PEROSOMUS ELUMBIS IN SHEEP

Eight lambs affected with perosomus elumbis were examined during a 3-year investigation; one died during birth, six died soon after birth without rising, and one died at two days. Typically, the affected lambs had an infantile pelvis, thinner and smaller femurs, tibias and metatarsal bones, muscular atrophy, arthrogryposis involving most joints of the hindlimbs, and five had tail malformations. Associated malformations were multiple and included atresia ani (5), unilateral renal agenesis (4), cryptorchidism (4), perineal and diaphragmatic hernias (1), synophthalmia (1), high septal defect (1), cerebellar hypoplasis (1), and hydrocephalus (1). Five of the affected lambs were males and three were females. The incidence of 0.18% in 4,417 lambs examined from a large sheep population over a 3-year period suggests that perosomus elumbis is not an uncommon congenital defect of sheep.     

CONGENITAL RESPIRATORY TRACT DEFECTS IN LAMBS

One hundred and forty-seven newborn lambs with congenital defects of the respiratory tract were examined during a 3-year investigation into the causes of perinatal lamb mortality. Respiratory defects were found in 3.3% of the 4,417 lambs examined and in one-third (36.6%) of the 401 congenitally malformed lambs. All the defects were secondary to other more extensive malformations. The upper respiratory tract was involved 3 times more than the lower tract. Males were involved more than females (4:3). The upper tract defects were harelip, cleft palate, atelorrhinia, arrhinia, proboscis, fused nostrils and choanal atresia. One of the facial clefts was a rare median harelip associated with cleft palate and fused nostrils. The lower tract defects were pulmonary agenesis, hypoplasia and duplication. The 2 most common defects were choanal atresia and secondary pulmonary hypoplasia. It was concluded that primary defects of the respiratory tract of sheep are rare and that secondary defects are relatively common.     

PERINATAL LAMB MORTALITY IN WESTERN AUSTRALIA 7. Congenital Defects

Four hundred and one malformed lambs were examined during a 3-year investigation into the causes of perinatal lamb mortality. Frequence of involvement of the various body systems was: musculo-skeletal 55.4%, digestive 12.7%, cardiovascular 9.7%, uro-genital 7.1%, nervous 6.0%, special senses 3.5%, integument 3.2%, and endocrine 1.5%. A third of the defects (32.9%) involved more than one body system. There was a sex difference of 3 males: 2 females. The common defects in the lambs autopsied in order of frequence were: agnathia, atresia ani, cardiac defects, arthrogryposis, micrognathia, scrotal bifurcation, embryonic duplications, hernias, meningocele, and perosomus elumbis. Agnathia, atresia ani and persistent umbilical haemorrhage appeared to be hereditary. There was no relationship between congenital defects and the time of lambing and phytoestrogens.     

Radiographic findings in induced bacterial pyelonephritis in dogs

Unilateral bacterial pyelonephritis was induced in nine dogs. The upper urinary tracts of these and six control dogs were evaluated by excretory urography prior to and 9 to 10 days following experimental manipulations. Two of the dogs with unilateral pyelonephritis and one control dog were evaluated at intervals throughout a 58-day period. At necropsy, all nine inoculated kidneys were infected, one experimental dog had bilateral pyelonephritis, and one control dog had unilateral pyelonephritis. Most of the infected kidneys had abnormal radiographic changes 9 to 10 days after induction of infection. There was no statistically significant radiographic change in size of infected kidneys at 9 to 10 days. Seven of the 11 infected kidneys and 7 of the 9 inoculated kidneys had renal pelvic and ureteral dilatation. Of the nine dogs with unilateral pyelonephritis, six had decreased opacity of contrast medium in the collecting system and of the vascular nephrogram on the infected side. The size of infected kidneys decreased progressively during the 58-day period. In one of the two dogs evaluated throughout the period, the collecting system of the infected kidney remained dilated; in the other, it returned toward normal size.     

