Arterial Blood Gases in Dogs with Bacterial Pneumonia

The purpose of this study is to report the aterial blood gas findings in dogs with bacterial pneumonia. Arterial blood gas samples were collected from 62 dogs with culture-confirmed bacterial pneumonia. These results were compared with 46 normal dog arterial blood gas samples. Results demonstrated that respiratory acidosis was not a problem in dogs with pneumonia in this study. Significant evidence of hypoxemia was noted with abnormal mean values in PaO₂ (P<0.001) and the Alveolar-arterial (A-α) gradient (P<0.001).     

Peripheral and Central Venous Blood Glucose Concentrations in Dogs and Cats with Acute Arterial Thromboembolism

Background

Acute limb paralysis because of arterial thromboembolism (ATE) occurs in cats and less commonly in dogs. ATE is diagnosed based on physical examination findings and, occasionally, advanced imaging.

Hypothesis/Objectives

Peripheral, affected limb venous glucose concentration is decreased in ATE, whereas its systemic concentration is within or above reference interval.

Animals

Client‐owned cats and dogs were divided into 3 respective groups: acute limb paralysis because of ATE (22 cats and 9 dogs); acute limb paralysis secondary to orthopedic or neurologic conditions (nonambulatory controls; 10 cats and 11 dogs); ambulatory animals presented because of various diseases (ambulatory controls; 10 cats and 9 dogs).

Methods

Prospective observational, clinical study. Systemic and local (affected limb) blood glucose concentrations were measured. Their absolute and relative differences (ΔGlu and %ΔGlu, respectively) were compared among groups.

Results

ΔGlu and %ΔGlu were significantly higher in the ATE cats and dogs groups, compared to both of their respective controls (P < .0001 and P < .001, respectively). No significant differences were observed between the control groups. Receiver operator characteristics analysis of ΔGlu and %ΔGlu as predictors of ATE had area under the curve of 0.96 and 0.99 in cats, respectively, and 1.00 and 1.00, in dogs, respectively. ΔGlu cutoffs of 30 mg/dL and 16 mg/dL, in cats and dogs, respectively, corresponded to sensitivity and specificity of 100% and 90% in cats, respectively, and 100% in dogs.

Conclusions and Clinical Importance

ΔGlu and %ΔGlu are accurate, readily available, diagnostic markers of acute ATE in paralyzed cats and dogs.     

氨氟醚吸入麻醉妊娠犬及其胎儿动脉血药浓度和血气分析

选用 10只妊娠犬 ,实施母体及胎儿股动脉血管插管后 ,测定了氨氟醚麻醉期间母犬及胎儿的动脉血药浓度和血液 p H、PO2 (动脉氧分压 )、PCO2 (动脉 CO2 分压 )、T- CO2 (血浆 CO2 总量 )、HCO- 3 (实际碳酸氢盐 )、SB(标准碳酸氢盐 )、BEb(全血碱超 )、Sat.O2 (血氧饱和度 )。结果 :氨氟醚可透过胎盘进入胎儿血液 ,胎儿血药浓度低于母犬 ,但两者上升和消除变化趋势接近 ;麻醉期间 ,母犬及胎儿血液 p H、BEb下降 (P<0 .0 1或 P<0 .0 5 ) ,PO2 、PCO2 、Sat.O2 升高(P<0 .0 1或 P<0 .0 5 ) ,HCO- 3 、T- CO2 表现升高趋势 (P>0 .0 5 ) ,SB表现下降趋势 (P>0 .0 5 )。结果表明 ,氨氟醚吸入麻醉期间 ,母犬及其胎儿呈现轻度呼吸性酸中毒和代谢性酸中毒并存 ,并随氨氟醚血药浓度的降低而逐渐恢复     

Arterial Catheterization,Interpretation, and Treatment of Arterial Blood Pressures and Blood Gases in Birds

Blood pressure monitoring of patients has become increasingly common in companion animal veterinary hospitals, especially during anesthesia, surgical procedures, critical care, and general health assessments. Determining an animal’s blood pressure has become a standard part of the routine diagnostic evaluation for monitoring hypertension in geriatric patients or patients affected with renal insufficiency, cardiac disease, vision loss, or endocrine disorders. To increase the standard of care in exotic and zoological medicine, new diagnostic techniques must be identified and implemented. Blood pressure measurements in avian species are more challenging because only direct blood pressure techniques have been reported to be accurate. Arterial catheterization and interpretation can be daunting without the knowledge of avian physiology and anatomy; however, techniques for placing arterial catheters are not difficult once clinicians have gained sufficient experience. This article describes the techniques, anatomy, and appropriate interpretation of blood pressure results obtained through arterial catheterization in birds.     

