Management of advanced tracheal collapse in dogs using intraluminal self-expanding biliary wallstents

Twenty-four client-owned dogs with tracheal collapse refractory to conventional treatment underwent management with an intraluminal self-expanding stainless-steel endoprosthesis (Wallstent). Initial improvement of clinical signs was observed in 95.8% of the dogs. Two dogs (8.3%) died within a median interval of 6 days after stent implantation due to incorrect placement and size of the stent and emphysema, respectively. A dry cough occurred temporarily in most of the patients. One dog each (4.1%) suffered mild transient tracheal hemorrhage and pneumomediastinum. The results showed that the initial survival rate of intraluminal stabilization was comparable with surgical implantation of extratracheal prostheses. Clinical reevaluation was performed in 18 dogs within a median interval of 68 days after treatment. Of the dogs treated, 30.4% were reported to be asymptomatic after stent implantation, 60.9% improved markedly, and 4.3% remained symptomatic. In all patients undergoing endoscopy, the Wallstents were almost completely covered with tracheal epithelium. A median shortening of 27.3% of the endoprosthesis within a median interval of 175 days after stent implantation in 15 of 18 dogs was noted. The shortening was associated with clinical signs in 2 patients. In 5 dogs, steroid-responsive granuloma formation resulted in a severe reduction of the tracheal lumen in 3 patients. The results suggest that implantation of Wallstents was minimally invasive and provided stabilization of collapsed thoracic tracheal portions in addition to the cervical part of the trachea. This minimally invasive method for the management of severe tracheal collapse therefore provides an attractive alternative to surgery.     

Automated flow cytometric cell count and differentiation of canine cerebrospinal fluid cells using the ADVIA 2120

Background: Microscopic cell counts in cerebrospinal fluid (CSF) are time-consuming and prone to imprecision. The recently introduced automated hematology analyzer ADVIA 2120 offers an automated cell count and differential for CSF in the veterinary software mode based on laser light scatter and absorbance measurements. Objectives: The purpose of this study was to evaluate the precision, linearity, and accuracy of the ADVIA 2120 CSF assay. Methods: Sixty-seven CSF samples were analyzed on the ADVIA 2120 and total nucleated cell counts (TNCC) and RBC counts were compared with the hemocytometer results. In 21 samples with TNCC >5/muL, ADVIA 2120 results were compared with 100-300 cell manual differentials performed on cytocentrifuged preparations. Statistical analysis included Spearman's rank correlation, Passing-Bablok regression, and Bland-Altman analysis. Results: Repeatability (intra-assay) coefficients of variation (CVs) ranged from 4.19% to 25.94%. Interassay CVs ranged from 2.56% to 28.67%. Accurate results within 30% were achieved for TNCC up to 4000/muL. Except for low TNCC, deviation from the expected value was higher (TNCC of 8/muL instead of 4/muL). The following correlation coefficients (r) and biases were achieved compared with the reference method: r=.90 and bias 2.3/muL for TNCC; r=.88 and bias 32.0/muL for RBC counts; r=.86 and bias +/-13.4% for mononuclear and polymorphonuclear cell percentages; r=.88 and bias -6.1% for lymphocyte percentage; r=.56 and bias 19.4% for monocyte percentage; and r=.75 and bias -9.7% for neutrophil percentage. Conclusion: Our results demonstrated that the automated ADVIA 2120 CSF assay generally compares well with reference methods although there are some limitations for the automated monocyte count and for samples with only mild pleocytosis.     

