Hiatal hernia controversies - a review of pathophysiology and treatment options     

RK SIVACOLUNDHU  RA READ  AM MARCHEVSKY 《Australian veterinary journal》2002,80(1):48-53

Objective To provide a detailed discussion of the aetiology and pathophysiology of hiatal hernia in both humans and small animals, and review current medical and surgical treatments.
Design Review article.
Summary Hiatal hernia is not completely understood in humans or animals. It has a complex multifactorial aetiology and pathophysiology. A primary disturbance of the lower oesophageal sphincter has not been shown in humans or animals. Knowledge of pathophysiology is necessary to institute appropriate treatment.
Medical and/or surgical therapy is not indicated in asymptomatic cases. Medical treatment should be used for up to 1 month in stable cases of sliding hiatal hernia. Paraoesophageal hiatal hernias and any large sliding hiatal hernia should be considered for prompt surgical treatment. Surgical techniques used depend on the type of hiatal hernia present.
Surgical treatment of hiatal hernia cases should be performed by experienced surgeons, and must include hiatal closure and gastropexy. The Nissen fundoplication procedure has been discontinued in the veterinary field due to poor success rates, coupled with the published view that there is a marked difference in pathophysiology between humans and dogs. Reported complications associated with the original Nissen fundoplication technique are identical in the human and veterinary literature. There have been no complications reported with use of the modified or 'floppy' Nissen fundoplica-tion in dogs. Both oesophagopexy and Nissen fundoplication require further evaluation in small animals.  相似文献   

Molecular identification of Phialophora oxyspora as the cause of mycetoma in a horse     

Lopez MJ  Robinson SO  Cooley AJ  Prichard MA  McGinnis MR 《Journal of the American Veterinary Medical Association》2007,230(1):84-88

CASE DESCRIPTION: An 18-year-old mare was evaluated for an oral mass that developed after extraction of a broken incisor. CLINICAL FINDINGS: An ulcerated, firm, darkly pigmented, approximately 5-cm-diameter spherical mass involved the gingiva lateral and dorsal to the right first to third maxillary incisors. Osteolysis of the roots of the first and second right maxillary incisors and periosteal proliferation of the adjacent premaxilla margins were apparent on radiographs. Histologic examination of the mass revealed multiple coalescing and ramifying foci of abscess formation, each containing a well-defined, discrete, black mass (2 to 7 mm in diameter). Myriad fungal hyphae enmeshed in a black, granular, cementlike material were within each of the black structures. Mycetoma was the histologic diagnosis. The causative agent could not be identified via culture because of lack of distinguishing characteristics. Fungal DNA was isolated from frozen fungal cultures and paraffin sections. The D1/D2 domains of the large subunit P gene rDNA were amplified and sequenced. The sequences of the D1/D2 domains of both isolates were 96% homologous with those of Phialophora oxyspora. TREATMENT AND OUTCOME: The mass was surgically excised, the local area curetted, and the wound allowed to heal by second intention. Postoperative treatment consisted of administration of phenylbutazone and IV administration of sodium iodide followed by oral administration of potassium iodide. There was no evidence of recurrence 1 year later. CLINICAL RELEVANCE: Mycetomata should be a differential diagnosis for equine gingival masses. Identification of the fungal agent can be critical for selection of optimal treatments. Molecular methods may permit definitive identification when standard phenotypic-based identification criteria are inconclusive.  相似文献   

Carpal and fetlock conformation of the juvenile Thoroughbred from birth to yearling auction age     

Santschi EM  Leibsle SR  Morehead JP  Prichard MA  Clayton MK  Keuler NS 《Equine veterinary journal》2006,38(7):604-609

