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1.  Genetic regulation of canine skeletal traits: trade-offs between the hind limbs and forelimbs in the fox and dog 
Synopsis
Genetic variation in functionally integrated skeletal traits can be maintained over 10 million years despite bottlenecks and stringent selection. Here, we describe an analysis of the genetic architecture of the canid axial skeleton using populations of the Portuguese Water Dog Canis familiaris) and silver fox (Vulpes vulpes). Twenty-one skeletal metrics taken from radiographs of the forelimbs and hind limbs of the fox and dog were used to construct separate anatomical principal component (PC) matrices of the two species. In both species, 15 of the 21 PCs exhibited significant heritability, ranging from 25% to 70%. The second PC, in both species, represents a trade-off in which limb-bone width is inversely correlated with limb-bone length. PC2 accounts for approximately 15% of the observed skeletal variation, ~30% of the variation in shape. Many of the other significant PCs affect very small amounts of variation (e.g., 0.2–2%) along trade-off axes that partition function between the forelimbs and hind limbs. These PCs represent shape axes in which an increase in size of an element of the forelimb is associated with a decrease in size of an element of the hind limb and vice versa. In most cases, these trade-offs are heritable in both species and genetic loci have been identified in the Portuguese Water Dog for many of these. These PCs, present in both the dog and the fox, include ones that affect lengths of the forelimb versus the hind limb, length of the forefoot versus that of the hind foot, muscle moment (i.e., lever) arms of the forelimb versus hind limb, and cortical thickness of the bones of the forelimb versus hind limb. These inverse relationships suggest that genetic regulation of the axial skeleton results, in part, from the action of genes that influence suites of functionally integrated traits. Their presence in both dogs and foxes suggests that the genes controlling the regulation of these PCs of the forelimb versus hind limb may be found in other tetrapod taxa.
doi:10.1093/icb/icm023
PMCID: PMC2367254  PMID: 18458753
2.  Borrelia burgdorferi migrates into joint capsules and causes an up-regulation of interleukin-8 in synovial membranes of dogs experimentally infected with ticks. 
Infection and Immunity  1997;65(4):1273-1285.
Twenty 6-week-old specific-pathogen-free beagles were infected with Borrelia burgdorferi by tick challenge, and five uninfected dogs served as controls. During the study, all dogs were monitored for infection, clinical signs, and antibody response against B. burgdorferi. During episodes of lameness or postmortem, synovial fluids from each dog were examined for volume, cell number, polymorphonuclear leukocyte (PMN) content, cell viability, and chemotactic activity. Twenty-five tissues collected postmortem from each dog were tested for interleukin-8 (IL-8) mRNA, tumor necrosis factor alpha (TNF-alpha) mRNA, presence of live spirochetes, and histopathological changes. Thirteen infected dogs (group A), which seroconverted rapidly (maximum titers within 50 to 90 days), developed acute and severe mono- or oligoarthritis almost exclusively in the limb closest to the tick bite (median incubation period, 66 days). Synovial fluids of the arthritic joints collected during episodes of lameness had significantly elevated volume, cell count, PMN proportion, cell viability, and chemotactic activity for PMNs. The remaining joints of the same animals contained synovial fluids with elevated chemotactic activity and cell viability. Twelve dogs tested positive for IL-8 mRNA in multiple tissues (synovia, pericardium, and peritoneum), and 10 dogs expressed TNF-alpha mRNA, but only in the tributary lymph nodes of the inflamed joints. Histological examinations revealed severe poly- or oligoarthritis and moderate to severe cortical hyperplasia in draining lymph nodes of the inflamed joints in all 13 dogs. Seven infected dogs with mild or no clinical signs (group B) seroconverted slowly (peak titers after 90 days), and only some joint fluids showed chemotactic activity, which on average was lower than that in inflamed and noninflamed joints from dogs in group A. Four dogs expressed IL-8 mRNA (in the synovia and pericardium), and three dogs had TNF-alpha mRNA in tributary lymph nodes. Histologically, nonsuppurative arthritis was found in multiple joints, and mild to moderate cortical hyperplasia was found in draining lymph nodes. Five uninfected dogs without lameness (group C) had normal synovial fluids and tissues. In all infected dogs, live spirochetes were demonstrated more frequently in tissues of the somatic quadrant closest to the tick bite than in tissues further from the site of infection, suggesting that dissemination of B. burgdorferi occurs more by migration than by blood-borne spread. From these studies employing a canine model of B. burgdorferi infection, we conclude that IL-8 is involved in the pathogenesis of acute Lyme arthritis.
PMCID: PMC175128  PMID: 9119462
3.  THE EFFECT OF SODIUM CHLORIDE ON THE CHEMICAL CHANGES IN THE BLOOD OF THE DOG AFTER PYLORIC AND INTESTINAL OBSTRUCTION 
Experiments to determine the effect of furnishing an ample supply of sodium chloride on the toxemia of pyloric and intestinal obstruction are reported. A fall in chlorides is the first and seemingly most significant change to take place in the blood after pyloric and intestinal obstruction. The chloride is apparently utilized by the body as a protective measure against the primary toxic substance. Two dogs with pyloric obstruction were given 50 cc. of 10 per cent NaCl subcutaneously daily. One lived 3 days, the other 4. The blood showed little change, except a marked terminal rise in chlorides. Animals given a like amount of distilled water or 25 per cent glucose showed the changes typical of untreated animals. The obstruction of the pylorus was released in six dogs 48 to 72 hours after the initial operation. Two died within 24 hours after the second operation with a high non-protein nitrogen in the blood. Two survived but showed a high level of non-protein nitrogen in the blood and a high nitrogen excretion in the urine, low blood chlorides, and a marked alkalosis. One dog in such a state died on the 13th day from peritonitis, arising in a wound infection. The other showed a marked fall in non-protein nitrogen in the blood following the administration of 10 gm. of sodium chloride by mouth, but died following the intravenous injection of 25 per cent sodium chloride. Two animals were given 50 cc. of 10 per cent NaCl subcutaneously, at the time of the second operation. The blood rapidly returned to normal and complete recovery followed. Two dogs with the duodenum obstructed by section and inversion of the cut ends were treated with 10 per cent sodium chloride after the obstruction had existed for 48 hours and the characteristic blood changes had developed. The non-protein nitrogen returned to normal within 48 hours after treatment was begun. One dog died following a lateral anastomosis for relief of the obstruction. A second operation was not attempted in the other animal. Two dogs in which the duodenum was obstructed by section and inversion of the cut ends were given 500 cc. of 0.85 per cent NaCl subcutaneously on the day of operation and each day thereafter until death. One dog lived 21 days, the other 28. Both dogs showed a marked alkalosis, but never any rise in the non-protein nitrogen of the blood. The animals at autopsy showed intussusception of the ileum with extensive ulceration. In one there was a perforation and terminal peritonitis. The operation wounds healed normally. Three dogs with section of the duodenum were given 500 cc. of distilled water every day. One died in 24 hours, one in 48 hours, and the third in 72 hours. Autopsy showed no cause for death other than toxemia. One dog with section of the duodenum was given 500 cc. of 2 per cent glucose every day. The blood showed a rapid rise in non-protein nitrogen and carbon dioxide-combining power, and a fall in chlorides. The animal died 72 hours after operation. Three dogs with section of the duodenum were given 500 cc. of 1 per cent sodium bicarbonate every day. One dog died in 72 hours, one lived 7 days, and the third lived 9 days. All developed a high non-protein nitrogen in the blood and two showed marked clinical symptoms of an alkalosis. These results demonstrate that solutions of sodium chloride have a marked effect in preventing and controlling the toxemia of pyloric and intestinal obstruction as shown in clinical symptoms and in chemical changes in the blood. Dogs given an abundant supply of distilled water died more quickly than untreated control animals. Solutions of glucose have no specific value, and sodium bicarbonate solutions prolong life only a short while. Good therapeutic results have been obtained with very concentrated sodium chloride solutions, and with dry sodium chloride given by mouth. It seems evident that sodium chloride has a specific action in preventing and possibly in controlling the changes produced by the toxic body. Sodium chloride is a valuable therapeutic agent in pyloric and high intestinal obstruction.
