The Past,Present and Future of Domestic Equines in Tanzania

Equines are minor species in Tanzania’s array of domestic livestock. Attempts to use them for transport by early explorers from the mid-nineteenth century usually failed. Donkeys were used extensively as pack animals to complement human porters by both British and German forces in the First World War, but their advantages were often outweighed by slow progress and competition with troops and porters for water, and they died in huge numbers. The British had regular cavalry troops in their campaign and mules found limited use as individual mounts for officers. In modern times, there are very few horses in Tanzania but they find several uses. Exotic safaris are made on horseback, they are used as stock horses on ranches, there is a polo club in northern Tanzania and there are leisure riding activities around the capital city. Official census records for donkeys estimate numbers at under 300,000 with concentrations in the northern pastoral and agropastoral areas where they are used as pack animals with water being the main commodity transported. Elsewhere donkeys are used to a limited extent in transport and traction work. There is little interest in equines by the central and local governments or the general public and the status quo can be expected to continue.     

A survey on the prevalence of internal parasites of equines in macedonia and Thessalia-Greece

A 3-year survey was conducted to determine the incidence of endoparasitic infection of equines in several regions of Macedonia and Thessalia, Greece. Three hundred fecal and 252 blood samples were examined. Fecal examination was carried out using. Teleman and Faust techniques while blood was examined according to the modified Knott technique. The Graham test was also performed. The prevalence of infection found was 62.4% for horses, 75.7% for donkeys and 89.2% for mules. Strongyles (large and small) were the most common parasitic species found, with a corresponding prevalence of 42.5% and 45.6% for horses, 73.0% and 37.8% for donkeys, and 89.2% for mules. Other parasites found were: Eimeria leuckarti (2.6% in horses and 8.1% in donkeys), Anoplocephala perfoliata (0.4% in horses), Parascaris equorum (1.7% in horses), Oxyuris equi (4.1% in horses and 8.7% in mules), Strongyloides westeri (2.2% in horses, 5.4% in donkeys and 10.8% in mules), Dictyocaulus arnfieldi (0.9% in horses and 2.7% in donkeys) and Setaria equina (2.2% in horses and 2.7% in donkeys).     

Gastrointestinal nematode burden in working equids from humid tropical areas of central Veracruz, Mexico, and its relationship with body condition and haematological values

The east coast of Veracruz, Mexico, has an important equine population used for working in rural production systems. The objectives of this study were (1) to calculate the prevalence of tropical working equids (donkeys, mules and horses) infected with gastrointestinal nematodes (GINs) and the GINs involved, and (2) to measure the body condition score (BCS) and haematological values for each working equid and its relationship with faecal worm egg count (EPG). One hundred and forty working equids were randomly selected from five different villages along the central coast of the state of Veracruz and faecal and blood samples were obtained from each animal. Gastrointestinal parasite burdens were determined using the McMaster technique. Packed cell volume, total plasma proteins, red blood cell count and white blood cell count were measured from each blood sample. Prevalence of infected equids was higher than 90 %. Mules had the highest median faecal worm egg counts (875 EPG), followed by horses and donkeys with 400 EPG. There was no correlation between EPG and BCS or haematological values (p?>?0.05). Results suggest that despite the high prevalence and parasite burdens, equids involved in this trial are not being seriously affected. This study provides information which might help in designing future strategies to control nematode infections in working equids in the Mexican tropics; more emphasis should be placed on other inputs (nutrition perhaps), with individual anthelminthic treatment to those animals with the highest EPG or when signs present themselves.     

Pharmacokinetics of sulfamethoxazole and trimethoprim in donkeys, mules, and horses

OBJECTIVE: To compare serum disposition of sulfamethoxazole and trimethoprim after IV administration to donkeys, mules, and horses. ANIMALS: 5 donkeys, 5 mules, and 3 horses. PROCEDURE: Blood samples were collected before (time 0) and 5, 15, 30, and 45 minutes and 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 8, 10, and 24 hours after IV administration of sulfamethoxazole (12.5 mg/kg) and trimethoprim (2.5 mg/kg). Serum was analyzed in triplicate with high-performance liquid chromatography for determination of sulfamethoxazole and trimethoprim concentrations. Serum concentration-time curve for each animal was analyzed separately to estimate noncompartmental pharmacokinetic variables. RESULTS: Clearance of trimethoprim and sulfamethoxazole in donkeys was significantly faster than in mules or horses. In donkeys, mean residence time (MRT) of sulfamethoxazole (2.5 hours) was less than half the MRT in mules (6.2 hours); MRT of trimethoprim in donkeys (0.8 hours) was half that in horses (1.5 hours). Volume of distribution at steady state (Vdss) for sulfamethoxazole did not differ, but Vdss of trimethoprim was significantly greater in horses than mules or donkeys. Area under the curve for sulfamethoxazole and trimethoprim was higher in mules than in horses or donkeys. CONCLUSIONS AND CLINICAL RELEVANCE: Dosing intervals for IV administration of trimethoprim-sulfamethoxazole in horses may not be appropriate for use in donkeys or mules. Donkeys eliminate the drugs rapidly, compared with horses. Ratios of trimethoprim and sulfamethoxazole optimum for antibacterial activity are maintained for only a short duration in horses, donkeys, and mules.     

