Ability to work and owner satisfaction following surgical repair of common calcanean tendon injuries in working dogs in New Zealand.

AIM: To report the long-term outcome (return to work and owner satisfaction) following surgical treatment of common calcanean tendon (Achilles tendon) injuries in working dogs in New Zealand. METHODS: Ten New Zealand Huntaway or Heading dogs (working Collies) with complete or partial tears of the common calcanean tendon, were treated using locking-loop suturing and casting, with (7) or without (3), a calcaneo-tibial screw. All dogs were actively in work on sheep or cattle farms at the time of injury, and return to work was the desired outcome. Ability to work and owner satisfaction were investigated using a telephone questionnaire at a mean followup interval of 14.6 months. RESULTS: Overall, 7/10 dogs returned to full or substantial levels of work. Post-operative complications occurred in two dogs that did not return to full or substantial levels of work. Moderate persistent lameness (score 3 on a scale of 0-5) was present in 2/7 dogs that returned to full or substantial levels of work, equating to a 71% good-to-excellent functional outcome within this group. Seven owners felt the financial investment in opting for surgical repair was worthwhile. A screw and cast method of rigid immobilisation was thought to be superior to casting alone. CONCLUSIONS: Surgical treatment of common calcanean tendon injury in working dogs carries a good prognosis if an appropriate tenorrhaphy technique is used and rigid immobilisation is achieved for 6 weeks. Care must be taken to limit post-operative complications. CLINICAL RELEVANCE: This study justifies the use of surgical repair of such injuries in the working dog even when return to work is the only acceptable outcome.

The effects of polyester (terylene) fibre implants on normal equine superficial digital flexor tendon.

AIM: To determine the effect of polyester (terylene) fibre implants on normal equine superficial digital flexor (SDF) tendon structure. METHODS: Normal forelimb SDF tendons (n=24) of 12 horses were divided into unoperated, sham-operated, and implanted (terylene fibre implant) groups. Horses were assessed for lameness and ultrasonographic changes to SDF tendons at intervals up to 48 weeks post-operatively. After euthanasia, SDF tendons were collected for histological and ultrastructural examination. Histological sections were examined for alcian blue staining intensity, cellularity, fibril bundle alignment, fascicle separation and crimp morphology. Mass-average diameters (MADs) of collagen fibrils were calculated from electron micrographs and compared between treatment groups. RESULTS: Insertion of terylene fibre implants resulted in short-term (8 weeks) lameness in implanted limbs. Ultrasonographically, the implants could be detected in 50% of implanted tendons, but were associated with tendon swelling and the presence of hypoechoic core lesions in 7/8 implanted limbs. There were significant alterations in alcian blue staining, cellularity and crimp morphology in the central fascicles of sham-operated and implanted tendons, and alteration in fibril alignment in the central fascicles of implanted tendons. Unoperated tendons remained histologically normal. MADs of collagen fibrils did not differ between sham-operated, implanted and unoperated limbs. CONCLUSIONS: Both the sham procedure and the insertion of terylene fibre implants led to alterations in tendon structure that persisted for up to 48 weeks. Persistence of disorganised connective tissue at the proximal and distal ends of the terylene fibre implants may predispose implanted tendons to continued risk of injury. CLINICAL RELEVANCE: It is unlikely that terylene fibre implants offer any advantage over standard non-surgical treatments for mild to moderate cases of SDF tendonitis in the horse.

Pros and cons of barium-impregnated polyethylene spheres in gastrointestinal disease.

Barium-impregnated polyethylene spheres are an alternative contrast agent for radiographic studies of the gastrointestinal tract. The spheres are a practical, efficient, and relatively inexpensive way to diagnose a number of relatively common gastrointestinal conditions. They are most useful in the diagnosis of chronic conditions. Radiographic interpretation relies on a thorough understanding of the pathophysiology of gastrointestinal disease and how various disease states influence gastrointestinal function.

Multiple endocrine neoplasia type 1 in a crossbred dog.

