The same trends were recorded from recovery of vitamin A from the liver (26.8% after parenteral administration versus 15.0% in the wake of oral doses). Storage in and recovery from vitamin-A depleted animals were below values recorded from young cattle with sufficient vitamin A supply. These findings are likely to confirm that one single parenteral vitamin A administration was of clearly higher effectiveness, as compared to oral application.     

Evaluation of injury severity and hematologic and plasma biochemistry values for recently captured North American river otters (Lontra canadensis).

As part of a reintroduction program, blood samples from free-ranging, recently captured Nearctic river otters (Lontra canadensis) in eastern New York state were collected and analyzed to determine baseline hematology and plasma biochemistry values for the source population, and to determine whether these values were significant predictors of trap-injury status. Based on physical exam, each otter was classified as uninjured, moderately injured, or severely injured. Clinical pathology parameters were compared across sex, age class, and injury classification. The increase in likelihood of a change in each parameter in injured versus uninjured otters was determined using logistic regression. Baseline hematology and plasma biochemistry values did not differ significantly from published values for captive otters in zoos or other reintroduction programs. Plasma aspartate aminotransferase levels increased as time from capture to venipuncture decreased. Some otters in this study showed clinical signs consistent with exertional myopathy, possibly altering our calculation of baseline values. Our results suggest that the hematology and plasma biochemistry values obtained in this recently captured population of otters are generally not good predictors of capture-related injury. This could be due to disease processes that are not readily visible upon physical examination or because changes in these values may be associated with factors independent of capture-related injury.     

Evaluation of matrix metalloproteinase concentrations in precorneal tear film from dogs with Pseudomonas aeruginosa-associated keratitis

OBJECTIVE: To evaluate the changes in concentrations of matrix metalloproteinase (MMP)-2 and MMP-9 in the precorneal tear film of dogs with Pseudomonas aeruginosa-associated keratitis during corneal healing and stromal remodeling. ANIMALS: 10 dogs with unilateral P aeruginosa-associated keratitis and 10 clinically normal dogs. PROCEDURES: Precorneal tear film samples were collected from both eyes of 10 dogs with unilateral P aeruginosa-associated keratitis on the day of admission to the hospital and then at various time points until complete healing of the cornea was achieved. Precorneal tear film samples were also collected from both eyes of 10 clinically normal adult dogs (control group). Concentrations of MMP-2 and MMP-9 in precorneal tear film samples from each group were determined via gelatin zymography for comparison. RESULTS: The proteolytic processes in the ulcerated eyes decreased as corneal healing progressed. On the day of admission, concentrations of latent and active forms of MMP-2 and MMP-9 in ulcerated eyes were significantly higher than values in the contralateral unaffected eyes in dogs with P aeruginosa-associated keratitis; concentrations of latent MMP-2 and MMP-9 were also greater than control group values. Concentrations of latent and active forms of MMP-2 and MMP-9 in the healed eyes of dogs with P aeruginosa-associated keratitis were significantly lower than concentrations in the ulcerated eyes on the day of admission. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that reduction of precorneal tear film concentrations of MMPs by use of proteinase inhibitors may be effective in the treatment of dogs with P aeruginosa-associated keratitis.     

Immunohistochemical study of retinol-binding protein in livers of polar bears (Thalarctos maritimus)

Liver tumors of unknown cause have frequently been described in polar bears. Concurrent decrease of vitamin A levels and chronic liver disease are associated with hepatic carcinogenesis in humans. More than 90% of the body's vitamin A is stored in the liver, where it is bound to an intracellular retinol-binding protein (RBP). Therefore, in this retrospective study, RBP was assessed by immunohistochemistry in liver sections of 11 polar bears. Two of these polar bears had hepatocellular carcinoma, four showed other chronic liver changes, and five had normal livers. In normal livers, the cytoplasm stained diffusely positive with intensely staining cytoplasmic granules. RBP staining was evaluated and the abundance of diffuse cytoplasmic staining and intracytoplasmic large granules was determined. All cases with pathologic liver changes had markedly decreased staining intensities for RBP compared with normal livers. The findings of this study suggest that in polar bears, as in humans, vitamin A metabolism may play a role in hepatic carcinogenesis.     

The effect of stress on blood levels of vitamin A and E in piglets

In five trials with 99 suckling or weaned piglets, the effects of the increased adrenocortical function, caused by cold, weaning from the sow or fasting or by stimulation with exogenous adrenocorticotrophic hormone (ACTH) were studied as exerted on vitamin A and vitamin E concentrations in the blood serum. Three hours after an exposure of three-day and four-day piglets to the temperature of 8-12 degrees C, a small drop of the concentrations of both vitamins occurred. In four-week weanling piglets a decrease in vitamin E concentration was observed in two days, the trend being slight in vitamin A concentration. At the same time some sibs were left fasting, which considerably reduced the concentrations of both vitamins. The situation was similar in two hours after ACTH administration to suckling piglets, however the difference was insignificant in vitamin E concentrations. In seventeen hours elapsing from two administrations of the adrenocorticotrophic hormone (ACTH) when the increased secretion of corticosteroids was fading out, only the vitamin A concentration in suckling piglets was found to drop. The response in weanling piglets was negligible. The suppressive effects of stress on vitamin A concentrations were usually observed when the levels of circulating corticosteroids were high or in the period immediately following this status. The changes in nutrition after early weaning exert large negative effects on vitamin E concentrations in the blood serum. The differences in the response of the organism to the two vitamins may be due to various types of transport mechanisms in the blood circulation. The specific effects of stress factors are mentioned.     

Pathological changes and organochlorine residues in tissues of wild otters (Lutra lutra)

In 1984 two adult, wild otters (Lutra lutra) from north Norfolk were subjected to full post mortem examinations. One was found dead and the other sick. Both were thin. No evidence of infectious disease was found, but there were organochlorine concentrations of 433 and 75 mg/kg of fat (69 per cent polychlorinated biphenyls in both) in skeletal muscle. Leiomyoma of the reproductive tract and adrenocortical hyperplasia in one otter were similar to age associated changes in other mammals. Integumentary, including pedal, lesions were present in both otters. The possibility that the pedal lesions were caused by the toxic effects of polychlorinated biphenyls is discussed.