Extensive large colon resection in the pony. I. Surgical procedures and clinical results

The effect of resection of 75% (length measurement) of the large colon in ponies was studied. Ten ponies in good physical condition were divided into two groups: group I consisted of the six experimental ponies and group II of four control ponies. Preoperatively and postoperatively for five months, ten clinicopathological parameters were determined: body weight, venous blood pH, plasma bicarbonate, total plasma protein concentration, serum electrolyte values (sodium, potassium, chloride), and fecal osmolarity. Subjective assessment of attitude and appetite revealed no difference between the groups or within groups at any time. Resection of a major portion of the large colon did not significantly influence the clinicopathological parameters evaluated. The hematocrit of the ponies in group I did decrease during the first postoperative month and this was attributed to whole blood loss associated with the resection procedures. The results of this investigation indicated that resection of 75% of the large colon in ponies is compatible with life.     

Renal pathology in working dogs in the South African National Defence Force

Urine analysis, serum biochemical profile and a cortical wedge biopsy for histopathological examination was performed on 42 South African National Defence Force (SANDF) dogs from around the country. The only significant finding on urine analysis and serum biochemistry was a relatively large number (16/42) of dogs with elevated serum inorganic phosphate levels. Histopathology revealed that only 9 of the animals had normal kidneys reflected in the wedge biopsy material, with over 50% of them showing signs of glomerular pathology (primarily mesangioproliferative glomerulonephritis). Other conditions detected histopathologically were haemosiderosis (47% of animals), focal nephrosis (2.4%), membranoproliferative glomerulonephritis (2.4%), focal interstitial nephritis (4.7%) and acute tubular nephrosis (4.7%). The lesions observed were of limited distribution and extent; this histopathological finding may account for the absence of significant abnormalities on urine analysis or serum biochemistry profiles. It appears from these results that a large percentage of the SANDF population would be expected to have mild renal lesions, but that these lesions are not severe enough to lead to clinical signs. The findings of this study are similar to those of randomly selected populations of non-military dogs performed in other areas of the world, which also demonstrated an unexpectedly high incidence of histopathological renal pathology in dogs considered healthy. These lesions may well, however, play a role in later life, and it is recommended that military veterinarians maintain an index of suspicion for renal disease, particularly glomerular disease. The aetiology of the histopathological lesions is unknown.     

Clinical and clinicopathological changes in 6 healthy ponies following intramuscular administration of multiple doses of imidocarb dipropionate

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.     

Alterations in calcium, phosphorus and C-terminal parathyroid hormone levels in equine acute renal disease

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.     

Effect of acute acidemia on blood biochemical variables in healthy ponies

L-Lactic acid and D,L-lactic acid infusion in ponies resulted in metabolic acidosis with high anion gap (AG). Increased AG was explained entirely by increased blood L- and D-lactate concentrations. Hydrochloric acid infusion caused metabolic acidosis with decreased AG. Saline (NaCl) infusion caused mild metabolic acidosis, with no significant change in AG. Plasma K+ concentration was decreased by all types of infusions, with a maximum of 0.50, 0.25, 0.40, 0.50 mmol/L below baseline at the end of infusion in the L-lactic acid-, D,L-lactic acid-, HCl-, and NaCl-infused ponies, respectively. Only hydrochloric acid had a tendency to increase plasma K+ concentration. Hypophosphatemia developed in NaCl- and HCl-infused ponies, but not in the D,L-lactic acid-infused ponies. Serum inorganic phosphate concentration in L-lactic acid-infused ponies increased initially, but was significantly (P less than 0.05) lower than values in the other ponies at 4 hours after onset of infusion. In ponies, the effect of acidemia on plasma K+ and serum inorganic phosphate concentrations was similar to that reported for other species. Changes were small in magnitude and depended on the nature of the acid anion. Results indicate that large changes in plasma K+ and serum inorganic phosphate concentrations during acidosis are probably not a direct result of acidemia.     

