Karl Nuss

Identification, Molecular Characterization, and Occurrence of Two Bovine Hemoplasma Species in Swiss Cattle and Development of Real-Time TaqMan Quantitative PCR Assays for Diagnosis of Bovine Hemoplasma Infections

ABSTRACT Concomitantly with an outbreak of fatal anaplasmosis in a cattle herd in Switzerland in 2002, we detected two bovine hemoplasma species in diseased animals: Mycoplasma wenyonii (formerly Eperythrozoon wenyonii) and a second, novel bovine hemoplasma species later designated “Candidatus Mycoplasma haemobos” (synonym, “Candidatus Mycoplasma haemobovis”). The second species was characterized by a shorter 16S rRNA gene. The aims of the present study were to provide a detailed molecular characterization of this species, to develop specific quantitative real-time PCR assays for the two bovine hemoplasma species, and to apply these assays in order to evaluate the prevalence and clinical significance of the hemoplasmas. Sequencing of the near-complete 16S rRNA gene of the second hemoplasma revealed that it was 94% identical to that of Mycoplasma haemofelis, an anemia-inducing feline hemoplasma species, but less than 85% identical to that of the bovine hemoplasma M. wenyonii. Using the newly developed assays, a total of 159 animals from the anaplasmosis outbreak were reexamined. In addition, we tested 57 clinically ill and 61 healthy Swiss cattle, as well as 47 calves. Both hemoplasmas were highly prevalent in adult cattle but occurred rarely in calves. Animals from the herd with the fatal anemia outbreak were more frequently infected with M. wenyonii and exhibited higher M. wenyonii blood loads than animals with unrelated diseases and healthy animals. Coinfections may increase the pathogenicity and clinical significance of bovine hemoplasmosis.

Length asymmetry of the bovine digits.

The lengths of the digital bones of the fore- and hind-limbs obtained post mortem from 40 cattle of different ages were measured using digital radiographs. The lengths of the individual digital bones and the overall length of the digit were determined using computer software. The lateral metacarpal/metatarsal condyle, and lateral P1 and P2 were significantly longer than their medial counterparts, whereas P3 of the medial digit was longer than its lateral partner. Measured from the cannon bone epiphysis to the tip of the pedal bone, the mean increased length of the lateral digit was 0.8 mm in the fore- and 1.5 mm in the hind-limb. When the lengths of the digital bones were summed, the mean length of the lateral digit was 1.8 mm longer in the fore-limb and 2.1 mm longer in the hind-limb. Based on these findings, it can be concluded that the lengths of the paired digits differ in cattle. The majority of cattle have longer lateral digits in the fore- and hind-limbs. This asymmetry might explain why the lateral hind-limb claws are predisposed to sole ulcers on hard surfaces. In the hind-limbs, the impact is transferred from the pelvis directly to the longer lateral digit. In the fore-limb claws, the tenomuscular attachment to the trunk may be involved in a more even weight distribution and in a shift of weight to the medial claw.

Measurements of forelimb claw dimensions in cows using a standardised sole thickness: a post-mortem study.

Measurements of both front feet of slaughtered German Simmental cattle (17 heifers, 13 cows) were carried out to document the normal shape and size of the forelimb claws and to gain information about function and possible predisposition to disease. Only clinically normal feet were examined, and a standardised sole thickness of 5mm at the tip and 8mm in the heel region in both claws was established as a reference. The dorsal wall length, dorsal wall angle, heel length, height and width, sole and claw length and claw width, sole circumference and sole area were measured. After removal of the horn capsules, measurements of values at the level of the corium were carried out. The lateral front claws were wider and the medial claws longer than their partner claws. Overall, the sole surface areas and circumferences of the paired claws were similar, but were statistically larger in the medial claws. The front claws were characterised by long and high heel bulbs, and had a toe length:heel bulb length ratio of approximately 1.6:1. These properties, together with the musculo-tendinous attachment of the limbs to the trunk, are believed to provide better protection for the forelimb claws when standing or walking on hard surfaces. Functional mechanical relief of the medial front claws is probably best achieved by pairing the soles of the foot to the same level, which usually entails reduction of the lateral claw. For German Simmental cattle, a dorsal wall length of 75mm can be used as a guideline when trimming front and hind feet.

Even-toed but uneven in length: the digits of artiodactyls.