Glucosuria associated with renal calculi in Asian small-clawed otters

Urine from one female and 2 male Asian small-clawed otters (Aonyx cinerea) with bilateral renal calculi, one female with unilateral calculi, and one nonaffected male were evaluated for abnormal urinary crystalloid excretion. One otter with bilateral renal calculi had cystic calculi composed of calcium oxalate monohydrate and dihydrate. The 2 affected males were littermates, as were the 2 affected females, but the 2 litters were from different parents. At the time of the study, the otters did not have clinical signs of disease. Hematologic and serum biochemical, electrolyte, and enzyme values were normal. The urinary excretion of calcium, oxalate, uric acid, phosphate, citrate, and amino acids in otters with renal calculi was similar to that of the nonaffected otter. The 4 otters with renal calculi had glucosuria but the nonaffected otter did not have glucosuria. The glucosuria, in the absence of hyperglycemia, suggested a renal tubular transport defect for glucose. Other renal abnormalities were not found.     

Unilateral renal agenesis associated with additional congenital abnormalities of the urinary tract in a Pekingese bitch

An eight-month-old Pekingese bitch with urinary incontinence was found to have three congenital anomalies of the urinary tract: left renal agenesis, bilateral ectopic ureters with a left cranial blind-ending ureter, and urinary bladder hypoplasia. The diagnoses were made by retrograde vaginourethrography, excretory urography, ultrasonography and duplex Doppler ultrasonography. Although urological anomalies associated with renal agenesis have been frequently observed, a cranial blind-end ectopic ureter has not, to the authors' knowledge, been described in the bitch. The dog was managed medically with a restricted protein diet because of a compromised unilateral kidney with hydronephrosis and hydroureter.     

An outbreak of gonadal hypoplasia in a sheep flock: clinical, pathological and endocrinological features, and aetiological studies.

In 1984, 31 per cent of 437 ram lambs reared on one property were found to have either bilateral or unilateral testicular hypoplasia. Similar numbers of ram lambs were reared in the next three years and 13, 2 and 0.5 per cent were affected. Severely abnormal testicles typically produced no spermatozoa and presented a 'Sertoli cell only' picture. Sixty-six of 200 ewe lambs born in 1984 were not marked by a harnessed teaser before mating; 12 of these were examined further and eight were found to have bilateral ovarian hypoplasia. The ovaries were very small and contained no oocytes or follicles. Plasma gonadotrophin levels were higher than normal in bilaterally affected rams and ewes but plasma testosterone and inhibin concentrations in rams with bilateral hypoplasia were not significantly different from those in normal rams. A genetic cause of the gonadal hypoplasia was considered unlikely in view of the pattern of occurrence and an examination of the flock pedigrees. No environmental cause was found. Two environmental sources of toxins were considered worthy of further investigation; onion grass (Romulea species) with its leaf spot fungus Helminthosporium biseptatum and the water supply which could have contained high concentrations of arsenic or other toxins during the period when the mothers of the affected lambs were in early pregnancy.     

Isolation of Chlamydia psittaci and Moraxella bovis from infectious keratoconjunctivitis in lambs

Out of 189 lambs in the flock, 25 animals suffered from bilateral or unilateral conjunctivitis, or keratoconjunctivitis. By serological examination (RVK), positive levels of antibodies to the group-specific antigen of Chl. psittaci were found in three out of six lambs examined by laboratory methods. Bacteriological examination of eye smears of six lambs showed in four cases the infection by microorganisms of Moraxella bovis. Smears from the conjunctivas of these lambs were after preparation instilled in the yolk sacs of six to seven days old chicken embryos. One strain of Chlamydia psittaci was isolated from the same material as Moraxella bovis.     

Cryptosporidium parvum infection in orphan lambs on a farm open to the public

A longitudinal survey was undertaken on an open farm to investigate the occurrence of Cryptosporidium species infection in orphan lambs obtained from three local flocks. During an initial pilot study, Cryptosporidium oocysts were detected by a fluorescent antibody test (fat) in the faeces of two of 21 lambs aged between one and three weeks derived from one flock (flock A). Pooled pen samples of faeces were collected weekly from lambs derived from each flock; oocysts were detected by fat in 24 (49.0 per cent) of 49 samples from lambs from flock A, 18 (30.5 per cent) of 59 samples from lambs from flock B and 14 (29.8 per cent) of 47 samples from lambs from flock C. Oocyst counts of 1 x 10(3) to more than 2 x 10(6) per gram of faeces were detected in lambs up to 12 weeks old, with the peak counts occurring at six weeks of age in the lambs from flocks A and B and at four weeks of age in those from flock C. The oocysts were confirmed by molecular analysis as Cryptosporidium parvum. Virtually all the infections were subclinical.     