A Comparison of Simultaneously Collected Arterial, Mixed Venous, Jugular Venous and Cephalic Venous Blood Samples in the Assessment of Blood-Gas and Acid-Base Status in the Dog

Blood samples were collected simultaneously from the pulmonary artery, jugular vein, cephalic vein, and carotid artery in awake dogs. Blood-gas and acid-base values were measured from these blood samples in normal dogs and in dogs after production of metabolic acidosis and metabolic alkalosis. The values obtained from each of the venous sites were compared with those obtained from arterial blood to determine if venous blood from various sites accurately reflected acid-base balance and could therefore be used in the clinical patient. The results of this study demonstrated significant differences between the blood from various venous sites and the arterial site for PCO2 and pH in all acid-base states. Significant differences for standard bicarbonate (SHCO3) were found only when jugular and cephalic venous blood were compared with arterial blood in dogs with a metabolic acidosis. No significant differences were found for BE when blood from the venous sites was compared with arterial blood. The values for pH, HCO3, TCO2, BE, and SHCO3 measured on blood collected at the various venous sites were found to correlate well with those obtained from arterial blood, with a correlation coefficient of 0.99 for HCO3, TCO2, BE, and SHCO3. These correlation coefficients, together with similar values in BE at all collection sites, indicate that, in the dog with normal circulatory status, blood from any venous site will accurately reflect the acid-base status of the patient.     

Influence of Fasting on Canine Arterial and Venous Blood Gas and Acid-Base Measurements

Arterial and venous blood gas profiles were obtained from 33 clinically normal adult dogs of two breeds (German Shepherd Dog and English Pointer) 4 and 24 hours after eating. Fresh drinking water was available. All dogs were fed a nutritionally complete and balanced dry diet. Blood gas parameters measured included pH, pCO₂, pO₂, bicarbonate, base excess, total carbon dioxide, oxygen content, and oxygen saturation.
Statistically significant differences (P < 0.01) were found between sampling intervals (4 and 24 hours postprandial) for pCO₂, bicarbonate, total carbon dioxide, and base excess, for arterial and venous blood samples.
Statistically significant differences (P < 0.01) were found between arterial and venous blood for all parameters, at both sampling intervals.
No statistically significant interactions (P > 0.05) were found between sample type (arterial or venous) and sampling interval.
Correlations between arterial and venous samples were generally (but not exclusively) higher than correlations between sampling intervals. Breed differences were also noted.     

静松灵对马血气,酸碱值影响的研究

以１ｍｇ／ｋｇ体重的静松灵行肌肉注射，实验马的Ｐｏ２，Ｓａｔ·Ｏ２显著下降，ｐＨ显著升高，Ｐｃｏ２，Ｔ－ＣＯ２，ＡＢ，ＳＢ，Ｃ－Ｏ２，ＰＡ－ａＤＯ２等则没有显著变化。说明静松灵对马的血气、酸碱值有一定的影响。     

Comparison of Two Indwelling Central Venous Access Catheters in Dogs Undergoing Fractionated Radiotherapy

