Two clinical manifestations of desmopathy of the accessory ligament of the deep digital flexor tendon in the hindlimb of 23 horses

REASONS FOR PERFORMING STUDY: Desmopathy of the accessory ligament of the deep digital flexor tendon (ALDDFT) in the hindlimb is an unusual cause of lameness in horses, and reports of the condition are sparse. OBJECTIVES: To describe the clinical and ultrasonographic findings, therapy and outcome of 23 horses treated for desmopathy of the ALDDFT in the hindlimb. METHODS: Records of 23 horses with ultrasonographic evidence of desmopathy of the ALDDFT in one or both hindlimbs from 3 referral centres were reviewed retrospectively. Age, breed, sex, duration and nature of clinical signs, results of clinical and lameness examinations, treatment and outcome were recorded. RESULTS: In 13 horses (Group A), there was an acute onset of unilateral lameness. Ten horses (Group B) had an insidious or sudden onset of postural abnormality. There were 10 cobs, 5 British native-breed ponies and 8 horses of various larger breeds. Twenty horses were used for general purposes, and mean age was 12 years. Enlargement of the ALDDFT in the affected hindlimb(s) was identified in all horses. In 44% of horses, ultrasonographic abnormalities were localised to part of the ALDDFT. Treatment included box-rest and controlled exercise, and 10 horses were subjected to desmotomy or desmectomy of the ALDDFT. Seventy-three percent of horses in Group A returned to full function, while 90% of those in Group B remained lame. CONCLUSIONS: Two distinct clinical conditions are associated with the ALDDFT of the hindlimb. Traumatically induced injury resulting in acute onset lameness appears to have a favourable prognosis, with most horses returning to previous work. However, postural changes, once present, are irreversible and indicate a poor prognosis. POTENTIAL RELEVANCE: Desmopathy of the ALDDFT should be recognised as a potential cause of hindlimb lameness and this study provides clinical and prognostic information. Knuckling and/or semiflexion of the metatarsophalangeal joint may accompany the condition; therefore, if a horse is presented with a flexural deformity of this joint, desmopathy of the ALDDFT should be considered as a primary differential diagnosis.     

Desmitis of the accessory ligament of the deep digital flexor tendon: 27 cases (1986-1990).

Desmitis of the accessory ligament of the deep digital flexor tendon (ALDDFT) was diagnosed in 27 horses between September 1986 and December 1990. The first observed clinical sign in four horses was localised swelling in the proximal metacarpus. Twenty horses became lame suddenly during a work period and most developed swelling within 24 h of exercise. The injury was confirmed by ultrasonographic examination. Ten of 13 horses with uncomplicated desmitis of the ALDDFT resumed full work, within three to nine months of the onset of clinical signs, without recurrence of clinical signs in the period of follow-up (nine months to four years). Three horses presented with concurrent acute desmitis of the ALDDFT and superficial digital flexor (SDF) tendonitis and two horses had a history of SDF tendonitis; none of these resumed full work.     

Surgical Treatment of Septic Jugular Thrombophlebitis in Nine Horses

Objective: To report a technique for surgical treatment of septic jugular thrombophlebitis unresponsive to medical treatment. Study Design: Case series. Animals: Horses (n=9) with septic jugular thrombophlebitis unresponsive to medical treatment. Methods: Jugular vein thrombectomy was performed under standing sedation and local anesthesia. The contents of the affected portion of vein were removed by multiple incisions in the vein, with the incisions left open to drain and heal by second intention. Results: The technique was curative in all instances, although 2 horses required a 2nd procedure. One horse required ligation of the linguofacial vein to control postsurgical hemorrhage. Conclusions: The technique is an effective surgical treatment for septic jugular thrombophlebitis unresponsive to medical treatment. Clinical Relevance: Jugular vein thrombectomy is a straightforward technique, and has minimal postoperative complications. It allows expedient and cost‐effective resolution of medically recalcitrant cases of septic jugular thrombophlebitis.     

