The effect of route of infection and strain of virus on the pathology of Australian infectious bronchitis

The pathogenesis of infectious bronchitis in 4-week-old chickens was studied following administration of Australian T strain of IBV by the aerosol, conjunctival, intranasal, in-contact and drinking water routes.
Infected birds showed similar patterns of clinical signs, gross and histopathological lesions. While the birds infected by the aerosol route had earlier and slightly more severe respiratory tract disease it was concluded that the pathogenesis of infectious bronchitis virus nephritis was not significantly influenced by the route used to infect the birds.
In a second experiment, pathological changes produced in chickens infected with Australian S, A, A³ and T strains of IBV were compared in 18-day-old chickens infected by the aerosol route and housed in cold and warm environments. All 4 strains produced respiratory reactions and kidney lesions, and these changes were more severe and of longer duration in both respiratory tract and kidneys in the birds housed in a cold environment than those receiving supplementary heat.
The viruses differed in their virulence for the trachea and kidney and the effect of a virus on the respiratory trace was independent of the effect of that virus on the kidney.     

SCINTIGRAPHIC EVALUATION OF FOUR DOGS WITH PROTEIN-LOSING ENTEROPATHY USING 111INDIUM-INDIUM-LABELED TRANSFERRIN

The purpose of this sutdy was to determine the clinical utility of ¹¹¹ In-labeled transferrin ( 111 In-TF) scintigraphy for evaluating dogs suspected of having protein-losing enteropathies. Four dogs were injected intravenoulsy with autologous ¹¹¹In-TF after 30 min incubation (at 37°C) of 18.5 MBq (0.5mCi) ¹¹¹In CI₃ with one ml of autologous plasma, Serial right lateral, left lateral and dorsal images were obtained 2, 4, and 24 hours post ¹¹¹ In-TF administration, Images were subjectively evaluated for the presence or absence of ¹¹¹ within the gastrointestinal tract. The results of total protein, albumin and globulin legels and results form gastrointestinal tract. the results of total protein, albumin and globulin levels and results from gastrointestinal biopsies were recorded. In one dog, a follow-up scientigraphic study was done six months after initial evaluation and initiation of treatment for plasmocytic-lymphocytic enteritis. Gastrointestinal activity was noted by two hours in two dogs, while all four dogs had gastrointestinal activity on the 24 hour images. The mean (±std dev) plasma protein, albumin and globulin levels were 3.5 (±0.9), 1.7 (±1) and 1.8 (±0.3) respectively at the time of initial presentation. In the one dog that was evaluated after therapy, faint visualization of radioactivity within the colon was noted on the 24 hour image. Based on this study, ¹¹¹In-TF appears to be a viable scientigraphic method for evaluating dogs with suspected dogs withfd suspected protein-losing enteropathies, Potential limitations of tjis radiopharmaceutical include cost and prolonged isolation of the animal prior to release to the client due to the long physical half-life (T_½= 2.82 days).     

Hypoxemia in the Acutely Traumatized Canine Patient

One hundred acutely traumatized dogs were evaluated for the presence of cardiopulmonary abnormalities with thoracic radiographs, electrocardiography and arterial blood gas analysis. Fifty-seven dogs were found to have concurrent appendicular fracture(s) and thoracic injury as defined by an abnormality in one or more of the variables evaluated. Thoracic radiographs were abnormal in 44 dogs. Ventricular arrhythmias were identified in 17 dogs. Hypoxemia (PaO₂ < 80 mmHg) was detected in 25 dogs. Hypoxemia was noted with increased frequency in dogs with abnormal thoracic radiographs. Ventricular arrhythmias occurred more frequently in the hypoxemic group of dogs.
Although a relationship was noted between the presence of hypoxemia, radiographic changes of the thorax and ECG abnormalities, all three examinations provided important information for assessing the cardiopulmonary status of each patient.     