PMCID: PMC2128422  PMID: 19868771
4.  Myocarditis in dogs: etiology, clinical and histopathological features (11 cases: 2007–2013) 
Irish Veterinary Journal  2014;67(1):28.
Background
Myocarditis is a disease caused by numerous etiological factors and characterized by a non-specific course. The only method allowing for precise characterization of inflammatory changes is the histopathological examination of heart muscle specimens. The study was conducted on heart muscle preparations from 11 dogs with ante-mortem diagnosis of cardiac disease. Animals presented with a poor response to an applied treatment or had suspected sudden cardiac death. The heart specimens were taken post-mortem, preserved and stained with haematoxylin and eosin. Subsequently, the presence and intensity of changes, i.e. inflammatory infiltration, the amount of connective tissue and features of cardiomyocyte degeneration were estimated. The specimens from dogs suspected of having a myocarditis of bacteriological etiology underwent additional bacteriological and immunohistochemical examination.
Results
The examination revealed an inflammatory infiltration of variable intensity combined with the degenerative changes in all dogs. There were vegetative and abnormal cystic forms of Borrelia burgdorferi sensu lato in 6 dogs. A Staphylococcus aureus infection was confirmed in one dog and an acute coronary syndrome with neutrophil infiltration was revealed in another one.
Conclusions
Although the clinical pattern in patients with myocarditis is diverse, the definitive morphological diagnosis is made based on the histopathological examination. This examination can lead to a better understanding of the pathogenesis of the disease. To the best of our knowledge, this is the first description of myocarditis combined with the presence of spore forms of Borrelia burgdorferi sensu lato in the heart specimens of dogs.
Electronic supplementary material
The online version of this article (doi:10.1186/s13620-014-0028-8) contains supplementary material, which is available to authorized users.
doi:10.1186/s13620-014-0028-8
PMCID: PMC4311452  PMID: 25642323
Myocarditis; Heart; Borrelia burgdorferi; Dog
5.  “Alas poor Yorick”: What retrospective analysis of canine skulls can tell us about the impact of environmental factors on health 
Necropsies and extensive histological evaluation for clinical and sub-clinical disease of approximately three hundred Portuguese Water dogs are available as part of an ongoing study to assess their state of health at end of life. Throughout life these dogs enjoyed a variety of lifestyles and environments. Here we carry out retrospective quantitative assessments of life-time dietary input and physical activity for each dog. To do this, collagens from skull vault bone and from dentine have been analyzed for ratios of stable isotopes to determine differences in diet that individual dogs experienced during late or early life respectively. Robustness of skull bone (weight/unit of skull size) was used as a relative indicator of the amount of physical activity experienced during a dog’s lifetime. These environmental parameters were correlated with the frequency and severity of specific disease processes determined at necropsy. Both measures were shown to exert significant low-level (r < 25%) differential effects on specific diseases. The value of retrospective analysis of environmental influences is discussed.
doi:10.4236/ojas.2013.33A002
PMCID: PMC3891401  PMID: 24436781
Portuguese Water Dog; Necropsy; Histopathology; Exercise; Nutrition; Stable Isotope; Skull; Dentine; Collagen
6.  Comparison of Microbiological, Histological, and Immunomodulatory Parameters in Response to Treatment with Either Combination Therapy with Prednisone and Metronidazole or Probiotic VSL#3 Strains in Dogs with Idiopathic Inflammatory Bowel Disease 
PLoS ONE  2014;9(4):e94699.
Background
Idiopathic inflammatory bowel disease (IBD) is a common chronic enteropathy in dogs. There are no published studies regarding the use of probiotics in the treatment of canine IBD. The objectives were to compare responses to treatment with either combination therapy (prednisone and metronidazole) or probiotic strains (VSL#3) in dogs with IBD.
Methodology and Principal Findings
Twenty pet dogs with a diagnosis of IBD, ten healthy pet dogs, and archived control intestinal tissues from three euthanized dogs were used in this open label study. Dogs with IBD were randomized to receive either probiotic (D-VSL#3, n = 10) or combination drug therapy (D-CT, n = 10). Dogs were monitored for 60 days (during treatment) and re-evaluated 30 days after completing treatment. The CIBDAI (P<0.001), duodenal histology scores (P<0.001), and CD3+ cells decreased post-treatment in both treatment groups. FoxP3+ cells (p<0.002) increased in the D-VSL#3 group after treatment but not in the D-CT group. TGF-β+ cells increased in both groups after treatment (P = 0.0043) with the magnitude of this increase being significantly greater for dogs in the D-VSL#3 group compared to the D-CT group. Changes in apical junction complex molecules occludin and claudin-2 differed depending on treatment. Faecalibacterium and Turicibacter were significantly decreased in dogs with IBD at T0, with a significant increase in Faecalibacterium abundance observed in the animals treated with VSL#3 strains.
