Guttural pouch mycosis in six horses in New Zealand.

CASE HISTORIES: Six horses from several geographical locations in New Zealand presented with signs of guttural pouch mycosis. All horses had experienced epistaxis within 14 days of presentation. CLINICAL FINDINGS AND TREATMENT: In five horses with epistaxis, a diagnosis of guttural pouch mycosis was made on endoscopic observation of fungal plaques in the affected guttural pouches. One of these cases died before surgery was attempted. The remaining four cases underwent ligation and balloon catheter occlusion of the internal carotid artery of the affected pouch. Three of these horses survived and were reported to be healthy 1 year after surgery. One case died from haemorrhage 8 weeks after surgery. In a sixth horse, endoscopy was carried out but the affected guttural pouch which had recently haemorrhaged was not entered. This horse underwent ligation of the internal carotid and occipital arteries of the affected side but subsequently died. A diagnosis of guttural pouch mycosis of the maxillary artery was confirmed by post-mortem examination. Histology revealed fungal hyphae within thrombi in the lumen of the maxillary artery in the affected guttural pouch. Two horses displayed signs consistent with cranial nerve damage in the guttural pouch. DIAGNOSIS: Guttural pouch mycosis. CLINICAL RELEVANCE: This is the first report of which we are aware of the diagnosis and treatment of clinical cases of guttural pouch mycosis in horses in New Zealand. Practitioners in New Zealand should be aware of the presence and manifestations of this disease and be prepared to treat or refer horses for surgical treatment before fatal haemorrhage and/or profound neurologic signs occur.

Facial swelling and discharging lesions associated with abnormalities of the mandible in kunekune pigs.

CASE HISTORIES: Four adult kunekune pigs developed facial swelling at the base of the right ear that ruptured and discharged food material. A further six pigs that had similar clinical signs were reported by members of the New Zealand Kunekune Association who responded to an email survey, one of which was confirmed by post-mortem examination. CLINICAL FINDINGS: Inside the mouth of each pig there was an opening at the junction of the body and ramus of the mandible just lateral to the most caudal visible molar that was impacted with masticated feed. The food packed into the mandible resulted in infection and progressive erosion of the medullary cavity of the bone until it reached the ramus where it eroded through the lateral cortex. The feed material then tracked through the soft tissues to form a subcutaneous abscess, which eventually ruptured resulting in a draining lesion. In Case 2, which had had the lesion for 2 years, the cavity in the mandible was lined with mucosa that had healed to the skin to produce a fistula. In all four pigs there was also a lesion in the left side of the mandible that was not as developed as that on the right side. DIAGNOSIS: The facial swellings were produced by feed material that had impacted into the mandible through an opening immediately caudal to the cheek teeth and then emerged through one or more lesions in the lateral aspect of the ramus of the mandible. CLINICAL RELEVANCE: Although it has not been previously reported, anecdotal reports and our survey suggest that this condition may occur relatively frequently in kunekune pigs. It should be considered as a differential diagnosis for facial swellings and discharging lesions in these animals.

Multi-drug-resistant Enterococcus spp. as a cause of non-responsive septic synovitis in three horses.