Hypophosphatemia in Cats After Renal Transplantation

Objective— To report the prevalence of hypophosphatemia after renal transplantation in a historical cohort of cats. Design— Case series. Animals— Cats (n=86) that received a renal allograft. Methods— Medical records (January 200–June 2006) were reviewed. Signalment, clinical signs, pre‐ and postoperative diet, pre‐ and postoperative clinicopathologic variables, renal histopathology, and outcome were retrieved. Prevalence, onset, duration, treatment and associated clinical signs of hypophosphatemia were recorded. A χ² test was used to compare hemolysis frequency between cats with normal serum phosphorus concentration or a single spurious low serum phosphorus concentration for <24 hours duration (group 1) and confirmed hypophosphatemia for >24 hours (group 2). A Cox proportional hazards model was used to evaluate the effects of hypophosphatemia on survival while controlling for other potentially confounding variables (age, sex, weight, body condition score, and pre‐ and 24 hours postoperative clinicopathologic variables). Results— Eighty‐six cats (mean age, 7.7 years) were identified. Hypophosphatemia occurred in 32 cats (37%), with a median onset of 2 days and median duration of 4 days. Treatment was initiated in 48 (56%) of hypophosphatemic cats. Survival and hemolysis frequency was not significantly different between groups, and no risk factors were identified. Conclusion— Hypophosphatemia occurs in cats after renal transplantation and does not affect survival. Clinical Relevance— The clinical importance of hypophosphatemia in renal transplant recipients remains unknown.     

Failure of Psyllium Mucilloid to Hasten Evacuation of Sand From the Equine Large Intestine

Objective —To examine the efficacy of psyllium mucilloid in evacuating sand from the equine large intestine.
Animals —12 clinically healthy pony geldings.
Procedure—Twelve ponies were assigned to 2 groups of six each. One group was treated with psyllium and the second was a control group. All ponies had an exploratory celiotomy and 10 g/kg body weight of sand was placed into the cecum. Ponies were fed a grain mixture alone at 1 g/kg (controls), a grain mixture plus psyllium pellets, each at 1 g/kg body weight (3 ponies), or fed a grain mixture and given psyllium powder by nasogastric tube at 1 g/kg body weight divided into two daily doses in 3 L of water (3 ponies). Radiographs were taken on days 1 (3 per group), 5 (all ponies), and 11 (3 per group) to monitor sand transit through the large intestine. Ponies were euthanatized 11 days after surgery. Sand was collected from the contents of the cecum, ventral colon, dorsal colon, and small colon. Dry weight of the recovered sand was compared between the two treatment groups as a percentage of the dry weight of sand placed in the cecum.
Results —No significant differences were detected in the mean percentage of sand recovered between the two treatment groups ( P < .05), with 39.2% recovered in ponies treated with psyllium and 27.4% recovered in control ponies.
Clinical Relevance —Psyllium mucilloid had no apparent effect on sand evacuation from the equine large intestine. When intake of sand is prevented, the equine large intestine can reduce and possibly eliminate its sand burden.     

The influence of calcium intake on phosphorus digestibility in mature ponies

Literature data show conflicting results on the effect of feeding high calcium (Ca) levels on phosphorus (P) digestibility in ponies. None of the studies reported involved a dose response as to the effect of Ca intake on apparent P digestibility while keeping P intake constant. Thus, the influence of high dietary Ca level on apparent P digestibility was studied in balance trials by feeding six mature ponies three different Ca levels against a constant P intake. The ponies received 148, 316 and 535 mg Ca/kg BW/day with the low, intermediate and high Ca diet. Phosphorus intake was approximately 125 mg P/kg BW and magnesium (Mg) intake was approximately 35 mg Mg/kg BW/day. The intermediate and high Ca level decreased apparent digestibility, renal excretion and retention of P when compared with the low Ca level. However, apparent digestibility and renal excretion of P were not different between the intermediate and high Ca level. The high Ca level resulted in a retention of 66 mg Ca/kg BW/day. The percentage apparent digestibility of Ca was lower for the intermediate and high Ca level compared with the low Ca level. Magnesium digestibility was not affected by high dietary Ca level. In practice, high absolute amounts of Ca should be prevented especially when low amounts of P are fed; P digestibility will be depressed and a negative P balance may occur.     

喹乙醇在鸡体内的毒物动力学及其生化毒性和病理学研究 Ⅱ.喹乙醇对鸡的生化毒性和病理学研究

本文报道了喹乙醇多剂量给药时对ＡＡ鸡的生化毒性和病理学研究。４２只ＡＡ鸡随机分成７组,按喹乙醇５００ｍｇ／ｋｇ饲料连续饲喂７ｄ,测定生化指标并作病理学检查。结果表明,血浆醛固酮显著下降、血清Ｎａ＋下降而血清Ｋ＋显著上升、Ｎａ＋／Ｋ＋比显著下降、肝微粒体蛋白含量呈起伏变化、细胞色素Ｐ－４５０含量减少、血浆肌酐和血清尿酸均显著上升（Ｐ＜０．０５或Ｐ＜０．０１）,肝、肾和肾上腺组织结构均受损害。本研究证实,中毒剂量的喹乙醇对鸡的肾上腺皮质功能、肝微粒体酶系统及肾功能均产生抑制性损害。病理学变化与生化指标的变化相一致。     

