A randomized multicenter trial of Crotalidae polyvalent immune Fab antivenom for the treatment of rattlesnake envenomation in dogs

Objective – To determine clinical efficacy of the Crotalidae polyvalent immune F_ab (ovine) antivenom (OPCA) against progressive crotalid envenomation in the dog as reflected in stabilization or improvement of snakebite severity scores (SSS). Additionally, due to the potential decreased half‐life of the F_ab antibodies in dogs we compared SSS between dogs receiving 2 different dosing regimes. Design – Prospective, clinical trial. Setting – Five veterinary emergency and critical care facilities. Animals – One hundred and fifteen client‐owned Crotalid (rattlesnake) snake bitten dogs in whom worsening of the envenomation syndrome was observed before OPCA treatment. Interventions – In a multicenter randomized clinical trial a single dose (1 vial) of OPCA alone was compared with 2 doses (1/2 vial each) administered 6 hours apart. Standard supportive care was provided in all cases. Measurements and Main Results – Data were available for 115 patients, 9 of which were fatalities. All patients' clinical condition was documented with a standardized SSS system accounting for each major body system. Each fatality received maximum severity scores of 20. The mean severity score of the 115 patients decreased from 4.19 to 3.29 points and there was no difference between the 2 treatment groups. The mean severity score of the 107 patients without fatalities decreased from 4.16 to 2.15. Antivenin‐related acute reactions occurred in 6 dogs (6%), and no serum sickness occurred within the 95 cases contacted at the 2‐week posttreatment follow‐up. Conclusions – In the first randomized trial in dogs of antivenin in the United States, OPCA effectively stabilized or terminated venom effects. There were no statistical differences detected between treatment groups within the study time frame.     

Evaluation of atropine, glucagon, and metoclopramide for facilitation of endoscopic intubation of the duodenum in dogs.

Modification of gastroduodenal motility has been proposed to aid endoscopic examination of the duodenum in dogs. The objective of this study was to evaluate the use of the following pharmacologic agents for facilitation of endoscopic intubation of the duodenum in 6 clinically normal dogs: metoclopramide HCl (0.2 mg/kg of body weight), atropine sulfate (0.045 mg/kg), glucagon (0.06 mg/kg), and isotonic saline solution. In a randomized, blinded, crossover design, the ease of endoscopic duodenal intubation was qualitatively scored by 3 endoscopists (in random order), using the following scale: 1 - immediate entry; 2 - rapid entry--moderate manipulation; 3 - difficult entry--multiple attempts; and 4 - no entry after 2 minutes [corrected]. Anesthesia was induced with thiopental and maintained with halothane. The 4 agents were diluted to a fixed volume and randomly administered. Duodenal intubation was attempted 2 minutes after IV injection of 1 of the agents. Four endoscopic procedures (1 for each agent) were performed on each dog with a minimum of 5 days between each procedure. In this study, no agent facilitated endoscopic duodenal intubation at the dose used. Instead, atropine and metoclopramide made duodenal intubation significantly more difficult, compared with use of saline solution. Difference between intubation after administration of glucagon and saline solution was not seen. On the basis of our findings, the use of these agents for facilitating endoscopic duodenal intubation is not recommended. In addition, in this study, we found that experience in endoscopic intubation is an important factor in determining the ease of duodenal intubation.     

Laboratory procedures for the diagnosis of gastrointestinal tract diseases of dogs and cats

An increasing number of laboratory tests are available for diagnosis of gastrointestinal tract diseases in dogs and cats. Use of these tests can lead to more accurate and rapid diagnoses. This review discusses laboratory tests, both new and old, and the role they currently play in the evaluation of animals presented with gastrointestinal problems. A minimum database helps assess the severity of the disorder, detect extra-gastrointestinal causes of problems and assists in formulating diagnostic and therapeutic plans. Faecal examination remains one of the most important diagnostic procedures in the investigation of gastrointestinal problems. Zinc sulphate faecal flotation is an excellent routine screening technique for helminth and protozoal infections, including giardiasis. Rectal cytology can assist in the diagnosis of large bowel disorders. Interpretation of faecal immunodiagnostic tests is hampered by insufficient knowledge of test sensitivities and specificities. Routine faecal cultures are not warranted and faecal occult blood tests are rarely indicated. Serum tests for gastric inflammation are now under development. The serum trypsin-like immunoreactivity test remains the gold standard technique for the diagnosis of exocrine pancreatic insufficiency. Breath hydrogen tests can be helpful in assessing the functional relevance of mild abnormalities in small-bowel biopsy specimens. Subnormal concentrations of serum cobalamin appear to be more specific indicators of gastrointestinal disease in cats than in dogs. Tests for small intestinal bacterial overgrowth remain controversial and assessment of gastrointestinal permeability has yet to prove its value in the diagnostic assessment of companion animals with gastrointestinal problems. Faecal alpha1-protease inhibitor shows promise for the diagnosis of protein-losing enteropathy.     

THE TECHNIQUE OF PERCUTANEOUS ULTRASOUND GUIDED FINE-NEEDLE ASPIRATION BIOPSY AND AUTOMATED MICROCORE BIOPSY IN SMALL ANIMAL GASTROINTESTINAL DISEASES

Techniques for obtaining percutaneous ultrasound-guided biopsies of the gastrointestinal tract were evaluated. The efficacity of ultrasonographic detection of gastrointestinal lesions has been established in veterinary medicine. Percutaneous ultrasound-guided aspiration biopsies were performed using either a 22 gauge spinal needle or a 20 gauge Westcott needle. The microcore automated biopsy was performed using a 18 gauge Tru-cut-like needle, assisted by an automated biopsy gun. These techniques are rapid, and easily performed. The techniques were considered safe for the patient, no complications such as hemorrhage, peritonitis or abscessation have occured in our study. These techniques are of particular interest when lesion can not be biopsied successfully by endoscopy and when surgical resection is not recommended.     

Ultrasonographic findings in abdominal mast cell disease: a retrospective study of 19 patients

A retrospective survey from January 1989 to January 1999 of Tufts University Foster Hospital for Small Animals radiology records of 12 dogs and seven cats with cytologically or histopathologically confirmed abdominal mast cell disease was performed. Ultrasound changes in hepatic mast cell infiltration in dogs included a subjective increase in size, a diffuse increase in echogenicity, and one or more hypoechoic nodules. Ultrasound findings in the affected canine spleen included one or more hypoechoic nodules and a subjective increase in size. Two ultrasonographically unremarkable canine livers and one unremarkable spleen were found to be infiltrated by mast cells. The mast cell-infiltrated feline spleen was subjectively increased in size, mottled, irregular, or contained nodules. The affected lymph nodes in both dogs and cats were hypoechoic or inhomogeneous, subjectively increased in size, and rounded. Gastrointestinal involvement in cats was characterized by a thickened ileocecocolic junction or colon with loss of wall layering. Mast cells were not found in the gastrointestinal tract in any dog. One dog with mast cell infiltrate of the kidneys had multiple hypoechoic nodules in the cortex that distorted the outer contour of the kidney. Although these findings are not specific to the disease in either species, abdominal ultrasound is considered a useful tool for determining the extent of disease in small-animal patients with mast cell tumor if used in conjunction with histopathology or cytology.