Percent Of Dogs Research Articles

Clinical findings and diagnostic value of post‐traumatic thoracic radiographs in dogs and cats with blunt trauma

AbstractObjective: To characterize the clinical findings in dogs and cats that sustained blunt trauma and to compare clinical respiratory examination results with post‐traumatic thoracic radiography findings.Design: Retrospective clinical study.Setting: University small animal teaching hospital.Animals, interventions and measurements: Case records of 63 dogs and 96 cats presenting with a history of blunt trauma and thoracic radiographs between September 2001 and May 2003 were examined. Clinical signs of respiratory distress (respiratory rate (RR), pulmonary auscultation) and outcome were compared with radiographic signs of blunt trauma.Results: Forty‐nine percent of dogs and 63.5% of cats had radiographic signs attributed to thoracic trauma. Twenty‐two percent of dogs and 28% of cats had normal radiographs. Abnormal auscultation results were significantly associated with radiographic signs of thoracic trauma, radiography score and presence and degree of contusions. Seventy‐two percent of animals with no other injuries showed signs of thoracic trauma on chest radiographs. No correlation was found between the radiographic findings and outcome, whereas the trauma score at presentation was significantly associated with outcome and with signs of chest trauma but not with the radiography score.Conclusion: Thoracic trauma is encountered in many blunt trauma patients. The RR of animals with blunt trauma is not useful in predicting thoracic injury, whereas abnormal chest auscultation results are indicative of chest abnormalities. Thorough chest auscultation is, therefore, mandatory in all trauma animals and might help in the assessment of necessity of chest radiographs.

Humans, dogs and parasitic zoonoses--unravelling the relationships in a remote endemic community in northeast India using molecular tools.

Canine parasitic zoonoses pose a continuing public health problem, especially in developing countries and communities that are socioeconomically disadvantaged. Our study combined the use of conventional and molecular epidemiological tools to determine the role of dogs in transmission of gastrointestinal (GI) parasites such as hookworms, Giardiaand Ascarisin a parasite endemic tea-growing community in northeast India. A highly sensitive and specific PCR-RFLP was developed to detect and differentiate the zoonotic species of canine hookworm eggs directly from faeces. This allowed epidemiological screening of canine hookworm species in this community to be conducted with ease and accuracy. Seventy two percent of dogs were found to harbour A. caninum, 60% A. braziliense and 37% harboured mixed infections with both hookworms. No A. ceylanicum was detected in the dog population. The zoonotic potential of canine Giardiawas also investigated by characterising Giardia duodenalisrecovered from humans and dogs living in the same locality and households, at three different loci. Phylogenetic and epidemiological analysis provided compelling evidence to support the zoonotic transmission of canine Giardia. Molecular tools were also used to identify the species of Ascarisegg present in over 30% of dog faecal samples. The results demonstrated the role of dogs as a significant disseminator and environmental contaminator of Ascaris lumbricoidesin communities where promiscuous defecation practices exist. Our study demonstrated the usefulness of combining conventional and molecular parasitological and epidemiological tools to help solve unresolved relationships with regards to parasitic zoonoses.

The association of exercise, diet and other factors with owner-perceived obesity in privately owned dogs from metropolitan Perth, WA

Randomly selected dog-owning households ( n=657) were interviewed to identify exercise, dietary and other factors associated with obesity in dogs. Dogs ( n=860) were categorised by their owners as underweight, correct-weight or overweight and the weight of 386 dogs was also recorded. Twenty five percent of dogs were reported as overweight. In random-effects logistic regression, overweight dogs had higher odds of being neutered (OR=2.8), fed snacks (OR=1.5), fed once a day (OR=1.4) or living in single-dog households (OR=1.6). For each year of age, the odds of obesity increased (OR=1.1) and for each hour of weekly exercise the odds of obesity decreased (OR=0.9).

The mixed acid-base disturbances of severe canine babesiosis.

