Outcomes of Heimlich valve drainage in dogs

Objective and design   Retrospective study of the outcomes of Heimlich valve drainage in dogs.
Procedure   Medical records of the past 3 years were retrospectively reviewed. Heimlich valve drainage was used in 34 dogs (median body weight 30 ± 5 kg): lobectomy (n = 15), pneumonectomy (n = 9), intrathoracic oesophageal surgery (n = 2), diaphragmatic hernia repair (n = 1), traumatic open pneumothorax (n = 2), bilobectomy (n = 2), ligation of the thoracic duct (n = 1), and chylothorax and pneumothorax (n = 1 each). Evacuation of air and/or fluid from the pleural cavity was performed with the Heimlich valve following thoracostomy tube insertion. During drainage, the dogs were closely monitored for possible respiratory failure. Termination of Heimlich valve drainage was controlled with underwater seal drainage and assessed with thoracic radiography.
Results   Negative intrathoracic pressure was provided in 29 dogs without any complications. Post pneumonectomy respiratory syncope and post lobectomy massive hemothorax, which did not originate from the Heimlich valve, were the only postoperative complications. Dysfunction of the valve diaphragm, open pneumothorax and intrathoracic localisation of an acute gastric dilatation–volvulus syndrome caused by a left-sided diaphragmatic hernia following pneumonectomy were the Heimlich valve drainage complications.
Conclusions   The Heimlich valve can be used as a continuous drainage device in dogs, but the complications reported here should be considered by veterinary practitioners.     

Oestrus control in bitches with proligestone, a new progestational steroid

A study of oestrus control in bitches with a new type of progestagen, proligestone, in six Dutch and three UK practices is reported. The product was given subcutaneously, regardless of the stage of the sexual cycle and of the usual contraindications for progestagens. A 97% efficacy was obtained with dosages varying from 20–33 mg/kg for the smallest animals to 10–13 mg/kg for the largest animals, when the first treatment was given in anoestrus with repeated treatments after 3 months, 4 months and thereafter every 5 months.
Following treatment in pro–oestrus, heat symptoms disappeared in 96% of the animals within 5 days. By retreatment after 3 months, oestrus prevention could be maintained in 97% of these cases.
Where the animals had been treated only with proligestone (1608 treatments in 776 bitches) there were five cases of the cystic hyperplasia pyometra complex; none of these occurred after treatment in pro–oestrus. Of the animals previously treated with other progestagens for oestrus control (814 treatments in 307 bitches) there were 11 cases.
Forty–one out of 46 bitches which had a history of reproductive disorders did not show signs again.
Other side–effects were also negligible (<0–5%). Fertility at the first oestrus after treatment appeared normal.     

Cytokeratins of the matrices of the chestnut (torus carpeus) and periople in horses with acute laminitis

OBJECTIVES: To determine whether there is a change in the expression of cytokeratins in the epidermal cells of the non-weight-bearing parts of the limb in horses with acute laminitis and thus determine whether the morphologic changes that develop in the periople and chestnut (torus carpeus) of horses early in acute laminitis are caused by inhibition of keratinocyte differentiation. ANIMALS: 8 horses with acute laminitis. PROCEDURE: Tissue specimens were obtained from the chestnuts of all 8 horses and from the stratum externum of the hoof wall of 3 horses. Tissue specimens were obtained within 48 hours of the first clinical signs of laminitis. The cytokeratins were characterized by 1- and 2-dimensional gel electrophoresis, and the tissue distribution of the cytokeratins was studied by immunohistochemical staining. RESULTS: The biochemical findings indicated that the epidermal cells of tissues from horses affected by laminitis contained the same set of cytokeratins as corresponding tissues from clinically normal horses. Immunohistochemistry on sections from specimens of horses with laminitis versus clinically normal horses indicated a difference in the expression of cytokeratin in the basal cells in the matrix of the stratum externum of the hoof wall and in the matrix of the chestnut of horses with laminitis in which the most severe morphologic changes were observed. CONCLUSIONS: Inhibition of keratinocyte differentiation, as observed by immunohistochemical changes, in cells in parts of the chestnut and periople may indirectly indicate that the observed epidermal changes in horses with laminitis are primary and are unaffected by weight-bearing.     

