LEG AND FOOT INJURIES: GUIDE TO EFFECTIVE TREATMENT IN DONKEYS

Transcription

1 Vet Times The website for the veterinary profession LEG AND FOOT INJURIES: GUIDE TO EFFECTIVE TREATMENT IN DONKEYS Author : GRAHAM DUNCANSON Categories : Vets Date : August 4, 2008 GRAHAM DUNCANSON explains how the stoical donkey provides the veterinarian with a break from the equine norm MANY equine clinicians struggle with lame donkeys. The stoicism of donkeys means they do not react to pain or injury in the same manner as a horse or pony. My experience is that you get the odd very bad-tempered individual that seems to be able to kick out at all angles. Mercifully, however, these characters are rare. Most donkeys are good natured ready to do their work, but equally happy to be left alone. I had a team of 10 donkeys that carried my personal possessions when I was on foot safari in northern Kenya. The terrain in the northern frontier district was often too rough for my Land Rover; either that or the rain had made the black cotton soil a total morass. I would set off from my base at Lamu and carry sufficient supplies for a 10-day rinderpest vaccination campaign with the donkeys. I felt sorry for the donkey that carried the heavy box containing the vaccine (which was cocooned in dry ice); I always made sure the cargo was swapped around. They were good companions and I never had an example of lameness. This is not the case with pet donkeys in Norfolk, where lameness problems are common. 1 / 12

2 Think foot pus I consider the most common cause of horse lameness to be the foot. If you consider the donkey, pus in the foot is far and away the most common cause of lameness. It is a very painful condition and we owe it to donkeys to not only ameliorate the condition, but to also give them pain relief. However, diagnosis is not easy rarely will a donkey show pain on hoof testers. Paring away the hoof may reveal the source of infection but, sadly, many black tracts seem to peter out and fail to reward the clinician with the pus he or she seeks. A penicillin and streptomycin injection of 5ml does seem to help some individuals. However, I favour an animal lintex poultice, with extra magnesium sulphate paste and held in place with black gutter tape. Pain relief can be given orally; I get owners to give their animals a 200mg phenylbutazone tablet twice daily in a piece of apple. Donkeys will get tetanus, so remember to check their vaccination status. If there is any doubt, I give them a full horse dose of 7,500IU (7.5ml in most preparations) of tetanus anti-toxin. I try to encourage my donkey owners to keep their animals fully covered for tetanus. It is not very costly and I feel we owe it to our donkeys to protect them from this cruel disease. While I am on the subject of tetanus, I would like to warn the readers of the dangers of euthanising a horse or donkey with tetanus. If they are shot, or if they receive a lethal dose of a quinalbarbitone sodium and cinchocaine hydrochloride-based drug, they lurch forwards violently. Always stay to the side of these cases. Other foot problems Overgrown horns, which are totally due to neglect, are a common cause of lameness in the UK. This can occur in more arid parts of the world, but it is much rarer particularly if the donkey is working. Donkeys kept on meadows, particularly marshes, need regular foot care from a licensed farrier. If you are presented with a donkey with overgrown feet, I believe you must trim some of the horn away yourself. Obviously, the ideal protocol is to get a farrier but, if our area (Norfolk) is anything to go by, that would take some time. I believe you should give the donkey pain relief until the mechanical lameness has been corrected. Horn overgrowth or laminitis, which I will describe later, can result in white line separation or seedy toe. This is a difficult condition to treat, as there is a need to radically pare away the wall but, unlike horses, you cannot support the sole by shoeing the animal. A compromise has to be reached with radical paring and protection by using a poultice. 2 / 12

