Biomedical subjects

P B Fretz

Publications and source records attributed to P B Fretz.

At least 19 recordsLinked to original sources

PubMed1996

A case-control study of the congenital hypothyroidism and dysmaturity syndrome of foals.

A case-control study was conducted to identify risk factors for the congenital hypothyroidism and dysmaturity syndrome of foals. A questionnaire was used during personal interviews of foal owners and farm managers to collect information on animal signalment, farm environment, and mare management. Information on 39 foals with the congenital hypothyroidism and dysmaturity syndrome were compared with 39 control foals. Foals with the syndrome had a significantly (P < 0.0001) longer gestation (357.6 d) than control foals (338.9 d). Pregnant mares that were fed greenfeed, did not receive any supplemental mineral, left their "home farm" during gestation, or grazed irrigated pasture had 13.1 (P = 0.0068), 5.6 (P = 0.0472), 4.3 (P = 0.0076), and approximately 15.3 (P = 0.0245), respectively, greater odds of producing an affected foal than mares not experiencing these events. Greenfeed often contains high levels of nitrate (NO3-), which is known to impair thyroid gland function. In light of this, forage samples from participating farms were analyzed for nitrate levels. The odds of one or more congenitally hypothyroid and dysmature foals being born on a farm feeding forage with at least a trace of nitrate was 8.0 times greater (P = 0.0873) than the odds of the disease occurring on a farm that fed forage free of nitrate. Further, the odds of a mare producing an affected foal when fed forage containing at least a trace of nitrate were 5.9 times greater (P = 0.0007) than those of a mare fed nitrate free forage. This study suggests that congenital hypothyroidism and dysmaturity syndrome in foals may be the result of diets that contain nitrate or that are low in iodine being fed to pregnant mares.

Animal Feed↗

PubMed1996

Comparison of herniorrhaphy versus clamping of umbilical hernias in horses: a retrospective study of 93 cases (1982-1994).

Many uncomplicated umbilical hernias have been managed successfully in foals by the application of a hernia clamp. Isolated reports of complications following clamp application have led some authors to suggest that it is an unsuitable method of treatment. Little information has been published comparing the complication rates associated with the use of hernia clamps and herniorrhaphy in the treatment of umbilical hernias. The purpose of this retrospective study was to report the characteristics of clinical cases of umbilical hernia and to compare the complication rates following these 2 treatment approaches. Information was collected from records or from owners to identify the occurrence of complications and owner satisfaction following treatment. Of 93 cases, 10 complicated and 18 uncomplicated hernias were treated by herniorrhaphy, 40 uncomplicated hernias were treated by clamping, 1 originally uncomplicated hernia was treated by both techniques, and 24 cases were untreated. Nineteen percent of uncomplicated hernias treated by herniorrhaphy, and 19% of those clamped developed minor complications. This study demonstrates that although minor complications may be associated with either technique, they generally do not result in significant morbidity.

Animals↗

PubMed1995

Induction of intra-articular tumour necrosis factor during acute inflammatory responses in equine arthritis.

Synovial fluid (SF) was collected at 2, 12 and 26 h post racing from 5 Thoroughbred horses (6 joints) with degenerative joint disease. The effects of serial arthrocentesis on SF TNF alpha levels were controlled for by testing, in parallel, site- and time-matched samples from clinically normal horses (i.e. without arthritis). A significant induction in TNF alpha bioactivity was detected in SF from arthritic joints (compared to the control joints) over the 26 h following racing. After subtraction of values for the arthrocentesis control SF, TNF alpha and protein levels and WBC and mononuclear cell numbers each peaked at 12 h in the SF from the degenerative joints, although there were no statistically significant correlations between any of these parameters. The presence in the SF of TNF alpha, as well as immunoreactive IL-1 beta and IL-6, was confirmed through use of specific anti-human cytokine IgG antibodies in neutralisation and slot-blot radioimmunoassays. TNF beta was not detected in the SF by slot-blot radioimmunoassay. These results suggest that a significant increase in intra-articular TNF alpha occurs during acute inflammatory arthritis in horses. The lack of correlation between infiltrating inflammatory cells and SF TNF alpha levels further suggests that the source of TNF alpha may be resident cells of the joint, as opposed to infiltrating cells found within the joint fluids. SF from clinically normal and arthritic joints of racing and hospitalised horses were also screened for bioactive TNF alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

An examination of the occurrence of surgical wound infection following equine orthopaedic surgery (1981-1990).