Thirty-four dogs suffering from severe babesiosis caused by Babesia canis rossi were included in this study to evaluate acid-base imbalances with the quantitative clinical approach proposed by Stewart. All but 3 dogs were severely anemic (hematocrit <12%). Arterial pH varied from severe acidemia to alkalemia. Most animals (31 of 34; 91%) had inappropriate hypocapnia with the partial pressure of CO2 < 10 mm Hg in 12 of 34 dogs (35%). All dogs had a negative base excess (BE; mean of - 16.5 mEq/L) and it was below the lower normal limit in 25. Hypoxemia was present in 3 dogs. Most dogs (28 of 34; 82%) were hyperlactatemic. Seventy percent of dogs (23 of 33) were hypoalbuminemic. Anion gap (AG) was widely distributed, being high in 15, low in 12, and normal in 6 of the 33 dogs. The strong ion difference (SID; difference between the sodium and chloride concentrations) was low in 20 of 33 dogs, chiefly because of hyperchloremia. Dilutional acidosis was present in 23 of 34 dogs. Hypoalbuminemic alkalosis was present in all dogs. Increase in unmeasured strong anions resulted in a negative BE in all dogs. Concurrent metabolic acidosis and respiratory alkalosis was identified in 31 of 34 dogs. A high AG metabolic acidosis was present in 15 of 33 dogs. The lack of an AG increase in the remaining dogs was attributed to concurrent hypoalbuminemia, which is common in this disease. Significant contributors to BE were the SID, free water abnormalities, and AG (all with P < .01). Mixed metabolic and respiratory acid-base imbalances are common in severe canine babesiosis, and resemble imbalances described in canine endotoxemia and human malaria.

Population dynamics of inherited copper toxicosis in Dutch Bedlington terriers (1977-1997).

Inherited copper toxicosis in Bedlington terriers was 1st reported in 1975 and the entire Dutch population was examined from 1976 until the present for presence of the disease. To examine the effect on the prevalence of the disease of excluding affected dogs from breeding we have compared 2 time cohorts, the 1st consisting of dogs born from January 1, 1976, to January 1, 1986 (n = 155), and the 2nd of dogs born from January 1, 1990, to January 1, 1997 (n = 195). The diagnosis was made in the 1st cohort by evaluating liver biopsies, and in the 2nd cohort with a DNA marker. The population was also resolved into clusters of related dogs to analyze the familial distribution of the disease in the population and to search for ancient founders of the disease among the ancestors of sick dogs. Forty-six percent of dogs examined between 1976 and 1986 had copper toxicosis. Eleven percent of dogs examined in the 2nd cohort had evidence of disease. This reduction was achieved while maintaining the already limited genetic heterogeneity of the population: the number of clusters and the mean relatedness between the clusters were similar in both time cohorts. The disease was evenly distributed over the clusters of related dogs in both cohorts. All ancestors had contributed to the distribution of copper toxicosis and no specific founders could be identified. This indicates that when the breed was established in The Netherlands, the disease was already highly prevalent in the founding dogs.

A Rertrospective Analysis of Pulmonary Contusion Secondary to Motor Vehicular Accidents in 143 Dogs: 1994 ‐ 1997

SummaryMedical records of 143 dogs with pulmonary contusion secondary to motor vehicular trauma were evaluated retrospectively to determine length of hospitalization, oxygen supplementation, and associated injuries. Therapeutic interventions, including the dose of intravenous fluid administration, the use of antibiotics, and the use of glucocorticoids were recorded. Initial thoracicradiographs were reviewed, and pulmonary contusion was graded as mild, moderate or severe. Pulmonary contusion severity was compared to use of supplemental oxygen, oxygen administration time, hospitalization time, and the presence or absence of fractures. The length of hospital stay and the survival rate was calculated.The mean respiratory rate at admission was 55 ± 22 breaths per minute. Concurrent thoracicinjuries were common, and included pneumothorax and pleural effusion. Fifty‐two percent ofdogs received oxygen supplementation for a median of 35 hours. The median hospitalization time was 48 hours. Forty (28%) dogs were treated with antibiotics for a minimum of 5 days, and forty‐ five (31%) were administered glucocorticoids. Two (1%) dogs developed pulmonary infection. Dogs with more severe thoracic radiographic changes on presentation were more likely to receiveoxygen, received oxygen for longer periods of time, and had a longer hospitalization time. Eighty‐two percent of dogs survived to hospital discharge.