Twenty dogs with neoplasms requiring multiple radiation treatments received either percutaneous vascular access catheters (PVACs; Cook, Bloomington, IN) or subcutaneous vascular access ports (SVAPs; Vascular-Access-Ports, Norfolk Medical Products, Inc., Skokie, IL); 10 dogs were entered in each group. All catheters were implanted and removed aseptically and the catheter tips were cultured during implant removal. Complications with PVACs included mild incisional swelling and redness and accidental severance or rupture of the catheter. Complications with SVAPs included incisional or port swelling, bruising or redness, hematoma formation, and pain. Ports in 4 of these dogs could not be used for 1 to 3 days after surgery because of swelling and pain. Surgical wound complications, when pooled for comparison, occurred significantly more frequently with the SVAPs ( P = .023). Wound complications associated with both catheters were self-limiting and resolved within 7 days. Bacterial cultures were positive in two PVACs and four SVAP tips, however, none of these dogs had clinical signs of infection or sepsis. Although both types of indwelling catheters were functional in a clinical setting, PVACs were preferred to SVAPs for dogs undergoing radiation therapy because of decreased time for implantation and fewer overall complications.     

Systemic Arterial Dirofilariasis in Five Dogs

Systemic arterial dirofilariasis is an unusual manifestation of heartworm disease of dogs that results from aberrant migration of Dirofilaria immitis into the peripheral arterial circulation. To expand the clinical characterization of systemic arterial dirofilariasis, 5 dogs evaluated at the North Carolina State University's College of Veterinary Medicine were reviewed. Common clinical presentations included hindlimb lameness, paresthesia of hindlimbs, and interdigital ischemic necrosis resulting from thromboembolic disease. Visualization of heartworms with angiography or ultrasonography confirmed the diagnosis in all cases. All 5 dogs were treated with an adulticide; 3 dogs were treated with thiacetarsamide sodium and 2 with melarsomine dihydrochloride. Four of the 5 dogs survived the initial treatment period; 1 dog died of severe thromboembolic complications after thiacetarsamide sodium therapy. The treatment of systemic arterial dirofilariasis creates a therapeutic challenge because of multiple potential complications resulting from thromboembolic disease.     

A Portable Blood Gas Analyzer for Equine Venous Blood

Evaluation of a portable blood gas analyzer, (StatPal II, Unifet, Inc, La Jolla, CA) was performed using tonometered solutions and equine blood. Samples were analyzed by the StatPal II and either an Instrument Laboratory IL1306 (Lexington, MA) or a Radiometer ABL50 blood gas analyzer (Radiometer America Inc., Westlake, OH). Comparison of the StatPal II and the IL1306 was done by analysis of 3 tonometered solutions (acidic, normal, and alkalotic) and 27 equine venous blood samples. Blood pH, Pco₂, Po₂, and [HCO₃^-] values were altered by IV infusion of 5% sodium bicarbonate or exercising the horses on a treadmill. Comparison of the StatPal II and the Radiometer was performed by analysis of 78 blood samples collected from Standard-bred horses before a race. Data were analyzed for the venous blood samples using a paired two-tailed Student's t test and Bland-Altman plots, with significance set at P < .05. The coefficients of variation for pH, Pco₂, Po₂, and [HCO₃^-] values of the tonometered solutions analyzed by the StatPal II ranged from 0.067% to 0.087%, 2% to 3.21 %, 1.21 % to 2.67%, and 0.267% to 0.828%, respectively. Comparison of the equine blood samples analyzed by the StatPal II and the IL1306 demonstrated statistically significant, but clinically irrelevant differences in pH, Pco₂, and Po₂, but not [HCO₃^-]. There were statistically significant, but clinically irrelevant differences between the StatPal II and the Radiometer for pH, Pco₂, and [HCO₃^-], but not for Po₂-It is concluded that the StatPal II provides reproducible and acceptable analysis of equine venous blood gas samples.     