Desmotomy of the accessory ligament of the deep digital flexor tendon in the forelimb of 24 horses 2 years and older

Objective: To report outcome after desmotomy of the accessory ligament of the deep digital flexor tendon (ALDDFT) in adult horses (≥2 years) for treatment of desmitis of the ALDDFT or flexural deformity of the distal interphalangeal joint (FDDIJ). Study Design: Case series. Animals: Horses with desmitis of the ALDDFT (n=9) and FDDIJ (n=15). Methods: Records (April 1996–July 2008) of 24 adult horses (mean age, 6.7 years) that had ALDDFT desmotomy were reviewed. Follow‐up data was obtained 12–120 months after desmotomy. Results: Outcome was available for 22 horses; 18 (82%; 6 of 8 horses with desmitis of the ALDDFT and 12 of 14 with FDDIJ) returned to their intended use within 6–24 months (mean, 12 months). Conclusion: In mature horses, ALDDFT desmotomy resulted in successful return to intended use in most horses with ALDDFT desmitis (75%) or FDDIJ (86%).     

Standing enucleation in the horse: a report of 5 cases

Enucleation was performed in 5 horses under local anesthesia and sedation with the horse standing. Minimal hemorrhage occurred during the surgical procedure, and there were no other reported complications. Standing enucleation is a surgery that is safe to perform in horses.     

Removal of a nasogastric tube fragment from the stomach of a standing horse

An 82-cm fragment of nasogastric tube was removed from the stomach of an adult horse under standing sedation by use of an endoscope and electrocautery snare. This is the first report of successful non-surgical removal of a nasogastric tube fragment from the stomach of a horse.     

Two occurrences of presumptive venous air embolism in a gelding during cystoscopy and perineal urethrotomy

A 14‐year‐old Arabian gelding presented for evaluation of macroscopic haematuria. Routine cystoscopy was performed under standing sedation during which the horse collapsed with apparent seizure activity. General anaesthesia was induced and the horse recovered neurologically normal. Four days later, during a perineal urethrotomy procedure, the horse experienced a similar collapse with seizure‐like activity. General anaesthesia was again induced and cystoscopy performed through the urethrotomy incision. A ventral bladder mass was visualised and sampled. Cytology confirmed a neoplastic process and the horse was subjected to euthanasia. Histopathology confirmed transitional cell carcinoma. Air embolism was the suspected cause of loss of consciousness and seizure activity in both instances.     

Critical illness-related corticosteroid insufficiency in a dog with septic shock

Objective – To describe a case of hydrocortisone-responsive hypotension and critical illness-related corticosteroid insufficiency (CIRCI) in a dog with septic shock.
Case Summary – A dog with aspiration pneumonia developed septic shock with pressor-refractory hypotension. A standard ACTH stimulation test was performed that showed a blunted cortisol response consistent with CIRCI. Reversal of shock was achieved within 2 hours of hydrocortisone administration, and complete weaning from pressors was accomplished over the subsequent 8 hours. The patient recovered and was discharged from the hospital. An ACTH stimulation test performed 1 month after hospital discharge showed normal adrenal responsiveness consistent with resolution of CIRCI.
New or Unique Information Provided – This case is the first published report of hydrocortisone-responsive hypotension and transient CIRCI associated with naturally occurring septic shock in a dog.     

Application of Platelet-Rich Gel to Enhance Wound Healing in the Horse: A Case Report

A large torn wound of the dorsal elbow region was observed in a 17-year-old Arabian mare. Surgical reconstruction was performed with the horse in standing sedation, but suture dehiscence occurred 2 days later. Autologous platelet-rich gel (PRG) was then applied to the wound every 3 weeks for a total of 3 administrations to accelerate good-quality healing. The wound had healed rapidly and completely within 5 months of the first PRG treatment, without chronic effects or formation of exuberant tissue granulation and with minimum scarring. This case report suggests that topical treatment with autologous PRG, as additional therapy, might be considered beneficial in the management of large-wound healing in horses, and it can be regarded as safe and inexpensive treatment that can be used in field.     

Radiographic diagnosis of craniodorsal coxofemoral luxation in standing equids

Radiographic evaluation of the pelvis in standing horses has been used to diagnose fractures of the pelvis, head and greater trochanter of the femur, and luxations of the coxofemoral joint. Coxofemoral luxation injuries are more common in smaller horse breeds and donkeys, but, due to their size, the standing ventrodorsal projection is not possible, as there is insufficient space to place the radiography equipment under the animal's abdomen. The objective of the study was to report the advantages and limitations of the use of an oblique radiographic projection to diagnose unilateral craniodorsal coxofemoral luxation in 3 ponies and a donkey performed with the animals standing under light sedation. All cases had severe unilateral hindlimb lameness and asymmetry of the gluteal region; 2 also had concurrent intermittent upward fixation of the patella. A standing dorsolateral 20–30° ventral oblique radiograph of the affected coxofemoral joint was performed in all cases to obtain a definitive diagnosis. Radiography of the coxofemoral joint in standing ponies and donkeys can be carried out to identify craniodorsal coxofemoral luxation avoiding the need for general anaesthesia.     

