Surgical management and long-term outcome of umbilical infection in 65 foals (2010-2015).

OBJECTIVE: To report the short- and long-term outcomes of surgical management of umbilical infection in foals. STUDY DESIGN: Retrospective case series. ANIMALS: Foals (n = 65). METHODS: Medical records (2010-2015) of foals up to 1 month of age, surgically treated for an umbilical infection were reviewed. Short-term (at the time of discharge from hospital) and long-term (1 year after surgery) survival rates were obtained. Clinical variables influencing survival were assessed. Chi-square or Fisher's exact test were used to evaluate the relationship between the data retrieved and outcome. P ≤ .05 was considered statistically significant. RESULTS: Sixty-five foals were included in the study, representing 17.2% of all foals admitted to the hospital. Fifty foals were discharged from hospital (77%) and 43 foals (66%) were alive 1 year after surgery. Lower long-term survival rates were associated with: younger age at presentation, septic joints, multiple pathologies, higher creatinine level, higher heart rate, umbilical infection diagnosed at the hospital rather than prior to referral, prolonged hospitalization, longer period between arrival and surgery, and postoperative complications. The most common surgical findings were urachal enlargement followed by right arterial enlargement. CONCLUSION: Younger foals with worse systemic condition and concurrent disorders are at higher risk for treatment failure. Early diagnosis improves the outcome. Surgical treatment yields good results and should be considered upon diagnosis, after taking into account the clinical situation. CLINICAL SIGNIFICANCE: Based on the results of this study, diagnosis and surgical management of umbilical infection in neonatal foals should be performed as early as possible, and a good outcome can be expected after surgery.

Novel description of force of infection and risk factors associated with Theileria equi in horses in Israel and in The Palestinian Authority.

The objectives of this study were to determine the force of infection (FOI) for Theileria equi in horses in Israel and to evaluate risk factors associated with seroprevalence a decade after it was last determined by PCR, in 2002. Using a commercial cELISA kit, we demonstrated a widespread and constant exposure to T. equi in Israel (110/216; 50.9%) and the Palestinian Authority (32/108; 29.6%). Owing to the paired samples collected from the same horses approximately one year apart, we were able to determine the FOI rate with which susceptible individuals become infected. Out of the 75 naïve horses in the first collection, four seroconverted during 10-16 months, demonstrating an FOI of 5% for that period. Similar results were obtained by calculating FOI using age-specific seroprevalence (4.2% per year). Housing management type was significantly associated with T. equi seroprevalence with 87.9% seropositivity in horses on pasture and 32.6% seropositivity in horses in stalls/yards. This strong association and the very high seroprevalence found in horses held on pasture, prompted stratification of data accordingly. Geographical location of horses in Israel showed a strong association with seroprevalence to T. equi ranging from 34.5% in central Israel to 80.8% in the northern part of the country. However, when analyzing this association only in horses held in stalls/yards, the lower seroprevalence was noted in the north. In addition, age was significantly associated with seroprevalence for T. equi only in horses held in stalls/yards (R(2)=0.94). Environmental variables were not found to be associated with seroprevalence for T. equi. Here, we report for the first time the FOI for T. equi in horses and highlight the influence housing management type has on the evaluation of risk factors associated with a vector-borne disease, perhaps leading to the discrepancies observed between studies throughout the world.

Molecular characterization of the Babesia caballi rap-1 gene and epidemiological survey in horses in Israel.

Equine piroplasmosis imposes great concerns for the equine industry regarding international horse movement, and therefore requires reliable diagnostic tools. Recent studies from South Africa and Jordan, including a preliminary study in Israel, reported extremely low seroprevalence to Babesia caballi (B. caballi) (0-1%) using the acceptable rhoptry-associated protein-1 (RAP-1) cELISA. In accordance with the study from South Africa demonstrating a significant heterogeneity in the rap-1 gene sequence of South African B. caballi isolates, the objectives of this study were to phylogenetically characterize the rap-1 gene of the Israeli isolates and determine the prevalence of B. caballi in horses in Israel. Out of 273 horses tested using the RAP-1 cELISA, only one was sero-positive, while 9.3% were positive on PCR performed on the rap-1 gene. Phylogenetic analysis of the rap-1 gene grouped the Israeli isolates in a cluster together with the South African strains (99% nt identity), but in a separate cluster from the American/Caribbean strains (81-82% nt identity). These findings support the existence of heterogeneity in the RAP-1 amino-acid sequences of the Israeli and South African isolates as compared to that used in the cELISA commercial kit and raise doubts as to the ability of this assay to serve as a sole regulatory test for international horse movement. Risk factor analysis found management and age to significantly associate with prevalence of B. caballi, as higher prevalence was noted in horses held out on pasture and a negative association was recorded with age. In addition, B. caballi was not detected in horses in the steppe-arid and extreme-arid climatic regions as compared to the wetter regions. Findings of this study emphasize the need to combine several detection methods to ameliorate the control and spread of the disease.