3 Another common cause of pain in the foot is thrush. Once again, this is not a condition of arid areas, and is quite common in the UK. Applying a poultice is contraindicated. If possible, trim some of the frog away to open up the area. I initially get the owners to clean the feet twice daily and apply hydrogen peroxide. If that is not successful, I revert to an old-fashioned formulation called villates. This is a mixture of a saturated zinc, copper sulphate and glacial acetic acid solution. It should be applied twice daily to clean the hooves. If the condition is persistent, I treat the donkeys with metronidazole orally. I use dog tablets at a dose of 12.5mg/kg daily for five days, as there is now no licensed equine preparation available. Leg wounds Naturally, all wounds should be thoroughly investigated to find out the extent of the damage. If there is little blood and exudate, I advise covering the open area with a wound gel and then clipping the area this is easier with dry hair. I then clean the whole area with a garden hose. This may have to be done before clipping if the wound is very messy. The wound can then be examined carefully after drying it thoroughly. Any suspected puncturing of joint or tendon sheathes needs to be investigated, as in horses. However, I feel suturing wounds is unwise leaving full drainage is the best approach. The formation of proud flesh is a very rare occurrence in donkeys, but I do bandage any wounds below the knee and hock. I leave wounds located further up the body open, but I make sure they are liberally covered with oily creams, and try to ensure the area below the wound is protected by petroleum jell. Fly control is vital after giving tetanus cover, I give a minimum of five days worth of antibiotics and NSAIDs. I start with injections and continue with oral medication. I give this in the form of oral paste, as some donkeys are reluctant to eat medicated feed. It is vital to remember that donkeys are very prone to hyperlipaemia. Therefore, any inappetance is dangerous. Front leg lameness Fractures should always be considered with even moderate lameness. Obviously, any swelling will direct you to the source of the problem. However, in the absence of clues, it is important to work up the leg methodically once foot lameness has been eliminated. I have seen four cases of radial paralysis. The donkey appears fracture-lame initially, but careful observation will reveal that the animal is able to bear weight when the leg is placed in the correct position. Normally, there is a lack of sensation on the skin of the pastern s dorsal aspect. Prognosis in these cases is good, as the animal rapidly learns to flick the foot forward when walking. The animal appears sound within three months, but any sensation may not return for more than a year. 3 / 12

4 Osteoarthritis, which causes lameness, is common in elderly donkeys. The carpus is the most commonly affected joint and joint effusion is marked. One can be scientific and perform a joint block, but I feel this is an unnecessary procedure. I believe draining the fluid and injecting an intraarticular steroid is all that is required. This procedure gives considerable relief to the donkey, and can often last for more than 18 months. Naturally, this can be repeated but, in my experience, the effective relief is much shorter. Hindleg lameness Upward fixation of the patella is not uncommon in young, poorly developed donkeys. The need for a median ligament desmotomy is rare. Most of these cases will be cured with time, provided nutrition and exercise are improved. A short course of phenylbutazone is worthwhile. A much less common condition, which may confuse the practitioner, is the rupture of the peroneus tertius (part of the reciprocal apparatus). In this condition, the stifle will flex but the hock will remain in extension. I have seen this condition in old, debilitated donkeys. However, it is reported to occur in overworked animals. The prognosis is not good in old animals, but normal function will return in two to three months if debilitated donkeys are rested and fed well. The third condition in this group is when the Achilles tendon slips off the point of the hock. This condition will alarm the donkey, which will try to move and may even bolt, as the leg feels strange. However, I don t think this condition is actually acutely painful. The prognosis is good and normal function returns within two months. Laminitis Donkeys, like horses, may become laminitic for a variety of reasons. most commonly, too much lush grass or grain overload. Donkeys will suffer laminitis as a result of Cushing s disease, and it is very important that the afflicted animals are not starved. These animals are very prone to contracting hyperlipaemia, a condition that should be avoided at all costs. Summary Obviously, donkeys are equines and share many features with ponies. However, donkeys have certain peculiarities that should be remembered. 4 / 12

5 5 / 12

6 Photo: ISTOCKPHOTO/DIETER HAWLAN. 6 / 12

7 7 / 12

8 Osteoarthritis, which causes lameness, is common in elderly donkeys. The carpus is the most commonly affected joint and joint effusion is marked. 8 / 12

9 Getting mules or donkeys to trot may not be easy after foot problems. Fly control is vital after giving tetanus cover, the author gives a minimum of five days worth of antibiotics and NSAIDs. 9 / 12

10 The author says the stoicism of donkeys means they do not react to pain or injury in the same manner as a horse or pony. 10 / 12

11 One common cause of pain in the foot is thrush. This is not a condition of arid areas, and is 11 / 12

12 quite common in the UK. 12 / 12 Powered by TCPDF (