Multiple endocrine neoplasia type 1 was diagnosed in a 12-year-old male crossbred dog. Relevant history included polyuria and polydipsia of four months' duration. Physical examination revealed abdominal enlargement, seborrhoea and polypnoea. Diagnostic tests indicated hypercalcaemia, elevated serum alkaline phosphatase and alanine aminotransferase, an exaggerated response to adrenocorticotropic stimulation of the adrenal gland, lack of cortisol suppression with a low dose dexamethasone suppression test and suppression of cortisol secretion with a high dose dexamethasone test. An enlarged right parathyroid gland was removed surgically and confirmed histopathologically to be a parathyroid adenoma. The pituitary-dependent hyperadrenocorticism was treated successfully with mitotane for 14 months before the patient was euthanased for an unrelated problem.

Prevalence of laryngeal paresis in dogs undergoing general anaesthesia.

OBJECTIVE: To estimate the prevalence of laryngeal paresis within a selected population of dogs and identify some of the distinguishing characteristics of affected dogs. DESIGN: A prospective study involving laryngoscopic examination of 250 dogs. PROCEDURE: The laryngeal movements of 250 dogs undergoing general anaesthesia were observed. The severity of laryngeal paresis in these dogs was graded (0 = normal laryngeal movements, 4 = bilateral laryngeal paralysis). The following information was also recorded for each dog: age, sex, weight, breed, condition score, anaesthetic protocol, clinical suspicion of disease and observer. RESULTS: Twenty five percent of the dogs examined had some degree of laryngeal paresis. Affected dogs were significantly older than unaffected dogs (P < 0.001). There was a trend for the severity of laryngeal paresis to increase with age. There was no difference between the sexes. Dogs with laryngeal paresis were significantly heavier than normal animals (P < 0.02). Overweight animals had a significantly higher laryngeal grade than those with a normal condition score (P < 0.05). Labrador Retrievers and Rottweilers had a significantly higher risk of having laryngeal paresis (P < 0.05). Clinical suspicion was found to have high diagnostic value. An intra-class correlation coefficient for inter-rater reliability between the two observers was 0.95. CONCLUSIONS: Laryngeal paresis had a high prevalence in the animals surveyed and was strongly associated with age and breed. The results of this study are consistent with the concept of a progressive degenerative disease with a breed susceptibility. Clinical suspicion for the presence of the disease was a reliable indicator. The grading system used had a high degree of inter-observer agreement.

Bicipital tendinitis and tenosynovitis in the dog: a study of 15 cases.

AIM: To describe the clinical, radiographic, and sonographic features of 15 dogs with bicipital tendinitis and tenosynovitis, classify them according to cause, and evaluate the long-term efficacy of treatment. METHODS: Dogs exhibiting forelimb lameness with pain localised to the biceps tendon were included in the study. Sonographic examination of the tendon and tendon sheath, and radiographic examination including positive contrast arthrograms of the shoulder joint were performed, and assessed for features consistent with biceps tendon disease. In some cases, synovial-fluid analysis and surgical investigation were also undertaken. The causes of the conditions were classified as either traumatic, mechanical, neoplastic or inflammatory. Dogs were treated conservatively with rest and anti-inflammatory drugs, or surgically by either transection of the transverse humeral ligament or tenodesis of the biceps tendon. Assessment of the effects of treatment was made by re-examination at six weeks and from information gained by telephone interview with the dog's owner at longer-term follow-up. RESULTS: Bicipital tendinitis and tenosynovitis were common causes of forelimb lameness in active, middle-aged or older, medium to large-breed dogs. The most sensitive physical tests for localising pain to the biceps apparatus were shoulder flexion with the elbow extended, focal digital pressure applied directly to the biceps origin, and the biceps retraction test. Sonographic assessment was found to be more sensitive than shoulder radiography or arthrography for characterising the lesion. Conservative treatment of 11 traumatic cases resulted in good or excellent function at long-term follow-up. One mechanical bicipital tendinitis secondary to mineral deposits within the supraspinatus tendon improved following transection of the transverse humeral ligament and removal of the deposits. One of two cases of inflammatory tendinitis/ tenosynovitis improved following tenodesis. One dog with neoplastic disease did not improve and was euthanased. CONCLUSIONS: The diagnosis of bicipital tendinitis and tenosynovitis requires a careful examination using a combination of physical tests. Of the ancillary tests, sonography was the most reliable, however information gained from all tests was useful in fully evaluating the biceps apparatus and shoulder joint. The classification system employed in this study was helpful in selecting a treatment protocol and determining the likely prognosis.

