Surgical Repair of a Perforated Gastric Ulcer in a Foal

An 11-day-old Thoroughbred colt was presented because of acute colic and a swollen right carpus. Exploration of the abdomen revealed peritonitis secondary to a perforated gastric ulcer. The ulcer was repaired, and the peritoneal cavity was lavaged. The foal recovered from the perforated ulcer but was euthanized one and a half months later because of progressive septic arthritis.     

Resting concentrations of the plasma free amino acids in horses following chronic submaximal exercise training

Six horses were conditioned on a treadmill at a constant speed of 5.6 km/hr on a 12.5% grade for gradually increasing periods of time over 14 days in order to determine the effect of repeated submaximal exercise on the concentrations of plasma free amino acids, protein metabolism, and plasma volume. Following 14-days of training, plasma volume increased (29%, P<0.05), as did total circulating content of plasma protein, albumin and urea. Urinary urea nitrogen excretion decreased (P<0.05) with exercise training. After the first week of training, the concentration of glycine had decreased (P<0.05) and the concentrations glutamic acid, arginine and alanine were increased (P<0.05) when compared to their corresponding pre-training (control week) levels. Compared to pretraining levels, there were decreases (P<0.05) in aspartic acid, histidine, arginine, valine, phenylalanine, isoleucine, and lysine, following the second week of training. Following a week of recovery, all resting concentrations of plasma free amino acids; when compared to their pretraining control; had decreased, with the exception of three nonessential amino acids (glutamic acid,serine, and glycine). Based upon the results of the present study, it would appear that exercise training produced a significant change in the amino acid and protein metabolism of the horse.     

Neuroanesthesia: A Review of the Effects of Anesthetic Agents on Cerebral Blood Flow and Intracranial Pressure in the Dog

Successful anesthetic management of dogs with reduced intracranial compliance requires a knowledge of the effects of various anesthetic agents on cerebral blood flow and intracranial pressure. The major physiologic factors that influence cerebral blood flow and intracranial pressure (ICP) include the cerebrovascular autoregulatory mechanism, intracranial compliance, blood pressure, and the partial pressure of carbon dioxide. Intravenous and inhalation anesthetic agents alter cerebral blood flow and intracranial pressure in the dog. These alterations can have profound effects in dogs with reduced intracranial compliance, necessitating proper anesthetic management. Suggested guidelines for neuroleptanesthetic and inhalation anesthesia regimens in dogs with reduced intracranial compliance include thorough presurgical evaluation, minimal patient stress during induction, use of an anesthetic protocol that minimizes ICP effects, and hyperventilation to maintain a Pco₂ within a range of 25 to 35 mm Hg.     

Plasma Taurine Concentrations and M-mode Echocardiographic Measures in Healthy Cats and in Cats with Dilated Cardiomyopathy

M-mode echocardiography was completed and plasma taurine concentrations were determined in 79 healthy cats and 77 cats with dilated cardiomyopathy (DCM). In healthy cats, a relationship was not observed between plasma taurine concentrations and any M-mode echocardiographic measurement. End-systolic and end-diastolic cardiac chamber dimensions were larger; wall thickness measures were smaller; and calculations of fractional shortening were less in cats with DCM than in healthy cats. Plasma taurine concentrations less than 30 nmol/mL were detected in 7/79 healthy cats and in 52/77 cats with DCM. Of the 52 cats with DCM and an initial plasma taurine concentration less than 30 nmol/mL, 23 died or were euthanized during the first post-treatment week, 7 were lost to further study, and 22 improved after taurine supplementation. Of the 25 cats with DCM and an initial plasma taurine concentration greater than or equal to 30 nmol/mL, 9 died or were euthanatized during the first post-treatment week, and 9 were lost to further study. Two cats did not improve, of which one died and one was euthanatized 4 to 8 weeks after initiation of taurine supplementation. Five cats with a plasma taurine concentration greater than or equal to 30 nmol/mL improved after taurine supplementation. Myocardial function subsequently deteriorated in three of these cats. Two of the three cats had signs of congestive heart failure redevelop.     

UTILIZATION OF INSTANTANEOUS EJECTION VOLUME IMAGES TO PRODUCE VENTRICULAR VOLUME CURVES FROM AN EQUILIBRIUM RADIONUCLIDE VENTRICULOGRAM

Equilibrium radionuclide ventriculograms were performed in 6 normal dogs during resting and isoproterenol challenged states. A new method of analysis of the equilibrium radionuclide ventriculograms using a simple digital subtraction technique was compared to traditional methods of analysis and echocardiography. There was no significant difference between ejection fraction values from the three methods tested. The equilibrium radionuclide ventriculograms ejection fraction was significantly increased following isoproterenol administration using both the new and traditional methods of analysis but the pre versus post-isoproterenol increase ejection fraction derived from echocardiographic measurements of ejection fractions was not significantly different. The new digital subtraction method consistently produced reproducible, high quality ventricular volume curves for the left and right ventricle. Left and right ventricular maximum and average emptying and filing rates were determined from the slopes of the volume curve and the results were similar to those previously published for man and dog. The emptying and filling rates of both ventricles were significantly increased following isoproterenol administration. The time to peak emptying significantly decreased following isoproterenol. Time to peak filing decreased following isoproterenol but the difference was not significant.     

