Autonomic and Cardiovascular Effects of Neuromuscular Blockade Antagonism in the Dog

Autonomic and cardiovascular changes were studied when neuromuscular blockade was antagonized in 96 dogs with one of eight anticholinesterase-antimuscarinic drug combinations. Neostigmine (50 or 100 micrograms/kg) was administered before or after atropine (40 micrograms/kg) or glycopyrrolate (10 micrograms/kg). The high dose of neostigmine (100 micrograms/kg) caused bradyarrhythmias, salivation, and signs of bronchosecretion when used with either antimuscarinic agent and irrespective of the administration sequence. The heart rate increased, but not significantly, when atropine was injected before either dose of neostigmine. This did not occur when this administration sequence was reversed. Arrhythmias and cardiovascular and autonomic changes did not occur when glycopyrrolate was injected before or after neostigmine at 50 micrograms/kg.     

Levator Nasolabials Muscle Transposition to Prevent an Orosinus Fistula after Tooth Extraction in Horses

The ventral part of the levator nasolabialis muscle was transposed to the alveolar defect after sinusotomy and tooth extraction in five normal horses and six horses with a tooth root abscess and sinusitis. In the normal horses at weeks 6, 10, 14 and 18, the transposed muscles remained viable and were incorporated into the recipient sites, and orosinus fistulae did not form. Histologically, there was a progressive transition from muscle to fibrous tissue. There was no facial deformity or loss of nasal function at the donor site. A localized abscess was associated with incomplete removal of tooth root fragments in one horse. After 1 year or more, five horses treated for dental disease had complete resolution of clinical signs. One horse continued to have intermittent mild nasal discharge.     

Skin Fold Advancement Flaps for Closing Large Sternal and Inguinal Wounds in Cats and Dogs

Skin fold advancement flaps can be created from the elbow and flank folds to close large wounds in the pectoral and inguinal regions of cats and dogs, respectively. The attachments of the laterally facing (outer) and medially facing (inner) layers of the skin fold to the adjacent limb are divided to produce a U-shaped pedicle graft attached to the trunk. This mobilizes skin that can be advanced over large wounds involving the ventral chest or abdomen, or both. The use of skin fold advancement flaps enables direct closure of large skin defects without undue tension and without compromising the mobility of the adjacent limb.     

Measurements of the Accuracy of Clinical Diagnoses of Equine Neurologic Disease

Parameters for the accuracy of clinical diagnosis of neurologic diseases in the horse were determined from 210 horses in which a definitive pathologic diagnosis was confirmed. The overall efficiency of diagnosis for all diseases was 0.95 although the validity varied from 0.79 to 1.00, the sensitivity varied from 0.73 to 0.95, and the specificity varied from 0.88 to 1.00 for individual disease categories. Equine protozoal myeloencephalitis was overdiagnosed, whereas Eastern equine encephalomyelitis, equine degenerative myeloencephalopathy, and traumatic neurologic disease were underdiagnosed. The use of such measurements of accuracy of diagnosis parameters in clinical practice will allow new diagnostic techniques to be objectively evaluated, resulting in greater efficiency of diagnosis and therapy.     

Gastric Acid Secretion in Basenji Dogs With Immunoproliferative Enteropathy

Gastric acid secretion was studied in 13 Basenji dogs with immunoproliferative enteropathy. Considerable variation in the severity of gastritis and enteritis existed among dogs. Basenji dogs were categorized into two groups on the basis of postmortem gastric and intestinal histology (group I, gastritis and enteritis; group II, only enteritis). Pentagastrin-induced gastric acid secretory capacity was increased (P less than 0.002) in group II dogs as compared to healthy Beagle controls. Gastric acid secretory capacity of Basenji dogs with gastritis and enteritis (group I) was not different from that observed in control dogs. Basal serum gastrin concentrations and secretin-stimulated serum gastrin concentrations of either group of Basenji dogs did not differ from controls. On the basis of symptomatology, Basenji dogs with diarrhea had significantly increased basal and postsecretin stimulation gastrin concentrations (P = 0.01) when compared with asymptomatic Basenji or healthy control dogs. These findings support a potential role for altered gastric acid secretory capacity in the pathogenesis of immunoproliferative enteropathy of Basenji dogs. Results of the secretin stimulation studies support previous pathologic studies that failed to detect gastrin-secreting tumors. Incorporated into this investigation was a trial to determine whether the combination of oxymorphone and acepromazine could be used for acid secretory studies. Compared to pentobarbital, which has been frequently used for acid secretory studies in a research setting, the drug combination resulted in increased gastric fluid volumes, a comparative increase in acid secretion, and a rapid uneventful recovery. We conclude that the combination of oxymorphone and acepromazine provides an acceptable means of restraint in dogs undergoing acid secretory studies.     