Skeletal Malignancies Among Beagles Injected With 241Am

Seventy skeletal malignancies in 44 dogs were identified among 117 beagles injected as young adults with graded dosages of approximately 0.07 to 104 kBq 241Am kg-1 and maintained for lifetime observation. All of these tumors were osteosarcomas except four fibrosarcomas of bone and four chondrosarcomas of bone. Of these 117 animals, 114 survived beyond the minimum age (of 2.79 y) for radiation-induced bone cancer, and all are now dead. An expression was derived that described the dependence of percent occurrence of bone sarcoma on skeletal radiation dose of A = 0.76 + 30D, where A = percent of dogs with skeletal malignancy within any dosage group, D = average skeletal dose (< 3 Gy) at 1 y before death (average skeletal dose was calculated to the presumed start of tumor growth, which we have taken to be 1 y before death), and 0.76 represents the lifetime percent malignant bone tumor response among 132 suitable control dogs in our colony not given any radioactivity. All dosage groups with skeletal doses of > 3 Gy at 1 y before death exhibited close to 100% occurrence and appeared to be beyond the region of linearity. Therefore, they were excluded from the derivation of this expression. Similar analysis of corresponding data for beagles given 226Ra as young adults, excluding the two highest dosage groups in which the bone tumor response was approximately 100%, yielded the expression, A = 0.76 + 4.7D, (D < 20 Gy). A ratio of the coefficients in these two expressions indicates the effectiveness at low radiation doses for bone-cancer induction of 241Am relative to 226Ra, or (30 +/- 2.6)(4.7 +/- 0.47)-1 = 6 +/- 0.8. This compares to the relative effectiveness at low radiation doses that was obtained earlier for a 239Pu:226Ra toxicity ratio of about 16 +/- 5.

Bone Cancer Occurrence Among Beagles Given 239Pu As Young Adults

The occurrence of skeletal malignancies has been documented among 234 young adult beagles given single intravenous injections of monomeric 239Pu citrate. Occurrence has also been documented among 132 comparable control group animals surviving the minimum latent time period of 2.79 y for radiation-induced bone cancer, who were maintained for lifespan observation. Injected amounts ranged from about 0.02-106 kBq kg-1 body mass with factors of 2 or 3 between dose levels. There were 84 radiographically apparent bone tumors in 76 plutonium-injected dogs and one tumor in a control group dog. Most of these were osteosarcomas except for seven chondrosarcomas, one liposarcoma, and one plasma cell myeloma of bone. The relationship between percent of dogs at any dose level with bone malignancy and average skeletal dose at the presumed time of tumor initiation of 1 y before death appeared to be linear below about 1.3 Gy average skeletal dose. The observed data can be approximated by the expression A = 0.76 + 75 D, where A = percent of dogs with bone cancer at any dose level, D = average skeletal dose in Gy (for doses up to 1.3 Gy) at tumor initiation, and 0.76 represents the percent tumor response in the control animals not given plutonium. Similar analysis of our corresponding data for beagles given 226Ra, excluding the two highest dose levels (approximately 100% occurrence), yielded the expression A = 0.76 + 4.7 D, where D = the average skeletal dose in Gy (for doses up to 20 Gy) at 1 y before death. The ratio of coefficients indicates the effectiveness for bone cancer induction of 239Pu relative to 226Ra, or [(75 +/- 22.5)(4.7 +/- 0.47)-1] = 16 +/- 5 for a single, brief intake of either nuclide into blood.

