Indices for M-mode measurements in dogs usually have been based on the assumption that a linear relationship exists between these measurements and body weight (BW) or body surface area (BSA). The relationships between the geometry of 3-dimensional objects do not support this assumption. The purposes of this study were to retrospectively examine M-mode data from a large number of dogs of varying sizes and breeds that were examined by a large number of ultrasonographers, to use the allometric equation to determine the appropriate BW exponent required to predict these cardiac dimensions, and to determine normal mean values and prediction intervals for common M-mode variables. Linear regression analyses of data from 494 dogs (2.2-95 kg) revealed a good correlation between M-mode measurements and BW after logarithmic transformation of the data (r 2 .55-.88). Most variables were most closely related to an index of body length, BW 1/3 , although the exponent that best predicted diastolic and systolic left ventricular wall thicknesses was closer to 0.25. No variable indexed well to BW or BSA. With these data, appropriate mean values and prediction intervals were calculated for normal dogs, allowing veterinarians to correctly and appropriately index M-mode values. The equations developed from this study appear to be applicable to adult dogs of most breeds.

Indices for M-mode measurements in dogs usually have been based on the assumption that a linear relationship exists between these measurements and body weight (BW) or body surface area (BSA). The relationships between the geometry of 3-dimensional objects do not support this assumption. The purposes of this study were to retrospectively examine M-mode data from a large number of dogs of varying sizes and breeds that were examined by a large number of ultrasonographers, to use the allometric equation to determine the appropriate BW exponent required to predict these cardiac dimensions, and to determine normal mean values and prediction intervals for common M-mode variables. Linear regression analyses of data from 494 dogs (2.2-95 kg) revealed a good correlation between M-mode measurements and BW after logarithmic transformation of the data (r 2 ϭ .55-.88). Most variables were most closely related to an index of body length, BW 1/3 , although the exponent that best predicted diastolic and systolic left ventricular wall thicknesses was closer to 0.25. No variable indexed well to BW or BSA. With these data, appropriate mean values and prediction intervals were calculated for normal dogs, allowing veterinarians to correctly and appropriately index M-mode values. The equations developed from this study appear to be applicable to adult dogs of most breeds.Key words: Canine; Echocardiography; Heart; Reference range. M-mode echocardiography is commonly used to measure linear cardiac dimensions of cardiac chambers, walls, and great vessels. Because adult dogs range in weight from Ͻ2 to Ͼ90 kg, any definition of normal heart size must take into account the variation caused by differences in body size. Consequently, it is important to identify equations that accurately describe the relationships between body size and cardiac dimensions. Several authors have published equations, nomograms, or tables that are intended to be used as reference ranges for M-mode measurements for adult dogs of varying size and breed. [1][2][3][4][5][6][7][8][9][10][11] Critics have questioned the usefulness of some of these reference ranges because of small sample sizes, lack of data points for the extremes of body size, wide prediction intervals, and the use of inappropriate statistical methods. 5,[10][11][12][13][14][15] In addition, many authors have assumed that a linear relationship exists between linear cardiac dimensions and either body weight (BW) or body surface area (BSA), which might not be true. Evidence also has been presented suggesting that a general equation might never be accurate because breed is a factor Davis, CA 95616-8747; e-mail: cccornell@ucdavis.edu. Submitted March 7, 2003; Revised July 1 and October 31, 2003; Accepted December 11, 2003. Copyright that can cause M-mode measurements in dogs of the same weight to differ. 13The statistical methods used to produce the previously mentioned reference ranges were not described in every case, but in 2 studies in which the authors detailed their methods, reference ranges we...

We report the first documented case of endocarditis associated with Bartonella clarridgeiae in any species. B. clarridgeiae was identified as a possible etiological agent of human cat scratch disease. Infective vegetative valvular aortic endocarditis was diagnosed in a 2.5-year-old male neutered boxer. Historically, the dog had been diagnosed with a systolic murmur at 16 months of age and underwent balloon valvuloplasty for severe valvular aortic stenosis. Six months later, the dog was brought to a veterinary hospital with an acute third-degree atrioventricular block and was diagnosed with infective endocarditis. (1,5,8,19,20,45,49).At present, only two Bartonella species have been identified to cause clinical diseases in dogs. B. vinsonii subsp. berkhoffii has been shown to cause endocarditis, arrhythmia, and myocarditis (6, 9, 31), as well as granulomatous lymphadenitis and granulomatous rhinitis (40), and B. henselae was recently associated with a case of peliosis hepatis (27). During an active investigation of canine endocarditis cases, we cultured a fastidious, gram-negative organism that we identified to be B. clarridgeiae from the blood of a dog with an aortic endocarditis. We describe the clinicopathologic and histopathologic features as well as the microbiologic and genotypic identification of the organism isolated from the dog's blood and detected by molecular methods in the infected aortic valve. MATERIALS AND METHODSStrain sources. The type strains of B. vinsonii subsp. berkhoffii (ATCC 51672) and B. clarridgeiae (ATCC 51734) were obtained from the American Type Culture Collection (Rockville, Md.). Isolate B. henselae strain U4 was obtained from our culture collection at the University of California, Davis (UC Davis). Isolate UCD-dog1 was cultured from the blood of the dog described in this report.Clinical samples. Blood (6 ml) was collected aseptically from the dog's external jugular vein and both lateral saphenous veins at the time of acute thirddegree atrioventricular (AV) block, infectious endocarditis, and just prior to death. Blood samples were submitted for aerobic and aero-anaerobic cultures, as well as for specific Bartonella isolation on fresh blood agar (5% defibrinated rabbit blood) (16). Serum was submitted for determination of Bartonella antibody titers and for detection of several tick-borne pathogens (Ehrlichia spp., Borrelia burgdorferi) and of Coxiella burnetii, a known agent of endocarditis in humans and animals.Similarly, on 22 June 2000, blood (0.5 to 2 ml) was collected aseptically from the external jugular vein of three cats from the household of origin for Bartonella culture and serology. A serum sample was also obtained from the dog's owner for possible detection of Bartonella antibodies.Tissue samples. Fragments of the aortic and pulmonic valves were frozen for PCR and electron microscopic examination and fixed in 10% buffered formalin for histology. After 24 h, formalin-fixed tissues were embedded in paraffin, sectioned, and stained with hematoxylin and eosin or silver (Wa...