Transtracheal aspiration in the diagnosis of pulmonary blastomycosis (17 cases: 2000-2005)

Blastomyces dermatitidis is a common etiologic agent of fungal pneumonia in dogs. Definitive diagnosis is based on cytologic demonstration of the organism in affected tissues. Fluid obtained through transtracheal aspiration has previously been reported to have a low diagnostic yield for B. dermatitidis organisms. This retrospective study identified B. dermatitidis organisms in 76% of samples when transtracheal aspiration was performed in 17 nonsedated dogs with pulmonary blastomycosis. Transtracheal aspiration is a noninvasive and simple procedure that should be considered as an early diagnostic test whenever blastomycosis is a differential diagnosis in dogs with pulmonary disease.     

Cytokine expression by neutrophils of adult horses stimulated with virulent and avirulent Rhodococcus equi in vitro

Rhodococcus equi is an intracellular pathogen of macrophages that causes rhodococcal pneumonia in foals and immunocompromised people. Evidence exists that neutrophils play a vital role in resistance to infection with R. equi; however, the means by which neutrophils exert their effects have not been clearly defined. In addition to directly killing bacteria, neutrophils also may exert a protective effect by linking innate and adaptive immune responses. In the present study we evaluated the cytokine expression profiles of adult equine neutrophils in response to stimulation with isogenic strains of virulent and avirulent R. equi in vitro. After 2 and 4 h incubation with virulent or avirulent R. equi, adult equine neutrophils expressed significantly (P < 0.05) greater tumor necrosis factor alpha (TNFα), interleukin (IL)-12p40, IL-6, IL-8 and IL-23p19 mRNA, but not interferon gamma (IFNγ) or IL-12p35 mRNA than unstimulated neutrophils. Furthermore, virulent R. equi induced significantly greater IL-23p19 mRNA than avirulent R. equi. These results demonstrate that R. equi-stimulated neutrophils are a source of many proinflammatory cytokines. Furthermore, these results suggest that IL-23 may be preferentially expressed over IL-12 in response to exposure with R. equi, and that this response may be more strongly induced by virulent R. equi than avirulent R. equi. Collectively, the data presented herein suggest a non-phagocytic role for neutrophils that may influence the type of adaptive immune response to R. equi.     

In vitro biomechanical study of rotational stabilizers of the canine elbow joint

OBJECTIVE: To develop a model for measuring rotary stability of the canine elbow joint and to evaluate the relative contribution of the anconeal process (AN), lateral collateral ligament (LCL), and medial collateral ligament (MCL). SAMPLE POPULATION: 18 forelimbs from 12 canine cadavers. PROCEDURE: Forelimbs were allocated to 3 experimental groups (6 forelimbs/group). Each intact forelimb was placed in extension at an angle of 135 degrees and cycled 50 times from -16 degrees (pronation) to +28 degrees (supination) in a continuous manner at 2.0 Hz. Cycling was repeated following sectioning of the structure of interest (group 1, AN; group 2, LCL; and group 3, MCL). Torque at -12 degrees (pronation) and +18 degrees (supination) was measured for each intact and experimentally sectioned limb. A Student t test was performed to compare torque values obtained from intact verses experimentally sectioned limbs and for comparison with established criteria for differentiation of primary (> or = 33%), secondary (10 to 33%), and tertiary rotational stabilizers (< 10%). RESULTS: In pronation, the AN was the only primary stabilizer (65%). For supination, the LCL was a primary stabilizer (48%), AN was a secondary stabilizer (24%), and MCL was a tertiary stabilizer (7%). CONCLUSIONS AND CLINICAL RELEVANCE: With the elbow joint in extension at an angle of 135 degrees, the AN is a primary rotational stabilizer in pronation, and the LCL is a primary stabilizer in supination. Disruption of the AN or LCL may affect rotary range of motion or compromise stability of the elbow joint in dogs.     

The effect of a low molecular weight heparin on coagulation parameters in healthy cats

The low molecular weight heparin (LMWH), dalteparin sodium, was administered subcutaneously (100 IU/kg) to 8 healthy cats twice daily for 13 doses. Anti-activated factor X (anti-Xa) activity was measured prior to administration (time 0), and 4, 6, 8, and 12 h after the 1st dose, 4 h after administration of the 3rd dose, and at 4, 6, 8, and 12 h after the last dose. Four cats developed measurable anti-Xa activity 4 h following a single dose, returning to baseline by 6 h. Anti-Xa activity was not detected at any time point in 4 cats. Prothrombin time (PT), activated partial thromboplastin time (APTT), and antithrombin (AT) concentrations were unaffected by LMWH administration. Dalteparin, at 100 IU/kg SC, did not achieve anti-Xa activity in 4 out of 8 cats and failed to maintain anti-Xa activity beyond 4 h in the other 4 healthy cats.     