Molecular detection of Rickettsia africae, Rickettsia aeschlimannii, and Rickettsia sibirica mongolitimonae in camels and Hyalomma spp. ticks from Israel.

In this study, we aimed to identify and genetically characterize spotted fever group (SFG) rickettsiae in ticks, domestic one-humped camels, and horses from farms and Bedouin communities in southern Israel. A total of 618 ixodid ticks (Hyalomma dromedarii, Hyalomma turanicum, Hyalomma excavatum, and Hyalomma impeltatum) collected from camels and horses, as well as 152 blood samples from 148 camels and four horses were included in the study. Initial screening for rickettsiae was carried out by targeting the gltA gene. Positive samples were further analyzed for rickettsial ompA, 17kDa, ompB, and 16S rRNA genes. Rickettsia aeschlimannii DNA was detected in the blood of three camels and 14 ticks (H. dromedarii, H. turanicum, and H. excavatum). Rickettsia africae was found in six ticks (H. turanicum, H. impeltatum, H. dromedarii, and H. excavatum). In addition, Rickettsia sibirica mongolitimonae was detected in one H. turanicum tick. These findings represent the first autochthonous detection of R. africae in Israel. Previous detections of R. africae in Asia were reported from the Sinai Peninsula (Egypt) and Istanbul, only. Furthermore, we report for the first time the finding of R. aeschlimannii in H. turanicum and H. excavatum ticks, as well as the first identification of R. sibirica mongolitimonae in H. turanicum ticks. The tick species identified to harbor R. africae and other SFG rickettsiae have been reported to occasionally feed on people, and, therefore, physicians should be aware of the possible exposure of local communities and travelers, especially those in contact with camels, to these tick-borne rickettsial pathogens.

Successful medical management of intra-abdominal abscesses in 4 adult horses.

Four adult horses with large intra-abdominal abscesses, suspected to be complications of strangles, were treated with systemic antibiotics alone and made a full recovery. The 100% survival rate is significantly better than other reported survival rates. The median duration of treatment (35 days) was shorter than in most previous reports. This study suggests that penicillin G can be used for successful treatment of strangles associated intra-abdominal abscesses in horses.

Gestion médicale réussie d'abcès intra-abdominaux chez 4 chevaux adultes. Quatre chevaux adultes avec des abcès intra-abdominaux de grande taille, suspectés d'être des complications de la gourme, ont été traités seulement à l'aide d'antibiotiques systémiques et se sont rétablis complètement. Le taux de survie de 100 % est significativement meilleur que les autres taux de survie signalés. La durée médiane du traitement (35 jours) a été plus courte que celle indiquée dans la plupart des rapports antérieurs. Cette étude suggère que la pénicilline G peut être utilisée avec succès pour le traitement des abcès intra-abdominaux associés à la gourme chez les chevaux.(Traduit par Isabelle Vallières).

Prevalence of Trypanosoma evansi in horses in Israel evaluated by serology and reverse dot blot.

Trypanosoma evansi is the cause of surra in horses, camels and other domestic animals. Following the first outbreak of surra in horses and camels in Israel in 2006, a survey of the prevalence of the parasite in the Israeli horse population was conducted using serology, PCR followed by the reverse dot blot (RDB) technique and blood smear microscopy. In total, 614 horses from 7 regions were sampled. The CATT/T. evansi kit was used for serology for all the horses. Horses from the Arava and Dead Sea region, where the first outbreak occurred, were sampled again one year later and both samples were subjected to serology and the RDB technique. The country wide seroprevalence was 4.6% (28/614). The seroprevalence in the Arava and Dead Sea region was 6.5% (9/139) in the first sampling compared with 4.1% (5/122) in the second, whereas the prevalence of RDB-positivity was 18.7% (26/139) in the first sampling and only 0.8% (1/122) in the second. All horses were asymptomatic except for one horse from the Arava and Dead Sea region that demonstrated clinical signs of surra combined with positive serology and RDB. The results of this study indicated that surra is prevalent in most regions of the country and thus should be considered an important differential diagnosis in horses and other domestic animals in Israel with chronic weight loss, edema or neurological signs.

Demographic and environmental risk factors for infection by Theileria equi in 590 horses in Israel.