NORMAL THORACIC AND ABDOMINAL DISTRIBUTION OF 2-DEOXY-2-[18F]FLUORO-d-GLUCOSE (18FDG) IN ADULT CATS

Positron emission tomography (PET) with 2-deoxy-2-[¹⁸F]fluoro- d -glucose (¹⁸FDG) is an important imaging modality for diagnosis and staging of human neoplastic disease. The purpose of this study is to describe the normal ¹⁸FDG uptake in adult cats. Six adult healthy female cats were used. Cats were sedated and then injected intravenously with 74.0±13.0 (mean±SD) MBq of ¹⁸FDG. General anesthesia was induced and cats were placed in ventral recumbancy on the PET scanner's bed. Static images using multiple bed positions were acquired approximately 60–90 min after injection. A transmission scan was acquired at each bed position utilizing a ⁵⁷Co point source to perform attenuation and scatter correction. Regions of interest (ROIs) were drawn over the liver, right and left renal cortices, left ventricular wall, and wall of ascending and descending colonic segments. Standardized uptake values (SUV) were calculated using an established formula. Kidneys and intestinal tract had relatively intense uptake of ¹⁸FDG; liver activity was intermediate; the spleen was not identified in any of the cats. Cardiac activity was variable but intense activity was noted in the left ventricular myocardium in most cats. No appreciable lung uptake was noted. Mean±SD SUV values were calculated. This study established the normal pattern of uptake of ¹⁸FDG in adult cats and provided baseline data for comparison with future studies evaluating a variety of neoplastic and nonneoplastic diseases.     

RADIOGRAPHY AND IMAGE-INTENSIFIED FLUOROSCOPY OF BARIUM PASSAGE THROUGH THE GASTROINTESTINAL TRACT IN SIX HEALTHY AMAZON PARROTS (AMAZONA AESTIVA)

Gastrointestinal contrast studies were performed in six clinically healthy blue-fronted Amazon parrots (Amazona aestiva) using radiography and image-intensified fluoroscopy. During examination, the birds were confined in a perspex cage. The quality of the lateral radiographs was adequate for assessment of the contrast medium-filled gastrointestinal tract. Thirty minutes after administration of 20 mL/kg of a 25% barium sulphate suspension directly in the crop, in all birds the ventriculus was totally outlined by barium. After 60 min, the small intestine was filled in five of six birds. After 180 min, the crop was empty in all birds. The barium-outlined ventriculus had differences in shape on radiographs of individual birds and also between birds. The colon and cloaca had further filling after 120 to 300 min. With image-intensified fluoroscopy, gastrointestinal motility was evaluated. Contractions of the crop were seen, and boluses of contrast medium passing through the esophagus toward the proventriculus were easily identified. Proventricular contractions were rarely noted, but ventriculus motility was present and clearly defined. The ventriculus had a mean of 3.7 contraction cycles/min. In the duodenum and small intestine, rapid antegrade and retrograde peristaltic movements in combination with segmental contractions were seen. In the colon, occasionally very slow peristaltic activity, mainly of segmental nature, was present. During the examinations, no defeacation was recorded. Confinement in a small perspex cage provides an adequate and handy radiological set-up for evaluation of gastrointestinal passage and motility in birds, minimizing the influences of stress and anesthesia.     

TECHNETIUM-99M AND IODINE-131 THYROID SCINTIGRAPHY IN NORMAL AND RADIOTHYROIDECTOMIZED COCKATIELS (NYMPHICUS HOLLANDICUS)

Thyroid scintigraphy using sodium ^99mTechnetium pertechnetate (⁹⁹TcO₄-) was performed in normal and radiothyroidectomized cockatiels ( Nymphicus hollandicus ). ¹³¹I scintigraphy was performed in the course of ablating the thyroid glands. The thyroid glands in normal birds were clearly visualized, but were not individually resolvable. Thyroid glands were not visualized in thyroid-ablated birds. With ^99mTcO₄ scans, thyroid (or other region of interest)/body count density ratios were used for comparisons of normal and thyroid-ablated birds. Normal ^99mTcO₄- thyroid/body ratios (mean +/− SD) for the dorsal and lateral views were 1.83 +/− 0.31 and 1.70 +/− 0.34 respectively. Pertechnetate thyroid/body count density ratios decreased (to 0.93 -/−0.14 and 0.88 +/− 0.12 for dorsal and lateral views respectively) after thyroid ablation, while crop/body ratios increased. ^99mTcO₄- thyroid scintigraphy, therefore, was capable of detecting hypofunctional thyroid abnormalities in ¹³¹I radiothyroidectomized cockatiels.     