Selected health and management issues facing working donkeys presented for veterinary treatment in rural Mexico: some possible risk factors and potential intervention strategies

The examination of 216 donkeys presented for treatment at the Donkey Sanctuary–World Horse Welfare–Universidad Nacional Autonoma de Mexico mobile clinics revealed a number of health and welfare problems. A general overview of the donkeys’ health was made and showed that the median body condition score (BCS) in this population was 2.5. Underweight animals only accounted for 26% of the population. Females, 0–5-year-olds and >21-year-olds, were more likely to be underweight. When analysed, there was no correlation between faecal worm egg count (FEC) and BCS. The prevalence of strongyle infection as assessed by FEC was shown to be 80% with a median FEC of 600 eggs per gramme. Donkeys were assessed for body lesions and showed a high prevalence (71%), particularly in the facial region (54%). Analysis showed that mature animals (6–15 years old) were at increased risk of body lesions compared to older animals (16+ years old) as were donkeys with dental disease and those in particular villages. Risk factor analysis for lesions of the face showed that stallions and geldings are at increased risk as were donkeys wearing halters made from nylon rope. This study has identified areas for further investigation and potential areas where targeted interventions may be made to improve the health and welfare of working donkeys in Mexico.     

Anaesthesia and analgesia of the donkey and the mule

The number of donkeys and mules throughout the world is stable, and awareness of their use and concern for welfare, pain recognition and treatment are receiving increasing veterinary interest. Therefore, accurate information about anaesthesia and analgesia in donkeys and mules is important to ever more equine practitioners. Since donkeys are physiologically and pharmacologically different from horses, knowledge on species specific aspects of anaesthesia and analgesia are very important. Mules combine elements from both donkey and horse backgrounds, leading to great diversity in size, temperament and body type. Physiologically, they seem to resemble horses more than donkeys. This review highlights the current knowledge on various anaesthetic and analgesic approaches in donkeys and mules. There is still much information that is not available about donkeys; in many circumstances, the clinician must use available equine information to treat the patient, while monitoring carefully to observe for differences in response to therapy compared to the horse.     

Prevalence of cutaneous pathological conditions and factors associated with the presence of skin wounds in working equids in tropical regions of Veracruz,Mexico

A wide spectrum of welfare issues is encountered on working equids. The objectives of this study were: (i) to determine the prevalence of cutaneous lesions in working equids in tropical regions of the North-Central of Veracruz State, Mexico, (ii) to identify the most prevalent cutaneous pathological conditions in this population of working equids, and (iii) to identify risk factors associated to the presence of work-related skin wounds. A number of 467 working equids presented for treatment at Donkey Sanctuary Mobile Clinic Program - National Autonomous University of Mexico from seven different villages in the North-Central region of Veracruz State were evaluated. Animals with signs of cutaneous pathology underwent a physical examination and samples were obtained of exudates, hair, and tissue for cytology examination, fungal cultures, and dermo-histopathology examination. The overall prevalence of cutaneous pathological conditions in working equids was 20.6 %. The prevalence per species was 22.6 % for horses, 18.2 % for donkeys, and 14.3 % for mules. The most common cause of skin lesions was trauma (abrasions, lacerations, and abscesses) followed in frequency by parasitic dermatitis and sarcoids. No strong associations among species were observed (P?>?0.20). Multivariate analysis showed that there was greater association between BCS and age with the presence of skin wounds (P?<?0.05). Equids who's BCS was rated as “moderate” as well as adult animals showed significantly more skin wounds compared with the young and the elderly (P?<?0.05). These findings can help to develop a better management practices to improve the welfare of equids in tropical regions of Veracruz, Mexico.     