Efficacy of tramadol for postoperative pain management in dogs: systematic review and meta-analysis

ObjectiveTo evaluate the evidence of analgesic efficacy of tramadol for the management of postoperative pain and the presence of associated adverse events in dogs.Databases usedA comprehensive search using PubMed/MEDLINE, LILACS, Google Scholar and CAB databases with no restrictions on language and following a prespecified protocol was performed from June 2019 to July 2020. Included were randomized controlled trials (RCTs) performed in dogs that had undergone general anesthesia for any type of surgery. Two authors independently classified the studies, extracted data and assessed their risk of bias using Cochrane’s tool. RevMan and GRADE methods were used to rate the certainty of evidence (CoE).ConclusionsOverall 26 RCTs involving 848 dogs were included. Tramadol administration probably results in a lower need for rescue analgesia versus no treatment or placebo [moderate CoE; relative risk (RR): 0.47; 95% confidence interval (CI): 0.26–0.85; I² = 0%], and may result in a lower need for rescue analgesia versus buprenorphine (low CoE; RR: 0.50; 95% CI: 0.20–1.24), codeine (low CoE; RR: 0.75; 95% CI: 0.16–3.41) and nalbuphine (low CoE; RR: 0.05; 95% CI: 0.00–0.72). However, tramadol administration may result in an increased requirement for rescue analgesia versus methadone (low CoE; RR: 3.45; 95% CI: 0.66–18.08; I² = 43%) and COX inhibitors (low CoE; RR: 2.27; 95% CI: 0.68–7.60; I² = 45%). Compared with multimodal therapy, tramadol administration may make minimal to no difference in the requirement for rescue analgesia (low CoE; RR: 1.12; 95% CI: 0.48–2.60; I² = 0%). Adverse events were inconsistently reported and the CoE was very low. The overall CoE of the analgesic efficacy of tramadol for postoperative pain management in dogs was low or very low, and the main reasons for downgrading the evidence were risk of bias and imprecision.     

Influence of Gonadotrophin‐Induced First Oestrus on Gilt Fertility

The aim of this study was to determine the association between the oestrous response of pre‐pubertal gilts to gonadotrophin injection or boar exposure and their subsequent farrowing rate and litter size. At 154 days of age, randomly selected pre‐pubertal gilts received an intramuscular injection of 400 IU equine chorionic gonadotrophin plus 200 IU human chorionic gonadotrophin (PG600^®; Merck Animal Health; n = 181). From the remaining pool of animals not treated with hormones, the first gilts showing signs of oestrus were selected to act as controls (n = 201). Boar exposure began at 155 days of age for both groups, and gilts were bred at a weight of approximately 130 kg. Comparisons were made between PG600^®‐treated gilts exhibiting oestrus or not within 7 days post‐injection (early and late responders, respectively) and control gilts exhibiting oestrus or not within 30 days after beginning of boar exposure (select and non‐select control gilts, respectively). By 162 days, oestrus was detected in 67.5% of PG600^®‐treated gilts compared with 5.7% of control gilts (p < 0.0001). The proportion of animals observed in oestrus at least three times before breeding was greater for select control gilts compared with early and late responder PG600^®‐treated gilts (p ≤ 0.001). There were no significant differences in farrowing rate and litter size between the four treatment groups. These data indicate that PG600^® is an effective tool to induce an earlier oestrus in gilts, that subsequent farrowing rate and born alive litter size compare favourably to that of select gilts and that gilts failing to respond promptly to hormonal stimulation do not exhibit compromised fertility.     

Experimental infection with BCG as a model of tuberculosis in the brushtail possum (Trichosurus vulpecula)

AIMS: To study the development and progression of lesions produced following experimental inoculations of possums with Bacille Calmette-Guérin (BCG) Pasteur Strain 1173P2 and to compare these with lesions that occurred following natural Mycobacterium bovis infection.

METHODS: Possums were inoculated with 5 x 10⁶ colony forming units (cfu) of BCG via the intra-dermal (I/D) route into the dorsum of the neck (n=38) or the left brachium (n=7), orally (n=10), via the endo-bronchial (E/B) route (n=12), or intravenously (I/V) (n=10, half of which received 5 x 10⁶ cfu and half of which received 5 x 10⁷ cfu of BCG). The possums were humanely killed between 1–4 weeks post inoculation (p.i.), and the nature and distribution of lesions examined grossly and histopathologically.