The prevalence of Theileria equi infection as well as the environmental and demographic risk factors for infection was studied in 590 healthy horses from 46 farms in Israel. The prevalence of T. equi DNA was assessed using a polymerase chain reaction for a segment of the Theileria 18S rRNA gene. The overall prevalence was 26.4% (156/590). There was a significant geographical variation in the prevalence of T. equi infection, ranging from 9.3% (25/270) in the central lowlands to 81.7% (49/60) in the Golan Heights. The prevalence of T. equi infection was found to be significantly associated with management types with more horses with access to pasture being positive. Breed was identified as a risk factor for T. equi infection in a univariate analysis with relatively high infection rates in the Quarter horse and local breeds (41.1% and 36.3% respectively), while ponies and Arabian horses had a relatively low prevalence (10% and 9.1%, respectively). However, since a correlation between geographic location and breed was found, it is difficult to draw definite conclusions regarding this risk factor. Age and gender were not found as risk factors for T. equi infection in this study. The environmental variables that were significantly associated with positivity were relative humidity and minimum land surface temperature at day which both showed negative correlation with T. equi prevalence. In conclusion, Israel was found to be enzootic for T. equi infection, as indicated by the high sub-clinical infection rate, which differed between geographical areas.

Longitudinal study of an outbreak of Trypanosoma evansi infection in equids and dromedary camels in Israel.

An outbreak of trypanosomoasis caused by Trypanosoma evansi involving horses, camels and donkeys occurred in a farm in Israel. A longitudinal study of two outbreak phases was conducted which included clinical monitoring, blood smears, packed cell volume (PCV), serology and polymerase chain reaction (PCR) followed by reverse dot blot (RDB) for the molecular detection of infection. This was the first reported T. evansi outbreak in domestic animals in Israel. Most of the camels on the farm (8/10; 80%) were diagnosed with T. evansi infection whereas infection was less prevalent in the horses (3/7; 43%) and donkeys (6/13; 46%). Clinical disease was evident in 4 camels and 1 horse exhibiting characteristic clinical signs, anemia and parasitemia detected on blood smears and by positive RDB. Six other animals were diagnosed as asymptomatic latent carriers by positive RDB and 6 additional animals were only seropositive and were considered suspected carriers. A significant difference was found in the mean PCV between symptomatic and latent carriers with severe anemia observed only in the symptomatic animals. An anaphylactic-like reaction, fatal in one case, was observed in 2 camels diagnosed with severe trypanosome parasitemia immediately following treatment with melarsenoxide cysteamine. Furthermore, recurrence of infection was documented in one camel 4 months post treatment.

Disseminated central nervous system disease caused by Trypanosoma evansi in a horse.

Trypanosomiasis caused by Trypanosoma evansi ("Surra") is mainly a wasting disease affecting equids, camels and cattle as well as other domestic and wild animal species. In horses, infection may cause severe neurological abnormalities; however, the clinical progression, pathogenesis and molecular ante-mortem detection of this form of the disease have not been described in detail. A mare with progressive ataxia, head tilt, nystagmus and cranial nerve deficits submitted to treatment was diagnosed with central nervous system trypanosomiasis following the detection of a Trypanosoma tryposmastigote in cerebrospinal fluid cytology. Histopathology following necropsy showed that the brain, spinal cord and kidneys were the main affected tissues with disseminated multifocal non-suppurative meningoencephalitis of the central nervous system and membranoproliferative glomerulonephritis. Serology for T. evansi was positive and PCR indicated the presence of parasite DNA in the cerebellum, brain stem, spinal cord and bone marrow but not in other organs and confirmed the identity of causative agent as T. evansi. This is the first report of ante-mortem detection of T. evansi in the cerebrospinal fluid of a horse and the first description of post-mortem PCR identification of the parasite DNA in the nervous system.

Concentrations of ionized and total magnesium and calcium in healthy horses: effects of age, pregnancy, lactation, pH and sample type.

Magnesium (Mg) and calcium (Ca) are the main divalent cations in the body. The free ionized fraction is the physiologically active form of both Mg and Ca. As ion-selective-electrode (ISE) analyzers are becoming widely used in veterinary practice it will be useful to establish reference intervals for horses. In the present study, reference intervals were established for ionized, total and the ratio of the ionized to total Mg and Ca concentrations in four horse groups: adults, neonatal foals, and pregnant and lactating mares, as well as in three sample types, whole blood, plasma and serum, using an ISE-analyzer. Sample pH effect was assessed. Concentration differences in both total and ionized cations were recorded for some measures between horse groups and different sample types. The most significant differences were recorded between neonatal foals and other groups. These results demonstrate the need to use specific reference intervals for horses of different physiologic status and in specific sample types.