Vestibulovaginal leiomyosarcoma in a mare

A 14-year-old Quarter Horse mare presented for a mass within the vestibule and vagina resulting in external compression and incomplete occlusion at the external urethral opening with subsequent difficulty urinating. Examination revealed an approximately 15 × 10 cm lobulated mass within the vestibule and caudal vagina attached via a broad base dorsally. Histopathology of the mass identified a low-grade leiomyosarcoma. Complete resection was not possible, and surgical debulking of the mass was performed during standing sedation using a vessel-sealing and dividing device. The mare was discharged 3 days post-operatively without any complications. Recheck examinations performed at 1 month and 8 months’ post-surgery revealed excellent healing of the surgical site and no apparent tumour regrowth.     

A simplified surgical technique for correction of orbital adipose prolapse in the horse

A Quarter Horse gelding underwent standing surgical correction of an orbital adipose prolapse through a subconjunctival approach removing the prolapsed fat without use of electrocautery or closure of the conjunctiva. This technique provided an acceptable long‐term cosmetic outcome. There was no recurrence of orbital adipose prolapse up to 15 months post operatively. The surgical procedure performed in this case is a simple technique, which could be performed in the field under sedation and local anaesthesia.     

Ophthalmic procedures and surgery in the standing horse.

Although many ophthalmic procedures can be performed on the standing horse, the decision to perform a procedure under sedation rather than general anesthesia must be made on the basis of the temperament of the horse, severity of the injury, and skill of the veterinarian. For example, veterinarians who are not comfortable with small suture material may find accurate repair of an eyelid laceration easier after general anesthesia rather than attempting to handle this suture in a moving patient. Correct use of nerve blocks and topical anesthesia will greatly facilitate examination, diagnosis, and treatment, and, in addition, will serve to prevent further damage to the eye during these procedures.     

The most important local anesthesia in cattle: a review

Surgical interventions in cattle are frequently performed under local analgesia. Local analgesia may be carried out in the standing animal without or with slight sedation or with the animal in recumbency after deep sedation. Injection of local analgesics is less time consuming than induction and maintenance of general analgesia and is, therefore, frequently used in private veterinary practice. Precise anatomical knowledge of the nerve supply to the area to be operated is a prerequisite for the successful introduction of a local analgesia. The goal of the present review is to summarize nerve supply and indications for surgery in the area of the head, male genital tract, teat and the claws of the hind limb of cattle.     

Standing placement of transphyseal screw in the distal radius in 8 Thoroughbred yearlings

This retrospective study describes placement of distal radial transphyseal screws in Thoroughbred yearlings with carpal varus deformities while standing, and identifes short- and long-term complications following the procedure. Data gathered from 2009 to 2013 identified 8 yearlings that met the inclusion criteria. Horses were sedated intravenously and a single 4.5-mm cortical screw was placed in the distal lateral radial physis following application of local anesthetic and surgical preparation of a pre-placed hole. All horses were evaluated weekly after surgery and screw removal was performed standing and under sedation when correction of the angular limb deformity was achieved. The mean time for screw removal was 46 days. No short- or long-term complications were identified. Findings indicate that placing a single transphyseal screw in the lateral aspect of the distal radial physis with the horse standing is a viable option to treat varus angular limb deformity of the carpus in horses.     

Hormonal, metabolic and physiological effects of laparoscopic surgery using a detomidine-buprenorphine combination in standing horses