Conclusions
A protective effect of VSL#3 strains was observed in dogs with IBD, with a significant decrease in clinical and histological scores and a decrease in CD3+ T-cell infiltration. Protection was associated with an enhancement of regulatory T-cell markers (FoxP3+ and TGF-β+), specifically observed in the probiotic-treated group and not in animals receiving combination therapy. A normalization of dysbiosis after long-term therapy was observed in the probiotic group. Larger scale studies are warranted to evaluate the clinical efficacy of VSL#3 in canine IBD.
doi:10.1371/journal.pone.0094699
PMCID: PMC3983225  PMID: 24722235
7.  ON THE COMPOSITION OF URINARY ALBUMIN 
A few findings which seem to be of importance may be pointed out:— Table I shows the analytical figures of serum-albumin, serum-globulin, and fibrin of the normal dog. The main difference between albumin and globulin appears in the relation of the precipitable to the non-precipitable total nitrogen and amino-nitrogen. Precipitable total nitrogen as well as amino-nitrogen is considerably larger in the albumin than in the globulin. In the cases of uranium nitrate nephritis (table II), the important figures approximate very closely those of normal serum-albumin. The samples from dog 3, that had been poisoned at the same time with phosphorous oil and uranium nitrate, show relatively large variations as compared with the figures from specimens from the other dogs, chiefly as regards the amino-nitrogen distribution: i. e., in dog 3, (1) the amount of amino-nitrogen to the total nitrogen in the solution before precipitation is higher; (2) the percentage of precipitable amino-nitrogen is larger; and (3) the ratio of precipitable amino-nitrogen to precipitable total nitrogen exceeds that of the other cases. All these changes, together with the fact that the total precipitable nitrogen did not undergo any quantitative variation, suggest that in the case of dog 3 the analyzed material contained a higher amount of lysin or cystin. It may further be mentioned that the analytical figures in this case differ also from those of the normal serum-albumin and still more from those of the serum-globulin. These changes, however, were not found in the case of dog 4, although this animal was treated in the same manner as the preceding dog. In the cases of nephritis in man (table III), striking differences were met with in the case of acute scarlet fever nephritis (No. 1a) and in the case (No. 2) of a patient with chronic nephritis and Pott's disease. This patient died a few weeks after the specimen for analysis was collected. The autopsy showed a general amyloidosis. The variations in both cases consist in a lowering of the ratio of amino-nitrogen to total nitrogen in the solution before precipitation, and corresponding to this, a fall of the same ratio in the filterable nitrogen. Such a change points to a relatively larger amount of prolin and oxyprolin or tryptophan in these cases. As a whole, one may conclude that Van Slyke's method, carefully applied and sufficiently controlled, may also be used for the study of urinary albumin. The results already obtained indicate that definite differences in the composition of urinary "albumin" may be detected. As yet it is premature to establish a definite relationship between the chemical composition of the "albumin" and the clinical or pathological conditions under which it appears, but it seems hopeful that further work may lead to the finding of such a relationship.
PMCID: PMC2124773  PMID: 19867474
8.  Prevalence and varieties of Helicobacter species in dogs from random sources and pet dogs: animal and public health implications. 
Journal of Clinical Microbiology  1996;34(12):3165-3170.
Gastric bacteria of a variety of ultrastructural morphologies have been identified in or isolated from domestic carnivores, but their prevalence in different populations of animals and their clinical significance are still unknown. The purposes of this study were (i) to evaluate the prevalence and morphologic types of gastric bacterial in three different populations of dogs; (ii) to determine which of the organisms were culturable, and if the cultured organisms were morphologically similar to the organisms seen in situ; (iii) to identify the isolated organisms; and (iv) to determine if gastric bacteria were associated with gastritis. Three groups of dogs were examined: healthy laboratory dogs, healthy dogs from an animal shelter, and pet dogs with various nongastric illnesses. Of these, 100% of laboratory and shelter dogs and 67% of pet dogs were colonized by large, tightly coiled gastric spiral bacteria morphologically similar to Gastrospirillum hominis or Helicobacter felis (referred to as gastrospirilla). Regardless of the presence or density of gastric bacteria, all of the dogs in the study except one had mild to moderate gastritis. Helicobacter spp. were isolated from only 6 of 39 stomachs cultured, and only three of the organisms isolated were morphologically similar to the bacteria seen in situ. Five helicobacters were identified by 16S rDNA (genes coding for rRNA) sequence analysis. Three were strains of H. felis, one was H. bilis, and one was a novel helicobacter morphologically similar to "Flexispira rappini." Gastrospirilla are almost universal in the stomachs of domestic dogs, and in most infected dogs, they do not appear to be associated with clinical signs or histologic lesions compared with uninfected dogs. Nongastrospirillum helicobacters are rare in dogs and are not histologically detectable. Helicobacter pylori was not isolated from domestic dogs.
PMCID: PMC229476  PMID: 8940465
9.  The importance of histologic parameters of lacteal involvement in cases of canine lymphoplasmacytic enteritis  
Background: The most frequent form of inflammatory bowel disease (IBD) in dogs is represented histologically, by lymphoplasmacytic enteritis (LPE), a histological category, often associated with other morphologic alterations including lymphangiectasia (LE). However, literature data on this latter topic are quite scarce and have mostly been obtained in single reports or in small series.
Aim: We evaluated some morphologic parameters of intestinal villi and lacteals in a large cohort of dogs, and correlated them with serum albumin and cholesterol values.
Patients and methods: We investigated 136 dogs (94 with LPE, and 42 with gastrointestinal problems different from IBD) and analyzed their clinical, laboratory (albumin and cholesterol values), endoscopic, and histologic variables.
Results: The LPE group showed significantly impaired clinical, laboratory, endoscopic, and histologic variables compared to controls. Affected dogs showed significant correlations between canine inflammatory bowel disease activity index (CIBDAI) scores and endoscopic and histologic variables. Moreover, the grade of hematologic changes were strongly related to the intestinal histologic variables, in particular those concerning villous and lacteals morphology.
Conclusion: Dogs with LPE had intestinal histologic abnormalities (height, width, height/width ratio, calculated for both villi and lacteals), whose degree correlated with the severity of hypoalbuminemia and hypocholesterolemia. Evaluation of endoscopic and histologic variables in association to the clinical findings may reveal useful insights for the pathogenesis of LPE and, hopefully, might lead to more targeted therapeutic approaches.