Pharmacokinetics of flunixin meglumine in donkeys, mules, and horses

OBJECTIVE: To compare serum disposition of flunixin meglumine after i.v. administration of a bolus to horses, donkeys, and mules. ANIMALS: 3 clinically normal horses, 5 clinically normal donkeys, and 5 clinically normal mules. PROCEDURE: Blood samples were collected at time zero (before) and 5, 10, 15, 30, and 45 minutes, and at 1, 1.25, 1.5, 1.75, 2, 2.5, 2.75, 3, 3.5, 4, 4.5, 5, 5.5, 6, and 8 hours after i.v. administration of a bolus of flunixin meglumine (1.1 mg/kg of body weight). Serum was analyzed in duplicate by the use of high-performance liquid chromatography for determination of flunixin meglumine concentrations. The serum concentration-time curve for each horse, donkey, and mule were analyzed separately to estimate noncompartmental pharmacokinetic variables RESULTS: Mean (+/-SD) area under the curve for donkeys (646 +/- 148 minute x microg/ml) was significantly less than for horses (976 +/- 168 minute x microg/ml) or for mules (860 +/- 343 minute x microg/ml). Mean residence time for donkeys (54.6 +/- 7 minutes) was significantly less than for horses (110 +/- 24 minutes) or for mules (93 +/- 30 minutes). Mean total body clearance for donkeys (1.78 +/- 0.5 ml/kg/h) was significantly different from that for horses (1.14 +/- 0.18 ml/kg/h) but not from that for mules (1.4 +/- 0.5 ml/kg/h). Significant differences were not found between horses and mules for any pharmacokinetic variable. CONCLUSION AND CLINICAL RELEVANCE: Significant differences exist with regard to serum disposition of flunixin meglumine in donkeys, compared with that for horses and mules. Consequently, flunixin meglumine dosing regimens used in horses may be inappropriate for use in donkeys.     

Seroprevalence of Fasciolosis in Equines of the Black Sea Region,Turkey

This study determined the seroprevalence of fasciolosis in equines (n = 140) by enzyme-linked immunosorbent assay and Western blot. Blood samples were collected from different locations of the Black Sea Region of Turkey. The overall seroprevalence of fasciolosis in equines was 19.3%: 18% of horses (15), 22.6% of donkeys (7), and 19.2% of mules (5). The seroprevalence rates across provinces were as follows: 25% (5/20) in Samsun, 21.9% (7/32) in Tokat, 31.4% (11/35) in Amasya, 7.4% (2/27) in Ordu, and 7.7% (2/26) in Sinop. Three protein bands with molecular weights of 13, 30-40, and 40-65 kDa were determined in antigen clusters in sera from Fasciola spp-infected equine animals.     

Diagnostic orientation values for ACTH and other parameters for clinically healthy donkeys and mules (insulin,triglycerides, glucose,fructosamines, and ɣ-GT)

Pituitary pars intermedia dysfunction is the most prevalent endocrine disease in horses. Although donkeys and mules may also be affected, only a few data have been published. Reference values for diagnostic parameters, such as adrenocorticotropic hormone (ACTH), are especially scarce or even lacking. Therefore, in the present study, available data from the literature have been verified and completed to facilitate a reliable diagnosis. Clinical inspections and haematological and biochemical examinations were carried out four times in a three-month interval (February to November) in 44 donkeys and 31 mules. Data from clinically healthy animals were used as an orientation. Plasma ACTH concentrations showed seasonal changes in both animal groups. However, it was generally higher in donkeys than mules. Although blood glucose (EDTA plasma) showed no difference between groups, serum insulin concentrations were consistently higher in donkeys. Serum fructosamine levels were slightly higher in mules, whereas, in some cases, serum triglyceride levels were considerably higher in donkeys. Serum gamma-glutamyltransferase showed a striking peak in mules in August, whereas the remaining gamma-glutamyltransferase values were lower compared to donkeys. By comparing donkeys and mules, the present work reveals differences in various blood parameters which should be considered for diagnoses and future studies.     

