Hematologic changes associated with half-body irradiation in dogs with lymphoma

BACKGROUND: Reports describe the technique and efficacy of half-body irradiation (HBI) of dogs with lymphoma, but few describe the distinctive toxicoses associated with the combination of HBI and chemotherapy. HYPOTHESIS: HBI would transiently affect myelocytic and erythroid variables as assessed by serial analysis of complete blood counts. ANIMALS: Twenty-nine dogs with lymphoma treated with HBI during 2002 and 2003. METHODS: A retrospective study of medical records of 29 dogs was performed. Two HBI protocols were used, resulting in delivery of either 6 Gy or 8 Gy to each half of the body, 1 month apart. Dogs received chemotherapy before, during, or after irradiation, or at multiple times. Serial hematology was available for all dogs. Data were analyzed between collection periods by analysis of variance (ANOVA) RESULTS: The mean granulocyte count significantly (P < .01) decreased from 10,017 cells/microL (data range 3,001-20,170 cells/ microL) before the first radiation treatment to 3,250 cells/microL (820-4,400 cells/microL) at week 5 (P < .01). Three weeks after this nadir, the mean increased to 10,150 cells/microL (900-26,700 cells/microL). The hematocrit did not change (36-38%). Thrombocytopenia (<100,000/microL) occurred in 10 dogs. Two dogs died because of complications associated with thrombocytopenia. No significant difference in toxicity was found between the 6 Gy and 8 Gy group. CONCLUSIONS AND CLINICAL IMPORTANCE: HBI was myelosuppressive but effects were short term and resolved in 22 of 24 dogs. Further studies are needed to elucidate the safety and role of HBI in the treatment of dogs with lymphoma.     

Anomalous portosystemic anastomoses associated with chronic hepatic insufficiency in six young dogs.

Chronic hepatic insufficiency due to anomalies of the portal venous system was diagnosed in 6 young dogs. The disorder was characterized by a variety of abnormal central nervous system signs or ascites, or both. Laboratory findings were characteristic of chronic, generalized hepatic dysfunction. The diagnosis was established by angiographic studies of the portal venous system. Of the 6 dogs, 3 died, 1 was euthanatized, and 2 are still alive and require medical management for ascites.     

Hematologic changes associated with weekly low-dose cisplatin administration in dogs

This study prospectively describes the systemic toxicity of cisplatin (20 mg/m(2),IV) when given in weekly doses prior to localized irradiation in dogs with solid malignancies. Eleven dogs received a total of 54 weekly doses of cisplatin. Two dogs did not complete the 5-week protocol due to progressive disease and two dogs received 6 weekly doses of cisplatin. Repeated administration of cisplatin caused a significant decline in the leukocyte count, segmented neutrophil count, and platelet count. These changes were related to the number of cisplatin doses. The dogs did not have any significant alteration of blood urea nitrogen, serum creatinine, or urine specific gravity during the treatment period. Weekly low-dose cisplatin, as used in this study, is safe for use in tumor-bearing dogs. However, the significant decline in the leukocyte, segmented neutrophil, and platelet counts in these 11 dogs suggest that cisplatin prescribed at 20 mg/m(2) IV once per week should not exceed five consecutive treatments.     

Predicting behavioral changes associated with age-related cognitive impairment in dogs

OBJECTIVE: To monitor the progression of age-related behavioral changes in dogs during a period of 6 to 18 months and to determine whether signs of dysfunction in any of 4 behavioral categories can be used to predict further impairment. DESIGN: Age-stratified cohort study. ANIMALS: 63 spayed female and 47 castrated male dogs 11 to 14 years of age. PROCEDURE: Data were collected from randomly selected dog owners who were interviewed by telephone twice at a 12- to 18-month interval; data were included if the dog had lived > or = 6 months between interviews. The interview focused on signs of impairment in the following behavioral categories: orientation in the home and yard, social interactions with human family members, house training, and the sleep-wake cycle. Dogs were determined to have impairment in 0 behavioral categories (on the basis of < or = 1 sign for each category), impairment in 1 category (> or = 2 signs of dysfunction in that category), or impairment in > or = 2 categories. RESULTS: Between interviews, 22% (16/73) of dogs that did not have impairment in a category at the time of the first interview developed impairment in that category by the time of the second interview. Forty-eight percent (13/27) of dogs that had impairment in 1 category at the time of the first interview developed impairment in > or = 2 categories by the time of the second interview and were significantly more likely to develop impairment in > or = 2 categories, compared with dogs that initially had impairment in 0 categories. Dogs with 1 sign of dysfunction in orientation were significantly more likely to develop impairment in that category, compared with dogs that had 0 signs of dysfunction in orientation. CONCLUSIONS AND CLINICAL RELEVANCE: Age-related behavioral changes in dogs are progressive. Clinicians should consider trying to predict which dogs are most likely to become progressively impaired during the subsequent 6 to 18 months.     