A Comparison of Laparoscopic and Belt-Loop Gastropexy in Dogs

A simplified technique for laparoscopic gastropexy (group 1) was compared to belt-loop gastropexy (group 2) in eight adult male dogs randomly divided into two groups of four dogs each. Our hypothesis was that a satisfactory laparoscopic gastropexy would approximate the strength and operative time required for belt-loop gastropexy. Operative time, surgical complications, postoperative morbidity, gross and histological appearance, radiographic microvascularization, and maximal tensile strength were measured and compared between the two groups. All dogs recovered from surgery. No morbidity was associated with either procedure. The mean (±SD) duration of surgery was 69.75 ± 7.23 minutes for group 1 and 58.75 ± 7.63 minutes for group 2. Fifty days after surgery, the microvascular appearance of the gastropexy site was similar for both groups. Blood vessels were observed within each seromuscular flap but vascular ingrowth to the abdominal musculature was observed in only two dogs, one from each group. The maximum tensile strength at 50 days was 76.55 ± 22.78 for group 1 and 109.21 ± 22.29 N for group 2. Differences between surgical duration and maximum tensile strength were not statistically significant ( P >.05). Histologically, all gastropexies consisted of an adhesion composed of dense fibrous connective tissue. The results of this study indicate that laparoscopic gastropexy provides a minimally invasive alternative to open abdominal prophylactic gastropexy in dogs.     

Endotoxin Concentrations Measured by a Chromogenic Assay in Portal and Peripheral Venous Blood in Ten Dogs With Portosystemic Shunts

A chromogenic Limulus amebocyte lysate assay was used to measure portal and peripheral venous endotoxin concentrations in ten medically managed dogs undergoing surgery for correction of a single extrahepatic portosystemic shunt. In all dogs, both peripheral and portal venous blood samples were obtained at the time of surgical manipulation of the anomalous vessel. In six dogs, peripheral venous samples were obtained an average of 8.0 months after surgery. Five physically normal dogs without biochemical or histologic evidence of liver disease served as controls. Data analysis failed to demonstrate significant differences in peripheral and portal venous endotoxin concentrations between the control and study groups. Postoperatively five of six dogs showed a measurable reduction in peripheral venous endotoxin concentration over intraoperatively obtained values, but the differences were not statistically significant (P = 0.06). Based on results of this study it was concluded that systemic endotoxemia was not present in dogs with a single extrahepatic portosystemic shunt that were medically stable prior to surgery.     

A Comparison of Liver Sampling Techniques in Dogs

Background

The liver sampling technique in dogs that consistently provides samples adequate for accurate histopathologic interpretation is not known.

Hypothesis/Objectives

To compare histopathologic results of liver samples obtained by punch, cup, and 14 gauge needle to large wedge samples collected at necropsy.

Animals

Seventy dogs undergoing necropsy.

Methods

Prospective study. Liver specimens were obtained from the left lateral liver lobe with an 8 mm punch, a 5 mm cup, and a 14 gauge needle. After sample acquisition, two larger tissue samples were collected near the center of the left lateral lobe to be used as a histologic standard for comparison. Histopathologic features and numbers of portal triads in each sample were recorded.

Results

The mean number of portal triads obtained by each sampling method were 2.9 in needle samples, 3.4 in cup samples, 12 in punch samples, and 30.7 in the necropsy samples. The diagnoses in 66% of needle samples, 60% of cup samples, and 69% of punch samples were in agreement with the necropsy samples, and these proportions were not significantly different from each other. The corresponding kappa coefficients were 0.59 for needle biopsies, 0.52 for cup biopsies, and 0.62 for punch biopsies.

Conclusion and Clinical Importance

The histopathologic interpretation of a liver sample in the dog is unlikely to vary if the liver biopsy specimen contains at least 3–12 portal triads. However, in comparison large necropsy samples, the accuracy of all tested methods was relatively low.     

A Comparison of 2 Pluse Oximeters in Dogs

Readings from 2 veterinary pulse oximeters (SDI Vet-Ox #4402 and Nellcor N-20V) were compared in 6 isoflurane-anesthetized dogs. Simultaneous readings Of S_p0₂were recorded from 2 sites (toe and ear) over a range of inspired oxygen concentrations (15-100%), and compared to directly measured S_aO₂ readings. Greater variability of readings was obtained from the Vet-Ox, which failed to give readings 25% of the time. The bias (mean S_aO₂-S_p0₂) and precision (SD of bias) were calculated from the data for each oximeter. For the Vet-Ox, bias (precision) from the toe was +4.O (5.2) and from the ear +1.7 (2.2). The bias (precision) for N-20V readings from the toe was +1.6 (1.5) and from the ear +0.7 (1.5). Generally, both oximeters tended to underestimate S_aO₂; however, both overestimated at the lowest P_a0₂ values. Pearscn cowelation coeefficients were 0.81 for the Vet-Ox and 0.94 for the N-20V for the combined data, including value from probes placed on the toe and ear at all inspired oxygen concentrations. In the two locatiom from which readings were obtained, the 2 units performed quite differently.     

