An unusual cause of colic in a neonatal foal

A case of a neonatal foal with acute colic and respiratory distress is described. The foal presented with signs of acute colic and was treated medically. The foal did not respond to treatment and 2 h after admission the foal began to demonstrate signs of respiratory distress. Thoracic and abdominal radiographs were obtained and a diagnosis of a diaphragmatic hernia was made. Surgical repair of the hernia was recommended but the owner declined and the foal was subjected to euthanasia. Post mortem findings confirmed the diagnosis and revealed that the defect was of congenital origin. Congenital diaphragmatic hernia is an unusual cause of colic in a neonatal foal.     

Use of Renal Replacement Therapy in a Neonatal Foal with Postresuscitation Acute Renal Failure

A newborn foal was presented because it was unresponsive and in cardiopulmonary arrest. Aggressive cardiopulmonary cerebral resuscitation was administered to the foal, which revived the foal; however, acute renal failure developed. Fluid retention and azotemia occurred although the foal was alert and able to suckle. A 6‐hour renal replacement therapy session using hemodiafiltration and a continuous renal replacement therapy machine was administered to the foal at 3 days of age which lowered the foal's azotemia and facilitated removal of some of the excess body fluid. Despite therapy, the foal developed pulmonary edema and was euthanized. Although the foal in this case did not survive, this report highlights the possibility of developing postresuscitation complications such as acute renal failure and describes the use of renal replacement therapy using hemodiafiltration as a viable option in neonatal foals with acute kidney injury.     

Aggression to a foal after 4 months of nursing

A 4-month-old male Arabian foal was examined because of a kicking trauma to the right frontal region. The foal had been kicked by its dam when it was seeking the udder the previous day. Radiographic inspection of head and neck showed no defect or bone fracture. Treatment consisting of intravenous administration of hypertonic solution, dexamethasone, and furosemide improved the clinical signs temporarily; however, second head trauma due to falling of the standing foal resulted in deterioration of clinical condition and finally death. At necropsy, epidural, subdural, and subarachnoid hemorrhages, a hematoma at cerebrocerebellar fissure and cerebellar herniation were observed. Continuous assessment of foal rejection-related signs in susceptible mares should be considered until foal weaning.     

Maternal behavior

Parturition in mares is rapid and is followed by a brief period of sensitivity to imprinting on a foal. There is large individual variation in normal maternal style, but normal mothers actively defend their foal, remain near the foal when it is sleeping, tolerate or assist nursing, and do not injure their own foal. Disturbance of a mare and foal during the early imprinting period can predispose a mare to rejection of her foal; therefore, it should be avoided. There are a variety of forms of foal rejection and numerous etiologies. Therefore, each case should be evaluated individually.     

A case of equine hydrocephalus

Dystocia in a pony mare was due to hydrocephalus of the foal. Delivery of the foal was by caesarean section.     

Foal with Overo lethal white syndrome born to a registered quarter horse mare

A 16-hour-old white foal, born to a registered quarter horse mare, was examined for signs of colic. The foal had Overo lethal white syndrome, which causes ileocolonic agangliosis. This was confirmed by DNA testing. Since there is no treatment for Overo lethal white syndrome, the foal was euthanized.     

Reproductive performance and factors that decrease pregnancy rate in heavy draft horses bred at the foal heat

Reproductive performance and factors that decrease the pregnancy rate in heavy draft horses bred at the foal heat were investigated. The study was based on a total of 422 mares varying from 4 to 20 years in age, which had foaled during the period 1991 to 1994. Over the four years, the percentage of the mares bred at the foal heat was 62.6% and the pregnancy rate was 60.2%. The pregnancy rate following breeding at the foal heat in 1991 (67.7%) was significantly higher than that in 1992 (44.1%). Significant correlation was observed between the pregnancy rate and the mean placental retention time and also between the pregnancy rate and the mean temperature during the winter season. When compared on a monthly basis, the pregnancy rate following breeding at the foal heat in February was 53.3% and in May, 48.2%. The mean number of covers per mare at the foal heat was 2.3; this figure decreased to 1.8 for those bred in May. The mean number of days from parturition to the first breeding date was 11.3 days and the number of days from parturition to the last breeding day at the foal heat was 14.0 days. The number of days from parturition to the last breeding day at the foal heat decreased to 12.5 days in May. The latter may have been influenced by factors involving the stallion. When compared on a monthly basis, the mean placental retention time was longest in January (219 min.) following which it decreased gradually up to mid-summer. The mean placental retention time of mares which were not bred at the foal heat was significantly longer (197 min.) than in mares bred at the foaling heat (143 min.) and also in mares that conceived following breeding at the foal heat (135 min.). The pregnancy rate was less in mares bred shortly after parturition. The findings of this study would suggest that certain factors decrease the pregnancy rate in mares bred at the foal heat. The stress of low temperature in winter, prolonged placental retention time, breeding too early after parturition and factors pertaining to individual stallions may be involved. Expulsion of the placenta as soon as possible after foaling and appropriate breeding timing are significant factors that can influence the pregnancy rate following breeding at the foal heat.     