Effect of chronic pain associated with lameness on plasma cortisol concentrations in sheep: a field study

Plasma cortisol concentrations were measured in two groups of sheep taken from 29 flocks in north Devon. The first group were healthy adult females and the second group were adult females suffering from footrot in one forefoot. These sheep were assessed for the severity of the lesion and the level of lameness and assigned a score. The plasma cortisol concentration was significantly higher in the lame sheep than in the healthy sheep and remained so for up to three months after the apparent resolution of the clinical lesion. There was no correlation between the severity of the footrot and the concentration of plasma cortisol.     

Renal microcirculatory and correlated histologic changes associated with dirofilariasis in dogs

Nine 7-month-old Beagle dogs were inoculated with 200 third-stage larvae of Dirofilaria immitis. The development of cardiac disease secondary to heartworm infection was confirmed by thoracic radiography, echocardiography, and angiography with blood pressure measurements. The only indication of renal disease was mild-to-moderate proteinuria. The dogs were euthanatized approximately 18 months after inoculation. The mean microfilarial count in blood at the time of euthanasia was 88,700/ml, with a mean of 89 adult heartworms in the vena cavae, heart, and pulmonary arteries. The kidneys were perfused for microangiographic and correlative histologic examination of the intrarenal microvasculature and associated renal morphologic features. Angiograms of whole kidneys from 6 dogs revealed attenuation or truncation of the major renal vessels. Microangiograms of all kidney slices revealed attenuation in the microangiographic appearance of the glomerular capillaries. Histologic examination of all kidney slices revealed mild-to-intense, diffuse, chronic interstitial nephritis and generalized membranoproliferative glomerulonephritis. Microfilariae were observed within the glomerular capillaries and the medullary vessels. The microangiographic changes correlated with and were explained in part by the histologic changes in the renal parenchyma.     

Prevalence of owner-reported behaviours in dogs separated from the litter at two different ages

The present study examined the prevalence of behaviours in dogs separated from the litter for adoption at different ages. Seventy adult dogs separated from their dam and littermates and adopted between the ages of 30 and 40 days were compared with 70 adult dogs that had been taken from the litter for adoption at two months. Owners were asked to complete a questionnaire eliciting information on whether their dog exhibited potentially problematic behaviours when in its usual environment. Binary logistic regression analysis was performed to investigate whether the age at which the dog was separated from the litter might predispose it to developing undesirable behaviours. The odds of displaying destructiveness, excessive barking, fearfulness on walks, reactivity to noises, toy possessiveness, food possessiveness and attention-seeking were significantly greater for the dogs that had been removed from the litter earlier during the socialisation period. In addition, dogs purchased from a pet shop at 30 to 40 days of age were reported to exhibit some of the listed behaviours with a significantly higher frequency than dogs purchased from a pet shop at two months. No significant differences were observed with dogs obtained from other types of sources. The dogs in the youngest age group (18 to 36 months) had a higher probability of displaying destructiveness and tail chasing. These findings indicate that, compared with dogs that remained with their social group for 60 days, dogs that had been separated from the litter earlier were more likely to exhibit potentially problematic behaviours, especially if they came from a pet shop.     

Prevalence of behavioral changes associated with age-related cognitive impairment in dogs

OBJECTIVE: To determine the prevalence of age-related behavioral changes, namely impairment, in a randomly chosen population of dogs. DESIGN: Age-stratified cohort study. ANIMALS: 97 spayed female and 83 castrated male dogs that were 11 to 16 years old. PROCEDURE: Data on possible impairment in 4 behavioral categories (ie, orientation in the home and yard, social interaction, house training, and sleep-wake cycle) linked to cognitive dysfunction were obtained from dog owners, using a structured telephone interview. Hospital records of dogs had been screened to exclude dogs with dysfunction in organ systems that may cause behavioral changes. Dogs with behavioral impairment were those with > or = 2 signs of dysfunction within a category. Dogs with impairment in 1 category were considered mildly impaired and those with impairment in > or =2 categories were considered severely impaired. RESULTS: Age by sex interactions for dogs with impairment in any category were not significant, and, therefore, data on castrated males and spayed females were pooled for analyses across ages. The prevalence of age-related progressive impairment was significant in all categories. The percentage of 11- to 12-year-old dogs with impairment in > or = 1 category was 28% (22/80), of which 10% (8/80) had impairment in > or = 2 behavioral categories. Of 15- to 16-year-old dogs, 68% (23/34) had impairment in > or =1 category, of which 35% (12/34) had impairments in > or = 2 categories. There were no significant effects of body weight on the prevalence of signs of dysfunction in the behavioral categories. CONCLUSIONS AND CLINICAL RELEVANCE: Data collected provide estimates of the prevalence of various degrees of age-related behavioral changes associated with cognitive dysfunction in dogs. Age-related behavioral changes may be useful indicators for medical intervention for dogs with signs of cognitive impairment.     

Severe bilateral fibrosing pleuritis associated with chronic chylothorax in five cats and two dogs.