Use of a high-molecular-weight carboxymethylcellulose in a tissue protective solution for prevention of postoperative abdominal adhesions in ponies

OBJECTIVE: To evaluate efficacy and safety of IP administration of high-molecular-weight carboxymethylcellulose (HMW CMC) for the prevention of postoperative intra-abdominal adhesions in ponies. ANIMALS: 10 ponies. PROCEDURE: A 1% solution of HMW CMC was instilled intra-abdominally prior to surgery in 5 ponies, whereas 5 control ponies did not receive HMW CMC. Postoperative adhesions were induced by use of a bowel-abrasion method comprising laparotomy, typhlotomy, and abrasion of jejunal serosa at multiple sites with placement of 3 sutures at each site. Day of surgery was day 0. After surgery, ponies were monitored, and hematologic, serum biochemical, and peritoneal fluid analyses were performed on days 1, 2, 3, 5, 7, and 10. On day 10, ponies were euthanatized. Intra-abdominal adhesions were recorded, and tissue samples were collected for histologic examination. RESULTS: A significantly greater number of adhesions, number of multiple adhesions, and mean incidence of adhesions were identified in control ponies, compared with CMC-treated ponies. Mean peritoneal fluid WBC count on day 7 and serum fibrinogen concentrations on days 5 and 7 were significantly higher in control ponies, compared with CMC-treated ponies. Results of serum biochemical analyses did not differ significantly between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE: Intra-abdominal use of 1% HMW CMC during surgery was effective for preventing postoperative adhesions in ponies. Use of HMW CMC did not have detrimental effects on wound healing, intra-abdominal defenses, or patient health. A 1% solution of HMW CMC may be used routinely during abdominal surgery of horses for prevention of postoperative adhesions.     

Hypophosphatemia induced by dietary aluminium hydroxide supplementation in pigs: effects on growth, blood variables, organ weights and renal morphology

Twenty-four pigs, 13-14 weeks of age, were studied during an experimental period of 10 weeks. The pigs were randomly divided into 3 groups. Two groups were fed a commercial feed supplemented either with a suspension of aluminium hydroxide (Al(OH)₃) or aluminium phosphate (A1PO₄). The third group served as a control. The same total amount of aluminium was given to each of the 2 experimental groups. After three weeks the Al(OH)₃-pigs developed severe hypophosphatemia, with an average decrease in serum phosphate of 60%, a decreased growth rate and a lower concentration of 2,3-diphosphoglycerate in the erythrocytes as compared to controls. Intense hypercalcemia developed in the Al(OH)₃-group during the first 6 weeks, whereas the AlPO₄-pigs and the control group developed neither hypophosphatemia nor hypercalcemia. At necropsy, the consequence of the long lasting hypophosphatemia was found to be increased relative kidney weights with morphological signs of tubular damage and dyscalcification. No similar changes were observed in the AlPO₄-groups and there were no organ weight deviations compared to the control group.     

Probstmayria vivipara pinworms in ponies.

From 1967--1978 observations were made on the presence of the small equine pinworm, Probstmayria vivipara, in seven experimental ponies. The life cycle of this nematode is unusual in that it is endogenous with development of all stages occurring within the host's digestive tract. Initially, worms were found in the feces of four of seven ponies following treatment with thiabendazole but the infection was later transmitted to all ponies possibly via coprophagy. Still later, based on fecal and postmortem examinations, four of the seven ponies lost their pinworm burdens. At necropsy, the principal sites of infection were observed to be the cecum and right ventral colon. Despite the large number of pinworms present, clinical signs were not observed.     