Postoperative Myositis in a Neonatal Foal: A Case Report

A foal with azotemia, acidemia, and electrolyte abnormalities was diagnosed with uroperitoneum. The foal was anesthetized with isoflurane, and throughout the 4 hours of anesthesia and abdominal surgery, its mean arterial pressure ranged between 45 and 65 mm Hg. The foal developed a myopathy postoperatively and died 24 hours after surgery.     

Immunotherapy in two foals with combined immunodeficiency, resulting in graft versus host reaction.

Immunotherapy was attempted in 2 Arabian foals with combined immunodeficiency. One foal was given a transplant of bone marrow from a selected full sibling, and 1 foal was given a fetal thymus transplant. Both foals died. Genetic evidence was obtained for survival of the transplanted tissues in both cases; however, a graft versus host reaction developed in the foal given the fetal thymus transplant.     

Fecal Isolation of Corynebacterium equi from a Foal with Chronic Diarrhea

Corynebacterium equi was isolated from the feces of a foal with chronic diarrhea. The foal had multiple walnut-sized masses associated with the intestine on rectal examination. These were thought to be enlarged lymph nodes and/or abscesses. The foal also had an elevated plasma fibrinogen. The diarrhea was controlled with antibiotics but recurred when the treatment was stopped.     

Molecular and cytogenetic paternity testing of a male offspring of a hinny

An alleged male foal of a female mule, whose sire and grandparents were unknown, was identified for its pedigree. Parentage testing was conducted by comparing polymorphism of 12 microsatellite DNA sites and mitochondrial D‐loop sequences of the male foal and the female mule. Both the sequence analysis of species‐specific DNA fragments and a cytogenetic analysis were performed to identify the species of the foal and its parents. The results showed that the alleged female mule is actually a hinny, and the male foal, which possesses 62 chromosomes, qualifies as an offspring of the female hinny and a jack donkey.     

Transfer of tumour necrosis factor-α via colostrum to foals

This study aimed to determine whether TNF-α is transferred to equine neonates via colostrum and the relationship between TNF-α and IgG concentrations in the equine neonate. Colostrum, presuckle and postsuckle foal serum samples were collected from healthy mares and their foals. Equine TNF-α ELISA and IgG SRID kits were used to determine the concentrations of TNF-α and IgG, respectively. Statistical analysis was performed using the Spearman rank correlation. TNF-α concentrations in all presuckle foal serum were below the limit of detection in 15/16 foals and increased in postsuckle foal serum to a mean concentration of 7.7 x 10(4) pg/ml. TNF-α concentrations in postsuckle foal serum and colostrum showed significant correlation (rho=0.668; P=0.005). However, TNF-α and IgG concentrations in colostrum or postsuckle foal serum did not correlate (rho<-0.016; P>0.05). Ratios of TNF-α/IgG in colostrum or postsuckle foal serum showed significant correlation (rho=0.750; P=0.0008). These results indicate that TNF-α is transferred to the foal via colostrum absorption and may play a role in early immunity.     

A case of transplacental transmission of Theileria equi in a foal in Trinidad

Equine piroplasmosis due to Theileria equi and Babesia caballi is endemic in Trinidad. A case of equine piroplasmosis due to T. equi was diagnosed in a thoroughbred foal at 10h post-partum. A high parasitaemia (63%) of piroplasms was observed in a Wright-Giemsa(?) stained thin blood smear from the foal. In addition, the 18S rRNA gene for Babesia/Theileria was amplified from DNA extracted from the blood of the foal and the mare. Amplified products were subjected to a reverse line blot hybridization assay (RLB), which confirmed the presence of T. equi DNA in the foal. The mare was negative by RLB but was positive for T. equi using a nested PCR and sequence analysis. In areas where equine piroplasmosis is endemic, severe jaundice in a post-partum foal may be easily misdiagnosed as neonatal isoerythrolysis. Foals with post-partum jaundice should be screened for equine piroplasmosis, which may be confirmed using molecular methods if available.     

Placental teratocarcinoma in a mare with possible metastasis to the foal.