CASE HISTORY: Three Thoroughbred horses, a 6-week-old filly (Case 1), a 15-year-old broodmare (Case 2) and a yearling filly (Case 3), sustained synovial sepsis secondary to trauma. CLINICAL FINDINGS: Case 1 presented with a heel bulb laceration communicating with the distal interphalangeal joint. Arthroscopic lavage was performed and treatment commenced using systemic and local broad spectrum antimicrobial drugs. A pure growth of multi-drug-resistant (MDR) Enterococcus gallinarum was cultured from samples of synovium and joint fluid. Antimicrobial treatment was changed according to the susceptibility results. Response to treatment was poor and despite repeat arthroscopic lavage and intra-osseous regional perfusion of antimicrobials the filly was subject to euthanasia 24 days after the initial injury. Post-mortem examination confirmed septic synovitis, cartilage degeneration and osteomyelitis. Case 2 sustained a full thickness wound to the carpus which was sharply debrided and closed. The wound dehisced with effusion within the tendon sheath. Drainage was established and treatment included systemic broad spectrum antimicrobials, topical lavage with povodine-iodine and manuka honey infusion. A mixed infection including MDR Enterococcus faecalis was cultured from the synovial fluid. Antebrachiocarpal joint effusion developed 21 days after initial injury and joint sepsis was confirmed. Arthroscopic lavage and tendon sheath debridement were performed, followed by treatment with systemic and local antimicrobials. The mare improved and was discharged. Three months later lameness recurred and corticosteroids were administered intra-articularly. The mare became non-weight bearing lame and was subject to euthanasia. Post-mortem examination confirmed joint sepsis of the antebrachiocarpal and intercarpal joint. Case 3 presented with a complete articular open fracture of the tibial crest. Under general anaesthesia the fracture was stabilised and the wounds debrided and closed. Systemic broad-spectrum antimicrobials were administered. Six days later the wound dehisced and a bone fragment was removed. Three weeks post-surgery the wound deteriorated with a purulent discharge. Culture of the discharge revealed a mixed bacterial infection, including a MDR Enterococcus faecalis. Femoropatellar joint involvement was confirmed, and treatment included joint lavage, local and systemic antibiosis, and manuka honey instilled into the wound. The filly initially improved, and then deteriorated such that euthanasia was performed. DIAGNOSIS: All three cases had synovial sepsis with MDR Enterococcus spp. CLINICAL RELEVANCE: Increased awareness of MDR pathogens in equine wound infections is essential. Prompt diagnostic testing, appropriate therapy, infection control strategies and on-going monitoring and management are vital to limit the clinical impact of these organisms.

Granulosa theca cell tumour in a pregnant mare: concentrations of inhibin and testosterone in serum before and after surgery.

CASE HISTORY: A 14-year-old Thoroughbred mare was presented for evaluation of a rapidly enlarging ovary at 73 days gestation. The mare's owner reported behavioural changes in the mare since she returned from stud, notably aggression towards other horses. CLINICAL FINDINGS: Transrectal palpation and ultrasonography of the reproductive tract revealed a viable pregnancy, an enlarged, multiloculated right ovary, and a normal-sized left ovary with a corpus luteum present. Concentrations of inhibin and testosterone in serum were 13.8 ng/mL and 1,150 pg/mL, respectively, being markedly higher than reference ranges. Concentration of progesterone was 4.5 ng/mL, consistent with the presence of functional luteal tissue. A presumptive diagnosis of a granulosa theca cell tumour (GTCT) was made, and the ovary was surgically removed. Histopathological examination of the removed ovary confirmed a benign GTCT. At 31 days after surgery concentrations of inhibin in serum had decreased 18-fold, and testosterone had decreased 10-fold. Pregnancy was reconfirmed at 115 days gestation by rectal palpation and transrectal ultrasonography. DIAGNOSIS: Granulosa theca cell tumour associated with elevated concentrations of inhibin and testosterone in serum. CLINICAL RELEVANCE: While ovarian enlargement and aggressive behaviour may be considered normal in some pregnant mares, a GTCT should be included as a differential diagnosis. Measurement of concentrations of inhibin and testosterone in serum are useful to support a presumptive diagnosis of GTCT in mares.

Distal aortic aneurysm presumed to be secondary to an infected umbilical artery in a foal.

CASE HISTORY: A 3-month-old female Warmblood foal was presented after displaying signs of colic with pyrexia for 5 days. CLINICAL AND PATHOLOGICAL FINDINGS: The foal continued to show signs of colic, frequently passed urine, and was pyrexic with an elevated white blood cell count. The umbilical stalk was thickened but there was no evidence of purulent material. Exploratory laparotomy revealed an enlarged left umbilical artery remnant tightly adhered to the bladder wall. The left umbilical artery continued to an aneurysm involving the distal aorta. The foal was subject to euthanasia and post-mortem examination confirmed a spherical aortic aneurysm, in the dorsal midline caudal to the kidneys that contained a large thrombus. Histopathological examination revealed inflammation and necrosis of the tunica intima and tunica media of the left umbilical artery with suppuration and bacterial colonies evident in the periarterial tissues. DIAGNOSIS: Infected aortic aneurysm presumably caused by an umbilical artery infection. CLINICAL RELEVANCE: A previously undetected umbilical infection appears to have resulted in an unusual delayed complication causing signs of colic in a foal. Veterinarians should be aware of this condition, and the possibility that it may be a cause of signs of colic in foals. Diagnosis based on ultrasonography should be possible, but may require sedation, visceral analgesia and careful examination.

Cutaneous fungal granulomas due to Alternaria spp. infection in a horse in New Zealand.