LONG-TERM FOLLOW-UP OF HYPERTHYROID CATS TREATED WITH IODINE-131

A long-term follow-up study of hyperthyroid cats treated with iodine-131 was conducted at the Texas A&M University Veterinary Teaching Hospital. Between January 1985 and December 1990, 255 cats were treated. Basic demographic data, information on treatment, and diseases at the time of diagnosis were recorded. Two hundred and thirty seven cats had long-term follow-up data collected by telephone interviews with the referring veterinarian and/or the owner on outcome of therapy, diseases that developed during the follow-up period and survival. Risk for developing hyperthyroidism was highest for cats greater than 10 years of age. There was no breed predisposition. Neutered cats were slightly over-represented among the cases compared to intact animals. Eighty-five percent of treated cats became clinically normal and remained euthyroid for a median time of 17.5 months. Four percent remained hyperthyroid and 9% became hypothyroid, requiring thyroid hormone supplementation.     

Evaluation Of An Additive Solution For Preservation Of Canine Red Blood Cells

The effect of an additive preservative solution on canine red blood cell posttransfusion viability (PTV) and on selected canine red blood cell biochemical parameters was studied. One unit (450 mL) of blood was collected from 6 clinically normal dogs into the anticoagulant citrate phosphate dextrose, centrifuged, and the plasma removed. The red blood cells were then suspended in 100 mL of a saline, adenine, dextrose, and mannitol solution and stored at 4°C. Aliquots were removed for study at 1, 10, 20, 30, 37, and 44 days. The 24-hour PTV of autologous red blood cells was determined using a sodium chromate (⁶¹Cr) label. Red blood cell concentrations of 2,3-diphosphoglycerate (2,3-DPG), adenosine-5'-triphosphate (ATP), and pH were also determined. Canine red blood cell PTV, pH, ATP, and 2,3-DPG concentrations decreased during storage ( P < .05). The PTV decreased from 94% using day 1 red blood cells to 80% and 75% using day 37 and day 44 red blood cells, respectively ( P < .05). Although the mean PTV of the day 44 stored units equaled the Food and Drug Administration (FDA) minimum standard for human red blood cells, the PTV was substandard in 75% of the day 44 units. The FDA standard was exceeded in 83% of the day 37 units. It was concluded that 37-day-old canine red blood cells preserved with a saline, adenine, dextrose, and mannitol solution are of acceptable quality for transfusion.     

Evaluation of Fibular Head Transposition for Repair of Experimental Cranial Cruciate Ligament Injury in Dogs

Unilateral cranial cruciate ligament excision and fibular head transposition (FHT) were performed on 30 adult dogs. Vertical ground reaction forces were determined using force plate data before and after surgery. Cranial drawer motion, tibial rotation, and varus-valgus motion were measured at monthly intervals. Radiographic, gross, and histological examinations of the stifle joints that had been operated on were performed 3 weeks, 4 months, and 10 months after surgery. A scoring system was used to evaluate lameness, osteophyte formation, and meniscal damage. Rank correlation coefficients were calculated between variables tested in pairs. Cranial drawer motion and abnormal tibial rotation were present in all of the joints that had been operated on. Peak vertical force and associated impulse were not restored during the study time period. Meniscal damage was noted in 25% of the dogs at month 4 and in 50% of the dogs at month 10. Progressive gross and histological deterioration of the articular cartilage was observed in all joints. Positive correlations were noted between the degree of stifle joint instability and meniscal injury or radiographic changes. FHT did not control cranial drawer motion and rotational instability, was not successful in restoring limb function, and did not prevent joint degeneration, especially meniscal damage.     

Repair of a Mandibular Defect With a Free Vascularized Coccygeal Vertebra Transfer in a Dog

Bilateral mandibular defects in a male mongrel dog were repaired. On the left side, a free vascularized coccygeal bone graft that included the median caudal artery and caudal vein was used to correct the defect. On the right side, the defect was bridged with a bone plate and screws. For further immobilization, the muzzle was temporarily taped for 3 weeks and a pharyngostomy tube was used for nutritional support. The dog was able to eat dry commercial food satisfactorily within 2 months of surgery despite mild malocclusion. Radiographs taken 2 months and 18 months postoperatively showed bony union with graft hypertrophy in the left mandible, whereas the right mandibular defect showed protracted nonunion. The results indicate that vascularized coccygeal vertebra transfer provides an alternative for the management of canine mandibular defects.