Iron Status in Blood Donor Dogs

Background

Despite the popularity of canine blood donor (BD) programs, there is scarce scientific information regarding iron status in this canine population of dogs.

Objective

To assess iron status in dogs used in a blood donor program.

Animals

A total of 130 healthy dogs (75 BD, 55 controls [C]) were included. A subset of dogs (n = 12) were used to evaluate the effects of repetitive donations by having a second and more recent sample analyzed.

Methods

Serum iron concentration (SI), unsaturated iron‐binding capacity (UIBC), total iron‐binding capacity (TIBC), and percentage transferrin saturation (%SAT) were obtained. Values were compared using a 2‐way ANOVA (factors: BD status, breed). For the subset of BD, the first sample (less frequent donors ‐LD‐, after a mean of 3.8 donations) was compared to a second sample (experienced donors ‐ED‐, mean 13.6 donations) using a paired t‐test.

Results

SI (183.7 ± 55.3 μg/dL) and %SAT (55.7 ± 17.4%) were higher and UIBC (152.6 ± 73.3 μg/dL) was lower in BD dogs than in C (153.9 ± 51.7 μg/dL, 43.8 ± 17.8%, and 224.1 ± 120.6 μg/dL, respectively). Also, UIBC and TIBC were lower, and %SAT higher in Greyhounds when compared with non‐Greyhounds. ED had decreased %SAT and increased UIBC and TIBC when compared with LD.

Conclusions and Clinical Importance

Our canine BD population did not have iron deficiency and had higher SI concentration than C. However, ED (~14 consecutive blood donations every ~8 weeks) developed a mild iron deficiency, although values were still within canine reference intervals. Greyhounds have higher %SAT than non‐Greyhounds, which might be a breed‐specific peculiarity.     

A Comparison of Manual and Power-Assisted Thoracolumbar Disc Fenestration in Dogs

Thoracolumbar disc fenestration was performed in eight canine cadavers. A hole was cut in the anulus fibrosus with a scalpel in four dogs, and with a high speed drill and burr in four dogs. A curette was used to remove as much of the nucleus pulposus as possible. Sixty-five percent of the nucleus pulposus was removed with the power-assisted technique and 41% was removed by manual fenestration. Manual and power-assisted disc fenestration were performed on alternate intervertebral discs from T11-12 to L5-6 in four dogs. Six months after surgery, results of high-detail radiographic and histologic evaluation of the vertebral bodies and discs showed minimal difference in the sequelae of the two techniques. A retrospective medical records analysis and follow-up of 60 clinical cases treated with prophylactic, power-assisted disc fenestration failed to identify any cases with postoperative recurrence of neurologic deficits. Ten percent of the dogs had periodic back pain of unknown etiology, without other signs of intervertebral disc disease. The findings of this study indicate that power-assisted disc fenestration permits more complete evacuation of the nucleus than manual fenestration, causes no more postoperative complications, and results in a low recurrence rate of neurologic deficits.     

End-to-End Colonic Anastomosis A Comparison of Techniques in Normal Dogs

Colonic resections were repaired in normal dogs by crushing suture, inverting suture, or staple anastomosis techniques. Dogs were sacrificed 2, 4, 7, 10, 14, 21, and 28 days following surgery. Bacterial cultures, breaking strength measurement, adhesion formation, and gross and histopathologic examinations were made. Anastomoses closed by staples showed the least tissue reaction, least neutrophilic infiltration, most mature fibrous connective tissue, most normal arrangement of muscle layers, and fewest numbers of mucoceles and necrotic areas. The staple and crushing anastomosis techniques caused significantly less reduction in luminal radius than did the inverting anastomosis technique. Bacteria were isolated least frequently and adhesions were least severe following staple anastomosis, though these results were not statistically significant. Stapled anastomosis appeared to result in a higher tensile strength of the wounds at the anastomotic sites compared with the other techniques studied.