Neurologic disease associated with hypernatremia in 2 young Vietnamese potbellied pigs is discussed. Both pigs had recent dietary changes likely associated with excessive salt intake. Case 1 was changed from a commercial mini pig ration to a commercial cat food diet containing up to 1.5% salt 3-4 days before the onset of clinical signs. Case 2 was being maintained on a commercial mini pig ration, however the owner often fed the pig potato chips as treats since its purchase 3 weeks previously. There was no history of water deprivation in either pig. Clinical signs in case 1 included facial-motor seizures, sialorrhea, generalized seizures, tenesmus, disorientation, circling, head pressing, and blindness. Case 2 was disoriented, ataxic, underweight, and appeared blind. Both pigs fully recovered with medical therapy. The rationale for fluid and ancillary therapy are discussed in light of the pathophysiology of salt toxicosis in commercial swine.
Gastroendoscopic surveys have shown that horses in race training have a greater prevalence of gastric ulceration than sedentary horses. To determine if exercise affects gastric endocrine function the following experiment was performed. Four horses were fed total mixed ration of ground corn and chopped hay at 2% of their body weight, divided into 2 equal portions, daily. Horses were fasted overnight, and serum gastrin concentration was determined just before and 2 hours after feeding. The horses were then sprint trained on a high speed treadmill for 6 weeks. The response of serum gastrin to feeding was then repeated as before. Serum gastrin increased following feeding both before and after training, however the postfeeding gastrin value was higher [p = 0.035] after training (68.1 +/- 6.9 pg/ml [mean +/- 1 SEM]) than before (42.7 +/- 3.8 pg/ml). These data show that treadmill exercise has an effect upon the gastric hormonal response to a meal in the horse. The relationship of this finding to the development of gastric ulcer disease is unknown at present, but warrants further investigation.
Two young Jacob sheep which presented with severe ataxia and torticollis had abnormally formed atlanto-occipital joints. Postmortem examination revealed marked dissimilarity in size between the left and right occipital condyles, with reduction in size of the foramen magnum. The atlantoaxial joint and dens were normally formed, and were not abnormally positioned in radiographs taken of one lamb. Histological evaluation of the cervicomedullary junction demonstrated extensive loss of axons and myelin, gliosis, and mild hydromyelia in one lamb.
The influences of facial airflow, exercise and wearing a facemask on gas exchange and upper airway (Pu), transpulmonary (PTP) and transdiaphragmatic (PTD) pressures were investigated in 6 horses performing an incremental exercise test on an inclined (10%) treadmill. The test consisted of a 2 min walk followed by two 2 min exercise bouts at intensities which produced 40% and 80% of maximal oxygen consumption. Horses performed the test 4 times, once for each of 4 protocols, which involved not wearing a facemask (A), wearing a mask with either no biased flow through it (B), with an expiratory bias of 6300 L/min through it (C), or with an inspiratory bias of the same magnitude (D). Although no statistically significant differences in arterial blood gases, Pu, PTP, or PTD could be attributed to the various protocols, trends that may have been physiologically important were detected. Hypoxemia and hypercapnia associated with exercise were most marked with protocol B and least severe with protocols A or D. PTP was lowest for all tests with protocol D. Of the 3 conditions that required the wearing of a mask, protocol D was associated with the lowest Pu. While impelling air into the respiratory tract, as presumedly occurs with horses exercising over ground, may enhance respiratory function during exercise, this preliminary study does not clearly demonstrate this. Because this is an important consideration when conducting studies involving horses on treadmills, further investigations at higher exercise intensities and with additional methodologies are needed to clarify the issue.