RESULTS: The distribution of lesions following I/D inoculation via either route was similar to that of the natural disease, but there were few lesions in the lung. Endo-bronchial inoculation resulted in pulmonary disease but produced few lesions outside the respiratory tract. Lesions produced by I/V inoculation were similar in distribution to those seen in terminally ill tuberculous possums. No lesions were produced following oral inoculation. Regression of lesions commenced after 3 weeks p.i.

CONCLUSIONS: Although the phenomenon of lesion resolution restricts the use of BCG to the study of early lesion development, it avoids the overwhelming disease induced using M. bovis and thus allows the early phases of the development and progression of tuberculosis in this species to be observed. Intra-dermal inoculation produced evidence that infection through the skin is associated with lesions in superficial lymph nodes, whereas pulmonary disease was associated with E/B inoculation. The results are consistent with the hypothesis that both percutaneous and respiratory routes are important in natural infection of possums with M. bovis.     

Crypt abscesses in the caeca of feral rabbits in a rabbit haemorrhagic disease endemic region of New Zealand

AIM: To describe the pathology of crypt abscesses in the caeca of feral rabbits in the Manawatu region of New Zealand, and to examine the possible relationship between their prevalence and rabbit haemorrhagic disease (RHD) virus (RHDV) infection.

METHODS: During the course of a 3-year study of RHD, 173 wild rabbits (Oryctolagus cuniculus) were shot on three pastoral livestock farms in the Manawatu region of New Zealand. All rabbits were necropsied, and tissue samples of the caeca were examined histologically. The age of each animal was determined, and blood samples collected for the detection of RHDV antibodies. Logistic regression was used to model the odds of rabbits having crypt abscesses.

RESULTS: At necropsy, 63/173 (36.4%) rabbits were found to have small circular black nodules on the mucosal surface of their appendix caecum and/or sacculus rotundus. Microscopically, these were identified as small crypt abscesses composed of dilated sacs at the base of the mucosa that were often lined by a thin layer of attenuated epithelial cells. They usually contained large amounts of concentrically-laminated mucopolysaccharide material that was sometimes pigmented, inflammatory debris, and were often the site of a moderate multifocal appendicitis. Although RHDV was active in the study area, no association was found between RHDV antibodies in serum and the presence of lesions. The lesions were more common in older individuals and those born in summer or autumn.

CONCLUSIONS: This is the first report of crypt abscesses with inflammation and necrotic debris in the caeca of rabbits. No association between the occurrence of crypt abscesses and RHDV infection was identified. Wild rabbits born in a particular season were presumably exposed very early in life to conditions that caused the crypt abscesses to develop. Alternatively, association with season of birth may represent rabbits that were of similar age in a later stage of their lives, when they became exposed to the cause of the lesions, which remains unidentified.     

Optimization Protocol for Storage of Goldfish (Carassius auratus) Embryos in Chilled State

A series of five experiments were conducted to explore suitable conditions for storing of goldfish embryos in a chilled state. The factors studied were embryo stage, storage temperature, physiological saline solutions and goldfish artificial coelomic fluid (GFACF) medium, antibiotics (penicillin and streptomycin), antioxidants (vitamin E, vitamin C), buffer (Hepes, Tris) and BSA (bovine serum albumin). First, goldfish embryos at eight developmental stages were incubated in aerated and dechlorinated tap water at 0°C for 24 h. Result shows that early developmental stages were most sensitive to chilling. Heartbeat‐stage goldfish embryos were chilled at 0, 4 or 8°C for up to 72 h in water, and chilled storage was possible only for up to 18, 24 and 48 h at 0, 4 and 8°C, respectively, without a decrease in viability. Chilling of goldfish embryos at 8°C in GFACF medium and Dettlaff's solution instead of water and other physiological saline solutions prolonged their viability (p < 0.01). Nevertheless, viability of chilled embryos in GFACF medium was slightly, but non‐significantly, higher than in Dettlaff's solution. Supplementation of the GFACF medium with antibiotics, Hepes or BSA increased the viability of chilled embryos, but the tested vitamin E analogue Trolox, vitamin C or Tris concentration had no effect on embryo viability. The outcome of this series of experiments shows that heartbeat‐stage goldfish embryos could be chilled for 60 h in GFACF supplemented with 25 mm Hepes, 100 U/ml penicillin, 10 μg/l streptomycin and 1 g/l BSA in such a way that embryonic development does not proceed, and viability is not lost.     