Hypophosphatemia and Hemolytic Anemia Associated With Diabetes Mellitus and Hepatic Lipidosis in Cats

Hypophosphatemia associated with hemolytic anemia was diagnosed in five cats with diabetes mellitus and in one cat with idiopathic hepatic lipidosis. The hematocrit began decreasing within 24 to 48 hours after documented hypophosphatemia in each case. The anemia resolved in all five surviving cats. Because of the temporal relationship and lack of other detectable causes, hemolytic anemia was presumed to be caused by hypophosphatemia. There were increased Heinz bodies in three of six hypophosphate-mic cats during episodes of hemolysis. Intravenous potassium phosphate administration corrected the hypophosphatemia in four of five cats. The effective dosages of intravenous phosphate ranged from 0.011 to 0.017 mmol of phosphate/kg/h for 6 to 12 hours. Hypocalcemia (5.4 to 8.7 mg/dL) occurred in four of five cats treated with intravenous phosphate; however, only one cat developed clinical signs attributable to hypocalcemia. Based on this retrospective study, we recommend monitoring serum phosphorus concentration every 6 to 12 hours in cats likely to become hypophosphatemic. Treatment of hypophosphatemia in cats is warranted because of the apparent increased susceptibility of cats to hypophosphatemia-induced hemolysis. Cats with severe hypophosphatemia (≤1.5 mg/dL) should be given oral or parenteral phosphate if contraindications do not exist. (Journal of Veterinary Internal Medicine 1993; 7:266–271. Copyright © 1993 by the American College of Veterinary Internal Medicine.)     

Hypercalcemia associated with malignancy in a horse

Hypercalcemia associated with malignancy was diagnosed in a 2-year-old Thoroughbred filly admitted because of weight loss and reduced exercise tolerance of approximately 2 months' duration. Laboratory findings included hypercalcemia, hypophosphatemia, anemia, marked neutrophilia with lymphopenia and eosinopenia, and normal immunoreactive parathyroid hormone concentration. At necropsy, a 53.6-kg tumor was located in the cranioventral aspect of the abdominal cavity. Gross renal lesions were not noticed. Bone tissue appeared to be normal on gross and histologic examinations. The parathyroid glands were not grossly identified at necropsy. A specific test does not exist for detection of hypercalcemia associated with malignancy. The diagnosis of hypercalcemia associated with malignancy was made on the basis of clinical history, physical examination, radiographic interpretation, laboratory findings, histologic examination, and ruling out other causes of hypercalcemia. Hypercalcemia, increased renal phosphate excretion in the presence of hypophosphatemia, absence of bone metastases, and identifying an abdominal mesenchymal tumor that may have originated from the left ovary satisfied the basic criteria for hypercalcemia associated with malignancy from a solid tumor.     

Enterocolitis caused by Ehrlichia sp. in the horse (Potomac horse fever)

Potomac horse fever was reproduced in 15 ponies by transfusion of whole blood originally from two natural cases and subsequently from ponies infected by the transfusions. Incubation periods varied from 9 to 15 days. Affected ponies developed varying degrees of fever, diarrhea, anorexia, depression, and leukopenia. Eleven affected ponies were killed, three died in the acute phase of the disease, and one did not show clinical signs. The most consistent post-mortem findings were fluid contents in the cecum and large colon, and areas of hyperemia (of inconstant degree and distribution) in mucosae of both small and large intestines. Multifocal areas of necrosis occurred in mucous membranes. Ehrlichial organisms were most common in the cytoplasm of epithelial cells, macrophages, and mast cells of the large colon.     

Attempts to restore abduction of the paralyzed equine arytenoid cartilage. II. Nerve implantation (pilot study).

The purpose of this project was to attempt restoration of abduction of a recently experimentally denervated left dorsal cricoarytenoid muscle by implanting a transected nerve-end into the paralyzed muscle. In six ponies the cut end of the second cervical nerve was implanted into a slit made in the left dorsal cricoarytenoid muscle. The nerve end was secured in place with one 5-0 polypropylene suture connecting the epineurium to the epimysium. The left recurrent laryngeal nerve was transected during this procedure. All six ponies showed signs of complete left laryngeal hemiplegia immediately after surgery. Postoperatively all ponies were evaluated qualitatively on a monthly basis by subjective examination for evidence of abduction of the arytenoid cartilages on endoscopy and quantitatively by measurement of the cross sectional area of the left and right half of the rima glottidis. Subjective endoscopic evidence of partial abduction was seen in four of the six ponies six months postoperatively. Measurement of the cross sectional area of the rima glottidis revealed a total loss of 38% of the area immediately postoperatively. There were no significant changes in cross sectional areas of the rima glottidis between the immediate postoperative evaluation to the six months postoperative evaluation. Gross postmortem examination revealed partial dorsal cricoarytenoid muscle atrophy as evidenced by a 24-55% decrease in muscle mass compared to the right dorsal cricoarytenoid muscle. Histopathological studies revealed regions with clusters of large muscle fibers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intake, digestion and gastrointestinal transit time in resting donkeys and ponies and exercised donkeys given ad libitum hay and straw diets