Evaluation of microchip migration in horses, donkeys, and mules

OBJECTIVE: To determine whether microchips used for identification migrate after implantation in horses, donkeys, and mules. DESIGN: Prospective study. ANIMALS: 53 horses, donkeys, and mules. PROCEDURE: Twenty horses that had had microchips implanted in the nuchal ligament at a veterinary teaching hospital from 1996 through early 2000 were included (group 1), and the poll-to-withers distance and location of the microchip were determined, measured, and recorded. Additionally, the poll-to-withers distance was measured in 16 horses, 12 donkeys, and 5 mules (group 2), and microchips were implanted in the nuchal ligament on the left side of the neck. Forty-two to 67 days after implantation, the location of the microchip was determined, measured, and recorded. RESULTS: Microchips implanted in the nuchal ligament < or = 4 years previously did not migrate. All microchips were detected with a multimode identification tag reader from the left side of the neck in the midcervical region, and microchips were located at the midpoint between the poll and withers for all 53 horses, donkeys, and mules. CONCLUSIONS AND CLINICAL RELEVANCE: Microchips implanted in the nuchal ligament < or = 4 years earlier did not migrate in horses. Microchips may be useful for identification in horses.     

Pack wounds of donkeys and mules in the Northern High Atlas and lowlands of Morocco

Reasons for performing study: Wounds are one of the primary welfare concerns of working equids and are often related to harness or load‐bearing packs. Objectives: To identify and quantify factors associated with the presence of pack wounds in donkeys and mules working in the wood trade in the Midelt (Northern High Atlas) region of Morocco, and to compare wounds of these donkeys and mules to those working in other trades. Methods: The study population comprised equids working in the Midelt region involved in the wood trade. Comparison populations were comprised of equids working in other trades, in the same region and in Khemmiset region (lowlands of Central Morocco). Wounds were numbered and scored according to their severity. Questionnaires were used to gather data from owners, and objective data regarding the animal, berdaa (back‐pack) and load were collected. Data were analysed using multilevel uniand multivariable regression models to allow for clustering of wound sites within an equid. Results: Analysis showed an overall pack wound prevalence of 54% (n = 80/147). The most common site was the withers. Equids working in the wood trade were at increased risk of suffering pack wounds. Equids in the lowland study population were at increased risk of developing pack wounds, and donkeys were at increased risk of suffering pack wounds compared to mules both overall and within the wood trade. Other factors affecting the prevalence of wounds included the cleanliness of the berdaa and the frequency and distances of work imposed on the equid. Conclusion: Pack wounds in donkeys and mules are common in the 2 study regions of Morocco and appear to be associated with work factors including the trade the equids work in, the frequency and distances of work imposed and cleanliness of the pack. Donkeys are more susceptible than mules to developing pack wounds. Potential relevance: These results allow recommendations to be made to owners of equids that may decrease the prevalence of wounds and, therefore, improve welfare and working capability of these equids. Research is required to identify reasons for regional difference in prevalence of pack wounds in equids not working in the wood trade.     

Validity of a behavioural measure of heat stress and a skin tent test for dehydration in working horses and donkeys

REASONS FOR PERFORMING STUDY: Dehydration and heat stress are serious welfare issues for equids working in developing countries. There is a lack of any standardised method or validated interpretation of the skin tent test in horses and donkeys. Owners of dehydrated and heat-stressed animals often depend on veterinary examination for identification of these conditions, leading to delays in treatment and unnecessary reliance on external sources to effect welfare improvement. OBJECTIVES: To validate a standardised skin tent test for dehydration and a behavioural measure of heat stress in working equids; and to examine the effect of heat stress and dehydration on tripping and staggering behaviour. METHODS: The study was carried out on 130 working horses and donkeys in Pakistan. Associations between skin tent and blood parameters (packed cell volume [PCV], serum total protein [TP], serum osmolality), clinical parameters, resting and drinking behaviour were examined. Heat stress behaviour (increased respiratory rate and depth, head nodding, flared nostrils, apathy) was observed in conjunction with rectal temperature. Tripping and staggering were assessed using a simple obstacle course. RESULTS: In both species, heat stress behaviour was significantly associated with increased rectal temperature (P<0.001). A positive skin tent test was not significantly associated with PCV or TP, although in donkeys it was significantly associated with lower serum osmolality (P<0.001). More animals age >15 years had a positive skin tent than those in younger age groups (P = 0.037). Very thin horses were more likely to have a positive skin tent than those in thin or moderate condition (P = 0.028). There was no significant correlation between skin tent and tripping or staggering in either species. CONCLUSIONS AND POTENTIAL RELEVANCE: Heat stress behaviour is related to increased body temperature in working horses and donkeys. Owners may use this to make judgements regarding rest and cooling, precluding the need to seek veterinary attention. The skin tent test for dehydration used in this study did not show a significant relationship with PCV or TP. However, the use of blood parameters to validate the skin tent test may be confounded by anaemia, hypoproteinaemia or electrolyte depletion. Alternative methods are needed to confirm or refute the validity of the skin tent test in working equids.     