Isolation of leptospires from the genital tract and kidneys of aborted sows

Twenty sows were examined as part of an investigation into the relative importance of the genital and urinary tracts as sites of leptospiral persistence in pigs. The sows had previously either aborted leptospire-infected fetuses or aborted on farms where leptospire infection had been demonstrated in other litters. Leptospires belonging to the Australis serogroup were recovered from the upper genital tract of all the sows. In contrast, leptospires were only recovered from 75 per cent of their kidneys. Isolates from 10 of the sows were identified to serovar level: six were serovar muenchen and four were bratislava. Persistence was observed in renal and genital tissues for up to 147 days after abortion.     

EMBRYONIC DUPLICATIONS IN SHEEP

Twenty-seven embryonic duplications were examined during a 3-year investigation into the causes of perinatal lamb mortality. Twenty of the 27 were anomalous twins with 19 being conjoined (diplopagus 9 and heteropagus 10). The various duplications were: haloacardius acephalus 1, diprosopus 2, dicephalus 2, dipypus 3, diprosopus dipygus 1, syncephalus dipygus 1, pygopagus parasiticus 1, heteropagus dipygus 3, melodidymus 6, polyury 4, penile duplication 2, and bilateral otognathia 1. Four lambs were living and the time of death of the others was: parturient 8, and post-parturient 15. Average dry weight of the lambs was 3.35 kg (range 1.59 to 5.45 kg). Breed distribution was: Merino 77.8%, Crossbred 14.8%, Dorset Horn 3.7%, and Corriedale 3.7%. The caudal region was involved in 10 of the conjoined twins (52.6%), anterior region in 7 (36.9%), and both anterior and caudal regions in 2 (10.5%). Associated defects were present in 70.4% of the 27 lambs, the most common being atresia ani.     

Multiple congenital urogenital abnormalities in a Tennessee Walking Horse colt

A 9-month-old, Tennessee Walking Horse colt was examined for urinary incontinence. Cystoscopy revealed a single identifiable ureter that appeared abnormal, and sabulous urolithiasis. Only the left kidney, which appeared lobulated and hydronephrotic, could be located using ultrasound. Results of serum chemistries were consistent with renal failure. Necropsy revealed unilateral agenesis of the right kidney and ureter with severe left ureterolithiasis, bilateral cryptorchidism and segmental aplasia of the ductus deferens. Histopathological examination revealed cystitis and diffuse interstitial fibrosis of the left kidney. Congenital malformations should be included as differential diagnoses for urinary incontinence and urogenital disease. Ultrasonography and cystoscopy can be useful to diagnose suspected agenesis of the urinary system in adult horses.     

Arthroscopic Surgery for the Treatment of Osteochondritis Dissecans in the Equine Femoropatellar Joint

Forty limbs with femoropatellar osteochondritis dissecans in 24 horses were treated with arthroscopic surgery. Lesions were bilateral in 16 horses and unilateral in eight horses. Diagnostic examination and surgical treatment were performed through a single arthroscopic portal; five different instrument portal locations and six instrument approaches were used. Lesions were localized to the lateral trochlear ridge of the femur in 31 affected joints, medial trochlear ridge in two joints, lateral and medial trochlear ridges together in two joints, lateral trochlear ridge plus patella in four joints, and patella alone in one joint. The lesions consisted of subchondral defects containing chondral or osteochondral flaps or fragments, or were seen as dimpling, cracking, fibrillation, or erosion of articular cartilage, or intact cartilage over a subchondral defect. Loose bodies were found in three joints. There was a poor correlation between radiologic and arthroscopic findings. Surgical manipulations included removal of flaps, fragments, and undermined articular cartilage, and debridement of the subchondral defect. Three horses were euthanized: one electively to assess the joint grossly, one because of complications following surgery and salmonellosis, and one because of unrelated forelimb abnormalities. Immediate clinical improvement after surgery was seen in the 22 horses permitted to survive. Long-term follow-up on seven of 10 racehorses revealed that two have raced successfully, two are "ready to race," three are training sound, two are sound at pasture (still in convalescence), and one has been reoperated. Of six horses used for show or pleasure, three are being shown sound, one is sound for pleasure, and two are training sound. The remaining horses are convalescing.     