Pulmonary Mycobacterium bovis infection in a dog.

AIM: To describe the clinical course of a dog infected with Mycobacterium bovis causing a granulomatous pneumonia. CLINICAL FINDINGS: The dog initially presented with a persistent cough, inappetence and weight loss. Clinical findings included a fever, dyspnoea and tachypnoea, with haematological evidence of a mild neutrophilia and hypoalbuminaemia. Radiographs of the chest demonstrated a concomitant pneumothorax, pleural effusion, and a consolidated area within the left caudal lung lobe. An exploratory thoracotomy revealed this to be a ruptured granulomatous lesion. Subsequent histopathological, microbiological and genetic studies identified M. bovis as the causal agent. CLINICAL SIGNIFICANCE: Mycobacterium bovis infections should be included in the differential diagnosis of pulmonary disease and pleural effusions in dogs living in regions of New Zealand known to have a high incidence of mycobacterial infection in wildlife and farm animals.

Progressive myelopathy and neuropathy in New Zealand Huntaway dogs.

AIM: To investigate the nature and cause of a progressive ataxia in three 20-month-old Huntaway dogs that were litter mates. METHODS: Affected dogs were examined before they were humanely killed and submitted to necropsy. Selected formalin-fixed tissues were examined by light and electron microscopy. RESULTS: The lesions were those of axon and myelin degeneration within sensory, proprioceptive and motor tracts of the spinal cord and to a lesser degree some peripheral nerves. CONCLUSION: A progressive myelopathy and neuropathy, tentatively described as a central-peripheral distal axonopathy, was present in all 3 dogs. The cause was not determined but was likely to be either genetic or nutritional. CLINICAL RELEVANCE: In the early stages of this disease, careful examination may be necessary to distinguish the signs of ataxia from orthopaedic disease such as hip dysplasia. Affected animals are unlikely to be of use as working dogs.

Unusual congenital deformities of the lower limb in two calves.

Congenital deformities of the lower limb were observed in 2 calves from different properties. One was a newborn Holstein-Friesian bull calf with polydactyly and polypodia of the right fore-limb. The other was an 8-month-old Friesian/Jersey crossbred heifer calf, which had a mirror image duplication of the plantar/palmar half of the distal portion of the digits. The abnormalities in the second calf have not previously been described in cattle. This paper presents details of the clinical, radiological and necropsy findings in these 2 calves.

Presence of cervical vertebral malformation in Dobermann puppies and the effects of diet and growth rate.

OBJECTIVE: To investigate the relationship between diet, growth rate and the presence of caudal cervical malformation in Doberman puppies. DESIGN: A prospective study of 15 Dobermann puppies from three unrelated litters, aged from 0 to 16 weeks. PROCEDURE: The growth rate in terms of body weight gain and increase in ulna length were measured weekly for all puppies. In addition the nutritional quality of the diets was assessed. Radiographs of the cervical spine were taken at 6 and between 12 and 16 weeks of age and examined for the presence of caudal cervical vertebral malformation. A mixed model for repeated measures data was used to investigate the relationship between the growth rate of the puppies and the fixed effects age, dam, diet, gender and presence of caudal cervical malformation. RESULTS: Five of the puppies had changes consistent with caudal cervical malformation. The diets fed were either balanced or transiently deficient in protein, calcium, phosphorus and/or magnesium. There was no significant association between growth rate and the variables dam, gender and the presence of caudal cervical vertebral malformation. There was no significant association between diet and increase in ulna length, but a trend existed between body weight gain and the feeding of a balanced diet (P = 0.0672). CONCLUSION: Caudal cervical vertebral changes can be detected radiographically as early as 6 weeks of age in some Dobermann puppies. A balanced diet and growth rate are not significant factors in its initial development.