PMCID: PMC4285930  PMID: 25584174
Dogs; Histology; Intestine; Lymphangiectasia; Lymphoplasmacytic enteritis
10.  Genetic evaluation of Addison's disease in the Portuguese Water Dog 
Background
Addison's disease, also known as hypoadrenocorticism, has been reported in many individual dogs, although some breeds exhibit a greater incidence than the population as a whole. Addison's is presumed to be an autoimmune mediated hereditary defect but the mode of inheritance remains unclear. In particular, the heritability and mode of inheritance have not been defined for the Portuguese Water Dog although Addison's is known to be prevalent in the breed.
Results
The analyses present clear evidence that establishes Addison's disease as an inherited disorder in the Portuguese Water Dog with an estimate of heritability of 0.49 (± 0.16); there were no differences in risk for disease across sexes (p > 0.49). Further, the complex segregation analysis provides suggestive evidence that Addison's disease in the Portuguese Water Dog is inherited under the control of a single, autosomal recessive locus.
Conclusion
The high heritability and mode of inheritance of Addison's disease in the Portuguese Water Dog should enable the detection of segregating markers in a genome-wide scan and the identification of a locus linked to Addison's. Though the confirmation of Addison's disease as an autosomal recessive disorder must wait until the gene is identified, breeders of these dogs may wish to keep the present findings in mind as they plan their breeding programs to select against producing affected dogs.
doi:10.1186/1746-6148-2-15
PMCID: PMC1481556  PMID: 16670022
11.  Concentrations of cardiac Troponin I before and after ovariohysterectomy in 46 female dogs with pyometra 
Background
Canine pyometra is a common disease in countries where routine spaying of young dogs is not common practice. This disease is known to lead to systemic inflammation potentially affecting multiple organs in the body, including the heart. Cardiac-specific Troponin I (cTnI) is a sensitive marker of myocardial cell damage, which can result from ischemia, trauma, toxins or inflammation. Dogs with pyometra are also exposed to anaesthesia which can potentially result in myocardial cell damage. The aims of the study were 1) to evaluate the occurrence of myocardial cell damage as indicated by increased serum concentrations of cTnI in dogs with pyometra and relate these to presence of systemic inflammation and 2) to evaluate the change in cTnI-concentrations after anaesthesia and surgery.
Methods
Serum cTnI concentration was measured preoperatively and one day after surgery in 46 female dogs with pyometra and 15 female dogs that underwent surgery for other reasons (ovariohysterectomy and mammary tumours).
Results
Forty-six female dogs of different breeds diagnosed with pyometra were included. The dogs had a median age of 8.5 years (IQR 7.5–10) and a median weight of 29 kg (IQR 9–32). Of the 46 dogs, 37 (80%) fulfilled the chosen criteria for systemic inflammatory response syndrome (SIRS) at inclusion. Thirteen (28%) of the dogs had increased cTnI concentrations (> 0.2 μg/l) before surgery and 18 (39%) had increased cTnI-concentrations the day after surgery. The cTnI concentrations in the 13 dogs with increased preoperative cTnI concentrations decreased in 8 dogs, increased in 4 dogs, and was unchanged in one dog. Seven dogs with nondetectable preoperative cTnI concentrations had increased postoperative concentrations. The only significant association between the studied laboratory or clinical variables (including SIRS) and cTnI concentration was preoperative percentage band neutrophils (PBN) and postoperative cTnI concentration (P = 0.016). In total, 20 dogs (43%) had increased pre- or postoperative cTnI concentrations. Seven dogs (15%) had pre-or postoperative concentrations of cTnI of 1.0 μg/l or higher.
Conclusion
Mild to moderate increases in cTnI appears to be common in dogs with pyometra before and after surgery, but the clinical importance of this finding is uncertain. None of the studied clinical variables were found to reliably predict increased preoperative cTnI concentrations. Because of the pre- and postoperative variation in cTnI concentrations, it was not possible to identify a negative effect of anaesthesia and surgery on myocardial cell integrity.
doi:10.1186/1751-0147-50-35
PMCID: PMC2546406  PMID: 18786242
12.  Decreased plasma Chromogranin A361-372 (Catestatin) but not Chromogranin A17-38 (Vasostatin) in female dogs with bacterial uterine infection (pyometra) 
Background
Pyometra often induces systemic inflammatory response syndrome (SIRS) and early diagnosis is crucial for survival. Chromogranin A (CgA) is a neuroendocrine secretory protein that is co-released with catecholamines from the adrenal medulla and sympathetic nerve endings. A prognostic value of CgA has been found in humans that are critically ill or that have SIRS associated with infection. CgA has not yet been studied in dogs with bacterial infection. The aim of the study was to investigate CgA, measured by Chromogranin A361-372 (Catestatin; Cst) and Chromogranin A17-38 (Vasostatin; VS) in healthy dogs and in dogs with pyometra.
Results
Fifty dogs with pyometra, sampled prior to surgery and 64 healthy female dogs were included. In 19 pyometra cases, blood samples were also collected postoperatively. Concentrations of Cst and VS were measured in heparinised plasma and Cst also measured in EDTA plasma, by in-house radioimmunoassays. Student’s t-test and Wilcoxon two-sample test was used to test for differences between dog groups. Pre- and postoperative samples in dogs with pyometra were analysed by paired t-test. Pearson correlation was used to investigate associations of laboratory variables and hospitalization. P < 0.05 was considered significant.
Concentrations of Cst were decreased in pyometra dogs (mean ± SE, 1.01 ± 0.05 nmol/L) compared to healthy dogs (mean ± SE, 1.70 ± 0.03 nmol/L) (p ≤ 0.0001). VS concentrations did not differ significantly between dogs with pyometra (0.40 ± 0.04 nmol/L) and healthy dogs (0.42 ± 0.03 nmol/L). Mean ± SE pre- and postoperative concentration of Cst (1.0 ± 0.04 nmol/L and 0.9 ± 0.2 nmol/L) and VS (0.36 ± 0.04 nmol/L and 0.36 ± 0.04 nmol/L) in dogs with pyometra did not differ significantly. Neither Cst nor VS concentrations were associated with duration of hospitalization and were not significantly different in the four dogs with pyometra that had prolonged (≥3 d) postoperative hospitalization.