In captive ruminants housed in small enclosures, hypertrophy of the outer hooves of the hindlimbs is often observed. We hypothesised that the underlying cause is overload attributable to an asymmetry of the digits, especially with respect to their length. To test this hypothesis, the bones of the digits of four species of artiodactyls, which included 11 wild chamois (Rupicapra rupicapra), 11 captive fallow deer (Dama dama), 11 captive bison (Bison bison) and 11 European moose (Alces alces; 9 wild, 2 captive), were radiographed post mortem and measured using a computer programme. In addition, the dimensions of the outer and inner hooves were measured directly with a caliper. The mean lengths of the epiphysis of the fourth metacarpal/metatarsal bone and the first and second phalanges of the fourth digit were greater than that of the third digit, whereas the third phalanx of the third digit had a greater mean length. The mean total length of the fourth digit of the forelimbs was greater than that of the third digit in 73-95% of specimens, depending on species. In the hindlimbs, the fourth digit was longer in 91-100% of the specimens. The hooves of the fourth digit were significantly broader than the hooves of the third digit, whereas the inner hooves of the third digits had a greater toe length than those of the fourth digit. The paired digits of artiodactyls are uneven in length, which suggests a different function during stance and weight bearing. It is conceivable that this asymmetry is the result of selection processes that favoured locomotion on soft ground.

Difference in the Length of the Medial and Lateral Metacarpal and Metatarsal Condyles in Calves and Cows – A Post-Mortem Study

Measurements were taken in the metacarpal and metatarsal bones in 42 calves and 10 dairy cows post‐mortem to determine whether there are anatomical differences in bone length. Manual and digital measurements of various bone length parameters were taken. There was a significant difference in the mean length of the condyles of the metacarpal and the metatarsal bones in calves and cows, the lateral condyle being longer than the medial. In all but one metatarsal bone (98.8%), the lateral condyle was longer than the medial. In the metacarpal bones, the lateral condyle was longer in only 52.4% of the bones, in 21.2%, they had the same length and in 27.4% the medial condyle was longer. These intrinsic anatomical differences can help distinguish between the left and right metacarpal and metatarsal bones, for instance, in anatomical and archaeological studies. Knowledge of these differences might be useful for studies on digit function and on the possible predisposition of cattle to claw diseases in the lateral claws of the hind limbs.

Ultrasonographic findings in three cows with ureteral obstruction due to urolithiasis