Post operative surgical wound infection rates were determined 452 cases of equine orthopaedic surgery performed at the Western College of Veterinary Medicine, Saskatoon, Saskatchewan, between January 1, 1981 and December 31, 1990. Only surgical procedures classified as clean or clean-contaminated by the National Research Council were included in this study. The overall post operative infection rate was 10.0% (45 of 452). Clean surgeries (n = 433) had an 8.1% infection rate while clean-contaminated surgeries (n = 19) had a 52.6% infection rate. Information collected from the medical records was used in univariate and multivariate logistic regression models to evaluate significant determinates of post operative infection. Significant determinates of post operative infection were: surgical classification, orthopaedic involvement, duration of surgery, administration of preoperative antibiotics and gender. Clean-contaminated surgeries had an increased risk of infection compared to clean surgeries (odds ratio (OR) = 24.3), procedures involving long bones had an increased risk of infection compared to procedures involving articular surfaces (OR = 5.1), surgeries lasting 90 minutes or longer had an increased risk of infection compared to those less than 90 minutes (OR = 3.6), administration of preoperative antibiotics was associated with an increased risk of infection (OR = 4.6) and female patients were 2.6 times more likely to develop post operative infection than male patients.

Animals↗

PubMed1994

Hyperplasia of the thyroid gland and concurrent musculoskeletal deformities in western Canadian foals: reexamination of a previously described syndrome.

A syndrome of neonatal foals characterized by hyperplasia of the thyroid gland and concurrent musculoskeletal deformities (TH-MSD) has been described in western Canada and may be increasing in incidence. In an attempt to improve recognition and understanding of this syndrome, 2946 records of equine abortuses, stillborns, and dead neonatal foals were examined to determine the laboratory involved, the year and month of submission, the breed and sex of the fetus or foal, the type of perinatal loss, the length of gestation, and whether or not the submission had evidence of a lesion of the thyroid gland, the musculoskeletal system, or other abnormal clinical or postmortem findings. One hundred and fifty-four (5.2%) records indicated the presence of an abnormal thyroid gland. Of these, 79 (2.7%) had additional lesions consistent with the TH-MSD syndrome described in the 1980s, while 75 (2.5%) were without these additional lesions. Comparisons among these two groups and a third group of fetuses and foals without lesions of the thyroids glands are described. The results confirm that the TH-MSD syndrome is a specific and unique disease with no breed or sex predilection. It is argued that there may be an "exposure-related" cause, and based on a review of similar disease syndromes of the horse, it is suggested that an examination of the feed is indicated in outbreaks of the TH-MSD syndrome.

Abortion, Veterinary↗

PubMed1991

Experimental cutaneous free flap transfers in the horse.

Equine limb wounds often heal slowly by epithelialization, and large scars are a frequent end result. In some ways, they resemble the wound associated with human tibial injuries. The literature indicates that previous investigators have failed to transfer free skin flaps successfully in the horse. In this paper, we review our experimental work with the deep circumflex iliac flap in the horse. Dissections of 20 cadavers confirmed the anatomical consistency of the flap. Four flaps survived well when elevated as island flaps, but five orthotopic and nine heterotopic free flap transfers all failed. The cause of failure is still unknown, but our experiments suggested that the horse must be highly susceptible to ischemic reperfusion injury.

Animals↗

PubMed1990

Prekallikrein deficiency in a family of Belgian horses.

A 7-year-old Belgian stallion hemorrhaged excessively after castration; the hemostatic mechanism was investigated. The horse had normal one-stage prothrombin time and markedly prolonged activated partial thromboplastin time (APTT). Results of intrinsic coagulation factor assays were all normal with the exception of prekallikrein activity, which was markedly reduced (less than 1% activity; value for control population, 63 to 150%). Two of this horse's full siblings, a brother and sister, had markedly prolonged APTT and low prekallikrein values (2.5% and less than 1%, respectively). The addition of plasma from a normal equine plasma pool corrected the prolonged APTT in the 3 Belgian sibling with low prekallikrein activity. Prekallikrein activity in 10 other closely related Belgian horses ranged between 12.5 and 64% (mean, 29.3%), compared with 63 to 150% (mean, 91%) in 10 mixed-breed horses. In the 3 Belgian siblings with low prekallikrein activity, the APTT approached normal after prolonged incubation (15 minutes) with the contact activator and in response to addition of an ellagic acid activator. The 3 Belgian siblings with low prekallikrein activity may be homozygous for prekallikrein deficiency, whereas the other close relatives may be heterozygous for the genetic defect.