Conclusion
Concentrations of Cst, but not VS, were decreased in pyometra. Cst and VS concentrations before and after ovariohysterectomy did not differ significantly and were not associated with duration of hospitalization. Further studies are warranted to evaluate a possible diagnostic or prognostic value for Cst and VS.
Electronic supplementary material
The online version of this article (doi:10.1186/s12917-015-0328-6) contains supplementary material, which is available to authorized users.
doi:10.1186/s12917-015-0328-6
PMCID: PMC4318355  PMID: 25636335
Pyometra; Chromogranin A; Catestatin; Vasostatin; C-reactive protein; Biomarker; Dog; Uterine infection
13.  Seroepidemiology of leptospirosis in dogs from rural and slum communities of Los Rios Region, Chile 
Background
Leptospirosis is a zoonotic disease of global importance and often neglected as a public health problem due to lack of awareness, under-diagnosis and under-reporting. Animals serve as a source of transmission through the shedding of Leptospira in their urine. Because of their proximity to humans, dogs may play a role in human infections. In order to assess and mitigate leptospirosis in dogs and the risk of transmission to humans it is important to understand the epidemiology of leptospirosis under natural conditions. This study aimed to characterize leptospirosis in owned dogs from three distinct community types. Blood, dog and household data were collected from 265 dogs in 190 households from 12 communities representing farms, rural villages, and urban slums in the Los Rios region, Chile. Serologic profiles with a 20-serovar microagglutination test panel were obtained. Binomial and multinomial logistic regression models were used to evaluate the associations between spatial, ecological, socio-economic variables and overall seropositivity as well as seropositivity to serogroup Canicola.
Results
Results from 247 dogs with no history of vaccination were used. Overall seroprevalence was 25.1% (62/247) with significant differences by community type: 10.9% (9/82) in dogs from farms, 22.3% (21/94) from rural villages, and 45.1% (32/71) from urban slums (p <0.001). This trend by community type was also observed for dogs with evidence of seropositivity to the Canicola serogroup. Factors associated with seropositive dogs included dog density and precipitation two-weeks prior to sampling. Presence of Leptospira positive puddles collected from the peri-domestic household environment was also associated with increased seropositivity.
Conclusions
Results suggest that leptospirosis is actively maintained in the dog population in this study region with notably distinct patterns by community type. Dog populations from rural villages, and urban slums in particular, showed evidence of high levels of transmission probably as a result of the combined effects of dog living conditions as well as community-level ecological and environmental factors.
Electronic supplementary material
The online version of this article (doi:10.1186/s12917-015-0341-9) contains supplementary material, which is available to authorized users.
doi:10.1186/s12917-015-0341-9
PMCID: PMC4329218
Canine leptospirosis; Leptospira; Canicola serogroup; Zoonosis; Ecology epidemiology; Chile
14.  Detection of Canine Pneumovirus in Dogs with Canine Infectious Respiratory Disease 
Journal of Clinical Microbiology  2013;51(12):4112-4119.
Canine pneumovirus (CnPnV) was recently identified during a retrospective survey of kenneled dogs in the United States. In this study, archived samples from pet and kenneled dogs in the United Kingdom were screened for CnPnV to explore the relationship between exposure to CnPnV and the development of canine infectious respiratory disease (CIRD). Within the pet dog population, CnPnV-seropositive dogs were detected throughout the United Kingdom and Republic of Ireland, with an overall estimated seroprevalence of 50% (n = 314/625 dogs). In the kennel population, there was a significant increase in seroprevalence, from 26% (n = 56/215 dogs) on the day of entry to 93.5% (n = 201/215 dogs) after 21 days (P <0001). Dogs that were seronegative on entry but seroconverted while in the kennel were 4 times more likely to develop severe respiratory disease than those that did not seroconvert (P < 0.001), and dogs with preexisting antibodies to CnPnV on the day of entry were significantly less likely to develop respiratory disease than immunologically naive dogs (P < 0.001). CnPnV was detected in the tracheal tissues of 29/205 kenneled dogs. Detection was most frequent in dogs with mild to moderate respiratory signs and histopathological changes and in dogs housed for 8 to 14 days, which coincided with a significant increase in the risk of developing respiratory disease compared to the risk of those housed 1 to 7 days (P < 0.001). These findings demonstrate that CnPnV is present in the United Kingdom dog population; there is a strong association between exposure to CnPnV and CIRD in the kennel studied and a potential benefit in vaccinating against CnPnV as part of a wider disease prevention strategy.
doi:10.1128/JCM.02312-13
PMCID: PMC3838075  PMID: 24088858
15.  A 33,000-Year-Old Incipient Dog from the Altai Mountains of Siberia: Evidence of the Earliest Domestication Disrupted by the Last Glacial Maximum 
PLoS ONE  2011;6(7):e22821.
Background
Virtually all well-documented remains of early domestic dog (Canis familiaris) come from the late Glacial and early Holocene periods (ca. 14,000–9000 calendar years ago, cal BP), with few putative dogs found prior to the Last Glacial Maximum (LGM, ca. 26,500–19,000 cal BP). The dearth of pre-LGM dog-like canids and incomplete state of their preservation has until now prevented an understanding of the morphological features of transitional forms between wild wolves and domesticated dogs in temporal perspective.
Methodology/Principal Finding
We describe the well-preserved remains of a dog-like canid from the Razboinichya Cave (Altai Mountains of southern Siberia). Because of the extraordinary preservation of the material, including skull, mandibles (both sides) and teeth, it was possible to conduct a complete morphological description and comparison with representative examples of pre-LGM wild wolves, modern wolves, prehistoric domesticated dogs, and early dog-like canids, using morphological criteria to distinguish between wolves and dogs. It was found that the Razboinichya Cave individual is most similar to fully domesticated dogs from Greenland (about 1000 years old), and unlike ancient and modern wolves, and putative dogs from Eliseevichi I site in central Russia. Direct AMS radiocarbon dating of the skull and mandible of the Razboinichya canid conducted in three independent laboratories resulted in highly compatible ages, with average value of ca. 33,000 cal BP.