Equine trypanosomosis in the Central River Division of The Gambia: a study of veterinary gate-clinic consultation records

The objective of this study was to provide epidemiological information of equine trypanosomosis in the Central River Division (CRD) of The Gambia. Therefore, 2285 consultations records of equines, admitted in a gate-clinic at Sololo in CRD, were studied retrospectively. The data were recorded in the period between September 1995 and July 2002 and comprised consultations of 2113 horses and 172 donkeys.

‘Trypanosome infection’ was the most frequently diagnosed condition and accounted for 61% of the cases. Horses were more frequently diagnosed with trypanosome infections than donkeys (p < 0.001), with an occurrence of 63% compared to 43% in donkeys. In both horses and donkeys, trypanosome infections were mainly due to Trypanosoma congolense (64%) and T. vivax (32%). There was no difference observed in the occurrence of trypanosome infections in male or female donkeys (p = 0.585), but there were more female (67.8%) horses observed with trypanosome infections than male horses (60.7%; p = 0.003). There was no difference observed in the occurrence of trypanosome infections in donkeys older or younger than 1 year (p = 0.130), but more older horses (63.2% >1 year) were observed with trypanosome infections than young horses (54.5% <1 year; p = 0.033).

The number of donkeys and horses with trypanosome infections decreased during the rainy season (June–September).

The majority of equines that were admitted with trypanosome infections were severely anaemic. The average packed cell volume (PCV) declined with increasing parasitaemia (p = 0.006).

Seventy-four percent of the farmers’ predictions of trypanosome infections in their equines were confirmed by darkground-microscopy. That proved that farmers had a fairly accurate knowledge of the diseases affecting their equines.

The treatments executed at the gate-clinic were generally effective. The few (0.4%) relapses of the T. vivax infections that were previously treated with diminazene aceturate in this study were not sufficient to prove drug resistance.

The study showed that the analysis of consultation records at a gate-clinic can provide complementary information to conventional epidemiological studies in the same research area.     

Prevalence of equine herpesvirus-1 and equine herpesvirus-4 infections in equidae species in Turkey as determined by ELISA and multiplex nested PCR

In this report we examined the presence of specific antibodies against equine herpesvirus type 1 (EHV-1), and equine herpesvirus type 4 (EHV-4) in several equidae, including mules, donkeys, horses. The presence of EHV-1 and EHV-4 in respiratory diseases of equids, and ability of multiplex nested polymerase chain reaction (PCR) screening in simultaneous diagnosis of horses acutely infected by EHV-1 and EHV-4 were also investigated. Sera from 504 horses, mules and donkeys sampled were tested for the presence of EHV-1 and EHV-4 specific antibodies. Blood samples taken from 21 symptomatic horses and nasal swabs taken from 40 symptomatic horses were tested for the presence of EHV-1 and EHV-4 by a multiplex nested PCR. A total of 14.3% (3/21) of buffy coat samples and 32.5% (13/40) nasal swab samples were found to contain EHV-1 DNA, while 19% (4/21) buffy coat samples and 22.5% (9/40) nasal swab samples were found to be positive for EHV-4 DNA. By species, 14.5% of horses, 37.2% of mules and 24.2% of donkeys tested were EHV-1 seropositive. EHV-4 specific antibodies were detected in 237 (81.7%) of 290 horse sera tested. Results from this investigation demonstrate that EHV-1 and EHV-4 are prevalent throughout the equid population, and that donkeys and mules might also represent an important source of infection for other equids. We also showed that the multiplex nested PCR assay might be useful for diagnosis of mixed respiratory infections in horses due to EHV-1 and EHV-4.     

Prevalence and Chemotherapy of Parascaris equorum in Equines in Pakistan

The prevalence of Parascaris equorum in paddock horses, donkeys, and mules (n = 150 for each) of the Mona Remount Depot, Sargodha, Pakistan, was examined and the efficacy of two treatments, doramectin and garlic, measured on the basis of fecal egg counts. Parascaris equorum infection was found in 54 (36%) horses, 47 (31%) donkeys, and 42 (28%) mules. The final efficacy of treatment with doramectin was 92.5% in horses, 80.6% in donkeys, and 81.4% in mules, compared to 44.4%, 51,6%, and 37%, respectively, with garlic, making doramectin the more effective treatment.     