Cytokeratins of the stratum medium and stratum internum of the equine hoof wall in acute laminitis

The cytoskeleton of living keratinocytes consists mainly of cytokeratins that have polymerised into intermediate filaments. The aim of this study was to describe the expression of cytokeratins in the living epidermal cells of the weight-bearing parts of the equine hoof wall during acute spontaneous laminitis. A total of 9 hooves from 3 horses subjected to euthanasia within 48 h of the first clinical signs of laminitis were sectioned and examined. The cytokeratins in the stratum medium and stratum internum of the hoof wall were characterized by 1- and 2-dimensional gel electrophoresis, and the tissue distribution of the cytokeratins was studied by immunohistochemical staining. The biochemical results showed the same set of cytokeratins as was seen in 8 normal horses, reported on previously, used as controls. The immunohistochemical results indicated a difference between normal horses and horses with acute laminitis in the content of cytokeratins in the basal cells of the matrix of the stratum medium of the hoof wall and in the basal and suprabasal cells in the stratum internum at the mid level of the hoof wall. However, no conclusion could be drawn as to whether this change in the cytokeratin distribution in laminitis was primary or was caused by the initiation of the local tissue-repairing process.     

Ossification of ungular cartilages in front feet of cold-blooded trotters - a clinical radiographic evaluation of development over time

Background

It has not yet been shown that ossification of ungular cartilages (OUC) is a pathological condition. Beside heredity, factors such as sex, age, repeated concussion, local trauma, hoof and body size have been suggested as contributing factors for OUC development. By comparing radiographs of front hooves from cold-blooded trotters with different age we wanted to evaluate when development of OUC in cold-blooded trotters occurs and if and when it stabilizes in relation to age and workload. Diagnosis and grading of OUC were based on radiological field examinations of 649 Swedish and Norwegian cold-blooded trotters’ front hooves. A hundred and forty-seven of the horses were re-examined 3-13 years (mean age 9, median 8 years) after the first occasion. All radiographs were evaluated blind, using two different grading systems for OUC. Work load, in form of number of races completed, and body size score were collected from official data. Four statistical ordinal regression models were used, compared and evaluated.

Results

We identified a breakpoint at 2.8 ± 0.38 years of age when ossification ends and proposed a simpler grading system with more consistent results. There was no significant correlation between body size and grade of OUC. Comparison of different statistical methods for evaluation of ordinal data revealed a piecewise linear regression model as most suitable.

Conclusions

Individuals with OUC developed this condition during the stage of life when their hooves develop in size. Results from this study can assist equine practitioners when examining and for understanding this condition in their clinical work and is also beneficial for the Scandinavian equine industry when devising breeding programs.     

Description of a technique for orthograde endodontic treatment of equine cheek teeth with apical infections

An orthograde endodontic method, similar to that used in human dentistry, is described for use on endodontically diseased permanent cheek teeth in horses. The technique has been adapted to meet the anatomical and physiological differences between hypsodont and brachyodont teeth and is performed in sedated horses. The techniques of debriding the pulp cavity and use of dental materials which fulfil the requirements for equine teeth are presented here. The results of this technique appear to be promising but have yet to be evaluated in a peer‐reviewed study. By using orthograde endodontic therapy on sedated horses it is now possible to save endodontically diseased permanent cheek teeth.     

The prevalence of oral ulceration in Swedish horses when ridden with bit and bridle and when unridden

Oral soft tissue ulcers are common disorders of horses, but it is unclear if their prevalence is increased by riding horses with a bit and bridle. Oral examinations were performed on 113 horses and ponies, all which had received routine dental floating, that were divided into four groups depending on when they had last been ridden with a bit and bridle. The subjects comprised: group 1, a randomly selected population of ridden horses; group 2, a group of horses examined after being rested at pasture for 5 weeks; group 3, the previous group following 7 weeks of riding with a bit and bridle, and group 4, brood mares that had not been ridden for at least 11 months. Lip and intraoral soft tissue lesions were recorded at seven pre-determined locations, with lesions classified as large or small; acute or chronic.The examinations showed that horses that were currently being ridden with a bit and bridle had a significantly higher prevalence of large and acute buccal ulcers opposite the maxillary Triadan 06 teeth and of the commissures of the lips, as compared to horses that were not being currently ridden. It was concluded that using a bit and bridle can cause oral ulceration even in horses that have regular prophylactic dental floating. It is suggested that riding tack should be individually fitted for each horse and also that prophylactic dental treatments should be individually adapted for each horse.