Jan F. Hawkins

Treatment of acute epistaxis secondary to guttural pouch mycosis with transarterial nitinol vascular occlusion plugs in three equids

CASE DESCRIPTION 2 horses and 1 pony were evaluated for right-sided (1 horse and the pony) and left-sided (1 horse) acute epistaxis of 1 days to 1 months duration. CLINICAL FINDINGS Endoscopic examination of the 3 equids revealed that the hemorrhage originated from the right maxillary artery in 2 equids and from the left internal carotid artery in the third. Mycosis of the auditory tube diverticulum (guttural pouch) was detected in all 3 equids. TREATMENT AND OUTCOME All 3 equids underwent surgery, and transarterial nitinol intravascular plugs were placed to occlude affected blood vessels. All equids survived for a long period (ie, a minimum of 1 to 2 years) and returned to their previous use. All had complete regression of clinical signs of guttural pouch mycosis without additional medical treatment. CLINICAL RELEVANCE The use of transarterial nitinol intravascular plugs appeared to be an effective alternative to other techniques for the treatment of epistaxis secondary to guttural pouch mycosis, including transarterial occlusion devices such as embolization coils.

Local neurotoxins for prevention of laryngeal synkinesis after recurrent laryngeal nerve injury.

Objectives: Persistent vocal fold motion impairment after recurrent laryngeal nerve (RLN) injury is not characteristically due to absent reinnervation, but often results from spontaneous aberrant reinnervation (synkinesis). We administered local neurotoxins to selected laryngeal muscles after RLN injury to determine whether aberrant reinnervation could be selectively inhibited. Methods: Unilateral RLN transection was performed in 24 male rats. Three weeks later, the denervated laryngeal adductor complex was injected with phenol, high- or low-dose vincristine sulfate (VNC), or saline solution. One month later, rat larynges were evaluated via videolaryngoscopy and laryngeal electromyography (LEMG). Larynges from euthanized animals were analyzed via immunofluorescent staining for the presence of reinnervation. Results: One animal that received phenol and 3 animals that received high-dose VNC died of toxicity-related complications. In the surviving neurotoxin-treated animals, videolaryngoscopy showed increased lateralization of the immobile vocal fold. Only 1 phenol-injected rat had adductor complex motor recruitment (score of 3+) with LEMG. The other neurotoxin-treated animals demonstrated an absence of adductor complex reinnervation, with only insertional activity and fibrillations (no motor units/recruitment). Spontaneous ipsilateral abductor reinnervation was not affected by the adductor injections. Conclusions: Low-dose VNC injections appear to be relatively safe and effective in selectively inhibiting spontaneous aberrant reinnervation after RLN injury in an animal model.

Wooden, metallic, hair, bone, and plant foreign bodies in horses: 37 cases (1990-2005)

OBJECTIVE To characterize features of diagnosis, treatment, and outcome in horses with foreign bodies, exclusive of enteric, inhaled, and foot-penetrating foreign bodies. DESIGN Retrospective case series. ANIMALS 37 horses with foreign bodies. PROCEDURES The incidence of equine foreign bodies from 1990 through 2005 was determined by review of data from veterinary schools participating in the Veterinary Medical Database (VMDB). Medical records of horses with foreign bodies at Purdue University were reviewed, and the following information was retrieved: clinical history; signalment; results of physical, radiographic, and ultrasonographic examinations; results of microbial culture of the draining tract or foreign body material; surgical findings; antimicrobial and anti-inflammatory treatments; and complications of the surgical procedure. Long-term follow-up information was obtained from owners or referring veterinarians. RESULTS The incidence of foreign bodies in horses with records in the VMDB was 1730/10,000 horse admissions. A preoperative diagnosis of foreign bodies was confirmed via ultrasonography in most horses examined (15/17 horses) and with plain film radiography in a quarter of horses examined (7/24 horses). Wood foreign bodies were the most common (59%; 22/37), followed by metal (24%; 9/37), hair (8%; 3/37), nonsequestrum bone (5%; 2/37), and plant material (3%; 1/37). Postoperative complications associated with the foreign body were more likely to develop with wood foreign bodies (3/22) than with other types of foreign bodies (1/15). CONCLUSIONS AND CLINICAL RELEVANCE Wood was the most common penetrating foreign body in the horses in our study and was the type associated with the highest incidence of complications. Ultrasonography was more effective in locating foreign bodies than was radiography (plain and contrast) and should be performed in all horses with suspected foreign bodies.