In 4 mares suffering from dystocia, general anesthesia was induced with xylazine (1.1 mg/kg, IV) and ketamine (2.2 mg/kg, IV) and maintained with continuous intravenous infusion of ketamine (2 mg/ml), xylazine (0.5 mg/ml) and guaifenesin (50 mg/ml) in 1 L of 5% dextrose. The duration of the procedure of these mares were 40, 45, 180, and 35 minutes, respectively. For procedures required more than 1 hour (Mare 3), the dose of ketamine and xylazine in the mixture was reduced to 1 mg/ml and 0.25 mg/ml, respectively. Average infusion rate of the mixture used to maintain anesthesia for each mare was 2.5, 2.67, 2.28, and 2.21 ml/kg/hr. Recovery to standing occurred at 55, 75, and 180 minutes after termination of infusion for mares 1, 2, and 3, respectively. Xylazine reversal agent, tolazoline (2.2 mg/kg), was given to mare 1 to hasten the recovery; the mare stood within 30 minutes after tolazoline administration. Continuous infusion of guaifenesin-ketamine-xylazine can be an alternative anesthetic technique for prolonged obstetrical procedures under field conditions when suitable anesthetic equipment is not available. If recovery to standing is extended over 30 to 40 minutes, yohimbine or tolazoline can be administered to hasten recovery.
A 4-month Arabian filly presented for abdominal pain of 30 hours duration was found to have tachycardia, tachypnea, congested mucous membranes and gross abdominal distension. Further examination disclosed gastric reflux and small intestinal distension. Dehydration, prerenal azotemia, electrolyte abnormalities and metabolic alkalemia were observed. There was a progressive nonresponse to analgesic medication and deterioration in the foal's physiologic condition consistent with a small intestinal strangulating obstruction. Surgical exploration was declined. Necropsy examination revealed incarceration of the mid-jejunum in the epiploic foramen with proximal jejunal distension. This case is remarkable as the first report of entrapment of the jejunum in the epiploic foramen of a young foal.
Equine leukoencephalomalacia (ELEM) affected 6 of 10 pleasure horses in adjacent paddocks at a boarding facility. Four of the 6 affected horses died or were euthanized. Two of 3 horses presented for treatment survived with complete resolution of clinical signs. Treatment was primarily supportive. Dimethyl sulfoxide, dexamethasone, flunixin meglumine and thiamine were administered as anti-inflammatory agents and to decrease or prevent cerebral edema. Fusarium monileforme was cultured from ear corn fed the affected horses. Fumonisin B1, B2 and B3 were isolated.
The efficacy intravenous plasma to transfer passive immunity to clinically healthy colostrum-deprived and clinically ill foals with failure of passive transfer was investigated. Efficacy of transfer was evaluated by the elevation of serum IgG per gram of IgG administered as a function of body weight. Colostrum deprived healthy foals had a significantly greater increase in serum IgG than did clinically ill foals with failure of passive transfer. Knowledge of the IgG content of plasma to be administered and the health status of a foal with failure of passive transfer should allow more accurate prediction of an individual foal's response to treatment.
A 3-year-old Appaloosa stallion with a 4 cm x 4 cm x 2.5 cm mass protruding from his nasal bone was evaluated. Radiographs revealed an osseous mass, with a radiopaque outer margin and several radiolucent areas within the body of the mass. The mass was surgically removed and evaluated histopathologically. The histopathological diagnosis was osteochondroma. This case represent the first reported occurrence of an osteochondroma arising from intramembraneous bone in the horse.
Two young Jacob sheep which presented with severe ataxia and torticollis had abnormally formed atlanto-occipital joints. Postmortem examination revealed marked dissimilarity in size between the left and right occipital condyles, with reduction in size of the foramen magnum. The atlantoaxial joint and dens were normally formed, and were not abnormally positioned in radiographs taken of one lamb. Histological evaluation of the cervicomedullary junction demonstrated extensive loss of axons and myelin, gliosis, and mild hydromyelia in one lamb.
Medical records were reviewed for 11 horses with squamous cell carcinoma of the larynx and/or pharynx. The average age at presentation was 15.3 years. No breed or sex predilection was present. At presentation, 6 of 11 horses were dyspneic and 4 horses had inspiratory stridor. Endoscopy was performed in all cases and was more useful in demonstrating a mass in the laryngopharyngeal region than laryngeal or guttural pouch radiography. Surgical excision was attempted in 3 horses and in 1 horse alleviated clinical signs for 4 months. Ten horses were euthanatized and 1 horse died. Results of this study indicated that laryngopharyngeal squamous cell carcinomas are difficult to surgically excise due to their location, size and invasiveness. Treatment is often not attempted because of the advanced state of the disease at the time of presentation.