Disseminated candidiasis secondary to fungal and bacterial peritonitis in a young dog

Objective – To describe a severe case of bacterial sepsis and disseminated candidiasis in a previously healthy dog.
Case Summary – Fungal sepsis was identified in a 2-year-old dog following intestinal dehiscence 4 days after abdominal surgery. Septic peritonitis was identified at admission and evidence of dehiscence at the previous enterotomy site was found during an exploratory laparotomy. Both gram-positive cocci and Candida albicans were cultured from the abdominal cavity. Candida sp. was also subsequently cultured from a central venous catheter. Euthanasia was performed due to failure to respond to therapy. Fungal organisms, morphologically consistent with Candida spp., were found in the lungs and kidney on postmortem histopathologic examination indicating disseminated candidiasis.
New or Unique Information Provided – Candida peritonitis is a well-recognized entity in humans and contributes to morbidity and mortality in critically ill patients. Abdominal surgery, intestinal perforation, presence of central venous catheters, and administration of broad-spectrum antibiotics are all considered to be suspected risk factors. This report describes the first known case of systemic candidiasis occurring secondary to Candida peritonitis and bacterial sepsis in a critically ill dog.     

Accidental entrapment of cats in front-loading washing machines

Two clinical cases of accidental entrapment of cats in front-loading washing machines are described. One cat died the day after presentation as a result of aspiration pneumonia and head trauma, despite supportive care. The second cat survived with supportive treatment, but developed dermatologic complications 10 d later.     

Spontaneous gastroduodenal perforation in 16 dogs and seven cats (1982-1999)

The records of 23 dogs and cats diagnosed with spontaneous gastroduodenal perforation (GDP) were retrospectively reviewed. Survival was 63% in dogs and 14% in cats. Rottweilers <5 years of age were overrepresented. Clinical evidence of gastrointestinal bleeding was common in dogs but not in cats. Shock was an uncommon presenting condition in dogs and was not closely linked to outcome. In fact, progression of an ulcerating lesion to GDP was not associated with marked changes in symptoms exhibited by many patients in this study. Most GDPs were associated with histopathological evidence of subacute or chronic peritoneal reaction at the time of diagnosis. This suggests that diagnostic methods employed lacked sensitivity in identifying early perforating lesions, and that dramatic signs of acute abdomen following gastroduodenal perforation may not be as common as was previously thought.     

Molecular and serologic characterization, pathogenicity, and protection studies with infectious bronchitis virus field isolates from California

In this study, we characterized three variant infectious bronchitis virus (IBV) strains isolated in 2003 and 2004 from broiler chickens in California and compared them to previously isolated California variant viruses and to common vaccine serotypes used in the United States. We conducted genetic, serologic, and pathogenicity studies on all three isolates, then tested different vaccines against one of the viruses. Genetically the three variant IBV strains, designated CA557/03, CA706/03, and CA1737/04, were not related to each other. GenBank BLAST database search and phylogenetic analysis of the hypervariable region of the S1 subunit of the spike gene to determine the most closely related viruses to the three variants showed the CA557/03 variant to be 81.8% similar to the CAV/CA56b/91 whereas the CA706/03 and CA1737/04 variant viruses were only distantly related to Dutch/D1466/81 (72.2%), a vaccine strain used in Europe, and Korea/K142/02 (72.7%), a Korean field isolate, respectively. Cross virus-neutralization testing showed that none of the 2003-04 California IBV variant viruses were serologically related to each other or to Ark, Conn, or Mass vaccine strains. In addition the CA1737/04 isolate was also tested against DE072 and found not to be serologically related. All three variant viruses were pathogenic in 1-wk-old broilers and vaccination with Mass/Conn followed by Holland/Conn provided 80% protection against the CA1737/04 virus. The 2003-04 California variant viruses were not compared with variants isolated in California during 1970s and 1980s because, to our knowledge, no genetic information is available and those viruses are no longer obtainable. This study shows that the CA557/03 virus was distantly related to the CAV-type viruses isolated in California in the early 1990s, but that none of the 2003-04 viruses were similar genetically or serologically to the CAL99-type viruses, indicating that new IBV variants continue to emerge and cause disease in commercial chickens in California.     

Effect of oral administration of electrolyte pastes on rehydration of horses

OBJECTIVE: To determine whether the composition of electrolyte pastes formulated for oral administration influences voluntary water intake (WI) by horses recovering from furosemide-induced dehydration. ANIMALS: 6 horses. PROCEDURES: Voluntary WI, body weight, and blood and urine constituents were measured before and after induction of dehydration by furosemide administration and overnight withholding of water; these same variables also were measured during a 36-hour rehydration period. Each horse was evaluated 4 times with random application of 4 treatments (electrolyte pastes) that provided 0.5 g of KCl/kg of body weight, 0.5 g of NaCl/kg, 0.25 g of NaCl and 0.25 g of KCl/kg, or no electrolytes (control treatment). Electrolyte pastes were administered 3 times (4, 8, and 12 hours after start of the rehydration period). RESULTS: Administration of all electrolyte pastes resulted in significantly greater voluntarily WI, compared with the control treatment, and was accompanied by significantly greater recovery of body weight when NaCl was a component of the paste. Administration of NaCl and NaCl-KCl pastes tended to produce a state of transient hyperhydration; however, electrolyte administration also resulted in significantly greater urine production and electrolyte excretion during the final 24 hours of the rehydration period. Adverse effects of oral administration of hypertonic electrolyte pastes were not observed. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of electrolyte pastes to dehydrated horses increases voluntary WI and improves rehydration during the rehydration period. Rehydration is more rapid and complete when NaCl is a component of the electrolyte paste.