Evaluation of the effects of transendoscopic diode laser palatoplasty on clinical, histologic, magnetic resonance imaging, and biomechanical findings in horses

OBJECTIVE To determine the effects of diode laser palatoplasty on the soft palate in horses. ANIMALS 6 clinically normal horses and 6 euthanized horses from another study. PROCEDURES 6 horses underwent diode laser palatoplasty (treated horses); 3 received low-dose laser treatment (1,209 to 1,224 J), and 3 received high-dose treatment (2,302 to 2,420 J). Six other horses received no treatment (control horses). The upper respiratory tracts of all treated horses were evaluated immediately following surgery (day 0) and on days 2, 7, 14, 21, 30, and 45. Horses were euthanized on day 45, and magnetic resonance imaging (MRI) of the head was performed. The soft palate was removed from treated and control horses, evaluated grossly, and scored for edema, inflammation, and scarring. Soft palates from all horses were sectioned for histologic and biomechanical evaluations. RESULTS Endoscopic examination revealed a significant increase in soft palate scarring and decrease in edema and inflammation in treated horses by day 7. Gross postmortem findings corresponded with MRI findings. Gross and histologic examination revealed a significant increase in scarring, edema, and inflammation at day 45. Histologic evaluation of palatal tissue from high-dose-treated horses revealed full-thickness injury of skeletal muscle, with atrophy of muscle fibers; findings in low-dose-treated horses indicated superficial injury to skeletal muscle. After surgery, treated horses had a significant decrease in soft palate elastic modulus, compared with control horses. CONCLUSIONS AND CLINICAL RELEVANCE Laser palatoplasty resulted in soft palate fibrosis and skeletal muscle loss; however, the fibrosis did not result in an increase in soft palate elastic modulus.

Maintenance of arytenoid abduction following carbon dioxide laser debridement of the articular cartilage and joint capsule of the cricoarytenoid joint combined with prosthetic laryngoplasty in horses: an in vivo and in vitro study.

The objective was to evaluate CO2 laser debridement of the cricoarytenoid joint (CAJ) combined with prosthetic laryngoplasty to prevent post-operative loss of arytenoid abduction in seven horses. Horses were assigned to either laser debridement of the left CAJ and laryngoplasty (laser treated, n=5) or control laryngoplasty (sham, n=2), and were evaluated with endoscopic examinations and measurement of right to left angle quotients (RLQ) to assess maintenance of arytenoid abduction. The animals were euthanased at intervals after surgery and larynges were harvested for post-mortem testing, including determination of translaryngeal flow, pressure, impedance and RLQ. Measurements were obtained under increasing vacuum-generated negative pressure with laryngoplasty sutures intact and with the knot/crimp of the laryngoplasty sutures removed. Following post-mortem testing the cricoarytenoid joints were examined histologically. Post-operative endoscopic examinations revealed no significant differences between RLQ measurements calculated for day 1 following surgery to the termination date of the study for the seven horses. Post-mortem RLQ at airflows of 10 and 60 L/s was significantly higher in sham than in laser treated horses both before and after knot/crimp removal. Translaryngeal impedance at 10 and 60 L/s was not statistically different between groups. Histopathology revealed necrosis and loss of articular cartilage in the laser treated horses. The lymphoid cell infiltration subsided but joint capsule and periarticular fibrosis increased over the course of the study. Post-operative loss of arytenoid abduction after laryngoplasty can be minimized with CO2 laser debridement of the CAJ joint.

Diagnosis of sporotrichosis in a donkey using direct fluorescein-labeled antibody testing

A 4-year-old female donkey residing in an open field in Indiana was admitted for evaluation of facial lesions of 2 years duration. Cytologic and histologic examination of exudate and tissue from the lesions revealed a pyogranulomatous inflammatory reaction with numerous yeasts. Sporothrix schenckii was suspected to be the infectious agent; however, multiple culture attempts did not provide positive identification of the organism. Serologic examination supported infection with S. schenckii. A specific direct immunofluorescent antibody test performed on paraffin-embedded tissue sections confirmed the organism as S. schenckii. Clinical signs resolved after appropriate iodide therapy.

Cryptorchidectomy in equids: 604 cases (1977–2010)

OBJECTIVE To evaluate the management of equids undergoing cryptorchidectomy at a referral hospital. DESIGN Retrospective case series. ANIMALS 604 client-owned equids. PROCEDURES Medical records of all equids undergoing surgical treatment of cryptorchidism from 1977 to 2010 were retrospectively reviewed. Analyses of breed, location of retained testes, accuracy of palpation per rectum for determining the location of retained testes, surgical technique, and postoperative complications were performed. RESULTS The most frequently affected breed was the Quarter Horse (282/604 [47%]), which was significantly overrepresented. Of the 604 equids, 90 (15%) had undergone previous surgical attempts at castration. Preoperative palpation per rectum was performed in 395/604 (65.4%) patients, and was accurate in predicting the location of the retained testes in 354/395 (89.6%). Surgeons were significantly more likely to be incorrect in determining the location of the retained testis by means of palpation per rectum in patients that had undergone a prior attempt at castration. For equids with abdominal cryptorchidism (360/604 [59.6%]), the most common surgical technique was noninvasive cryptorchidectomy (298/360 [82.8%]). In unilateral cryptorchids (521/604 [86.3%]), the 2 most common sites were left abdominal (184/521 [35.3%]) and right inguinal (148/521 [28.4%]). For bilateral retention (80/604 [13.2%]), abdominal cryptorchidism was most common (48/80 [60%]). Fever was present in 138/324 (43%) equids on the first day after surgery. Postoperative fever was not significantly associated with any variables evaluated. Including postoperative (≤ 24 hours) fever, 150 of 604 (25%) patients developed postoperative complications. Excluding postoperative fever, 18 of 604 (3%) patients developed major postoperative complications; complications in 10 of 604 patients were deemed surgically related, and 3 of 604 patients died. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that cryptorchidectomy in equids performed with a variety of surgical approaches was associated with minimal postoperative complications. A history of previous attempts at castration decreased the ability to accurately predict the location of the retained testis.

