We investigated small-volume (5 ml/kg) 7% NaCl in 6% dextran 70 (HS/D70) as an alternative to large-volume (60 ml/kg) 0.9% NaCl for treatment of experimentally induced canine gastric dilatation-volvulus (GDV) shock. The stomach was surgically displaced and then distended with an intragastric balloon in 11 dogs anesthetized with pentobarbital. All dogs were subjected to GDV for 180 minutes before partial decompression and resuscitation. Hemodynamic values, blood gas values, and plasma volume were measured during control, shock, and resuscitation periods. Resuscitation started with 1 group (n = 6) receiving 5 ml of HS/D70/kg, IV, over 5 minutes, and the other group (n = 5) receiving 60 ml of 0.9% NaCl/kg, IV, over 60 minutes. Both groups received a surgical maintenance dosage (20 ml/kg/h of 0.9% NaCl after initial resuscitation. Resuscitative effects of small-volume HS/D70 were similar to large-volume 0.9% NaCl during the first hour of treatment; however, cardiac output was significantly higher in the HS/D70 group for the last 2 hours of resuscitation. Changes in heart rate, left ventricular pressure change, and systemic vascular resistance appeared to be responsible for improved perfusion. Mixed venous oxygen partial pressure data supported improved perfusion in the HS/D70 group. Packed cell volume remained higher in the HS/D70 group, indicating less hemodilution and improved oxygen delivery. Resuscitation of this GDV-induced shock model was better sustained with small-volume HS/D70, compared with conventional large-volume 0.9% NaCl.

Noninvasive determination of anal and genitoanal reflexes was evaluated in clinically normal cats. Thirty adult mixed-breed cats (15 sexually intact or castrated males, 15 sexually intact or spayed females) were sedated by IV administration of ketamine, acetylpromazine, and atropine. Anal reflexes were recorded from the anal sphincter muscle after ipsilateral and contralateral electrical stimulation of the perineal skin. Genitoanal reflexes were recorded from the anal sphincter muscle after electrical stimulation of the penis or clitoris. An anal sphincter response to tibial nerve stimulation was attempted. Anal reflexes from ipsilateral and contralateral stimulations and a genitoanal reflex were detected in all cats. Anal sphincter responses to tibial nerve stimulation were inconsistent (4/30) and were not included in any analyses. Anal reflexes had response latencies of 7.5 to 12.0 ms (ipsilateral stimulation) and 6.5 to 13 ms (contralateral stimulation). Genitoanal reflexes had latencies of 9.0 to 13.0 ms (males) and 6.5 to 9.0 ms (females). Anal reflex latencies were significantly (P < 0.05) longer for contralateral, opposed to ipsilateral, stimulation and were significantly (P < 0.05) longer in males than in females. Genitoanal reflex latencies were also significantly (P < 0.05) longer in males than in females, reflecting the more peripheral stimulation site in males. Anal reflex responses could be recorded in 2 feline clinic patients with such severe perineal trauma that pudendal nerve function could not be manually evaluated. A potentially favorable prognosis was given in each instance on the basis of detection of the response. One cat eventually recovered. The other was euthanatized because of other problems, and the sacral part of the spinal cord, sacral nerve roots, and pudendal nerves were found to be intact at necropsy.

Sixteen Holstein cows were used to test the effect of postmilking teat treatment on colonization and intramammary infection by Staphylococcus aureus on chapped teats. Treatments were (1) chapping the teat and using 1% I2/10% glycerin postdip solution, (2) 1% I2/10% glycerin postdip solution on nonchapped teats, (3) chapping the teat and using 10% glycerin postdip solution, (4) chapping the teat and not using a postdip solution. All mammary glands were free of S aureus teat skin colonization and intramammary infection at the start of the study. Teats selected for chapping were dipped in 1N NaOH prior to 3 applications of S aureus broth culture; cultures were applied at 12-hour intervals on all teats. Treatments were applied after each milking for 30 days and were initiated after the second broth dip. Teat skin swab specimens and milk samples were collected before treatment application. Teat skin condition was scored daily. Nonchapped teats (treatment 2) did not support skin or orifice colonization by S aureus. Treatment-1 teats healed most rapidly and supported less colonization in skin and orifice than did treatment-3 and -4 teats. Teat skin scores and skin colonization were lower for treatment-3 than treatment-4 teats. A correlation between teat skin colonization and teat skin conditions was found. Two intramammary infections were found in treatment-4 quarters and 1 in a treatment-3 quarter. On the basis of our findings, we concluded that poor teat skin condition will more readily support S aureus colonization, that a dip of 1% I2 with glycerin helped reduce S aureus colonization and was associated with faster healing, and that glycerin in teat dips may be of value in preventing colonization by S aureus and in promoting healing.