Equine cutaneous fungal granulomas have been previously referred to in New Zealand (Fairley 1998), and are described in the veterinary literature from around the world, including North America and Australia (Pascoe and Summers 1981; Genovese et al. 2001; Valentine et al. 2006), but no peer-reviewed reports appear published in the literature in New Zealand. Described here is a case of multiple cutaneous fungal granulomas caused by Alternaria spp. in a horse in New Zealand.

Evidence of bias affecting the interpretation of the results of local anaesthetic nerve blocks when assessing lameness in horses.

Eighteen observers were influenced to different extents in the grades of lameness they allocated to eight horses by whether they knew that a nerve block had been administered; on a scale from 0 to 10 the mean difference in grade allocated once the observer knew a horse had been nerve-blocked was increased by 0.4. The consistency of the assessments made by the individual observers was good, with a an average of 0.6 of a grade difference when grading the same horse on two occasions. The agreement between the assessments of four orthopaedic experts was reasonable (+/-1 grade), but significantly poorer for four non-experts and 10 final year veterinary students.

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.

Incidence and risk factors associated with exertional rhabdomyolysis syndrome in National Hunt racehorses in Great Britain.

A telephone survey of 51 National Hunt racing yards with 1140 horses in training was made in April and May 2003 to establish the incidence of exertional rhabdomyolysis syndrome during the previous year. A case-control study was used to investigate the risk factors for the syndrome in eight yards selected on the basis that cases had been confirmed by the analysis of serum muscle enzymes. The overall incidence of syndrome was 6.1 cases per 100 horses per year, and 55 per cent of the yards reported at least one case. The risk factors identified were sex, the average length of the training gallop, and the type of horse (steeplechaser, bumper/unraced or hurdler). There were no significant associations with the horses' temperament, age or Timeform rating.

[Occurrence of Vibrio parahaemolyticus in mussels (Perna perna, Linnaeus, 1758) from a natural coastal bed in the municipality of Palhoça, Santa Catarina, Brazil]. / Ocorrência de Vibrio parahaemolyticus em mexilhões (Perna perna, Linnaeus, 1758) de banco natural do litoral do município de Palhoça, Santa Catarina, Brasil.

A study was carried out on the occurrence of Vibrio parahaemolyticus in forty samples of mussels (Perna perna, Linnaeus, 1758) from a natural bed at Pinheira Beach, Municipality of Palhoça, Santa Catarina (Brazil), during a three-month period. The most probable number technique was used for isolation methodology with prior enrichment of samples in alkaline peptone water and subsequent planting on thiosulfate citrate bile salts sucrose agar. Vibrio parahaemolyticus was found in 52.5% of samples of mussels with a most probable number range of <3 to 93 organisms/g. Serotyping was performed on 61 isolates and our findings indicate that 36.1% of these isolates were serologically non-typable; 54.1% of isolates displayed only flagellate antigenic structures and 8.2% had both antigenic structures. None of the isolates were Kanagawa positive.

Familial occurrence of narcolepsy in miniature horses.

In an investigation of 2 closely related Miniature Horses with a history of excessive sleepiness, depression and episodes of collapse, a diagnosis of narcolepsy was made on the basis of neurological examination and pharmacological testing. Further investigations included electroencephalographic examination (EEG), and analysis of protein content, cell count and monoamine metabolite concentrations of lumbosacral cerebrospinal fluid (CSF). There were no abnormalities noted in the EEGs, and no consistent changes in CSF neurotransmitter metabolites in the narcoleptic horses when compared with 3 normal, unrelated Miniature Horses and 2 related, clinically unaffected animals. The breeding background of the 2 affected horses was investigated and a limited survey of Miniature Horse breeders in North America was conducted. These investigations have shown that narcolepsy is a rare but distinct syndrome in the Miniature Horse, and that the cases described here appear to represent a familial occurrence of the disease.

Anesthetic management of an incisional dehiscence in recovery following exploratory laparotomy in a horse.

A 5-year old Arabian mare fell during recovery from general anesthesia after an exploratory laparotomy. This fall resulted in dehiscence of the abdominal closure, and a substantial amount of intestines were exteriorized. Chemical and manual restraints were rapidly used to prevent trauma to the exposed intestines. A second general anesthesia was initiated to clean the intestines and close the incision. Multiple anesthetic problems were encountered, including arterial hypotension and hypoxemia. The horse recovered from the second general anesthesia and surgery, and all complications gradually resolved. The horse was discharged and has not had further problems to date.