What is your diagnosis? Peritoneal fluid from an Arabian horse after colic surgery.

A 16-year-old castrated male Arabian horse was presented to the Purdue University Veterinary Teaching Hospital with a 4-hour history of colic. Initial examinations provided strong evidence for small intestinal obstruction. Abdominal surgery revealed a strangulating lipoma, and 25 feet of small intestine were resected. Postoperatively, the horse developed obstructive ileus due to adhesion formation, which required a second laparotomy. During and after surgery, the abdomen was lavaged with sodium carboxymethylcellulose (CMC). One week after the second surgery, evaluation of peritoneal fluid revealed an inflammatory exudate, with many macrophages containing amorphous to granular, pink to magenta phagocytosed material. Extracellular aggregates of the material were also observed. The material was consistent with CMC. To our knowledge, this report is the first to demonstrate the phagocytosis of CMC by peritoneal fluid macrophages.

Comparison of hydroxyapatite-coated and uncoated pins for transfixation casting in horses

OBJECTIVE To determine the extent to which a hydroxyapatite coating promotes pin stability in the third metacarpal bone during transfixation casting in horses. ANIMALS 14 adult horses. PROCEDURES 7 horses each were assigned to either an uncoated or hydroxyapatite-coated pin group. Three transcortical pins were placed in the third metacarpal bone of each horse and incorporated into a cast for 8 weeks. Insertion and extraction torque were measured, and torque reduction was calculated. Radiography was performed at 0, 4, and 8 weeks. Lameness evaluation was performed at 2, 4, 6, and 8 weeks. Bacteriologic culture of pins and pin holes was performed at pin removal. RESULTS All horses used casts without major complication throughout the study. Insertion torque was higher in uncoated pins. There was no effect of group on extraction torque. Hydroxyapatite-coated pins had lower torque reduction. Five of 15 hydroxyapatite-coated pins maintained or increased stability, whereas all uncoated pins loosened. Pin hole radiolucency, lameness grades, and positive bacteriologic culture rates were not different between groups. CONCLUSIONS AND CLINICAL RELEVANCE Hydroxyapatite coating increased pin stability within the third metacarpal bone of horses during 8 weeks of transfixation casting but did not improve pin performance on clinical assessments. Clinical use of hydroxyapatite-coated transfixation pins may result in greater pin stability; however, further research is necessary to improve the consistency of pin osteointegration and elucidate whether clinical benefits will ultimately result from this approach in horses.

Comparison of omentopexy versus pyloro-omentopexy for treatment of left abomasal displacement in dairy cows: 87 cases (2001–2005)

OBJECTIVE To evaluate reproductive performance and productive longevity of dairy cows treated for left displaced abomasum (LDA) with 1 of 2 surgical techniques (omentopexy vs pyloro-omentopexy). DESIGN Retrospective case series. ANIMALS 87 Holstein cows that underwent omentopexy or pyloro-omentopexy for LDA during a 5-year period. PROCEDURES For each cow with LDA, the most recent date of calving, age at time of surgery, and surgical procedure were recorded. Dairy records of cows treated for LDA in the 5-year period were reviewed to determine their reproductive performance. Records available for up to 4 years after the last surgery (ie, when all treated cows had left the herd) were reviewed to determine cull dates and reasons for treated and untreated cows in the herd. RESULTS Of the 87 cows with LDA, 58 underwent pyloro-omentopexy and 29 underwent omentopexy. Cows in the 2 treatment groups did not significantly differ in age. Fifty-six cows completed > 1 subsequent lactation cycle after surgery. The median time that cows with LDA remained in the herd was 566 days (range, 24 to 1,838 days); the times for the 2 treatment groups did not significantly differ. For treated and untreated cows, cull rates for reproductive failure or other problems were similar. Four (14%) omentopexy-treated cows and no pyloro-omentopexy-treated cows had a reoccurrence of LDA. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that cows with LDA that underwent omentopexy or pyloro-omentopexy had similar cull rates and reasons as unaffected herd mates over their productive time in the herd. Between the 2 treatment groups, only the LDA reoccurrence rate differed.