A teratocarcinoma was diagnosed in the amnion of a 5-year-old Arabian mare that delivered a healthy, full-term foal. The foal died at 2.5 months of age as a result of metastasis of an undifferentiated component of the mass. This case is unique because it is the first reported case of placental teratocarcinoma in animals and the malignant component apparently metastasized to the foal resulting in its death.     

Mitral valvular insufficiency associated with ruptured chordae tendineae in three foals

Mitral valvular insufficiency associated with ruptured chordae tendineae was diagnosed in 3 foals with signs of congestive heart failure, which were believed to be secondary to the development of pulmonary hypertension associated with the valvular insufficiency. The septal leaflet of the mitral valve was affected in all 3 foals, and foal 2 also had ruptured chordae tendineae associated with the caudal mitral valve leaflet. Bacterial endocarditis and myocardial necrosis were associated with the ruptured chordae tendineae in foals 3 and 2, respectively. Idiopathic rupture was considered in foal 1. Two-dimensional echocardiography demonstrated a flail mitral valve leaflet in foals 2 and 3 and a ruptured chorda tendineae in foal 3. The ruptured chorda tendineae in foal 1 was not visualized with M-mode echocardiography.     

Surgical reconstruction of a ruptured medial collateral ligament in a foal

An avulsed carpal medial collateral ligament was diagnosed by clinical and radiographic examination in a 1-day-old foal that was unable to bear weight on the affected limb. The foal had a valgus deviation originating at the carpus and medial to lateral instability of the affected carpus. The ligament was reconstructed with screws and suture tape. Surgical reconstruction is a viable alternative to long-term casting or splinting for treatment of a ruptured carpal medial collateral ligament in a foal.     

ISOLATION OF AN ADENOVIRUS FROM AN ARAB FOAL WITH A COMBINED IMMUNODEFICIENCY DISEASE

Some details of the clinical and postmortem findings of an Arab foal that died as a consequence of adenoviral pneumonia superimposed on a combined immunodeficiency disease are provided. The foal was the 17th in a series of similar deaths that occurred on a farm since 1959. An adenovirus, which by haemagglutination inhibition and serum neutralisation tests was antigenically similar to 2 other equine adenoviruses isolated in Australia, was isolated from a nasal swab taken from the foal when it was 23 days of age.     

Multiple rib fracture in a neonatal foal using a nylon strand suture repair technique

OBJECTIVES: To report rib fracture repair using the Securos Cranial Cruciate Ligament Repair System (SCCLRS; Securos Veterinary Orthopedics, Charlton, MA) in a neonatal foal. STUDY DESIGN: Case report. ANIMALS: A 1-day-old Standardbred foal with fracture of left ribs 2-9. METHODS: Four days after admission the foal was anesthetized and rib fractures were repaired using open reduction and the SCCLRS. RESULTS: Rib fractures were successfully stabilized and the foal was discharged 7 days postoperatively without further complications. CONCLUSIONS: The SCCLRS provided a straightforward, effective method of rib fracture repair in neonatal foals. CLINICAL RELEVANCE: Effective rib fracture repair in neonatal foals can be achieved with the SCCLRS.     

Small colon obstruction by an ovarian pedicle as an acquired condition in a foal

This report describes the clinical course and the surgical findings in a 7‐day‐old foal referred for signs of abdominal pain. The foal underwent abdominal celiotomy due to the degree of pain unresponsive to medical treatment and, upon exploration, an ovarian pedicle was found to be wrapped around the small colon. The lesion was corrected, the foal recovered well from anaesthesia, and a 4 month follow‐up revealed no other signs of abdominal pain or complications.     

Hypogammaglobulinemia predisposing to infection in foals.

Measurement of serum immunoglobulins in 46 foals less than 2 weeks old revealed 9 foals with hypogammaglobulinemia. The hypogammaglobulinemia was attributed to failure in transfer of immunoglobulins from dam to foal via colostrum. Three of the affected foals did not nurse at all, or only slightly, and 2 of these died of infections within a few days after birth, whereas the 3rd foal did not grow as well as normal foals. Six of the affected foals nursed in an apparently normal manner, and 5 of these had nonfatal respiratory infections between 2 and 5 weeks of age. Analysis of serum samples from surviving foals demonstrated that immunoglobulins were eventually produced. One other foal examined had hypogammaglobulinemia at 57 days of age, an age when the foal should have produced large amounts of immunoglobulin independent of passive transfer. This foal had simultaneous infections and hypogammaglobulinemia, but eventually produced normal amounts of immunoglobulin. Cellmediated immunity was normal at 3 months of age. This condition was designated transient hypogammaglobulinemia and was thought to be due to a temporary inability to make immunoglobulins.