Malignant hyperthermia in a horse anesthetized with halothane

Ahealthy, 565-kg, 14-year-old Quarter Horse gelding, negative for equine protozoal myelitis on serum Western blot and for hyperkalemic periodic paralysis (HYPP) by polymerase chain reaction, was selected for use in an electrophysiology study performed under inhalation anesthesia. The study was performed by following the guidelines of an Animal Use and Care Committee Protocol of the University of California at Davis (UCD 8578). Anesthesia was induced with halothane delivered via a face-mask. The horse was intubated 17 minutes later with an orotracheal tube and anesthesia was maintained with halo-thane by using a semiclosed, large-animal breathing circuit. Although muscle relaxation was otherwise good, the horse's ears remained tensed in a caudal direction throughout the study     

Antimicrobial susceptibility of Mannheimia haemolytica isolates from cattle in Japan from 2001 to 2002

A total of 27 clinical isolates of Mannheimia haemolytica from cattle in Japan from 2001 to 2002 were examined for antimicrobial susceptibility to 25 antimicrobial agents. The minimum inhibitory concentrations of 25 different antimicrobials were determined by an agar dilution method according to the guidelines of the National Committee for Clinical Laboratory Standards. Of the 27 isolates, seven isolates (26.9%) were resistant to at least one of the 25 drugs and resistance rates ranged from 3.7 to 18.5%. Resistance rates to dihydrostreptomycin (18.5%), oxytetracycline (11.1%), and doxycycline (11.1%) were relatively high and those to the remaining drugs were less than 10%.     

An outbreak of systemic granulomatous disease in cows with high milk yields

Seven of 92 lactating Holstein cows on a dairy farm developed urticaria with alopecia and decreased milk production, and three of the seven died over the course of 7 to 18 days. Pathologic examination of the three cows, including the two dead and one euthanized cow, revealed that the skin, liver, spleen, kidneys, heart, salivary glands, pancreas, adrenal glands, mammary glands, lymph nodes, and trigeminal ganglia had lymphocytic to lymphogranulomatous inflammation. Inflammation predominated by lymphocytic infiltration was prominent in the heart, pancreas, mammary glands, adrenal gland, and trigeminal ganglia. Severe granulomatous inflammation with multinucleated giant cells was present in the spleen and kidneys. These lesions and their distributions were most similar to those seen in suspected cases of citrus pulp toxicosis and hairy vetch toxicosis. The outbreak of this disease resolved with the elimination of Citrus pulp from the feed. Immunohistochemical detection of lymphocytes and macrophage markers confirmed dramatic hyperplasia of CD3-positive T lymphocytes in these lesions. This strongly suggested that a type 4 hypersensitivity reaction played a role in the development of the lesions.     

Babesia microti-like parasites detected in feral raccoons (Procyon lotor) captured in Hokkaido, Japan

Raccoons (Procyon lotor), which have recently become feral in Japan, were examined for the presence of Babesia microti-like parasites. Out of 372 raccoons captured in the west-central part of Hokkaido, 24 animals with splenomegaly were selected and tested by nested PCR targeting the babesial 18S rRNA gene. B. microti-like parasites were detected in two of the 24 individuals, and their DNA sequences were identical to that of the B. microti-like parasite reported from raccoons in the United States, suggesting that the parasites were probably imported into Japan and that the life cycle of the parasite has already been established in the country. The potential risk of this B. microti-like parasite spreading among dogs and foxes in Japan will need to be carefully monitored, as parasitization by phylogenetically very close parasites has been reported from such animals.     

Development of gender differences in DBA/2Cr mouse kidney morphology during maturation

Although we recently clarified sex-based differences in mouse kidney morphology, the developmental processes responsible for these gender differences during maturation remain unclear. The present study analyzed the morphometry of kidneys from 20-, 30-, 50-, 60-, 70-, 90-, 120- and 150-day-old DBA/2Cr mice. Total kidney weight and ratio of kidney weight to body weight were larger in males than females beginning at 50 days of age. The percentage of renal corpuscles exhibiting a cuboidal parietal layer was higher in males than in females in the 70-day and older mice. The diameter of cortical renal corpuscles was larger in males than in females beginning on day 90. The number of proximal convoluted tubular cell nuclei was higher in females than in males from day 90 onward. Vacuolar structures in the proximal convoluted tubular epithelium became prominent in 70-day-old males. PAS-positive granules in the proximal straight tubular epithelium became prominent in females on day 50. This paper is the first to describe the development of gender differences in mouse kidney morphology.