18FDG-PET IMAGING IN CANINE LYMPHOMA AND CUTANEOUS MAST CELL TUMOR

Positron Emission Tomography (PET) using the glucose analog 2-deoxy-2-[¹⁸F]fluoro- d -glucose (¹⁸FDG) is a common imaging modality for diagnosis and management of many human malignancies. We evaluated ¹⁸FDG-PET in dogs with either multicentric lymphoma (LSA) or cutaneous mast cell tumor (MCT). A prototype large field-of-view PET scanner was used to collect whole-body images in nine dogs with LSA or MCT. Both tumors were characterized by avidity for ¹⁸FDG. In dogs with LSA, ¹⁸FDG-PET correctly identified involvement of superficial and internal lymph nodes, liver, and spleen. Repeated PET scans after induction chemotherapy demonstrated resolution of abnormal ¹⁸FDG uptake within these sites. In dogs with MCT, ¹⁸FDG-PET correctly identified MCT metastasis to regional lymph nodes in all dogs in which this was suspected or confirmed with cytology or biopsy before the PET scan. In two dogs, additional sites of mast cell disease were identified with ¹⁸FDG-PET that were undetected on physical examination and/or regional lymph node cytology. ¹⁸FDG-PET holds promise as a whole-body staging method for canine LSA and MCT.     

Some cardiopulmonary effects of sevoflurane in crested caracara (Caracara plancus)

Objective  To evaluate the cardiorespiratory changes induced by sevoflurane (SEV) anesthesia in the crested caracara ( Caracara plancus ).
Study design  Prospective experimental trial.
Animals  Eight crested caracaras ( Caracara plancus ) weighing 1.0 (0.9–1.1) kg were used for the study.
Methods  The birds were anesthetized by face mask with isoflurane for brachial artery catheterization. After recovery, anesthesia was re-induced with 6% SEV via face mask. After induction, a noncuffed endotracheal tube was placed and anesthesia was maintained with SEV (3.5% end-tidal) in oxygen (1 L minute⁻¹) using an Ayre's T-piece nonrebreathing circuit, with spontaneous ventilation. Electrocardiography (ECG), direct systolic, diastolic and mean arterial blood pressure (SAP, DAP, and MAP), respiratory rate (f_R), end-tidal carbon dioxide (P e' CO₂), and cloacal temperature (T°C) were measured before induction (baseline – under physical restraint) and after 5, 10, 15, 20, 25, 30, 35 and 40 minutes of SEV anesthesia. Arterial blood samples were collected for gas analysis at baseline and then at 10, 25 and 40 minutes.
Results  No ventricular arrhythmias were observed in the present study. Respiratory rate, SAP, DAP, MAP, T°C and pH decreased from pre-induction values, while arterial partial pressures of oxygen and carbon dioxide, bicarbonate concentration, and P e 'CO₂ were significantly higher than baseline. None of the birds were apneic.
Conclusion and clinical relevance  Sevoflurane anesthesia is suitable for use in healthy members of this species, despite the moderate cardiovascular and respiratory depression produced.     

Radiographic and Scintigraphic Evidence of Focal Pulmonary Neoplasia in Three Cats With Hyperthyroidism: Diagnostic and Therapeutic Considerations

Three cats were diagnosed as hyperthyroid based on clinical signs, historical findings, laboratory abnormalities, and basal serum thyroxine (T₄) concentrations, and/or nuclear thyroid scans. Additionally, a presumptive diagnosis of thyroid carcinoma with pulmonary metastasis was made in each cat based on radiographic or scintigraphic evaluation. All three cats had solitary pulmonary nodules 1.5 to 2 cm in diameter on survey thoracic radiographs; one cat also had chylous pleural effusion and pulmonary lobar consolidation. Focal pulmonary accumulation of sodium pertechnetate (^99mTcO₄ -) and/or radioiodine (¹³¹I) corresponding to radiographic lesions were seen in all cats. Two cats were treated with single ablative doses (1111 to 1480 MBq) of¹³¹I; the remaining cat was euthanatized.
One of the treated cats died 8 days later; the other cat was euthanatized 22 weeks following treatment. Histopathologic examination of tissue obtained at necropsy confirmed metastatic thyroid carcinoma in one cat and bronchogenic adenocarcinoma in two cats. Our findings indicate that increased radionuclide uptake in focal pulmonary lesions and cytologic evaluation of tissue obtained by fine-needle aspiration are not specific for thyroid tissue. (Journal of Veterinary Internal Medicine 1993; 7:303–308. Copyright © 1993 by the American College of Veterinary Internal Medicine.)     