Helping working Equidae and their owners in developing countries: Monitoring and evaluation of evidence-based interventions

There are an estimated 112 million Equidae (horses, donkeys, mules) in the developing world, providing essential resources for their owners’ livelihoods and well-being. The impoverished situation of their owners and the often harsh conditions in which they work mean that the animals’ welfare is a cause for concern. A number of equine non-governmental organisations (NGOs) operate within working equid communities providing veterinary care, education and training programmes aimed at improving equine welfare. However, there is little published information available that describes monitoring and evaluation (M&E) of such interventions using objective outcome-based indicators and where baseline data are available. The aim of this paper is to summarise the peer-reviewed reports of M&E in this sector and identify the key issues which need to be addressed in ensuring that such evaluations provide useful information on the work of these organisations.A rigorous evidence base for designing future interventions will provide an opportunity for enhancing the effectiveness of working equid NGO operations. Increased availability of M&E reports in the peer-reviewed literature will enable NGOs to learn from one another and disseminate to a wider audience information on the role of working Equidae and the issues they face.     

Epidemiological study of the cystic echinococcosis in Morocco

The objectives of this epidemiological study on cystic echinococcosis (CE) in Morocco (2001-2004) were to update the prevalence of CE in different animal species living in the most important areas of the country and to collect protoscoleces and germinal layers for genetic research purposes. The post mortem inspection concerned 2948 sheep, 2337 goats, 618 cattle, 482 camels and 455 equines (325 horses, 60 mules and 70 donkeys) in five different regions: the Rif (Mediterranean coast and high mountains of the Rif), the Loukkos (Atlantic northwest plain), the center (Rabat and Casablanca regions), the Middle Atlas mountains and the south (arid and semi desert areas). The global CE infection prevalence rates obtained were 22.98% in cattle, 10.58% in sheep, 12.03% in camels, 17.80% in equines and 1.88% in goats. The infection rates were especially high in the Middle Atlas in cattle (48.72%) and in the Loukkos in cattle and sheep (37.61 and 31.65%, respectively). The majority of infected cattle (49.6%) and sheep (52.1%) had hydatid cysts in both liver and lungs. Except for cattle, the liver was more infected than lungs in all the other animal species. Animals more than 5 years old were the most infected in all species. The mean CE infection rates of these animals were about 56% in cattle, 40% in sheep, 20% in camels, 17.80% in equines and 7% in goats. These rates were much higher in the Loukkos (85% of cattle and 59% of sheep) and in the Middle Atlas (68% of cattle and 45% of sheep) than in the other regions. Results showed that Echinococcus granulosus is in an endemic steady state with no evidence of protective immunity in the intermediate hosts. The mean numbers of infections per year are 0.099 for cattle, 0.063 for sheep, 0.03 for camels and 0.010 for goats.     

Echocardiographic and right-sidedcardiac pressure comparison of the mule and horse

There are few physiologic studies that substantiate thepopular belief that mules are superior to horses as working animals. The purpose of this study was to compare selected cardiac dimensions and right-sided cardiac pressures of mules and horses. Using 2-D real time and M-mode echocardiography and transjugular cardiac catheterization resting cardiac dimensions and right-sided pressures were recorded from 10 adult mules and 10 adult horses. The mules and horses were similar in size and physical condition, and both groups had served equally as pack animals. The end diastolic left ventricular lumen diameter, interventricular septal thickness, left ventricular free wall thickness, and aortic root diameter measured (mean ± SD) 9.51 ±0.92 cm, 2.63±0.34 cm, 2.28±0.31 cm, 7.9±0.57 cm, respectively, in mules, and 9.83±0.87 cm, 2.83±0.29 cm, 2.39±0.33 cm, 7.9±0.36 cm, respectively, in horses. The end systolic left ventricular lumen diameter measured 5.79 cm in mules and 5.94±0.99 cm in horses, yielding left ventricular luminal shortening fractions of 39.2±7.15% in mules and 39.7±6.91% in horses. Right atrial mean pressure was 5.3±2.3 mm of Hg in mules and 5.8±1.2 mm Hg in horses. Right ventricular peak systolic pressure was 47.9±4.9 mm Hg in mules and 47.7±3.5 mm Hg in horses. Pulmonary artery mean pressure was 27.3±3.2 mm Hg in mules and 28.1±3.6 mm Hg in horses. No significant differences were detected between mules and horses for the resting cardiac dimensions examined or right-sided pressures measured.