URINARY calculi are common in cattle. They are usually small, with a diameter of 1 to 5 mm, and not caused by inflammation (Grunder 2002). Affected cattle generally show no clinical signs unless the calculi obstruct the urethra or, less frequently, the ureter (Van Metre and others 1996). Obstructive urolithiasis is almost exclusively a disease of male cattle because the male urethra is long and narrow; female cattle have a short, wide urethra, and are rarely affected. There have been several reports of urethral obstruction due to urolithiasis in male cattle (Gasthuys and others 1993, Larson 1996, Streeter and others 2001). However, there are only two case reports involving female cattle, in which calculi obstructed one (Spadiut 1962) or both (Divers and others 1989) ureters. Most standard veterinary textbooks mainly limit the discussion of urolithiasis to male cattle (Radostits and others 2000, Grunder 2002), although Hofmeyr (1987) and Van Metre and Divers (2002) discussed ureterolithiasis in female cattle, including the previously mentioned case reports (Spadiut 1962, Divers and others 1989). This short communication describes the clinical and ultrasonographic findings in three cows with ureteral obstruction due to urolithiasis. The three cows were referred to the Department of Farm Animals, University of Zurich, between January 1, 1996 and December 31, 2004, because of colic. The cows had been ill for 12 to 24 hours before admission and had not responded to treatment with metamizole. A seven-year-old Swiss Braunvieh (cow 1) had shown signs of severe colic with sweating for a few hours. Cow 2, a six-year-old Swiss Braunvieh, had shown signs of colic since the day before referral; it had not passed any faeces, and the referring veterinarian had therefore administered the parasympathomimetic agent neostigmine. Cow 3, a six-year-old Holstein-Friesian x Eringer cross, had had a decreased appetite for one week and had shown signs of colic for one day. The referring veterinarian had made a tentative diagnosis of ileus because the cow had not passed any faeces. All of the cows had been inseminated artificially five to 27 days before referral. Cows 2 and 3 were referred with a tentative diagnosis of ileus, and no diagnosis had been made for cow 1. The general behaviour and condition of all the cows was moderately abnormal and their appetite was decreased or absent. Cows 1 and 2 were restless and showed signs of colic, such as shifting their weight on their hindlimbs, kicking at their abdomen, tail switching and assuming a sawhorse stance. Cow 3 was very quiet but groaned occasionally; the cow showed no signs of colic during an initial clinical examination. The heart rate of the cows varied from 52 to 76 bpm, and the respiratory rate ranged from 20 to 28 breaths/minute. The rectal temperature ranged from 38·2 to 39·0°C, and skin turgor was decreased in all the cows. The body condition was poor in cow 1, moderate in cow 2 and good in cow 3. The skin surface temperature was decreased in cows 1 and 2. Cows 2 and 3 had scleral injection. Ruminal motility was decreased in all three cows, and samples of rumen juice were inactive as judged by a methylene blue reduction test result of greater than six minutes (normal less than six minutes) (Dirksen 1990). The intestinal motility was decreased in cows 1 and 3, and absent in cow 2. Some of the tests for a reticular foreign body were positive in cows 1 and 2. In cow 2, ballottement and auscultation was positive on the right side. Rectal examination revealed a scant amount of faeces in cow 1 and no faeces in cow 2. In cows 1 and 3, the left ureter could be palpated transrectally as a cord with a diameter of approximately 1·5 cm. Cranial to the right wing of the ilium, a soft, non-painful swelling could be palpated in cows 2 and 3, which was approximately 25 cm x 25 cm x 20 cm in cow 2 and 30 cm x 20 cm x 15 cm in cow 3. All the cows could urinate spontaneously; in cows 1 and 2, the urine was pale yellow and clear, and in cow 3 it was pale pink and cloudy. The specific gravity of the urine was 1·025, 1·008 and 1·022, and the pH, measured with a urine test strip (Combur9-Test; Roche), was 7·0, 8·0 and 6·5, in cows 1, 2 and 3, respectively. Cows 1 and 3 had mild proteinuria, and all the cows had haematuria/haemoglobinuria, which ranged from + (mild) in cow 2 to +++ (severe) in cows 1 and 3 as measured by the urine test strip. The most important laboratory findings were elevated concentrations of urea, which varied from 12 to 15 mmol/l (reference range 3 to 7 mmol/l) and creatinine, which ranged from 138 to 368 μmol/l (reference range 88 to 133 μmol/l). The activity of gamma glutamyl transferase was increased to 31 U/l in cow 1 and to 37 U/l in cow 2 (reference range 6 to 27 U/l). The concentration of total protein was increased to 93 g/l in cow 1 and to 92 g/l in cow 3 (reference range 60 to 80 g/l). The serum concentration of potassium was decreased to 3·4 mmol/l in cow 1 and to 3·6 mmol/l in cow 3, and increased to 6·3 mmol/l in cow 2 (reference range 4 to 5 mmol/l). Cow 3 had hyponatraemia, with a serum concentration of sodium of 139 mmol/l (reference range 145 to 155 mmol/l). Cows 2 and 3 had hypocalcaemia, with serum calcium concentrations of 2·06 and 2·11 mmol/l, respectively (reference range 2·2 to 2·5 mmol/l). All the cows had moderate to severe hypophosphataemia, with serum concentrations of phosphorus of 0·97, 0·46 and 0·47 mmol/l in cows 1 to 3, respectively (reference range 1·5 to 2·7 mmol/l). Blood gas analysis in cows 2 and 3 was unremarkable. Ultrasonographic examination of the reticulum (Braun and Gotz 1994), liver (Braun 1990), urinary tract (Braun 1991, 1993) and abdomen (Braun 1997) was performed in all the cows. In cow 1 the left ureter was dilated to 11 mm in diameter (Fig 1). In cow 2, both kidneys were dilated and contained multiple echogenic concretions, which caused distal acoustic shadows (Fig 2); there were also pockets of hypFIG 1: Ultrasonogram showing dilation of the left ureter of a seven-year-old Swiss Braunvieh cow (cow 1). The ultrasonographic examination was carried out transrectally using a 7·5 MHz linear transducer. L Left, R Right, V Ventral, A Dilated left ureter in longitudinal section

