Spinal cord granuloma due to Coccidioides immitis in a cat

A6-year-old 5.5-kg female spayed domestic short-haired cat from Tucson, AZ, presented with an ˜5-day history of progressive pelvic limb weakness. The owners had returned from a weekend away to find the cat unable to use her left pelvic limb. Approximately 2 months previously, the cat had a cough and was treated for presumptive asthma with 5 mg prednisone PO q24h. The cat had a similar cough 1 year previously and seasonal allergy was suspected. The cough resolved and prednisone treatment was discontinued. Other past pertinent history included a skin problem ˜4 years previously that was described as alopecia, erythema, and pruritus of a pelvic limb. This problem had been diagnosed as an allergy and had since resolved. The cat was housed exclusively indoors and had been adopted as a kitten from a local retail store. Viral titers (FeLV and FIV) were negative, and regular vaccinations and veterinary examinations had been completed     

Dose-related antinociceptive effects of intravenous buprenorphine in cats

The dose-related antinociceptive effects of intravenous (IV) buprenorphine were evaluated in cats. Thermal (TT) and mechanical threshold (MT) devices were used for nociceptive stimulation. After baseline threshold recordings, buprenorphine was administered IV (0.01, 0.02 or 0.04 mg/kg; B1, B2 and B4, respectively) in a randomised, blinded and cross-over study. Data were analysed by ANOVA (P < 0.05) using 95% confidence intervals (CI). TT increased 15, 30, 45 min and 1 (5.2 ± 2.7 °C), 2, 3 and 4 h after B1; 15, 30, 45 min and 1 (5.1 ± 3.9 °C) and 2 h after B2, and 15, 30, 45 min and 1 (5.4 ± 3.3 °C), 2, 3, 6 and 8 h after B4. MT increased 15 and 45 min after B2 (260 ± 171 mmHg), and 30 (209 ± 116 mmHg) and 45 min and 1 and 2 h after B4. At 45 min, MT values were significantly higher after B2 compared to B1 (P < 0.05). With MT, B2 and B4 produced more antinociception and longer duration of action than B1, respectively. No dose response to thermal stimulation was detected.     

Canine leukocyte adhesion deficiency: presence of the Cys36Ser beta-2 integrin mutation in an affected US Irish Setter cross-breed dog and in US Irish Red and White Setters

Canine leukocyte adhesion deficiency (CLAD) is a primary immunodeficiency disease characterized by recurrent bacterial infections in the presence of marked leukocytosis. The disease was 1st described in the mid-1980s in a cross-breed Irish Setter Dog in the United States. It results from a defective beta-2 subunit of heterodimeric leukocyte adhesion proteins. The causative mutation for CLAD in Irish Setter Dogs from Europe has been identified as a missense mutation at base pair position 107 in the beta-2 integrin subunit gene (ITGB2) that results in an amino acid change from cysteine to serine at amino acid 36 (Cys36Ser) in the beta-2 integrin subunit protein. In the current work, the originally described dog with CLAD has been genetically tested and shown to have the same mutation as the European Irish Setters. This suggests that the mutation has been in the Irish Setter population for many generations spanning more than 2 decades. A related breed, the Irish Red and White Setter, has a history of interbreeding with Irish Setters and shares a common ancestry with the Irish Setter breed. DNA from Irish Red and White Setters residing in the United States was screened either by sequencing or by the newly developed restriction enzyme test for the Irish Setter Cys36Ser CLAD mutation. Seven of 54 dogs tested (13%) were found to be carriers of the Irish Setter CLAD mutation. Five of these were directly related to a sire from the UK, demonstrating the importation of an allele from another continent and establishing the need for genetic testing in this breed in the United States.     

Spirochetemia caused by Borrelia turicatae infection in 3 dogs in Texas

Spirochetemia was diagnosed in 2 Siberian Huskies and a Rottweiler from the northwestern region of Texas between June 1999 and October 2001. Clinical findings were nonspecific; tick exposure was documented in 2 of the dogs. Hematologic abnormalities included anemia (n=2), neutrophilia (n=2, including 1 with a left shift), lymphopenia (n=3), eosinopenia (n=3), and thrombocytopenia (n=2). One anemic dog had a positive Coombs' test. In 1 dog, Western blot analysis of serum yielded multiple positive bands with B turicatae lysate, indicating the spirochetemia most likely was due to B turicatae infection. In 2 dogs, spirochetes were cultured from the blood and identified using DNA analysis as Borrelia turicatae; 1 of these dogs also was seropositive for Ehrlichia canis and B burgdorferi. In 2 cases, spirochetemia was more prominent in blood smears prepared immediately after sample collection than in smears prepared from EDTA blood. Two dogs recovered with doxycycline treatment; 1 dog declined clinically despite treatment and was euthanized. B turicatae is the agent of tick-borne (endemic) relapsing fever in humans and is distinct from B burgdorferi, the agent of Lyme disease; however, serologic cross-reactivity may occur. B turicatae is transmitted by the soft tick, Ornithodoros turicata, and infection should be considered in dogs with spirochetemia and possible exposure to the tick vector.     