Four donkeys and four ponies maintained in climate rooms, were provided with meadow hay or barley straw supplemented with minerals and vitamins ad libitum. Both diets were given to all animals for periods of 21 days. Measurements were made during the last seven days following single doses of two non-absorbable markers (Cr-fibre and Co-EDTA). After six weeks the donkeys repeated the trial, walking 14 km and ascending 260 m five days per week. At rest ponies ate more than donkeys, however the donkeys showed a higher digestibility of dry matter (DM), organic matter (OM) and acid detergent fibre (ADF) than the ponies. Both species lost weight, ate less and had a lower digestibility of DM, OM and energy on the straw than on the hay ration. Fibre digestibility (neutral detergent fibre [NDF] and ADF) was higher on the straw than the hay diet. Gastrointestinal transit time was slower in the donkeys than in the ponies on both diets. Both species showed a higher mean retention time of digesta on straw than on hay. Exercise had no significant effect on food intake and liveweight changes in the donkeys. Although digestibility coefficients were higher in exercised animals, the effect was not significant. We conclude that, although it is generally considered that donkeys can thrive better on poor feeds than ponies, when the animals are allowed ad libitum access to hay and straw better intakes by ponies may compensate for any differences in digestibility seen in donkeys. Intake of barley straw by both species was not sufficient to meet maintenance requirements.     

The Effect of Sedation on Gastric Emptying of a Liquid Marker in Ponies

OBJECTIVE: The effect of sedation on gastric emptying was evaluated in six ponies by monitoring serum concentrations of acetaminophen (AP) after intragastric administration. EXPERIMENTAL DESIGN: Prospective randomized experimental study. ANIMALS: Six adult ponies, 135 to 275 kg. METHODS: Fifteen minutes after the intravenous administration of xylazine (1 mg/kg), butorphanol (0.05 mg/kg), acepromazine (0.05 mg/kg) or saline, ponies were given AP (20 mg/kg in 350 mL water) by stomach tube. Blood for AP analysis was collected at baseline and 15, 30, 45, 75, 90, 105, and 120 minutes after AP administration. The time (Tmax) to reach peak serum concentration (Cmax), and the area under the AP serum concentration versus time curve (AUC) were determined for each treatment group. RESULTS: Tmax was 31 mins in the control group, and this increased significantly (P<.05) after sedation. Cmax decreased (P<.05) after xylazine administration, and AUC decreased (P<.05) after acepromazine. CONCLUSIONS: This study indicated that sedation has a significant effect on the gastric emptying rate of a liquid in ponies.     

Blood biochemical response to sodium bicarbonate infusion during sublethal endotoxemia in ponies

Hypertonic NaHCO3 infusion caused blood volume expansion, increased blood bicarbonate concentration, and delayed the onset of hypophosphatemia in ponies with endotoxemia. However, NaHCO3 infusion did not normalize blood pH, and it increased blood L-lactate concentration, and caused hypokalemia, hypernatremia, and hyperosmolality. The deleterious effects of NaHCO3 infusion in endotoxemia ponies outweighed the beneficial effects. The role of hypertonic NaHCO3 given IV for treatment of endotoxemia in equids must be reevaluated.     

Phenolsulfonphthalein pharmacokinetics and renal morphologic changes in adult pony mares with gentamicin-induced nephrotoxicosis

Changes in renal function, determined by pharmacokinetics of phenolsulfonphthalein (PSP), and renal morphologic features were examined in adult pony mares given 20 mg of gentamicin sulfate/kg of body weight, IV, q 8 h (group A) n = 7 or isotonic saline solution, IV, q 8 h, n = 5 (group B) for 14 days. Susceptibility of ponies to gentamicin-induced nephrotoxicosis was varied. Two group-A ponies developed acute renal failure and were euthanatized before treatment day 14, whereas 5 group-A A ponies did not develop physical or behavioral abnormalities after 14 days of gentamicin administration. All group-A ponies but none of group-B ponies developed ultrastructural abnormalities of the proximal tubular epithelium, consistent with gentamicin-induced nephrotoxicosis. Significant (P less than 0.05) differences were not detected in pharmacokinetic values of either group. Clearance of PSP was reduced in 4 group-A ponies that developed the most severe gentamicin-induced nephrotoxicosis. Changes in clearance of PSP were significantly (P less than 0.05) correlated with changes in the serum creatinine concentration.