Objective To assess the hormonal, metabolic and physiological effects of laparascopic surgery performed under a sedative analgesic combination of detomidine and buprenorphine in standing horses. Study design Prospective study. Animals Eight healthy adult Dutch Warmblood horses and five healthy adult ponies undergoing laparoscopy were studied. Five healthy adult horses not undergoing laparoscopy were used as a control group. Methods The sedative effect of an initial detomidine and buprenorphine injection was maintained using a continuous infusion of detomidine alone. The heart and respiratory rate, arterial blood pH and arterial oxygen and carbon dioxide tensions were monitored, while blood samples were taken for the measurement of glucose, lactate, cortisol, insulin and nonesterified fatty acids (NEFA). The same variables were monitored in a control group of horses which were sedated, but which did not undergo surgery. At the end of the sedation period the effects of detomidine were antagonized using atipamezole. Results The protocol provided suitable conditions for standing laparoscopy in horses. Laparoscopy induced obvious metabolic and endocrine responses which, with the exception of NEFA values, were not significantly different from changes found in the control group. While atipamezole did not produce detectable adverse effects, it is possible that anatagonism may not be essential. Conclusions The technique described reliably produces adequate sedation and analgesia for laparoscopic procedures. The level of sedation/analgesia was controlled by decreasing or increasing the infusion rate. Antagonism of the effects of detomidine may not be necessary in all cases.     

Concurrent proximal suspensory desmopathy and injury of the proximal aspect of the accessory ligament of the deep digital flexor tendon in forelimbs or hindlimbs in 19 horses

Clinical features of proximal suspensory desmopathy (PSD) and concurrent injury of the proximal aspect of the accessory ligament of the deep digital flexor tendon (ALDDFT) have not been documented. The objectives were to describe clinical signs and diagnosis. This was a retrospective study. Patient details, lame limb(s), response to diagnostic analgesia, and radiographic and ultrasonographic findings were recorded. PSD and injury of the proximal aspect of the ALDDFT were identified in 19 horses, 14 with forelimb lameness (unilateral 5, bilateral 9) and 5 with hindlimb lameness (unilateral 2, bilateral 3). Localising clinical signs were seen in 7/31 lame limbs (subtle thickening in the region of the ALDDFT [n = 3], pain on palpation of the body of the suspensory ligament (SL) [n = 6], heat in the proximal metacarpal or metatarsal region [n = 2]). Forelimb lameness was abolished by perineural analgesia of the palmar metacarpal (subcarpal) nerves in 17/23 limbs. In the remaining limbs intra‐articular analgesia of the middle carpal joint (n = 2) or an ulnar nerve block (n = 4) were required to eliminate the lameness. Hindlimb lameness was abolished by perineural analgesia of the deep branch of the lateral plantar nerve (n = 2) or local infiltration of the proximal plantar aspect of the metatarsus (n = 3); a tibial nerve block resolved lameness in the remaining 3 limbs. Lesions of the SL and of the ALDDFT were characterised ultrasonographically by enlargement, heterogeneous echogenicity and loss of long linear echoes in longitudinal images. In 3 horses adhesions between the ALDDFT and the SL were identified post mortem. Close apposition of these structures seen ultrasonographically may indicate adhesion formation. It was concluded that the clinical features of PSD and concurrent injury of the ALDDFT are similar to those for PSD alone, highlighting the need for comprehensive and systematic ultrasonographic assessment.     

Acute normovolaemic haemodilution in a Clydesdale gelding prior to partial resection of the left ventral concha under general anaesthesia

A 16‐year‐old Clydesdale gelding underwent oral extraction of tooth 210 under standing sedation with partial resection of the left ventral concha under general anaesthesia 4 days later. Due to the highly vascular nature of the surgical site, significant intraoperative haemorrhage was anticipated. A lack of compatible donor horses confirmed by crossmatching prompted an autologous donation of 6 l of blood and acute normovolaemic haemodilution using a gelatine solution immediately prior to surgery. Intraoperative haemorrhage was estimated at 5% circulating volume and autologous transfusion was commenced once haemostasis was confirmed. The horse recovered uneventfully from general anaesthesia and surgery. To our knowledge this is the first report of acute normovolaemic haemodilution used in a clinical equine case.     

Surgical repair of a full-thickness ear pinna defect in a horse

A 5-year-old gelding used for showing was presented for surgical repair of a full-thickness 15 mm diameter defect in the right pinna, which had occurred as a delayed complication following laser excision of a sarcoid. The defect had resulted in progressive deformity of the ear, and the horse was considered at risk of further injury if the defect became entrapped on a fixed object. Two artificial dermis meshes were inserted to encourage the formation of granulation tissue across the defect, and a commercially available skin expander was implanted adjacent to the site. Eighteen days later, a second surgery was performed to remove the skin expander and to mobilise a local rotational skin flap to close the defect. Both surgeries were performed under standing sedation and local anaesthesia. The site healed well, avoiding further potential trauma to the ear and deformity due to tissue contracture at the site, although some deformation of the lateral aspect of the cartilage remained.