Animals↗

PubMed1990

Identification of a free skin flap from the region vascularized by the deep circumflex iliac artery of horses.

Areas of skin vascularized by large axial vessels potentially suitable for microvascular anastomosis were investigated in 10 horse cadavers. Eleven such areas were dissected, and the skin over the flank region vascularized by the deep circumflex iliac artery was most suitable. The anatomy of this area was further defined, using angiography and latex injection studies on 10 cadavers.

Animals↗

PubMed1989

Removal of a retropharyngeal foreign body in a horse, with the aid of ultrasonography during surgery.

Diagnostic ultrasonography was used during surgery to assist in the removal of a piece of wire from the retropharyngeal region. A 3-year-old Quarter Horse mare was referred with dysphagia of 2 days' duration. Radiography revealed a 9-cm piece of wire located caudodorsal to the larynx. A ventral surgical approach was performed, dissecting along the right side of the larynx and trachea. The surgical field was filled with 0.85% sterile physiologic saline solution. A 5 MHz-mm sector scanner probe immersed in the fluid was able to locate the wire and facilitate the direction and depth of dissection to where the wire was identified and removed.

Animals↗

PubMed1988

Surgical management of nasal adenocarcinoma in sheep.

Nasal adenocarcinoma was diagnosed in 5 sheep from a flock over 6 years. Surgical treatment, using a nasal flap approach, was completed in 3 ewes, 2 of which survived a year or more. In these 2 ewes, the mass was present at necropsy, but was not confirmed as the cause of death. The surgical procedure and care after surgery are described. Surgical resection of the mass was considered to be an acceptable procedure for salvage of an additional breeding season and lamb crop in valuable ewes.

Adenocarcinoma↗

PubMed1988

Effects of lesion size and location on equine articular cartilage repair.

The mechanisms and completeness of equine articular cartilage repair were studied in ten horses over a nine month period. Large (15 mm square) and small (5 mm square) full-thickness lesions were made in weight bearing and nonweight bearing areas of the radiocarpal, middle carpal and femoropatellar joints. The horses were euthanized in groups of two 1, 2.5, 4, 5 and 9 months later. Gross pathology, microradiography, and histopathology were used to evaluate qualitative aspects of articular repair. Computer assisted microdensitometry of safranin-O stained cartilage sections was used to quantitate cartilage matrix proteoglycan levels. Structural repair had occurred in most small defects at the end of nine months by a combination of matrix flow and extrinsic repair mechanisms. Elaboration of matrix proteoglycans was not complete at this time. Statistically better healing occurred in small weight bearing lesions, compared to large or nonweight bearing lesions. Synovial and perichondrial pannus interfered with healing of osteochondral defects that were adjacent to the cranial rim of the third carpal bone. Clinical and experimental experience suggests that these lesions are unlikely to heal, whereas similar lesions in the radiocarpal and femoropatellar joints had satisfactory outcomes. Observations made in this study support the use of early postoperative ambulation, passive flexion of operated joints, and recuperative periods of up to a year for large cartilage defects.

Analysis of Variance↗

PubMed1987

Balloon-tipped catheter arterial occlusion for prevention of hemorrhage caused by guttural pouch mycosis: 13 cases (1982-1985).

Epistaxis, caused by guttural pouch mycosis, was treated by balloon-tipped catheter and ligature occlusion of the involved arteries in 13 horses. In 7 horses, more than one artery was catheterized. Serious postoperative hemorrhage was prevented in all horses. Long-term endoscopic follow-up examination was possible in 8 horses, and all had complete regression of the fungal lesion as early as 5 weeks after surgery. Six of the 8 horses did not receive medical treatment. Problems related to the use of the balloon-tipped catheter technique were rare. There were incisional infections in 3 horses, catheter breakage during removal occurred twice, and in one horse, a catheter was inappropriately placed.

Angioplasty, Balloon↗

PubMed1986

Arthroscopic landmarks of the equine carpus.

The radiocarpal and middle carpal joints of 4 clinically normal horses and 24 necropsy specimens were examined with an arthroscope to describe the topographic anatomy of these joints. The carpal bones of the radiocarpal joint had congruent articular surfaces in extension, but carpal flexion resulted in a stairstep between the radial and intermediate carpal bones. The variable surface anatomy, as well as the restricted synovial space and the technical limitations of the arthroscope, contributed to the need for more than one arthroscopic approach to the radiocarpal joint to ensure a thorough examination. The middle carpal joint's hinge-like biomechanics resulted in a spacious synovial cavity that was more amenable to arthroscopic examination. Careful planning was necessary to ensure that areas of interest were distant from the arthroscope-insertion site to allow the best perspective possible. The lateral approach to the middle carpal joint provided the best viewing of both facets of the intermediate and third carpal bones as well as the dorsal rim of the radial carpal bone. The medial approach did not allow complete inspection of these areas.

