donkey

Laminitis is a commonly occurring, painful condition of the foot that can have a major impact on the welfare of affected donkeys. When faced with a donkey suspected to have laminitis, the approach is broadly similar to that in the horse, however there are certain factors unique to donkeys that this article aims to highlight including: the differences in use, behaviour, anatomy, therapy and management.

Three donkeys were presented with progressive lameness and distal suspensory ligament breakdown in multiple limbs. Treatment with nonsteroidal anti-inflammatory drugs was only partially effective and eventually the donkeys were euthanized due to further progression of the lameness and concerns for their welfare. At necropsy, the distal part of the suspensory ligaments in multiple limbs, including the suspensory ligament branches, was markedly thickened, enlarged, and mottled white and brown on cut section. In one case, adult Onchocerca sp. nematodes were grossly identified embedded within the suspensory ligaments. Histopathologic examination revealed chronic, multifocal to coalescing, moderate to severe, lymphoplasmacytic, eosinophilic, and fibrosing desmitis and tendinitis with intralesional, coiled adult nematodes of Onchocerca sp., accompanied by osseous and cartilaginous metaplasia. To the authors’ knowledge, this is the first histopathologic description of suspensory ligament desmitis and tendinitis associated with Onchocerca sp. in donkeys.

Mycobacterial infections are rare in horses, donkeys and mules. Although there are a few reports in horses, mycobacterial disease is poorly documented in the donkey. Mycobacterial infection of equine species typically affects the alimentary tract, causing granulomatous enterocolitis resulting in diarrhoea and chronic weight loss, while lymph nodes and liver may also be affected. We now document recurrent oesophageal obstruction, secondary to cranial mediastinal lymphadenitis caused by Mycobacterium avium complex (MAC). To the best of our knowledge, this is the first report of MAC infection in a donkey in the UK.

In Portugal, donkeys represent a large legacy of social, cultural, economic and ecological importance. The only native breed of donkeys, the Miranda Donkey, is composed by a small number of animals. The aim of this study was to evaluate the parasitic infection, particularly the variation in the rate of positivity, the level of parasitic infection (LPI) and the biodiversity of intestinal parasites in a population of 62 Miranda donkeys, exposed to an anti-parasitic control every 6 months, with subcutaneous injection of ivermectin 2% at the dosage of 1 ml/50 Kg BW, between July 2005 and February 2010. During this period, there was a decrease in the positivity rate, from 87% (54/62) in 2005 to 32% (20/62) in 2010, as well as a decrease in the LPI. In 2005, 70,4% of the infected animals had levels higher than 1000 eggs per gram (EPG), considered a high LPI and in 2010, 75% of the infected animals had levels under 500 EPG, low LPI. Biodiversity also decreased during this period, namely the decrease of Strongylinae in relation to Cyathostominae. Considering that consistent levels of parasitic infection are still observed in this population and that the most observed Strongylidae are the ones of genus Cyathostomum sensu latum, these results are worrying because these agents are frequently referred by its ability to acquire resistance to anti-parasitic drugs.

Objective

To determine the disposition of a bolus of meloxicam (administered IV) in horses and donkeys (Equus asinus) and compare the relative pharmacokinetic variables between the species.

Animals

5 clinically normal horses and 5 clinically normal donkeys.

Procedures

Blood samples were collected before and after IV administration of a bolus of meloxicam (0.6 mg/kg). Serum meloxicam concentrations were determined in triplicate via high-performance liquid chromatography. The serum concentration-time curve for each horse and donkey was analyzed separately to estimate standard noncompartmental pharmacokinetic variables.

Results

In horses and donkeys, mean ± SD area under the curve was 18.8 ± 7.31 μg/mL/h and 4.6 ± 2.55 μg/mL/h, respectively; mean residence time (MRT) was 9.6 ± 9.24 hours and 0.6 ± 0.36 hours, respectively. Total body clearance (CLT) was 34.7 ± 9.21 mL/kg/h in horses and 187.9 ± 147.26 mL/kg/h in donkeys. Volume of distribution at steady state (VDSS) was 270 ± 160.5 mL/kg in horses and 93.2 ± 33.74 mL/kg in donkeys. All values, except VDSS, were significantly different between donkeys and horses.

Conclusions and clinical relevance

The small VDSS of meloxicam in horses and donkeys (attributed to high protein binding) was similar to values determined for other nonsteroidal anti-inflammatory drugs. Compared with other species, horses had a much shorter MRT and greater CLT for meloxicam, indicating a rapid elimination of the drug from plasma; the even shorter MRT and greater CLT of meloxicam in donkeys, compared with horses, may make the use of the drug in this species impractical.

In the west of the Zamora Province in Castilla y León region, one of the most rural and isolated areas of Spain, the Zamorano – Leonés donkey – a native endangered breed -is still playing a central role in the traditional daily agriculture activities practiced by the local inhabitants. In February 2010 a study was carried out to understand the prevalence of equine piroplasmosis in the population of Zamorano – Leonés Donkey, collecting blood samples from 86 animals in 13 villages in the Zamora Proviince. Equine piroplasmosis is a tick-borne disease of equids, caused by Theileria equi and Babesia caballi. These intraerythrocytic parasites are responsible for a high morbidity and mortality in equids. The cELISA tests (competitive – inhibition Enzyme-Linked Immunosorbent Assay) revealed a positive seroprevalence of 21%, with 8 of the 86 donkeys positive for Theileria equi (9.3%), 10 for Babesia caballi (11.7%) and one of these 18 animals positive for both. The results of this study clearly demonstrate the importance of equine piroplasmosis affecting the Zamorano – Leonés donkey population. As far as we know this is the first study on intra-erythrocytic parasites in endangered Iberian breeds of donkeys and the results obtained reveal its importance in order to preserve this unique genetic heritage.