The accuracy and reliability of linear measurements of the ulna for anthropometrical studies in dogs.

This study investigated the accuracy and reliability of measuring the distance between two surface landmarks (the point of the tuber olecrani and the proximal aspect of the stopper pad) as an indication of ulna length in the live dog. It was found that the chosen skin landmarks did correlate well with the length of the ulna bone. The reliability of such measurements was high when performed by a single person, however this fell to unacceptable levels when multiple people were used to make the measurements. It was concluded that if this technique was to be used in studies to serially record the bone length in live growing dogs, then the measurements should be taken by a single person.

The canine intervertebral disk: part one: structure and function.

Intervertebral disk disease continues to be a common and debilitating condition of dogs. In the first of a two-part article on the canine intervertebral disk, the microscopic and ultrastructural anatomy of the normal, nonchondrodystrophoid disk is described. Specific attention is placed on elements of the structure which impart important functional attributes. Finally, the role of the intervertebral disk in providing flexibility to the vertebral column is discussed, with a description of its biomechanical properties and reaction to compressive loads.

The canine intervertebral disk. Part Two: Degenerative changes--nonchondrodystrophoid versus chondrodystrophoid disks.

In the second of a two-part article on the canine intervertebral disk, the morphological changes which occur within the disk during aging and degeneration are described. Degeneration of the intervertebral disk appears to be a self-perpetuating process as a consequence of disruption to the annulus fibrosus, cellular remodeling, altered biomechanical loading, and nutritional deficiencies. In the nonchondrodystrophoid disk, premature acceleration of the aging process can occur following traumatic disruption to the annulus fibrosus. This degeneration usually occurs in isolated disks along the length of the vertebral column. By contrast, disk degeneration in the chondrodystrophoid breeds occurs simultaneously in all disks along the vertebral column and usually is well advanced by two years of age. Ultrastructural differences between the intervertebral disk of the nonchondrodystrophoid dog and that of the chondrodystrophoid dog may explain the rapidity and severity of degenerative changes in the latter breeds.

Superficial digital flexor tendonitis in thoroughbred race horses: outcome following non-surgical treatment and superior check desmotomy.

OBJECTIVE: This study documents the results of non-surgical treatment and treatment by superior check desmotomy in Thoroughbred racehorses with superficial digital flexor (SDF) tendonitis. DESIGN: A prospective study was made of 124 thoroughbred racehorses with unilateral or bilateral SDF tendonitis. PROCEDURE: The flexor tendons were assessed by physical and ultrasonographic examination before treatment, and the lesions detected in affected tendons were characterised according to lesion type, length and cross-sectional area. Ninety three horses were managed non-surgically and 31 by superior check desmotomy. Recurrent or new injuries were defined as injuries affecting a previously injured superficial digital flexor tendon, the contralateral SDF tendon, or the suspensory ligament (interosseous muscle) in either forelimb. RESULTS: No statistically significant difference was found in ultrasonographic lesion severity between treatment groups. Horses managed by superior check desmotomy were 1.3 times more likely to complete five or more races than horses managed non-surgically (95% confidence limits 0.93-1.82). Horses treated surgically were 1.2 times more likely to develop recurrent or new injuries after returning to training than horses managed non-surgically (95% CL 0.95-1.55). Horses undergoing superior check desmotomy were 5.5 times more likely to develop suspensory desmitis than horses treated non-surgically (95% CL 1.13-26.4). There was no difference in the time to recurrent or new injury between treatment groups. CONCLUSION: There was no statistically significant difference between treatment groups in the proportions of horses able to complete five or more races after an episode of superficial digital flexor tendonitis. Superior check desmotomy did not appear to offer an advantage over non-surgical treatment in preventing recurrent or new injuries in Thoroughbred racehorses. Horses undergoing superior check desmotomy appeared to be at greater risk of developing suspensory ligament injuries than horses managed non-surgically.

Reconstruction of the medial collateral ligament for tarsocrural luxation in the dog: a preliminary study.