Detection of Border disease antigen in tissues of affected sheep and in cell cultures by immunofluorescence.

An account is presented of the distribution of fluorescence in cryostat sections of tissues from eight lambs with Border disease (BD). In young lambs fluorescence was observed in almost every organ, indicating a generalised infection with BD virus. Fluorescence was most prominent in the secretory glands of the alimentary and respiratory tracts, the basal cell layers of the epidermis and mucous membranes, and in the medullary rays of the kidneys. Abomasum, pancreas, kidneys, testicles and thyroid were most consistently affected. Although the number of fluorescing tissues decreased with age, viral antigen could still be detected in two sheep of 22 and 52 weeks old. Border disease viral antigen was demonstrated in cell cultures derived from the brain, kidney and testicle of six out of seven lambs despite the presence of neutralising antibody against bovine virus diarrhoea virus in three of them. The presence of the virus in the skin, the vascular walls and the endocrine system is discussed in relation to the aberrant development of fetal hair follicles, periarteritis and growth retardation respectively.     

Sacroiliac Fracture-Separation in the Dog: A Study of 92 Cases

The case records of 92 consecutive dogs that suffered sacroiliac fracture-separation were examined. Seventy-seven per cent (71 of 92) had unilateral sacroiliac injury and 23% (21 of 92) had bilateral sacroiliac injury. Of the unilateral cases, 93% (66 of 71) of the dogs had associated acetabular, ilial, femoral, or tibial fractures; coxofemoral luxations; or cruciate injuries. Eighty-five per cent (78 of 92) of the dogs had either bilateral sacroiliac injury or unilateral sacroiliac injury and other orthopedic injuries of the opposite limb, thus disabling both hind limbs.
Sixty-five per cent (60 of 92) of the dogs received lag screw fixation of the sacroiliac joint. Of 29 dogs that were re-radiographed on an average of 437 days following fixation, 38% (11 of 29) showed evidence of loosening of the lag screw fixation.a
Screws that were placed in the body of the sacrum in some dogs resulted in the fewest loosened fixations (12%, 2 of 17), compared to other locations of screw placement. The fixation had loosened in 7% (1 of 14) of dogs that had a cumulative screw depth/sacral width of 60% or more, compared with 48% of dogs (10 of 21) where cumulative screw depth was less than 60%. The number of screws per fixation and whether the separation was fully reduced or not did not affect whether the fixation loosened.     

Evaluation of clinical signs and causes of lower urinary tract disease in European cats

OBJECTIVES: To investigate the clinical signs and causes of lower urinary tract disease (LUTD) in 77 cats. METHODS: Cats diagnosed with LUTD over a two-year period were included in the study. RESULTS: The study population comprised 67 male and 10 female cats. Uroliths occurred in 17 of the 77 cats (22 per cent), urethral plugs in eight cats (10 per cent) and urinary tract infection in six cats (8 per cent). In 44 cats (57 per cent), no specific cause for the disease was found and they were classified as having idiopathic LUTD. In two of the 77 cats (3 per cent) no definitive diagnosis was established. Pain was less common in cats with uroliths and haematuria was more often seen in cats with urinary tract infection. At presentation, urethral obstruction was diagnosed in 45 of the 77 cats (58 per cent). CLINICAL SIGNIFICANCE: The causes of LUTD found in cats in this study are similar to those that have been previously documented, and idiopathic LUTD is the most frequent diagnosis. However, the rate of urethral obstruction, particularly in cats with idiopathic LUTD, was higher than in other reports. The cause of this difference is unknown.     

