More tips on caring for your ‘long ears’
October 16, 2013
Part two of two…see last week's paper for part one.
Owners should get their donkeys' and mules' teeth checked and floated routinely. "Since donkeys and mules live longer than horses, teeth become an issue in older animals," Carl Lind, DVM, of Bishop Veterinary Hospital, in Bishop, CA, says. And because of mules' and donkeys' inclination to protect themselves (e.g., kick), he suggests sedating them for safety when floating teeth. "I've seen them fight through sedation more than a horse will," he adds, due to their quick metabolism as well as behavior tendencies.
Neonatal isoerythrolysis (NI) Also called foal jaundice, neonatal isoerythrolysis is a condition in which the pregnant mare creates antibodies against the fetus' red blood cells, if it inherits a blood type from the sire that's incompatible with the mare. This problem occurs more frequently (about ten percent of the time) in mule foals because donkeys possess a blood component that mares do not have, explains Todd Bettin, DVM, of Breda Lake View Veterinary Services, in Lake View, IA.
"Normally there is very little blood going back and forth between mare and foal across the placenta (unless there's placental disease), but there is an increased amount of exchanged blood in mule foals," he says.
Newborn foals gain instant protection against disease if they ingest a proper amount of their dam's colostrum soon after birth. But if the colostrum also contains mare antibodies against the foal's own red blood cells, it can be deadly – if the antibodies destroy enough of his red blood cells. Severely affected foals show signs of jaundice (yellow mucous membranes) due to red blood cell breakdown, the cells' pigment leaking out into the tissues, and anemia, Bettin said.
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Veterinarians must take extra care to prevent excessive bleeding when castrating donkeys or mules, as these animals have larger testicles and, thus, larger blood vessels in the groin region than horses. Most recommend castrating colts that have both testicles descended before testicles and blood vessels become large – generally before six months of age – to prevent aggressive behavior.
"Complete ligation (suturing) of the spermatic artery in donkeys is very important," says Sybil Sewell, co-founder of the Canadian Donkey and Mule Association and Alberta Donkey and Mule Club, in Leslieville, AB. "I won't use a vet who doesn't put a stitch in and make sure those arteries are closed – as well as using the emasculator to crush the arteries and spermatic cord."
This rare parasitic disease caused by Besnoitia bennetti surfaced in North American donkeys in 2011 and is characterized by the development of cystic lesions both externally and in the throat and eyes. Currently, the mode of transmission is unknown, and there are no known effective treatments.
Donkeys and mules don't experience as many lameness-causing
injuries such as bowed tendons, torn ligaments, or navicular syndrome as horses do, but these problems do occur. Incidentally, "we do see more ringbone (a degenerative disease of the pastern and coffin joints) in mules, however, than in horses," says Lind. "This is partly because of what we ask them to do. Mules that jump may suffer more (foot) concussion because they don't have a big round foot like a Thoroughbred or Warmblood."
Sewell adds, "People are now using donkeys and mules in the show ring, to do all the things horses do, putting a lot of stress on their legs. Now we are seeing some of the horse leg problems occurring in donkeys and mules, especially if they are not carefully bred to have enough bone and leg structure. I've seen mammoth donkeys with 'toothpick' legs. Yet because they are 15 hands tall, they are asked to carry a rider … plus Western tack at a young age."
Maturity rate also plays a role in soundness: Donkeys and mules develop more slowly than horses, and knee closure (when the carpal growth plates change from cartilage to bone) takes longer. Sewell cites studies in which researchers evaluated carpal maturity in donkeys: Miniature Donkeys' knees closed at about three years of age (as a horse's would), but mules' and larger donkeys' knees didn't close completely until they were four or older.
Even though donkeys traditionally carry heavy burdens with ease, they do it at a slow walk. "In their native countries they are not asked to barrel race; they are asked to walk five miles back and forth to the local market," says Sewell. "When training a donkey/mule, give it time to grow up so it can stay sound and give many years of useful service."
And while bred for slow travel, it's important to note that "donkeys can perform in speed events – just about anything you'd do with a horse," she adds. "Just don't rush them into this at a young age."
Handling for Health Care
Mules and donkeys have a stronger self-preservation instinct than horses and are quick to defend themselves. "They have tremendous ability to kick (as a self-preservation tactic)," Miller notes. "Unlike a horse, you can be standing at the animal's head and a mule can reach you with its hind foot."
Because of this tendency, it can be especially challenging to perform health care and management procedures (e.g., deworming, vaccinating) on donkeys or mules if they haven't been handled consistently and properly. Getting them accustomed to this type of handling will foster respect for and trust in the handler, not to mention safety for both parties.
Starting early is key: Imprint training (handling the neonatal foal and habituating him to various stimuli immediately after birth) can be valuable for future handling and training of mules and donkeys, says Miller, allowing owners to address resistance to common procedures early.
Overall, Lind emphasizes using common sense when working with these equids. "They aren't any more needle-shy than a horse or more difficult to worm, float their teeth, or shoe, as long as you've handled them properly – with good experiences rather than bad ones," he observes. "They remember the bad ones and are less forgiving than a horse." Thus, keep painful and irritating experiences to a minimum, or the animal might become more difficult to handle for routine treatments.
As for tolerance, donkeys are quite stoic, responding to stimuli with obstinance rather than a flurry of activity. This naturally stoic nature can serve as a disadvantage to veterinarians when diagnosing medical issues, as it can mask an illness' seriousness.
If you own donkeys and/or mules, learn as much as you can about their nature, unique health characteristics, and handling considerations. Doing so, along with seeking the guidance of your veterinarian, will prepare you to recognize and address potential problems. F