Clinical and ultrasonographic findings in four cows with liver tumours

NEOPLASIA of the liver is rare in cattle. Its clinical signs are usually non-specific until the terminal stages of the disease, when signs of liver dysfunction, such as icterus, may occur (Radostits and others 2000, Stöber 2002). In addition, anorexia, indigestion, diarrhoea, weight loss and sometimes ascites and enlargement of the liver, as determined by percussion, are encountered in the later stages, particularly in cattle with malignant tumours (Stöber 2002). Occasionally, an enlarged liver can be palpated, and abdominal pain may be present because of stretching of the liver capsule (Radostits and others 2000). Polycythaemia may occur in cattle with hepatic carcinomas that produce erythropoetin (Braun and others 1997); affected cattle have dark red mucous membranes, severe scleral injection and a haematocrit of over 60 per cent, which usually cannot be decreased by intravenous fluid therapy. Tumours in the gall bladder may result in bile stasis, posthepatic icterus and hepatogenic photosensitivity (Stöber 2002). As a general rule, liver tumours are usually an incidental finding at postmortem examination. In only two bovine cases of polycythaemia has a liver tumour been diagnosed by ultrasonography in vivo (Braun and others 1997); in those cattle, focal hepatic lesions were seen on ultrasonograms, and in one, multiple vessels accompanied the lesions peripherally. This short communication describes the clinical and ultrasonographic findings in four other cows with hepatic tumours. All of the cows were referred to the Department of Farm Animals, University of Zurich, because of anorexia, weight loss and abnormal general condition. They had been ill for a period ranging from two weeks to two months. Cow 1 was a five-year-old Swiss Braunvieh, which had calved normally six weeks before admission and had since then had a reduced appetite and had been calm. The cow had been treated a number of times for ketosis and hypomagnesaemia by the referring veterinarian. Cow 2 was a 12-year-old Swiss Braunvieh, which had calved six months before admission; the owner reported that the cow had a poor appetite and chronic weight loss. Cow 3 was a seven-year-old Holstein-Friesian, which was four-and-a-half months’ pregnant; the owner noticed that the cow had lost weight, had a poor appetite and salivated excessively, regurgitated feed and was frequently recumbent. Treatment with intravenous calcium and rasping of dental points on the molar teeth did not lead to improvement. Cow 4 was a seven-year-old Simmental, which had calved 10 days before admission; it had a decreased appetite, weight loss, poor milk production, and had had a cough for three weeks before admission. The referring veterinarian reported that the cow had a stenotic nasal respiratory noise, reddened mucous membranes and a bilateral purulent ocular discharge. The general attitude and behaviour of all four cows was moderately altered, and they were depressed. Cows 1 and 3 had bruxism. The cows’ rectal temperature ranged from 38·4 to 38·7°C, and their heart rate ranged from 60 to 76 bpm. All of the cows were thin (Fig 1). Ruminal and intestinal motility were normal in cows 2 and 3, reduced in cow 1 and absent in cow 4. Cow 4 had an arched back and mild ruminal tympany. Testing for reticular foreign bodies, by methods including the withers pinch, pole test and percussion of the reticulum, was positive in cow 1 and negative in the others. The abdominal wall was tense in cows 1 and 2. Cow 2 had a bilateral purulent nasal discharge, and cow 4 had bilateral enopthalmos, a bilateral serous ocular discharge, a stenotic nasal respiratory noise, a dry muzzle and reddened mucous membranes. Methylene blue staining of a sample of ruminal fluid (Dirksen 1979) revealed inactivity in three cows. Evaluation of a urine sample for pH, nitrite, glucose, total proteins, ketones, bilirubin, urobilinogen and erythrocytes/ haemoglobin using a strip test was unremarkable in all of the cows. The most important findings of haematological and biochemical analyses were increases in the activities of glutamate dehydrogenase (GLDH), sorbitol dehydrogenase (SDH) and gamma glutamyltransferase (GGT) (Table 1) in all of the cows. The concentration of bilirubin was mildly increased to 7 to 14 μmol/l in cows 1, 3 and 4 (reference range 0·8 to 4·4 μmol/l) (Braun and others 2000). Cow 2 had a leucopenia, with 3600 leucocytes/μl blood (reference range 3900 to 9100 leucocytes/μl). The concentrations of fibrinogen, serum electrolytes and urea and the results of blood gas analysis were unremarkable in all of the cows. Serological testing for infectious bovine rhinotracheitis by ELISA was negative in all of the cows. Cow 4 was suspected of having malignant catarrhal fever, but was negative for ovine herpesvirus type 2 by PCR (Müller-Doblies and others 1998). Because of the increased liver enzyme activities, ultrasonography of the liver was performed in all of the cows (Braun 1990). In cow 1, a heterogeneous, echogenic mass with a diameter of approximately 11 cm was seen in the dorsal region of the liver, between the 10th and 12th intercostal spaces. The contour of the diaphragmatic surface of the liver bulged in the area of the mass. A similar lesion with a diameter of 3·0 cm was seen on the liver at the ninth intercostal space. Histological examination of a tissue sample obtained via percutaneous ultrasound-guided biopsy revealed a bile duct carcinoma. In cow 2, an echogenic, round mass with a diameter of 9·6 cm, surrounded by a hypoechogenic border with a width of approximately 1·0 cm, which demarcated the mass from the normal liver parenchyma, was seen at the ninth and 10th intercostal spaces (Fig 2). Histological examination