Osteochondrosis lesions of the lateral trochlear ridge of the distal femur in four ponies

Lesions of the lateral trochlear ridge (LTR) of the distal femur were investigated in four pony or pony cross horses. The animals were all geldings and were six to 15 months of age. Lesions were bilateral in three ponies and unilateral in one. Femoropatellar joint effusion and lameness were present in two ponies; clinical signs were absent in the others. The proximal LTR was affected in all four animals. The radiographic appearance of the lesions was a subchondral defect containing mineralised bodies. Arthroscopic and postmortem examination findings included an osteochondral flap, a fissured or irregular articular surface and a smooth surface overlying focally thickened cartilage that extended into subchondral bone. Thickened articular cartilage was a histological feature of all the lesions. Among the other histological features, the most common were chondronecrosis, chondrocyte clusters, phenotypically abnormal chondrocytes, horizontal fissures at the osteochondral junction and retained blood vessels. The signalment of the four ponies, their clinical signs and the pathological features of their lesions were consistent with osteochondrosis of the LTR in horses. The use of multiple criteria was considered to be important in making a specific diagnosis.     

Slaughterhouse survey of pyelonephritis in dairy cows

Twenty-one rejected kidneys from 2426 slaughtered dairy cows (0.87 per cent) had gross signs of pyelonephritis that were confirmed by histopathology. In all the kidneys the findings were consistent with a chronic rather than an acute infection. One species of bacteria was cultured from 12 of the kidneys and two species of bacteria were cultured from six. The most commonly isolated bacteria were Escherichia coli, from eight kidneys, Arcanobacterium pyogenes, from seven kidneys and Corynebacterium renale, from five kidneys. The other bacteria cultured were Corynebacterium cystitidis, Corynebacterium species, Streptococcus species group G and Enterococcus faecalis. E. coli was cultured from all the kidneys from which two species were isolated; the accompanying bacteria were A. pyogenes in three kidneys, C. renale in two and C. cystitidis in one. No bacteria were cultured from two of the kidneys and no significant bacteria were cultured from another. The kidneys with pyelonephritis were slightly larger than a comparison group of 72 kidneys without nephritis.     

Real-time ultrasonic scanning in sheep: the results of the first year of its application on farms in south-west Scotland

After a two-day period of instruction in the use of a linear real-time ultrasonic scanning machine the results obtained by three operators scanning a variety of types of ewe under different conditions were recorded and compared with the actual lambing results. In the first season an overall accuracy of 95 per cent was achieved for the diagnosis of barren ewes and ewes carrying either one or two or more lambs. However, monitoring the accuracy achieved for the diagnosis of zero, one, two, three or four lambs demonstrated an improvement in expertise with time, the accuracy increasing from below 70 per cent to over 90 per cent. A particular improvement was observed after a comparative session with an experienced operator. Analysis of the figures of accuracy for zero, one, two, three and four lambs highlighted the differences between operators which were less evident if only the results for zero, one or two or more lambs were analysed. These analyses showed that 'newly trained' operators were not at first able to scan successfully. However, after a period of acquaintance with the technique (approximately 500 ewes) and an 'appraisal session' with an expert the accuracy of the operators improved sufficiently to be of commercial value to hill flocks and possibly to low-ground flocks with limited housing.     

Fox predation as a cause of lamb mortality on hill farms

Data collected between 1993 and 1996 from two Scottish hill farms were used to assess the potential importance of predation by foxes as a cause of lamb mortality. Farm 1 was in Midlothian and farm 2 in West Perthshire. Overall lamb mortality rates from birth onwards were 10.2 per cent for farm 1 and 9.3 per cent for farm 2. Sixteen lambs were identified as killed by foxes on the two farms during the four-year period. The minimum rates of fox predation were 0.6 per cent for farm 1 and 0.2 per cent for farm 2. All confirmed cases of fox predation were recorded during the period until the lambs were marked at about six weeks of age, and during this period another 53 lambs went missing from the two farms. Both groups of missing lambs were characterised by having significantly more siblings than the remaining lambs. A logistic regression model was able to classify the lambs killed by foxes and the missing lambs with 75 per cent accuracy on the basis of their birth rank alone. Of the total potential revenue from lamb production, the maximum losses due to confirmed fox predation in any one year were equivalent to 1.5 per cent on farm 1 and 0.6 per cent on farm 2.