日粮中添加谷氨酰胺和维生素E对肉仔鸡肠道黏膜的影响

本试验目的是评估肉鸡日粮中添加谷氨酰胺（Gln）和维生素E对其肠道黏膜形态学的作用。试验采取2×3因子（维生素E×Gln添加时间）的完全随机设计,维生素E添加水平为10和500mg/kg,Gln按3种情况向肉鸡开食日粮中的添加：即不添加、从出壳后头7d内添加和头14d内添加。肉鸡生长期日粮处理仅由维生素E两种添加水平组成。试验肉鸡共1500羽,设6个处理,每个处理分5个重复50羽肉鸡。在出壳后第7、14、21和41天,每个重复随机取2羽肉鸡扑杀,取十二指肠、空肠和回肠样本各5cm长,经处理后测定肠道黏膜绒毛高度和隐窝深度,并用方差分析所得数据,用Tukey氏检验按5%的显著水平比较平均值。结果表明,十二指肠发育最快,随后依次为空肠和回肠,出壳后第41天,日粮添加10mg/kg维生素E并再添加1%Gln,对肉鸡肠道黏膜的发育具有促进作用。     

Effect of hemolysis on canine kaolin‐activated thromboelastography values and ADVIA 2120 platelet activation indices

Background: The impact of hemolysis on thromboelastography (TEG) and platelet activation indices has not been evaluated. Objective: The aim of this study was to investigate the influence of hemolysis induced mechanically (HM) and hemolysis induced by freezing (HF) on TEG, platelet counts (PLT), and platelet activation indicators. Methods: Blood from 17 dogs was divided into the following samples: controls, HM, and HF. HM was induced by 20 repetitions of expulsion of blood through a 23 g needle. Freezing was at −80°C, followed by warming to 37° and dilution with equal parts room temperature blood at 22°C. TEG variables that were examined included reaction time (R), coagulation time (K), angle (α), maximum amplitude (MA), and clot rigidity (G). Platelet indices were measured with the ADVIA 2120 hematology analyzer. Results: Hematocrit (HCT) (mean±SD) for controls, HM, and HF were 0.41±0.02, 0.39±0.03, and 0.25±0.02 L/L, respectively, consistent with decreases in HCT of 4.8% (HM) and 39.0% (HF). HM resulted in decreased R (2.5±0.9 minutes compared with 5.2±1.9 minutes for controls; P<0.001), and HF resulted in increased K (15.2±8.6 minutes compared with 5.3±4.0 minutes in controls; P<0.01) and decreased α (20±11° compared with 46±17° in controls; P<0.001). MA was decreased more in HF samples (26±2 mm) than in HM (38±8 mm) or control samples (49±9 mm; P<0.0001). The same applied to G values. PLT decreased after HM but not after HF. Hemolysis of both types resulted in decreased mean platelet component (MPC) concentration: control, 19.3±2.0, HM 15.5±3.4, and HF 14.3±0.7 g/dL (P<0.0001). Conclusion: In hemolyzed samples decreased MPC and R suggested activated primary and secondary hemostasis, respectively, but decreased MA and G indicated reduced clot firmness, possibly due to hyporeactive platelets. TEG and platelet activation indices should be interpreted cautiously after hemolysis.