Conclusions/Significance
The Razboinichya Cave specimen appears to be an incipient dog that did not give rise to late Glacial – early Holocene lineages and probably represents wolf domestication disrupted by the climatic and cultural changes associated with the LGM. The two earliest incipient dogs from Western Europe (Goyet, Belguim) and Siberia (Razboinichya), separated by thousands of kilometers, show that dog domestication was multiregional, and thus had no single place of origin (as some DNA data have suggested) and subsequent spread.
doi:10.1371/journal.pone.0022821
PMCID: PMC3145761  PMID: 21829526
16.  Stability of 3-bromotyrosine in serum and serum 3-bromotyrosine concentrations in dogs with gastrointestinal diseases 
Background
3-Bromotyrosine (3-BrY) is a stable product of eosinophil peroxidase and may serve as a marker of eosinophil activation. A gas chromatography/mass spectrometry method to measure 3-BrY concentrations in serum from dogs has recently been established and analytically validated. The aims of this study were to determine the stability of 3-BrY in serum, to determine the association between peripheral eosinophil counts and the presence of an eosinophilic infiltrate in the gastrointestinal tract, and to compare serum 3-BrY concentrations in healthy dogs (n = 52) and dogs with eosinophilic gastroenteritis (EGE; n = 27), lymphocytic-plasmacytic enteritis (LPE; n = 25), exocrine pancreatic insufficiency (EPI; n = 26), or pancreatitis (n = 27).
Results
Serum 3-BrY concentrations were stable for up to 8, 30, and 180 days at 4°C, −20°C, and −80°C, respectively. There was no significant association between peripheral eosinophil count and the presence of eosinophils in the GI tissues (P = 0.1733). Serum 3-BrY concentrations were significantly higher in dogs with EGE (median [range] = 5.04 [≤0.63-26.26] μmol/L), LPE (median [range] = 3.60 [≤0.63-15.67] μmol/L), and pancreatitis (median [range] = 1.49 [≤0.63-4.46] μmol/L) than in healthy control dogs (median [range] = ≤0.63 [≤0.63-1.79] μmol/L; P < 0.0001), whereas concentrations in dogs with EPI (median [range] = 0.73 [≤0.63-4.59] μmol/L) were not different compared to healthy control dogs.
Conclusions
The present study revealed that 3-BrY concentrations were stable in serum when refrigerated and frozen. No relationship between peripheral eosinophil count and the presence of eosinophils infiltration in the GI tissues was found in this study. In addition, serum 3-BrY concentrations were increased in dogs with EGE, but also in dogs with LPE and pancreatitis. Further studies are needed to determine whether measurement of 3-BrY concentrations in serum may be useful to assess patients with suspected or confirmed EGE or LPE.
doi:10.1186/s12917-015-0321-0
PMCID: PMC4299803  PMID: 25595676
3-bromotyrosine; Canine; Eosinophilic gastroenteritis; Stability
17.  SERIAL RENAL CLEARANCES IN DOGS WITH NEPHROGENIC AND SPONTANEOUS HYPERTENSION 
Evidence is presented on the occurrence of spontaneous hypertension in dogs. All dogs with spontaneous hypertension exhibited normal renal plasma flow and glomerular filtration rate. Clearances on nephrogenic hypertensive dogs revealed that some exhibited normal kidney function, while others had significant depression of renal plasma flow and glomerular filtration rate. In the latter, the filtration fraction may or may not be elevated. Serial renal clearances were done at intervals on 3 dogs with spontaneous hypertension during their 3rd year of known hypertension. They exhibited no tendency to develop impaired renal function in the face of prolonged benign hypertension. Serial renal clearances on nephrogenic hypertensive dogs revealed no tendency for kidney function to become progressively impaired. This was true, whether the immediate postoperative clearance values were normal or depressed. It was also true regardless of the duration of the hypertension. It is suggested that mechanisms other than elevated blood pressure per se operate to produce progressive kidney damage and impairment of renal function. No tendency was revealed over the course of a year or more for the kidney function to improve in Goldblatt dogs exhibiting depressed clearances immediately postoperatively. This is interpreted as evidence against the postoperative development in persistently hypertensive Goldblatt dogs of a renal collateral circulation sufficient to augment significantly effective renal blood flow. Pathological studies on 2 dogs with spontaneous hypertension revealed slight to moderate chronic focal lesions in the kidneys, and bilateral adrenal cortical adenomatous hyperplasia. Both lesions may have no pathogenetic significance. In accord with previous observations, autopsies on 3 Goldblatt dogs revealed minimal renal changes in one, and unilateral kidney atrophy with contralateral hypertrophy in the 2 others. The adrenals were normal. In general, data on renal clearances showed correlation with postmortem kidney findings. However, normal renal clearances are found in the presence of anatomically abnormal kidneys. The findings in canine spontaneous and nephrogenic hypertension are compared and contrasted with data obtained in human essential hypertension. Pathogenetic relationships are discussed.
PMCID: PMC2135930  PMID: 15394070
18.  In-Kennel Behavior Predicts Length of Stay in Shelter Dogs 
PLoS ONE  2014;9(12):e114319.
Previous empirical evaluations of training programs aimed at improving dog adoption rates assume that dogs exhibiting certain behaviors are more adoptable. However, no systematic data are available to indicate that the spontaneous behavior of shelter dogs has an effect on adopter preference. The aim of the present study was to determine whether any behaviors that dogs exhibit spontaneously in the presence of potential adopters were associated with the dogs' length of stay in the shelter. A sample of 289 dogs was videotaped for 1 min daily throughout their stay at a county shelter. To account for differences in adopter behavior, experimenters varied from solitary passive observers to pairs of interactive observers. Dogs behaved more attentively to active observers. To account for adopter preference for morphology, dogs were divided into “morphologically preferred” and “non-preferred” groups. Morphologically preferred dogs were small, long coated, ratters, herders, and lap dogs. No theoretically significant differences in behavior were observed between the two different dog morphologies. When accounting for morphological preference, three behaviors were found to have a significant effect on length of stay in all dogs: leaning or rubbing on the enclosure wall (increased median length of stay by 30 days), facing away from the front of the enclosure (increased by 15 days), and standing (increased by 7 days). When combinations of behaviors were assessed, back and forth motion was found to predict a longer stay (increased by 24 days). No consistent behavioral changes were observed due to time spent at the shelter. These findings will allow shelters to focus behavioral modification efforts only on behaviors likely to influence adopters' choices.
doi:10.1371/journal.pone.0114319
PMCID: PMC4281133  PMID: 25551460
19.  The transcriptomic profile of peripheral blood nuclear cells in dogs with heart failure 
BMC Genomics  2014;15(1):509.