An experiment was conducted to determine whether a persistent Salmonella newport infection could be established in swine, to determine duration of shedding and distribution of the organism in internal organs, and to determine whether changes occurred in antimicrobial susceptibility or plasmid profile of the organism during the course of long-term infection. Naturally farrowedSalmonella-free pigs (n = 22) were orally exposed to a multiply antimicrobial-resistant zoonotic strain of S newport when they were 7 weeks old. Tonsillar and rectal swab specimens were examined bacteriologically for S newport during the first week after exposure, then weekly for 7 weeks. Fecal samples were likewise examined weekly or every 2 weeks for 28 weeks after exposure. Necropsies of 2 or 3 randomly selected pigs were conducted at 2, 4, 8, 12, 16, 20, 24, and 28 weeks after exposure. A total of 45 specimens/pig representing the following internal organs or tissues were examined bacteriologically for S newport: liver, spleen, kidney, gallbladder, heart, heart blood, lung, stomach, and tonsils; segments of the intestinal tract with corresponding lymph nodes; and lymph nodes from lymphocenters of the head and neck, thoracic cavity, thoracic limbs, abdominal viscera, and abdominal wall. Exposure to S newport induced a mild and transient clinical response. The organism was recovered from 97% of tonsillar swab specimens and 89% of rectal swab specimens collected during 7 weeks after exposure and from 98% of fecal samples collected during 28 weeks after exposure. At necropsy, S newport was recovered most frequently from tonsils (86.4%), followed by segments of the intestinal tract from ileum to rectum (81.8% recovery from cecal contents), and from mandibular (68.2%), jejunal (50%), and ileocolic (45.5%) lymph nodes. Sporadic recoveries of the organism were made from other lymph nodes and from gallbladder, stomach, kidney, spleen, liver, and heart, varying from 2 to 20 weeks after exposure. The cranial portion of jejunum, medial iliac lymph nodes, dorsal superficial cervical lymph node, and heart blood of all pigs were culture-negative. Of 26 representative isolates of S newport recovered from body organs or feces during 28 weeks after exposure, 4 (15.4%) underwent changes in antimicrobial susceptibility pattern. Changes in plasmid profile of the organism were not detected during longterm infection of swine.

Mice with a severe combined immunodeficiency in B and T lymphocytes and natural killer cells (SCID-beige) were inoculated intranasally with sialodacryoadenitis (SDA) virus, a coronavirus of rats. Animals were killed at designated intervals and tissues were examined for evidence of viral infection by light microscopy and immunofluorescence microscopy. Based on these criteria, there was no evidence that these immundeficient mice were susceptible to infection with SDA virus.

A protected catheter brush introduced by fiberoptic bronchoscopy was used to sample the tracheal and bronchial mucosa in 28 horses with small airway disease. Tracheal and bronchial brushings were examined for the presence of fungi, aerobic and anaerobic bacteria, and a cytoiogical evaluation was also done on fluid collected by the bronchoalveolar lavage (BAL) technique. Microorganisms (bacteria and fungi) were isolated more often in tracheal brushings (53.6%) than in bronchial brushings (10.7%). Anaerobic bacteria were not isolated. Results of this study indicate that fiberoptic bronchoscopy using a protected catheter brush is an easy and practical technique to obtain minimally contaminated samples for isolation of microorganisms from the lower respiratory tract of horses. However, no association was observed between isolation of high numbers of microorganisms from the bronchi and severity of small airway disease.

To determine the position, dimensions, and structure of the right kidney in cattle by use of ultrasonography, the right kidney of 11 healthy Brown Swiss cows was examined 10 times within 2 weeks. A 3.5- and 5.0-Mhz linear and convex transducer was placed on the right side of the cow in the lumbar region, in the paralumbar fossa, and in the last intercostal space. The echogenicity of various renal structures differed. The lobulation of the kidney in cattle could be visualized ultrasonographically; however, the cortex and medulla could not be differentiated. The distance between body surface and the right kidney was almost 3 times larger (5.3 +/- 1.71 cm, mean +/- SD) in the lumbar region than in the paralumbar fossa (1.8 +/- 0.52 cm). The vertical diameter of the kidney was remarkably smaller (5.1 +/- 0.47 cm) than the horizontal diameter (9.4 +/- 0.98 cm). In 7 cows, the thickness of the renal cortex and medulla was between 1.9 and 2.1 cm. The medullary pyramids could be visualized when the transducer was placed in the paralumbar fossa. Fourteen of 19 variables measured had a coefficient of variation between 8 and 14%. It was concluded that the ultrasonographic values determined in this study can be used as references for the diagnosis of morphologic changes in the right kidney of domestic dairy cattle.