Clinical findings and treatment in cattle with caecal dilatation

BackgroundThis retrospective study describes the clinical and laboratory findings, treatment and outcome of 461 cattle with caecal dilatation.ResultsThe general condition and demeanor were abnormal in 93.1% of cases, and 32.1% of the patients had colic. Ruminal motility was reduced or absent in 78.3% of cattle. In 82.6% of cases, swinging and/or percussion auscultation were positive on the right side, and 82.4% had little or no faeces in the rectum. Caecal dilatation could be diagnosed via rectal palpation in 405 (88.0%) cattle. There was caudal displacement of the dilated caecum in 291 patients, torsion around the longitudinal axis in 20 and retroflexion in 94. The most important laboratory finding was hypocalcaemia, which occurred in 85.1% of cases. Of the 461 cattle, 122 (26.5%) initially received conservative therapy (intravenous fluids, neostigmine, calcium borogluconate) and 329 (71.4%) underwent surgical treatment. Ten patients were slaughtered or euthanased after the initial physical examination. Of the 122 cattle that received conservative treatment, 42 did not respond after one to two days of therapy and required surgical treatment. The final number of cattle that were operated was 371 (80.5%). Because of a grave prognosis, 24 cases were euthanased or slaughtered intraoperatively. Another 24 cattle did not respond to one or more operations and were euthanased or slaughtered. Of the 461 patients, 403 (87.4%) responded to either conservative or surgical treatment and were cured, and 58 were euthanased or slaughtered.ConclusionsCaecal dilatation can usually be diagnosed based on clinical findings and treated conservatively or surgically. Swinging and percussion auscultation as well as rectal examination are important diagnostic tools. Conservative treatment is not rewarding in cattle considered surgical candidates with suspected caecal torsion or retroflexion and surgery should not be delayed in these patients.

Clinical and ultrasonographic findings in five cows with a ruptured urachal remnant.

Blood Haematocrit (%) 25-37 ND 46 48 45 42 Total protein (g/l) 64-87 ND 81 92 96 105 Total leucocyte count (x 103/μl) 3·9-9·1 ND 12·8 9·2 6·4 8·7 Urea (mmol/l) 2·7-5·7 16·1 33·7 19·9 18·5 26·1 Creatinine (μmol/l) 88-133 260·0 608·0 451·0 251·0 350·0 Sodium (mmol/l) 143-157 148·0 141·0 144·0 133·0 136·0 Potassium (mmol/l) 3·8-5·3 4·1 5·4 5·4 5·3 3·6 Chloride (mmol/l) 98-190 89·0 92·0 99·0 82·0 84·0 Abdominal Colour Light yellow Colourless Colourless Light yellow Light yellow fluid Transparency Clear Clear Slightly cloudy Clear Clear Odour Smell like urine None None None Smell like urine Specific gravity 1008 101

Arthroscopic approaches to the fetlock joint of adult cattle: A cadaver study

The objective of the present study was to describe the arthroscopic anatomy of the bovine fetlock joint using one palmar/plantar and three dorsal joint approaches. A comparative anatomic, ultrasonographic and arthroscopic study using 20 cadaveric feet from 13 non-lame adult dairy cows was performed. Arthroscopy was accomplished using a rigid arthroscope to view the synovial cavities with their synovial villi and parts of the following structures: the distal ends of the metacarpal/metatarsal III/IV bones with their trochleae and sagittal ridges, synovial grooves, the articular surfaces of the proximal sesamoid bones, the proximal aspects of the first phalanges, the lateral and medial collateral ligaments, the suspensory ligament and the interdigital ligaments as parts of the interosseus muscle, the cruciate sesamoidean ligaments, the communication site between the lateral and medial pouch in the palmar/plantar area, and dorsally the septum between the lateral and the medial pouch. The technique allowed a good overall view of most relevant structures in the sound cadaver joint. Further investigations are warranted to evaluate the diagnostic, therapeutic and prognostic applications of these techniques in the treatment of septic arthritis.