Background
In recent years advances have been made in the investigative methods of molecular background of canine heart disease. Studies have been conducted to identify specific genes which, when pathologically expressed, could lead to the dysfunction of the canine heart or are correlated with heart failure. For this purpose genome wide microarray experiments on tissues from failing hearts have been performed. In the presented study a whole genome microarray analysis was used for the first time to describe the transcription profile of peripheral blood nuclear cells in dogs with heart failure. Dogs with recognized heart disease were classified according the ISACHC (International Small Animal Cardiac Health Council) classification scheme as class 1 (asymptomatic) - 13 dogs, class 2 (mild to moderate heart failure) - 13 dogs and class 3 (severe heart failure) - 12 dogs. The control group consisted of 14 healthy dogs. The clinical picture of the animals included: animal history, clinical examination, echocardiographic examination and where applicable electrocardiographic and radiographic examinations.
Results
In the present study we identified four sets of differentially expressed genes, namely heart-failure-specific genes and ISACHC1-specific genes, ISACHC2-sepcific genes and ISACHC-3 specific genes. The most important set consisted of genes differentially expressed in all dogs with heart failure, despite the ISACHC stage. We identified 71 heart-failure-specific genes which were involved in two statistically significant receptor signalling pathways, namely angiotensinR - > CREB/ELK-SRF/TP53 signalling and ephrinR - > actin signalling. The number of ISACHC1-specific genes was 83; ISACHC2-specific genes - 1247 and ISACHC3-specific - 200.
Conclusions
The transcriptomic profile of peripheral blood nuclear cells in dogs with heart failure seems to reflect the presence of clinical signs of the disease in patients based on the observation that the largest number of differentially expressed genes was identified in ISACHC 2 group of patients. This group consists of dogs just starting to show clinical signs of heart failure. A set of genes was also found to have changed expression in all dogs with heart failure, despite the stage of the disease.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-509) contains supplementary material, which is available to authorized users.
doi:10.1186/1471-2164-15-509
PMCID: PMC4092214  PMID: 24952741
Dogs; Heart failure; ISACHC; Transcriptomic profile; Microarrays
20.  Bartonella vinsonii subsp. berkhoffii and Related Members of the Alpha Subdivision of the Proteobacteria in Dogs with Cardiac Arrhythmias, Endocarditis, or Myocarditis 
Journal of Clinical Microbiology  1999;37(11):3618-3626.
Cardiac arrhythmias, endocarditis, or myocarditis was identified in 12 dogs, of which 11 were seroreactive to Bartonella vinsonii subspecies berkhoffii antigens. Historical abnormalities were highly variable but frequently included substantial weight loss, syncope, collapse, or sudden death. Fever was an infrequently detected abnormality. Cardiac disease was diagnosed following an illness of short duration in most dogs, but a protracted illness of at least 6 months' duration was reported for four dogs. Valvular endocarditis was diagnosed echocardiographically or histologically in eight dogs, two of which also had moderate to severe multifocal myocarditis. Four dogs lacking definitive evidence of endocarditis were included because of seroreactivity to B. vinsonii antigens and uncharacterized heart murmurs and/or arrhythmias. Alpha proteobacteria were not isolated from the blood by either conventional or lysis centrifugation blood culture techniques. Using PCR amplification and DNA sequencing of a portion of the 16S rRNA gene, B. vinsonii was identified in the blood or heart valves of three dogs. DNA sequence alignment of PCR amplicons derived from blood or tissue samples from seven dogs clustered among members of the alpha subdivision of the Proteobacteria and suggested the possibility of involvement of one or more alpha proteobacteria; however, because of the limited quantity of sequence, the genus could not be identified. Serologic or molecular evidence of coinfection with tick-transmitted pathogens, including Ehrlichia canis, Babesia canis, Babesia gibsonii, or spotted fever group rickettsiae, was obtained for seven dogs. We conclude that B. vinsonii subsp. berkhoffii and closely related species of alpha proteobacteria are an important, previously unrecognized cause of arrhythmias, endocarditis, myocarditis, syncope, and sudden death in dogs.
PMCID: PMC85709  PMID: 10523564
21.  Regulation of Cholesterol Metabolism in the Dog 
Journal of Clinical Investigation  1973;52(9):2368-2378.
In six adult pedigreed dogs the effects of high-cholesterol diets or bile diversion on the sizes of body cholesterol pools were studied at autopsy. Total body cholesterol was determined by measuring the cholesterol content of discrete organs and of the eviscerated carcass: neither cholesterol feeding nor bile diversion had altered total body cholesterol or the cholesterol content of individual organs and tissues. These results validated the conclusion based on sterol balance data obtained during life, that high-cholesterol feeding did not lead to substantial expansion of tissue cholesterol pools.
The total amount of exchangeable cholesterol in the animals with an intact enterohepatic circulation, when estimated from isotopic data, was essentially the same as that measured chemically: this indicated that there was little or no nonexchangeable cholesterol in these dogs, except in skin and nervous tissue, regardless of the cholesterol content of the diet. This correspondence of estimates was not obtained in the bile-diverted dogs: we propose that the defect in the isotopic estimates was due to the accelerated rate of cholesterol synthesis in these animals.
Gross and microscopic morphology of all organs and tissues was examined. Abnormal findings were limited to the biliary tract and the urinary collecting system of the two bile-diverted dogs: multiple bilirubinate gallstones were found, and mild pyelitis and ureteritis were present on the side of the bilio-renal shunt, but the urinary bladder was normal. Histologic evidence of moderate degree of cholangitis was found in one of the two bile-shunted dogs, but in neither dog was there evidence of impedance of bile flow.
PMCID: PMC333041  PMID: 4727465
22.  The immunosignature of canine lymphoma: characterization and diagnostic application 
BMC Cancer  2014;14(1):657.
Background
Cancer diagnosis in both dogs and humans is complicated by the lack of a non-invasive diagnostic test. To meet this clinical need, we apply the recently developed immunosignature assay to spontaneous canine lymphoma as clinical proof-of-concept. Here we evaluate the immunosignature as a diagnostic for spontaneous canine lymphoma at both at initial diagnosis and evaluating the disease free interval following treatment.
Methods
Sera from dogs with confirmed lymphoma (B cell n = 38, T cell n = 11) and clinically normal dogs (n = 39) were analyzed. Serum antibody responses were characterized by analyzing the binding pattern, or immunosignature, of serum antibodies on a non-natural sequence peptide microarray. Peptides were selected and tested for the ability to distinguish healthy dogs from those with lymphoma and to distinguish lymphoma subtypes based on immunophenotype. The immunosignature of dogs with lymphoma were evaluated for individual signatures. Changes in the immunosignatures were evaluated following treatment and eventual relapse.