Severe bilateral fibrosing pleuritis was diagnosed in 5 cats and 2 dogs with chronic chylothorax. All animals were dyspneic on initial examination and remained moderately to severely dyspneic after thoracentesis. Radiographic evidence of fibrosing pleuritis included rounded lung lobes and failure of the lungs to reexpand following effective pleural drainage. Fibrosing pleuritis was also suggested in several animals with radiographic evidence of pleural fluid, in which pleural fluid could not be retrieved. Macroscopically, the lung lobes of all animals were compressed and atelectatic to various degrees, and the pleura appeared to be diffusely thickened and roughened. In several animals, fibrous adhesions were found between the parietal and visceral pleura of some lobes. Lung lobes were markedly constricted and appeared as small, smooth, rounded hilar masses in 4 animals. Mild to moderate pulmonary edema was evident in 3 animals at necropsy. Six of the 7 animals died (2) or were euthanatized (4) within 72 hours after the diagnosis of fibrosing pleuritis. The fibrosing pleuritis developed in 1 animal with lymphoblastic lymphosarcoma and chylothorax after treatment via passive pleuroperitoneal drainage; this animal was euthanatized because of underlying neoplasia. One cat, in which decortication was performed and resulted in marked reexpansion of the lung lobes, died 4 hours after surgery with signs compatible with pulmonary edema. On the basis of our findings, we suggest that animals with chronic chylothorax are at risk to develop fibrosing pleuritis. Furthermore, animals with severe bilateral fibrosing pleuritis should be given extremely guarded prognoses.     

Therapeutic options for the treatment of chronic pain in dogs

Chronic pain is a widely recognised problem in humans and is being increasingly recognised as a significant problem in dogs. Whilst a large number of therapies are described and utilised to treat chronic pain in dogs, there is a severe shortage of evidence to guide practitioners in selection of treatments. Until more evidence becomes available, practitioners should adopt a cautious approach, utilising licensed treatments first when possible. Non‐pharmacological therapies should be incorporated into the chronic pain management plan whenever possible. Given the probable prevalence of chronic pain in dogs there is an urgent need for research to identify effective treatments.     

Pulmonary function changes and clinical findings associated with chronic respiratory disease in calves.

Thirteen field cases of chronic respiratory disease in crossbred calves aged between 1 and 8 months were subjected to a standardized examination in which clinical criteria were scored and weighted to allow quantification. Predicted values for pulmonary function variables were generated using regression equations previously established in normal calves which related measured pulmonary function variables to thoracic perimeter. Subsequent pulmonary function testing of each calf was undertaken and values obtained compared with predicted values and correlated with clinical scores. Diagnosis was confirmed at post-mortem examination. Calves with chronic respiratory disease had significantly reduced inspiratory and expiratory times, tidal volume, dynamic compliance and PaO2, significantly increased respiratory frequency, airway resistance and PaCO2 and more negative transpulmonary pressure values when compared to predicted pulmonary function values for the same calves. PaO2 and PaCO2 were the only variables correlated with clinical scores, suggesting their value in the assessment of severe cases of calf respiratory disease.     

Urinary tract infection associated with long-term corticosteroid administration in dogs with chronic skin diseases

Urinary tract infections were documented in 28 (39%) of 71 dogs receiving long-term corticosteroid therapy for chronic skin diseases. There were no significant differences regarding alternate-day versus daily corticosteroid administration, corticosteroid dosage, or duration of therapy when data for the infected and noninfected groups were compared. A significantly (P less than 0.01 and P less than 0.005, respectively) greater frequency of bacteriuria was seen in female dogs and castrated male dogs receiving corticosteroid therapy. Urine sediment analysis alone was not an adequate means of detecting urinary tract infections in these dogs.     

Ciclosporin therapy is associated with minimal changes in calcium metabolism in dogs with atopic dermatitis

Background – Ciclosporin is widely used in the management of canine atopic dermatitis. In humans, ciclosporin therapy has been linked to disturbances in calcium metabolism and resultant skeletal disorders. Objectives – The objective of this study was to assess calcium homeostasis in dogs before and after a 6 week course of once daily oral ciclosporin at the licensed dose (5 mg/kg). Animals – Sixteen client‐owned dogs with spontaneous atopic dermatitis. Methods – Serum concentrations of calcium, phosphate, creatinine, 25‐hydroxyvitamin D, 1,25‐dihyroxyvitamin D and plasma concentrations of ionized calcium and parathyroid hormone (PTH) were measured, together with the urinary fractional excretion of calcium and phosphate. The extent of skin lesions was scored using the Canine Atopic Dermatitis Extent and Severity Index (CADESI)‐03 and the degree of pruritus by the Edinburgh Pruritus Scale prior to and at the end of the study. Results – The CADESI‐03 and the Edinburgh Pruritus Scale scores decreased satisfactorily in all dogs by the end of the study. Plasma PTH concentrations were significantly increased (P = 0.02) following ciclosporin treatment, whereas all other biochemical parameters were not significantly different from their starting values. The increase in PTH was mild in most cases and the proportion of dogs that had a PTH concentration above the reference range was not significantly different following treatment. Conclusions and clinical importance – This study indicates that ciclosporin has minimal impact on calcium metabolism in dogs with atopic dermatitis when used at the licensed and clinically effective dosage for 6 weeks.