A morphologic and morphometric study was carried out on the facial nerve: to determine normal histologic data in myelinated fibers of clinically normal young adult dogs; to establish reference values for mean fiber diameter, and to delineate the relative diameter frequency distribution curve. Few degenerative changes were observed in single teased-nerve fibers and semithin cross-sectional nerve preparations. Statistical difference was not observed between left and right facial nerves. The distribution of fiber diameters in the facial nerve was unimodal. Mean (+/- SD) fiber diameter of the facial nerve was 3.92 +/- 1.18 micromole. Approximately 89% of fibers in the facial nerve had diameter between 3 and 6 micromole. Fiber diameter ranged from 2 to 12 micromole; however, < 1% of fibers had diameter > 8 micromole.

Twenty mature Holstein cows were randomized into 5 treatment groups. Cows of groups 2 to 5 were given 2 mg of elemental Pb/kg of body weight for 28 days. Clinical signs of plumbism were scored, and blood for Pb, progesterone, and hematologic analyses was collected weekly. Cows also were examined weekly for anomalous ovarian cycles. Starting on study day 28, cows in group 3 were treated once daily with 2 mg of thiamine HCl/kg (IM) for 13 days, cows in group 4 were treated twice daily with 62 mg of Na2,Ca-EDTA/kg (IV) for 4 days, and cows in group 5 were given thiamine (dosage regimen the same as for group 3) plus Na2,Ca-EDTA (dosage regimen the same as for group 4). On study days 96 through 139, cows were slaughtered in a commercial abattoir and samples of blood, skeletal muscles, bones, liver, and kidneys were collected and assayed for Pb concentration. Thiamine was not effective in reducing blood Pb concentration, and treatment with Na2,Ca-EDTA and thiamine plus Na2,Ca-EDTA was effective in reducing the concentration of Pb in blood. However, treatment with thiamine was more effective than treatment with Na2,Ca-EDTA or thiamine plus Na2,Ca-EDTA in inducing remission of clinical signs of plumbism. The concentration of Pb in blood was significantly (P < 0.05) correlated to the concentration of Pb in liver, kidneys, skeletal muscles, and bones. Significant (P < 0.05) relationship existed between number of days from Pb exposure to slaughter and concentration of Pb in blood, liver, and skeletal muscles. Exposure to Pb did not significantly alter CBC values. On the basis of progesterone analysis and ovarian examination, exposure to Pb and treatment for plumbism did not induce changes in the ovarian cycle.

To determine the effect of oral administration of prednisolone on thyroid function, 12 healthy Beagles were given 1.1 mg of prednisolone/kg of body weight every 12 hours for 22 days after 8 days of diagnostic testing of the dogs before treatment with prednisolone. Thyroid-stimulating hormone (TSH) and thyrotropin-releasing hormone (TRH) response tests were performed before treatment (days 1 and 8 of the study) and during treatment (days 21 and 28 of the study). Blood samples were collected daily at 8 AM and 2 and 8 PM to rule out normal daily hormone fluctuations as the cause of a potential decrease in serum triodothyronine (T3), thyroxine (T4), and free T4 (fT4) concentrations. Serum T3, T4, and fT4 concentrations before treatment and 1 day and 21 days after the first prednisolone dose were compared by analyses of variance. Post-TSH and -TRH serum T3 and T4 concentrations before and during treatment were compared, using the Student t test for paired data. Oral administration of prednisolone significantly (P < 0.005) decreased serum T3, T4, and fT4 concentrations in the 8 AM and 2 and 8 PM samples obtained 1 day and 21 days after the first prednisolone dose. Serum T4 and fT4 concentrations in 8 AM and 2 PM samples were significantly (P < 0.05) lower 21 days after the first prednisolone dose than they were at 1 day after the first dose. Before treatment, serum T4 concentration in the 2 PM samples was significantly (P < 0.05) higher than serum T4 concentration in 8 AM and 8 PM samples. Oral administration of prednisolone significantly (P < 0.01) decreased serum T3 and T4 concentrations 6 hours after TSH and TRH injections. Significant difference in the mean incremental change in serum T3 and T4 concentrations was not observed when comparing before- and during prednisolone treatment values for the TRH response test. However, for the TSH response test, the mean incremental changes in serum T3 and T4 concentrations were significantly (P < 0.01) lower during prednisolone treatment. Despite the decreased TSH response incremental change in serum T4 concentration during oral treatment with prednisolone, the lowest value observed fell within the before-treatment range. In addition, during treatment, baseline serum T3 and T4 concentrations after TSH administration increased, on average, 3.7 and 8.4 times, respectively.