Results
Despite being a clonal disease, both an individual immunosignature and a generalized lymphoma immunosignature were observed in each dog. The general lymphoma immunosignature identified in the initial set of dogs (n = 32) was able to predict disease status in an independent set of dogs (n = 42, 97% accuracy). A separate immunosignature was able to distinguish the lymphoma based on immunophenotype (n = 25, 88% accuracy). The individual immunosignature was capable of confirming remission three months following diagnosis. Immunosignature at diagnosis was able to predict which dogs with B cell lymphoma would relapse in less than 120 days (n = 33, 97% accuracy).
Conclusion
We conclude that the immunosignature can serve as a multilevel diagnostic for canine, and potentially human, lymphoma.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2407-14-657) contains supplementary material, which is available to authorized users.
doi:10.1186/1471-2407-14-657
PMCID: PMC4168252  PMID: 25199568
Cancer; Dog; Diagnostic; Antibody response; Peptide microarray
23.  Effects of Coronary Artery Reperfusion on Myocardial Infarct Size Calculated from Creatine Kinase 
Journal of Clinical Investigation  1978;61(4):1048-1056.
The effects of coronary artery reperfusion at 1 and 3 h after occlusion on infarct size (IS) in the conscious dog were compared with a second group of dogs that were not reperfused (24 h occlusion). Infarct size was calculated from creatine kinase (CK) appearing in blood samples (ISs) and myocardial CK depletion (ISm), and determined from gross and histological inspection of the pathological tissue (ISp). Under both conditions, ISm correlated well with ISp. In dogs with 24-h coronary occlusions, ISs correlated well with ISm (ISs = 14.26 + 1.18 × ISm, r = 0.92). In reperfused dogs, the relationship remained linear but was altered (ISs = 15.33 + 2.07 × ISm, r = 0.89). The slope was significantly greater, P <0.05, than that observed for dogs that were not reperfused, suggesting that more CK appeared in serum per gram of infarct. Similarly, significantly different relationships were observed in the reperfused and nonreperfused dogs, when ISs was compared with ISp. Moreover, the configuration of the serial blood CK curve was changed significantly by reperfusion. In dogs with a 24-h occlusion, CK rose gradually to a peak at 11.4±0.5 h. In dogs reperfused at 3 h, CK rose sharply at 3 h and reached a peak at 6.8±0.5 h, significantly earlier (P <0.01) than occurred in dogs reperfused at 1 h, i.e., when the peak occurred at 4.2±0.4 h. The rapid appearance of CK in blood after reperfusion at 1 and 3 h suggested a washout phenomena. Thus, reperfusion alters the shape of the serial blood CK curve and results in a different linear relationship between calculated and measured infarct size, resulting in greater recovery of CK in blood per unit of infarcted myocardium.
PMCID: PMC372622  PMID: 659577
24.  Does getting a dog increase recreational walking? 
Background
This study examines changes in socio-demographic, environmental and intrapersonal factors associated with dog acquisition in non-dog owners at baseline to 12-months follow-up and the effect of dog acquisition on minutes per week of recreational walking.
Methods
RESIDE study participants completed self-administered questionnaires (baseline and 12-months follow-up) measuring physical activity, dog ownership, dog walking behavior as well as environmental, intrapersonal and socio-demographic factors. Analysis was restricted to 'Continuing non-owners' (i.e., non-owners at both baseline and follow-up; n = 681) and 'New dog owners' (i.e., non-owners who acquired a dog by follow-up; n = 92).
Results
Overall, 12% of baseline non-owners had acquired a dog at follow-up. Dog acquisition was associated with working and having children at home. Those who changed from single to couple marital status were also more likely to acquire a dog. The increase in minutes of walking for recreation within the neighborhood from baseline to follow-up was 48 minutes/week for new dog owners compared with 12 minutes/week for continuing non-owners (p < 0.05). After adjusting for baseline variables the effect of dog acquisition on the increase in minutes of recreational walking within the neighborhood was 31 minutes (95% CI: 7.39, 54.22; p < 0.01). However, this reduced to 22 minutes (95% CI: -1.53, 45.42; p > 0.05) after further adjustment for change in baseline to follow-up variables. Increase in intention to walk was the main factor contributing to attenuation of the effect of dog acquisition on recreational walking.
Conclusion
This study used a large representative sample of non-owners to examine the relationship between dog acquisition and recreational walking and provides evidence to suggest that dog acquisition leads to an increase in walking. The most likely mechanism through which dog acquisition facilitates increased physical activity is through behavioral intention via the dog's positive effect on owner's cognitive beliefs about walking, and through the provision of motivation and social support for walking. The results suggest that behavioral intention mediates the relationship between dog acquisition and walking and that dogs may have a significant role in the maintenance of owner walking behavior.
doi:10.1186/1479-5868-5-17
PMCID: PMC2359767  PMID: 18366804
25.  The effects of the Ilizarov distraction technique on bone and muscle in a canine model: a preliminary report. 
This study examined the functional and morphological changes experienced by bone and muscle during Ilizarov distraction osteogenesis. Although extensive research has been conducted in the area of regenerate bone formation, the effect of limb lengthening on the biomechanical properties of bone and muscle has not been thoroughly addressed. In this study, an Ilizarov external fixator was applied to one tibia of nine skeletally mature dogs, and distracted 3 cm over thirty days. The contralateral tibia served as control. Histology and weekly radiographs assessed muscle morphology and bone growth. The contractile capabilities of the gastrocnemius muscles from the experimental and control limbs were measured prior to sacrifice, and the bending stiffness of the tibias of five dogs was determined. All dogs experienced loss of knee extension secondary to muscle contracture and/or stiffness about the joint. These dogs did not bear weight on the experimental limb. In one dog, spontaneous resolution of the muscle contracture allowed partial weight bearing during the last three weeks of consolidation. Despite 3 cm distraction, tibial lengthening ranged from 1.7 to 3 cm. Biomechanical testing revealed a significant reduction in the bending stiffness of the lengthened bones when compared with control values (p < 0.003). The weight of the lengthened muscles was 35% less than control values, a finding consistent with the histology which showed mild muscle fiber degeneration in all dogs. The contractile capabilities of the lengthened muscles were reduced to 29-80% of control values (p < 0.005). In contrast, the lengthened muscle from the weight bearing dog retained 85% of the weight and 104% of the maximum contractile force of the control muscle.
Images
PMCID: PMC2378139  PMID: 9129270

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