Upper respiratory tract infection caused by Cryptosporidium baileyi in three mixed-bred falcons (Falco rusticolus x Falco cherrug)

Three mixed-bred raptors (Falco rusticolus x Falco cherrug) from a German falcon breeder were presented with a history of respiratory distress. In one bird a laryngeal stridor was noted, and oral examination revealed an epiglottal swelling. In the other two birds, nasal discharge and sneezing were the main clinical symptoms. Nasal flushing samples and biopsies were collected for pathologic, bacteriologic, and parasitologic examination. Results confirmed a cryptosporidial infection. Polymerase chain reaction (PCR) and DNA analysis identified the causative agent to be Cryptosporidium baileyi. No cryptosporidia were detected in fecal samples, indicating the infection was confined to the respiratory system. Analysis of prey animals (pigeons, quail) failed to identify the source of infection. Treatment was initiated with paromomycin in all three birds, whereas in two birds an additional therapy with azithromycin was given. However, no clinical improvement was seen after several weeks of treatment, and the birds either died or were euthanatized. To the authors' knowledge, these are the first confirmed cases of disease caused by cryptosporidia in the order of Falconiformes.     

COMPARISONS OF RADIOGRAPHIC AND ELECTROCARDIOGRAPHIC ABNORMALITIES IN CANINE HEARTWORM DISEASE

Thoracic radiographs and electrocardiograms from 137 dogs with heartworm infection were independently evaluated and comparisons were made of (1) the presence or absence of right ventricular enlargement as assessed by these two diagnostic tests and (2) the presence or absence of right-sided congestive heart failure relative to the degree of right ventricular enlargement and ECG criteria of RVH.
Radiographic evidence of severe, but not moderate, right ventricular enlargement was associated with right-sided congestive heart failure. Similarly the presence of three or more, but not fewer than three, ECG criteria of RVH were associated with right-sided congestive heart failure. If either the thoracic radiographs or the ECG indicated that severe right ventricular enlargement was absent, right-sided congestive heart failure was seldom present. The most accurate correlation of the radiographic evaluation of severe right ventricular enlargement was afforded by the presence of three or more ECG criteria of RVH. ECG criteria of RVH such as R/S^v4, + T^v10 MEA^x, and S¹¹ are highly specific tests; while S^V2 is a highly sensitive but not highly specific test. The ECG is a good confirmation test of the presence of severe right ventricular enlargement and is a good exclusion test for the absence of right-sided congestive heart failure.     

黄牛呼吸道CD3+淋巴细胞分布的研究

CD3⁺是T细胞群的重要表面标志,呼吸道黏膜下分布的CD3⁺淋巴细胞作为抗感染黏膜免疫的基础,在保护机体抵抗呼吸道感染中发挥重要作用。为了解黄牛呼吸道CD3⁺淋巴细胞和淋巴组织的分布,本研究运用HE染色法和免疫组织学方法对5头7岁健康婆罗门黄牛的鼻黏膜、气管、肺内支气管及肺脏组织的CD3⁺淋巴细胞和淋巴组织的分布进行了研究。结果显示,黄牛的鼻黏膜、气管、肺内支气管和肺脏组织中均分布有CD3⁺淋巴细胞,且主要分布于黏膜上皮间及其下方固有层中及腺体周围;在鼻黏膜和肺脏组织中分布有CD3⁺淋巴细胞形成的弥散淋巴组织。牛呼吸道中CD3⁺淋巴细胞数量在鼻黏膜和肺脏组织中分布最多,气管黏膜、肺内支气管黏膜次之。本试验结果明确了CD3⁺淋巴细胞在黄牛呼吸道中的分布谱,表明黄牛呼吸道具备引发局部黏膜免疫的基础条件,为牛呼吸道黏膜免疫及呼吸道疾病防治研究提供了数据支撑。     