Animals↗

PubMed1986

Periorbital skull fractures in five horses.

Periorbital skull fractures were diagnosed in 5 horses, and were associated with ophthalmic complications including corneal ulceration, uveitis, and entrapment of the eye by retrobulbar bone fragments. Physical examination was of greater diagnostic use than radiography. Surgical repair was performed on all horses and was associated with a more favorable postoperative appearance in horses treated acutely; however, the cosmetic results were considered acceptable in all horses. Major postoperative complications were not observed.

Animals↗

PubMed1984

Management of proximal sesamoid bone fractures in the horse.

The case records of 49 horses with proximal sesamoid bone fracture were studied. The population consisted of 20 Thoroughbreds, 20 Standardbreds, 5 Quarter Horses, 2 Arabians, and 2 grade horses. The fractured bones were classified into 5 categories: apical fractures, basilar fractures, abaxial fractures, middle one-third fractures, and bilateral comminuted-distracted fractures. Apical fractures occurred most frequently in the Standardbred, with the prevalence of medial fracture being equal to that of lateral fracture. Basilar fractures occurred predominantly in the Thoroughbred, with the highest prevalence in the lateral sesamoid bone of the right front fetlock. Bilateral comminuted-distracted fractures also occurred primarily in the right front fetlock. The prognosis following surgical removal of apical fractures appeared to be superior to that for stall rest alone. The prognosis for basilar fractures was poor.

Age Factors↗

PubMed1984

Quantitative analysis of long-bone growth in the horse.

Long-bone growth at the distal ends of the radial bones, the distal ends of the 3rd metacarpal bones, the distal ends of the 3rd metatarsal bones, and the proximal ends of the proximal phalangeal bones (of thoracic and pelvic limbs) was quantitatively analyzed in 9 Thoroughbred-Quarter Horse foals from birth to 2 years of age. Metal growth markers were surgically implanted in the bones of the animals at 2 to 4 days of age. Radiographs of the bones were made on the day of surgical manipulation, the next day, and then once a week for 8 months, and once a month thereafter for an additional 18 months. On each radiograph, the intervals between the growth markers were measured and plotted, and these accumulated growth data were subjected to statistical analyses. Growth curves, cumulative growth, and relative growth rates were determined. The ages of radiographic growth plate closure also were determined. Total bone growth observed in these foals was proportionately greater than that observed in a similar study of Shetland-Welsh ponies, probably indicating a breed difference. The most rapid growth rate at the 5 anatomic sites in the foals occurred from birth to 10 weeks of age; however, in the distal part of the radius, there was a continuous, though declining growth rate until 60 weeks of age, whereas in the distal ends of the 3rd metacarpal and metatarsal bones and the proximal end of the proximal phalanges growth ceased abruptly and nearly plateaued after 10 weeks of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1983

Surgical correction of angular limb deformities in foals: a retrospective study.

The outcome of surgical treatment of angular limb deformities in 29 foals was evaluated through long-term monitoring of athletic performance. Foals were placed into 1 of 2 groups, depending on the site of the angular limb deformity. In group 1 foals, the deformity involved the carpus of distal end of the radius. In group 2 foals, the deformity involved the distal end of the 3rd metacarpal or metatarsal bone. Group 1 contained 20 foals and group 2 contained 11 foals. Two foals were in both groups. Sixteen foals in group 1 and 4 foals in group 2 progressed to some form of athletic use. The underlying reasons for the failures in both groups was poor selection of cases and inappropriate surgical treatment.

Animals↗

PubMed1983

Management of umbilical hernias in cattle and horses.

The medical records of 60 cattle and 47 horses treated for umbilical hernia at the Western College of Veterinary Medicine over a 3-year period were studied retrospectively. Age, hernia size, physical signs at admission, reducibility, method of repair, prevalence, and types of complications were evaluated. Most patients were less than 6 months old, with hernias less than 10 cm long. Affected cattle had a higher prevalence of organic diseases associated with umbilical hernias and more postsurgical complications than did affected horses.

Animals↗