Seven cases of tarsocrural subluxation/luxation resulting from ruptures of the medial collateral ligament were treated by double prosthetic replacement. The technique was a revision of an earlier described method without the use of metallic implants. Six (100%) of six cases not involving additional joint fractures had excellent clinical results with minimal compromise to range of joint motion. In three (50%) of six cases where braided polyester sutures were implanted as the prosthesis, fistulating tracts developed. Drainage resolved with removal of the suture in each of these three cases, and two of the three proceeded to excellent results after replacing the braided suture with monofilament suture.

Tendonitis of the branches of insertion of the superficial digital flexor tendon in horses.

OBJECTIVE: To describe clinical findings, ultrasonographic features and outcome of injury to the branches of insertion of the superficial digital flexor (SDF) tendon in horses. DESIGN: Retrospective study of 14 cases. PROCEDURE: Fourteen Thoroughbred horses with tendonitis affecting the branches of insertion of the SDF tendon were examined for lameness, location and amount of swelling, and the presence of other musculoskeletal abnormalities. The flexor tendons were assessed by ultrasonographic examination, and recommendations were made for management of the cases. Outcome was assessed by re-examination of some horses, direct communication with the owner or trainer, and examination of race records. RESULTS: The lateral SDF branch was affected in 10 horses; the medial branch in three, and both branches in one horse. Two horses had concurrent injuries to the SDF tendon in the metacarpal region of the contralateral limb. Ultrasonographic findings included swelling of the affected SDF branch, peritendinous fluid accumulation, disruption of normal fibre alignment on sagittal scan, and variable loss of echogenicity. As healing occurred, there was return of normal echogenicity, but normal fibre alignment did not return completely and apparent adhesions formed between the affected SDF branch and adjacent structures. Seven of 10 horses which returned to their previous use were able to compete without further tendon injury. Recurrence of injury occurred in one case, and another two horses developed tendonitis in the metacarpal region. One horse was retired from racing but was able to compete at dressage without recurrence of injury. Two horses were retired for breeding without returning to training, and one horse was sold and lost to follow up but did not race. CONCLUSION: The prognosis is fair for return to previous use following injury to the branches of insertion of the SDF tendon in athletic horses.

Neutropenia with a probable hereditary basis in Border Collies.

This paper documents a disease of Border Collies characterised by chronic neutropenia which probably resulted in recurrent bacterial infections manifesting as osteomyelitis and sometimes gastroenteritis. The neutropenia occurred despite hyperplasia of the myeloid cells in the bone marrow and a shift to the right in myeloid cell maturation. The underlying defect is currently unknown but may result from the inability of neutrophils to escape from the bone marrow into the peripheral circulation. Necrosis and new bone formation commonly involved the metaphyseal regions of long bones. Other findings included a fasting hypercholesterolaemia and the occasional presence of nucleated red blood cells in circulation, despite a non-regenerative anaemia. An autosomal recessive mode of inheritance is suspected. This condition has some features of a rare human disease called myelokathexis which is also believed to have in autosomal recessive mode of inheritance.

Ununited anconeal process: lag-screw fixation.

A technique of lag-screw fixation for ununited anconeal process is described, and the results of surgery in eight dogs (on 10 elbows) treated by this technique are presented. Approximation of the process was confirmed postoperatively, and union was confirmed by radiographic followup in six of the 10 forelimbs from two-to-six months after surgery. Four other cases were lost to radiographic follow-up. This report of a limited number of cases suggests encouraging results obtained by lag-screw fixation.

Treatment and outcome of chronic tenosynovitis in three horses.

Three horses were presented for treatment of chronic infections of the digital flexor tendon sheath. Clinical signs included severe lameness, and heat, pain and swelling of the digital flexor tendon sheath. The horses were treated with surgical lavage of the tendon sheath, systemic and local antibiotics, and analgesics. In each case, resolution of the lameness occurred over weeks to months. Only one horse returned to athletic activity, while the other two became comfortable at pasture. Response to treatment in cases of chronic tenosynovitis may not be as rapid or complete as that reported for acute tendon sheath infections.