UNILATERAL PERINEPHRIC PSEUDOCYST OF UNDETERMINED ORIGIN IN A DOG

Unilateral perinephric pseudocyst of undetermined origin was diagnosed in a 13^1/2 year old dog with a history of recurrent urinary tract infections. A presumptive diagnosis of pseudocyst was based on radiographic and sonographic findings. In survey radiographs, asymmetrical unilateral renomegaly was seen. The mass was anechoic. There was absence of opacification of the mass during excretory urography. A celiotomy was performed for removal of the perinephric mass, and histologic review of this structure confirmed it to be a pseudocyst. Perinephric accumulation of fluid is a rare condition in domestic animals. Seven examples of perinephric pseudocysts have been previously reported in the cat. Predominant clinical findings include progressive abdominal distension and nonspecific signs of renal disease. The presence of unilateral or bilateral renomegaly is a characteristic radiographic feature. This clinical report describes the first case of perinephric pseudocyst diagnosed in the dog.     

Blood oxygen and carbon dioxide tensions in normal dogs and in dogs with respiratory failure

Arterial blood samples were obtained from thirty normal conscious dogs breathing air. The mean values and standard deviations recorded were PaO₂ 101.3±5.6 mmHg, PaCO₂ 34.0±3.9 mmHg, oxygen saturation 93.8 ±1.2%, oxygen content 19.3 ± 1.8 ml/100 ml. Ten dogs with respiratory problems were also examined and of these animals seven had lower than normal oxygen tensions while three had carbon dioxide levels higher than those found in healthy dogs. It was concluded that, in severe respiratory disease, measurement of arterial oxygen tension gives a useful assessment of respiratory failure in dogs.     

RADIOGRAPHIC AND MYELOGRAPHIC EXAMINATION OF THE CERVICAL VERTEBRAL COLUMN IN 306 ATAXIC HORSES

This study consists of a review of 306 ataxic horses subjected to survey radiography and myelography of the cervical vertebral column. Fifty-eight percent of horses had evidence of compressive spinal cord lesion on myelography. Sixty-six percent of horses were less than 3 years old. Age had no effect on the distribution of spinal cord compressive lesions. No conclusion could be drawn from sex and breed distribution. The most common sites of cord compression on myelography in order of decreasing frequency were C_3–4, C_6–7, C_5–6, and C_4–5. Twenty-nine percent of horses with myelographic evidence of cord compression had multiple compressive sites. Survey radiographs were not reliable to diagnose compressive spinal cord lesions. Myelography was a safe and more accurate procedure. Several factors may result in misinterpretation of the myelographic examination.     

Endogenous lipid pneumonia in cats: 24 cases (1985-1998)

OBJECTIVE: To determine clinical signs, radiographic and histologic abnormalities, and concurrent diseases in cats with endogenous lipid pneumonia (EnLP) and to determine the pathologic importance of EnLP in cats. DESIGN: Retrospective study. ANIMALS: 24 cats. PROCEDURE: Medical records of cats in which EnLP was confirmed by histologic examination of necropsy specimens were reviewed. Information collected from the medical records included signalment, body weight, clinical signs, and results of clinicopathologic tests. Thoracic radiographs were reviewed by a radiologist; histologic specimens were reviewed by a pathologist. RESULTS: All cats had nonspecific clinical abnormalities, such as lethargy, anorexia, or weight loss; 16 had signs of respiratory tract disease. All cats had concurrent systemic diseases, and clinicopathologic abnormalities were reflective of these conditions. Nonspecific abnormalities were detected on thoracic radiographs from 9 of 11 cats. Most cats had macroscopic, multifocal, subpleural lesions; inflammatory infiltrates, cholesterol clefts, and multinucleated giant cells were common. Ten cats had an underlying obstructive pulmonary disease that was the likely cause of EnLP. Lesions of EnLP were not considered to be severe enough or extensive enough to be the cause of death in any of these cats. CONCLUSIONS AND CLINICAL RELEVANCE: EnLP is an uncommon respiratory tract disorder of cats with no pathognomonic clinical, laboratory, or radiographic findings. Although EnLP was not the cause of death in any of these cats, results of the present study do suggest that EnLP may be a marker for potentially severe underlying obstructive pulmonary disease.     