A study to evaluate buprenorphine at 40 μg kg(-1) compared to 20 μg kg(-1) as a post-operative analgesic in the dog

ObjectiveComparison of the analgesic effect of buprenorphine at 20 or 40 μg kg^?1.Study designAn investigator ‘blinded’, randomised study.AnimalsTwenty six dogs presented for ovariohysterectomy.MethodsDogs were premedicated intramuscularly with acepromazine 0.03 mg kg^?1 and buprenorphine at either 20 (B20, n = 12) or 40 μg kg^?1 (B40, n= 14) followed by anaesthetic induction with propofol and maintenance with isoflurane. During anaesthesia non invasive blood pressure, heart rate, respiratory rate, blood oxygen saturation, inspired and expired volatile agent, end-tidal carbon dioxide and ECG were recorded. Pain and sedation were assessed using interactive VAS scores; mechanical nociceptive thresholds were measured at the wound and hindlimb - all were assessed before and up to 22 hours after administration. Carprofen was used for rescue analgesia.ResultsThere were no significant differences between the two groups for any of the parameters examined. Rescue analgesia was required around 5 hours after administration of buprenorphine in a significant number of animals. Sedation was good preoperatively and scores decreased over time postoperatively. Hock thresholds did not change over time; wound thresholds decreased significantly compared to the baseline value from 3 hours onwards.ConclusionsAdministration of buprenorphine at either 20 or 40 μg kg^?1 IM with acepromazine provided good pre-operative sedation. Cardiovascular and respiratory values remained within clinically acceptable limits during anaesthesia. There was no evidence that increasing dose increased adverse events that may be associated with opioid administration (e.g. bradycardia and respiratory depression).Clinical relevanceIncreasing the dose of buprenorphine from 20 to 40 μg kg^?1 did not provide any benefits with respect to analgesia after ovariohysterectomy as assessed using the VAS scoring system.     

The influence of various confounding factors on mechanical nociceptive thresholds in the donkey

ObjectiveTo evaluate a mechanical nociceptive threshold (MNT) testing device in the donkey, and to investigate the influence of potential confounders on MNTs generated.Study designProspective, randomised.AnimalsSixteen castrated male donkeys aged 4–9 years, weighing 105–170 kg.MethodsMechanical nociceptive thresholds were measured using an actuator with three pins placed on the dorsal aspect of the distal limb, connected to a force meter. The pins (surface area 15 mm²) were extruded onto the limb by pressurising an air-filled syringe, until the MNT force (when foot-lift was observed) or 25 N (cut-off force) was reached. Effect on MNT of presence of a companion donkey, the limb tested, rate of application of force, testing location, level of distraction, ambient temperature and hair cover at the test site was evaluated. Long and short-term repeatability of MNT was assessed. Data were analysed using general linear models and Mann–Whitney U tests, p < 0.05 was considered significant.ResultsIncreasing the rate of force application significantly increased the mean ± SD MNT from 9.2 ± 2.0 N when applied at 0.4 N sec^?1 to 10.6 ± 2.1 N when applied at 1.2 N sec^?1 (p = 0.001). No other factors significantly influenced MNT. Mean MNT remained stable over a 3 week period, however MNTs were significantly (p = 0.006) higher (12.8 ± 3.0 N cf 10.3 ± 1.9 N) after a 12 month interval.Conclusions and clinical relevanceWhen designing studies measuring MNT in donkeys, rate of application of force must be standardised. Donkeys’ MNTs have good short-term stability suggesting this technique is appropriate for short-term analgesiometry studies; however variability of MNTs over the long-term is greater.     

MEASUREMENTS OF HINDLIMB BLOOD FLOW RECORDED USING DOPPLER ULTRASOUND DURING ADMINISTRATION OF VASOACTIVE AGENTS IN HALOTHANE-ANESTHETIZED HORSES

The purpose of the study was to determine the ability of Doppler ultrasound to detect changes in femoral blood flow during pharmacologic manipulation of arterial blood pressure. Doppler ultrasonography was performed in the femoral vessels of six halothane-anesthetized horses before and during administration of phenylephrine HCI and sodium nitroprusside. The time-averaged mean velocity and volumetric flow were calculated. The contour of the velocity waveform was assessed, and the early diastolic deceleration slope (EDDS) and pulsatility index (PI) were calculated. Administration of phenylephrine HCI resulted in increased mean aortic blood pressure (MABP) by 40% (29.3-53.0%). This caused significant decrease in cardiac output (26.8 to 13.5 l/min), femoral arterial velocity (left artery 7.20 to 4.00 cm/s; right artery 5.01 to 3.39 cm/s) and volumetric flow (left artery 556 to 221 ml/min; right artery 397 to 193 ml/min) in the femoral vessels and significant increase in systemic vascular resistance (163 to 433 dyn-s/cm5), EDDS (1a: 285 to 468: ra: 250 to 481) and PI (1a: 9.38 to 20.4; ra 17.1 to 29.1). Administration of sodium nitroprusside resulted in a decreased MABP of 27.2% (22.5-33%). This increased cardiac output (20.8 to 32.4 L/min), however, no significant changes were observed in femoral blood flow. Despite obvious changes in the waveform contour, no significant change occurred in EDDS or PI. These results suggest that Doppler ultrasound may be useful for measuring femoral blood flow in anesthetized horses. However, waveform analysis appears to be limited when multiple changes occur in central and peripheral haemodynamics.