REASONS FOR PERFORMING STUDY: There is little information available about conformational changes in the forelimbs of growing foals. OBJECTIVES: To describe the conformation of the carpus and fetlock of Thoroughbred foals from birth to yearling sale age. METHODS: Subjective assessments of the fetlock and carpal conformation of 119 Thoroughbred foals were made within the first month of life and then at 30 day intervals until at least age 120 days. At least 70 subjects were examined further at 60 day intervals until September of their second year. Conformation grades are reported for 5 age groups: first 7 days and at a mean of 46, 176, 362 and 525 days. The conformation of all available sires and dams of subjects was also graded. RESULTS: All subjects demonstrated carpal deviations, such as valgus, outward rotation and offset, and approximately 30% had fetlock deviations. Heavier birth weights were associated with carpal offset and fetlock inward conformation at most ages, and heavier yearlings were more likely to be carpal valgus. The carpal conformation of the sire (offset and outward rotation) was associated with similar yearling carpal conformation. During the study period, the carpal conformation of Thoroughbred foals became less valgus and more offset. Fetlock conformation became more inwardly deviated during the first 6 months of the study. CONCLUSIONS: Carpal and fetlock conformation change greatly in Thoroughbred foals up to age 18 months. The phenotype of the sire can be associated with yearling carpal conformation and bodyweight, particularly at birth and as yearlings, is associated with yearling fetlock and carpal conformation. POTENTIAL RELEVANCE: New factors associated with forelimb conformational deviations have been identified that may help breeders better to manage young racing stock.  相似文献   

Prolonged administration: A new concept for increasing the spectrum and effectiveness of anthelmintics     

R.K. Prichard  D.R. Hennessy  J.W. Steel 《Veterinary parasitology》1978,4(4):309-315

Cambendazole (CBZ), fenbendazole (FBZ), oxfendazole (OFZ) and thiabendazole (TBZ) all inhibited the fumarate stimulated oxidation of NADH in Haemonchus contortus mitochondria. These observations plus the phenomenon of cross resistance to benzimidazoles suggested that the different benzimidazole anthelmintics affect parasitic helminths in a similar manner.The variation in efficiency and spectrum of activity may therefore be due to differences in their pharmacokinetic behaviour. To test this hypothesis, the magnitude and duration of concentrations of TBZ, FBZ and OFZ in plasma and other body compartments after administration were compared with their effectiveness against parasites. The effects of similar doses against benzimidazole-resistant. Trichostrongylus colubriformis and H. contortus were found to correlate with the period high plasma concentrations were maintained.Further evidence of this relationship was obtained by infusion or multiple drenching of TBZ to cattle harbouring arrested Ostertagia ostertagi larvae, so as to maintain high circulating concentrations for an extended period. This resulted in the removal of 90% of the arrested larvae, whereas TBZ as normally administered is considered quite ineffective against these larvae.These observations suggest that the spectrum and effectiveness of benzimidazoles may be improved by extending the period during which parasites are exposed to toxic concentrations.  相似文献   

Xanthine oxidase formation during experimental ischemia of the equine small intestine.   总被引：4，自引：1，他引：3       下载免费PDF全文

M Prichard  N G Ducharme  P A Wilkins  H N Erb    M Butt 《Canadian journal of veterinary research》1991,55(4):310-314

We hypothesized that xanthine oxidase plays a role in the postischemic reperfusion injury in the equine small intestine. Under anesthesia, four horses and two ponies underwent ischemic strangulating obstructions of segments of the proximal jejunum, mid-jejunum and ileum. Prior to vascular occlusion, and at 1 h and 2 h of ischemia, full-thickness intestinal biopsies were collected for histopathological evaluation and for determination of combined xanthine dehydrogenase (XDH) plus xanthine oxidase (XO) activity, and XO activity alone. The level of XO activity was expressed in percentage according to the ratio of XO/(XDH + XO). We found a nearly threefold increase in the combined level of XDH plus XO activity from ileum to duodenum (p less than 0.04). However, the preischemic level of % XO activity did not vary significantly (p = 0.61) between segments of jejuno-ileum. Likewise, no significant difference was noted between intestinal segments after ischemia. Therefore, the data from all intestinal segments were pooled for each time and analyzed using Wilcoxon's signed rank test (one-tailed). Compared to the pre-ischemic level of % XO activity (median 27%), the % XO activity increased after 1 h of ischemia (median 37.0%), reaching statistical significance (p = 0.016). There were no statistical differences between the preischemic % XO activity and the % XO activity in non-ischemic bowel at the end of the anesthetic period. During ischemia, % XO activity increased, which lends credence to the importance of xanthine oxidase in previously-documented reperfusion injury in the equine small intestine.  相似文献   