A comparison of the sedative and analgesic effects of buprenorphine in combination with acepromazine, midazolam or medetomidine in dogs

The effects of buprenorphine in combination with acepromazine, midazolam or medetomidine were compared in dogs. Induction and recovery times, heart rate, respiratory rate and body temperature were measured. Posture, reaction to noise, analgesia and muscle relaxation were assessed and a global score of "sedation-analgesia" was calculated. There were 3 groups of 4 animals: group 1 received 0.1 mg.kg-¹ acepromazine IM and 20 minutes later, 10 g.kg-¹ buprenorphine IV; group 2 received 1 mg.kg-¹ midazolam IV simultaneously with 10 ig.kg-¹ buprenorphine IV and group 3 received 1 mg/m² body surface area medetomidine IM and 20 minutes later, 10 Hg.kg-¹ buprenorphine IV. Only one dog given acepromazine and buprenorphine reached a "sedation-analgesia" stage, denned as the inability to stand together with the absence of reaction to stimulation, including pain. Animals in this group showed a decrease in respiratory rate and in body temperature. None of the dogs given midazolam and buprenorphine became sedated or showed signs of analgesia. Following this combination, the dogs were excited and showed dysphoric reactions which disappeared within 20 minutes.
All of the dogs given medetomidine and buprenorphine showed good sedation and analgesia lasting more than 20 minutes. This drug combination produced a decrease in heart and respiratory rates and body temperature.     

GASTRIC EMPTYING OF SOLID RADIOPAQUE MARKERS IN HEALTHY DOGS

The gastric emptying of 1.5 mm diameter (small) and 5.0 mm diameter (large) radiopaque markers (BIPS) was assessed in 20 dogs. The markers were fed to the dogs in a test meal and abdominal radiographs were made hourly thereafter. Studies were repeated three times in each dog. The variation between two veterinarians interpreting the radiographs was low. The sex, age and day of the study did not have a significant effect on the lag phase or the time taken to empty 25%, 50% and 75% of the markers (T₂₅, T₅₀ and T₇₅ respectively). There was a weak but significant positive correlation between the body weight and T₅₀. There was no significant difference in gastric emptying parameters between the large and small markers.
The mean gastric emptying versus time curve of the small markers on day one was chosen to represent the reference curve for healthy dogs. The lag phase of the small markers on day one was 2.45 ± 2.04 hours, the T₂₅ was 4.85 ± 2.15 hours, the T₅₀ was 6.05 ± 2.99 hours and the T₇₅ was 8.32 ± 2.72 hours (mean ± SD).     

Chemoprophylaxis of cryptosporidiosis in chickens, using halofuginone, salinomycin, lasalocid, or monensin

Chemoprophylaxis of Cryptosporidium baileyi infections was attempted by feeding 4 groups of chicks diets containing 3 mg of halofuginone/kg of feed, 60 mg of salinomycin/kg, 75 mg of lasalocid/kg, or 110 mg of monensin/kg. Rations were fed 5 days before oral or intratracheal inoculation with oocysts and were continued for 20 days. None of the drugs prevented C baileyi infections. Clinical signs of respiratory tract disease and gross lesions of airsacculitis were observed in intratracheally inoculated birds in all treatment groups and nonmedicated controls. Orally inoculated birds did not develop clinical signs of infection. Pathogenic bacteria were not isolated from the respiratory tract systems of any chicks. Halofuginone delayed the establishment of infections of the bursa of Fabricius and cloaca, but not of the trachea.     

TREATMENT OF DIFFERENTIATED THYROID CARCINOMA IN 7 DOGS UTILIZING 131I

Seven dogs with thyroid gland carcinoma were treated with ¹³¹I and hormone suppressive therapy either alone (3 dogs) or in combination with surgery (3 dogs) or ¹³⁷Cs teletherapy and chemotherapy (1 dog). Empirically chosen doses of 75 to 137 mCi of ¹³¹I were given orally (2 dogs) and intravenously (5 dogs). Adverse effects were limited to acute, transient bone marrow hypoplasia and pancytopenia. Nominal objective reduction in tumor volume or size and number of pulmonary metastases was observed in 4 dogs treated with ¹³¹I and thyroxine. Of these 4 dogs, 2 had stable disease for periods of 4 and 12 months while a third dog had stable disease for 27 months following two ¹³¹I treatments at 3 month intervals. The fourth dog had progressive disease. Two dogs with mediastinal metastases showed reduction in localization of ^99mTc pertechnetate and radioiodine following 2 and 3 treatments using ¹³¹I. It appears that relatively high doses of ¹³¹I can be used safely for the treatment of canine thyroid tumors and that further investigation can be justified to define its efficacy.