A new model for total cerebral ischemia in dogs.

We have developed a new method producing total cerebral ischemia (TCI) in dogs; clamping ascending aorta with aorto-atrial bypass formation. Clamping ascending aorta provides TCI, the duration of which can be controlled up to the periods of 10 min. Beyond this interval, it is difficult to maintain TCI because of heart failure from high afterload. Blood outflow from left ventricle is completely obstructed except for coronary circulation which is small relative to the blood volume expelled from left ventricle, even if venous return to the heart is reduced. Aorto-atrial bypass formation during aortic clamping provides two distinctive advantages. First, adjusting aortic pressure in an appropriate level low enough not to overload myocardium but still high enough to maintain sufficient coronary blood flow is possible by regulating the blood flow through the bypass tubing, and secondly drug administration and blood volume control is possible through the tubing. These result in better preservation of myocardium, enabling longer TCI and longer survivals after TCI. We were successful in having up to 18 min of TCI with this method. Seventy-five percent of dogs of 12 min TCI and 40% of 15 min TCI survived 7 days, limit of experiment, after TCI, but no dogs of 18 min TCI survived for more than 3 days.

Ischemic ventricular fibrillation: The importance of being spontaneous

Although the energy level required to defibrillate normal myocardium is low and constant, as determined from studies of induced ventricular fibrillation, little is known of the specific energy requirements in regionally ischemic hearts for spontaneous or induced ventricular fibrillation. In this study the lowest energy threshold for defibrillation was determined in 10 open chest dogs with reversible 10 minute coronary occlusions at various sites for each of 44 events of ventricular fibrillation, using apical and superior vena caval electrodes with a generator providing variable output of 1 to 30 watt seconds. The ischemic mass, quantitated from postmortem angiographic and planimetric data, was 52 ± 9 percent (mean ± standard deviation) of the left ventricle in dogs with induced ventricular fibrillation (Group I), 52 ± 12 percent in dogs with spontaneous ventricular fibrillation after occlusion (Group II) and 54 ± 9 percent in dogs with spontaneous ventricular fibrillation after reperfusion (Group III). Defibrillation thresholds in watt seconds were 9 ± 7 in Group I (n = 12), 19 ± 10 in Group II (n = 13) and 18 ± 10 in Group III (n = 19). (Group I versus Groups II and III, probability [p]<0.025). In nonischemic hearts, the defibrillation threshold was 3 ± 2 (n = 32) (p <0.001 compared with values in Group I, II or III). Thus, despite similar masses of ischemia, twice as much energy was required for defibrillation of spontaneous ventricular fibrillation (whether after occlusion or reperfusion) as for induced ventricular fibrillation, suggesting that these conditions are caused by different metabolic or pathologic derangements. Such differences should be considered in assessing interventions such as drug therapy designed to inhibit the repetitive ventricular response and in design of implantable defibrillators.

Luminance-onset, pattern-onset and pattern-reversal evoked potentials in human albinos demonstrating visual system anomalies

Most fish, amphibians, reptiles and birds have laterally placed eyes and primarily panoramic vision. These vertebrates usually have complete crossing of optic fibres at the chiasm, i.e., optic ganglion fibres originating from each eye terminate in visual centres of the contralateral hemisphere. One of the features of the mammalian visual system is the appearance of an uncrossed optic projection terminating in visual centres of the ipsilateral hemisphere. As the eyes shift to a more frontal position on the head the number of ganglion fibres originating in temporal retinae increases. Concomitantly, stereoscopic vision and binocular overlap of visual fields increase. The number of optic fibres that do not cross at the chiasm varies: approximately l-5 percent in guinea pigs and mice, 5-10 percent in rats, 20 percent in dogs and horses, 30-40 percent in domestic cats, 4030 percent in primates (Giolli. and Creel, 1973; Hayhow et al, 1960; Polyak, 1957).