Solvents including ethanol, methylene chloride, acetone, hexane, and hot and cold water were used in separate procedures to extract needles and bark from ponderosa pine (Pinus ponderosa L.) to determine which system was optimal for the extraction of abortifacient compound(s). The extracts and residues therefrom were fed by gavage to pregnant cows beginning at day 250 of gestation. After methylene chloride extraction, the pine needle residue fed by gavage failed to abort 4 cows. Subsequently, 4 cows fed the methylene chloride extractable material, adsorbed on ground hay, but free of methylene chloride, aborted (days 253-260 of gestation) and all 4 cows retained fetal membranes. Only 2 of 6 cows fed the pine needle residue after ethanol extraction aborted (days 260 and 261 of gestation) and both retained their fetal membranes, while the other 4 cows calved normally. Hot and cold water extracts did not cause abortion, whereas the extracted plant residue did. One cow fed the plant residue after acetone extraction calved normally as did 1 of 2 cows fed residue after hexane extraction. One cow fed hexane extract absorbed on ground hay also calved normally. These results demonstrate that abortifacient compound(s) present in pine needles are most efficiently extracted by methylene chloride.
Femoral fractures in young horses can occur as a result of severe trauma and generally have a poor prognosis despite treatment. Four young horses with femoral diaphyseal fractures were managed with conservative treatment consisting of prolonged rest, analgesics, hind limb support, and corrective farriery. A favorable outcome in the form of pasture soundness with potential for limited athletic usefulness was obtained in 3 out of the 4 cases. This report supports the use of conservative treatment of selected diaphyseal femoral fractures in young horses.
Three horses examined for complaints of ptyalism and dysphagia were found to have metallic lingual foreign bodies. Metallic foreign bodies were located by oral examination combined with radiography. In 1 horse clinical signs resolved without removal of the foreign body. The foreign body was extracted via an oral approach in the second horse; a mandibular symphysiotomy and radiographic guidance were necessary for removal in the third horse. In all 3 cases, the presenting clinical signs subsided.
Persistent hyperbilirubinemia and icterus are described in a healthy 4-year-old Thoroughbred horse. Hyperbilirubinemia was not related to food intake and was not associated with evidence of increased hemolysis or with acquired hepatic disease. The hyperbilirubinemia was thought to be a result of inappropriate conjugation of bilirubin rather than any abnormality in bilirubin uptake or excretion. The bilirubinemia in this horse appears most similar to a human syndrome, caused by a familial deficiency of bilirubin-uridine diphosphate glucuronyl transferase.
Three horses examined for complaints of ptyalism and dysphagia were found to have metallic lingual foreign bodies. Metallic foreign bodies were located by oral examination combined with radiography. In 1 horse clinical signs resolved without removal of the foreign body. The foreign body was extracted via an oral approach in the second horse; a mandibular symphysiotomy and radiographic guidance were necessary for removal in the third horse. In all 3 cases, the presenting dinical signs subsided.
A 3-month-old llama with a presenting complaint of lethargy, anorexia, and a painful, distended abdomen was evaluated. The llama had intermittently strained to defecate during the 3 days prior to admission. Physical examination results, hematologic data and lateral abdominal radiographs were used to diagnose a large umbilical abscess, which was causing a partial obstruction of the gastrointestinal tract. Under general anesthesia, 3 liters of purulent exudate were drained from the abscess. The abscess cavity was then lavaged with saline solution and its capsule was marsupialized to the skin. Cultures of the abscess content yielded Proteus sp, Streptococcus equisimilis, and Clostridium septicum. Two days after surgery, the llama was drinking, eating, and passing feces. The abscess was lavaged daily for a total of 11 days. Six months after surgery, the llama was the same size as other llamas of the same age, and the owners were pleased with the cosmetic appearance of the ventral abdomen. Umbilical abscesses can vary in size and clinical presentation; they should be recognized as a possible cause of abdominal pain with a potential for causing intestinal obstruction in llamas.