Pharmacokinetics of ivermectin in sheep following intravenous, intra-abomasal or intraruminal administration   总被引：1，自引：1，他引：0  

R K Prichard  J W Steel  E Lacey  D R Hennessy 《Journal of veterinary pharmacology and therapeutics》1985,8(1):88-94

The pharmacokinetics of ivermectin in plasma following intravenous, intra-abomasal, and intraruminal administration to sheep was determined. When given intravenously, ivermectin was very slowly eliminated with a terminal half-life of 178 h and a volume of distribution at steady state of 5.3 l/kg indicating sequestration in a temporary depot. Intra-abomasal administration resulted in rapid absorption, a peak plasma concentration of 60.6 ng/ml at 4.4 h, and 100% bioavailability. However, intraruminal administration produced a much lower peak concentration (17.6 ng/ml at 23.5 h) and bioavailability (25.1%). A subsequent in vitro study indicated that ivermectin may be rapidly metabolized in the rumen.  相似文献   

Endocrine responses of sheep to infection with Trichostrongylus colubriformis     

R K Prichard  D R Hennessy  D A Griffiths 《Research in veterinary science》1974,17(2):182-187

  相似文献   

The role of absorbed drug in the efficacy of oxfendazole against gastrointestinal nematodes     

D. R. Hennessy  R. K. Prichard 《Veterinary research communications》1981,5(1):45-49

Comparisons were made of the relative efficacy of ozfendazole (OFZ), administered to sheep at 5 mg/kg either as an oral drench, single intravenous injection or 12 and 24 divided intravenous injections over 24 and 48 hours, against benzimidazole-resistanthaemonchus contortus andTrichostrongylus colubriformis. A single intravenous injection was at least equally potent as the oral drench whilst the divided dose intravenous regimes significantly increased OFZ efficacy against both parasite species.These findings demonstrate that (i) absorbed drug is important for the efficacy of OFZ against nematodes in the abomasum and small intestine and may be more important than unabsorbed drug passing down the gastrointestinal tract, and (ii) the maintenance of plasma OFZ levels of approximately 2 g/ml by divided dose regime increased efficacy compared with that achieved with the same total dose given as a single administration.  相似文献   

A dog with back pain     

RK CHURCHER 《Australian veterinary journal》1996,74(1):17-18

  相似文献   

Is anthelmintic resistance a concern for heartworm control? What can we learn from the human filariasis control programs?     

Prichard RK 《Veterinary parasitology》2005,133(2-3):243-253

Heartworm prophylaxis is currently largely dependent on the ability of avermectins and milbemycins to arrest the development of third and fourth stages of Dirofilaria immitis for prolonged periods, without producing adulticidal effects. Major control programs, dependent on the activity of ivermectin, are being implemented for human onchocerciasis and lymphatic filariasis. The avermectins and milbemycins act on glutamate-gated and gamma-aminobutyrate-gated chloride channel subunit proteins in nematodes. Ivermectin resistance has been widely described in trichostrongylid nematodes of ruminants. There is evidence that when ivermectin resistance occurs in nematodes, there may be selection on some, but not all of the genes that code for ligand-gated chloride channel subunit proteins as well as on some ABC-transporter genes, whose products may be involved in regulating macrocyclic lactone drug concentrations at receptors, and on some structural protein genes of amphidial neurones. Although ivermectin resistance has not been reported in filarial nematodes, there have recently been reports of suboptimal responses to ivermectin in Onchocerca volvulus. Evidence has been found of ivermectin selection on at least ABC-transporter genes and some neuronal structural protein genes in O. volvulus. To date, there is no evidence of avermectin/milbemycin resistance in D. immitis, also a filarial nematode. Chemotherapy against trichostrongylids of animals, human filariae, and D. immitis, relies on avermectins or milbemycins. However, control involves targeting different stages or processes in the nematode life cycles, different control strategies, different proportions of the nematode population in refugia, and different drug dosage rates. Consideration of the proportion of the D. immitis population normally in refugia, the life cycle stage targeted, and the anthelmintic dosages used suggest that it is unlikely that significant avermectin/milbemycin resistance will be selected in D. immitis with current treatment strategies.  相似文献