A comparison of techniques to enhance the evaluation of equine laryngeal function.

This study was designed to define a simple, unequivocal test for the evaluation of laryngeal function and the diagnosis of idiopathic laryngeal hemiplegia (ILH). ILH is a disorder that results from left recurrent laryngeal neuropathy and in which there is no movement of the left arytenoid cartilage and vocal fold. Laryngeal function was evaluated in seven horses using four techniques designed to stimulate laryngeal movements:-nasal occlusion, exercise, swallowing and administration of a respiratory stimulant. In addition, the effects of sedation and twitching on the endoscopic examination were also examined. The cross-sectional area of the rima glottidis was measured in each horse at rest and after each technique was performed. There was no statistically significant difference in the increase in area seen after nasal occlusion or exercise. Doxapram hydrochloride increased the cross-sectional area of the rima glottidis, whereas xylazine caused a decrease. Neither of these pharmacological agents exaggerated or decreased the amount of asynchronous movement or tremoring of the arytenoid cartilages. Manual occlusion of the external nares during endoscopy is a simple, yet effective method of stimulating arytenoid function and hence diagnosing ILH.

Vascular anatomy of the equine small colon.

The vasculature of 22 small colons from dead adult ponies was perfused with latex or barium sulphate solution. The vascular anatomy was studied by use of dissection and alkali digestion of the latex specimens and microangiography of the barium sulphate-perfused specimens. The small colon is supplied by the caudal mesenteric artery. The left colic artery arises from the caudal mesenteric artery, which then becomes the cranial rectal artery. Branches from the left colic and cranial rectal arteries form anastomosing arcades that become narrower distally along the length of the small colon. From these arcades arise terminal arteries, which enter the small colon wall and give rise to a subserosal, an intermuscular, and a large submucosal plexus, with frequent anastomoses between them. The venous drainage closely parallels the arterial supply, except near to its origin from the portal vein, when the left colic vein and caudal mesenteric vein are separate from the corresponding arteries.

A comparison of enterotomies through the antimesenteric band and the sacculation of the small (descending) colon of ponies.

Three pairs of longitudinal enterotomies were performed in the small colon of 10 ponies. Each pair consisted of one enterotomy through the antimesenteric band and one through the sacculation. The ponies were destroyed 96 h after surgery. The enterotomies in the two sites were compared for: speed of surgery, adhesions, bursting wall tension, neovascularisation by micro-angiography, and histological reaction. Enterotomies made through the antimesenteric band were superior because they were quicker to perform, stronger, more accurately apposed, and had less inflammation than those made through the sacculation.

Arthrodesis of the equine distal tarsal joints by perforated stainless steel cylinders.

Perforated stainless steel cylinders filled with autogenous cancellous bone were implanted in the distal tarsal joints of four horses. Graft cell survival was poor two weeks after surgery in one horse. In two horses, at 10 months there was partial arthrodesis of the joints with incorporation of the implants into the osseous union. The implants were filled with vascularised woven bone. These two horses were sound nine months after surgery. One horse fractured its third tarsal bone and was still positive to a hock flexion test 12 months after surgery.

Jejunojejunal intussusception associated with a transmural adenocarcinoma in an aged cow.

After 3 days of intestinal obstruction, a proximal jejunojejunal intussusception was resected during surgery in an adult Holstein cow. A transmural adenocarcinoma was found at the proximal margin of the intussusception. The cow recovered well from surgery and produced milk and embryos to expectation. During the seventh month after surgery, the cow developed pneumonia and, therefore, was euthanatized. Disseminated abdominal and thoracic neoplasia was observed at necropsy.

Narcolepsy in a Brahman bull.

Behavioral, electrophysiologic, and pharmacologic tests were performed on a 2 1/2-year-old Brahman bull suspected of having narcolepsy. Placement on a tilt table or electroejaculation induced apparent sleep and cataplexy. Electrophysiologic recordings during the episodes revealed the low-voltage, high-frequency electroencephalogram, reduced electromyogram amplitude, and rapid eye movements in the electrooculogram associated with rapid eye movements sleep. Physostigmine salicylate appeared to elicit and potentiate the episodes, whereas atropine sulfate and imipramine reduced or blocked them. The combined results of the tests supported the diagnosis of narcolepsy.