Some owners look forward to winter, with an end to summer problems such as sweet itch and sunburn, and a diminished risk of laminitis. But for others, the change in season brings its own difficulties.
Recent research has predicted that our winters will be wetter and less cold than before. So what does the season mean for horse health, and how can owners prepare for it?
Winter is clearly a bigger issue for those horses at the extreme ends of the age range. A new study at Manchester University has confirmed what common sense already tells us, namely that people who suffer from arthritis and bad backs feel more pain in cold weather.
The same is almost certainly true for horses. For the very old, this problem can be compounded by winter weight loss. A decrease in muscle mass and strength, plus increased joint stiffness, means that it can be an increasing struggle both getting up and moving around. Old horses are often put to sleep in winter simply because they become too weak and stiff to get up.
Joint supplements probably have some low-level benefit, but the best solution for those with significant arthritis can be a daily dose of phenylbutazone (bute). Bute comes from the same family of drugs as aspirin and is quite safe even long term, provided the dose is kept low.
While nothing can match grass for keeping condition on an older horse, careful planning of his diet is vital. Adding vegetable oil to the feed — up to half a cup, twice a day — is a simple way to boost calorie intake.
One factor often neglected in older horses is exercise. Most retirees don’t actually move much in the field, particularly if it is wet and muddy. Walking out or even light lungeing will help maintain muscle mass and prevent joints from seizing up.
Veterans should be tested for Cushing’s disease, which causes loss of muscle. Controlling the medical conditions of old age will also help the horse’s general wellbeing and outlook.
Quality of life
Owners of very old horses always face a tough decision in late autumn: whether or not to put their horse through another winter. The answer has to depend on whether the horse is still enjoying a good quality of life and looks able to maintain that throughout the coming months. He must be in reasonable body condition and sufficiently pain-free to behave like a normal horse.
Not every horse which is stiff or lame has to be put to sleep. Everyone gets a bit doddery with increasing years, owners included, but most of us would still be fairly upset to be summarily bumped off. Winter lasts a long time, however. So if you are going to put your veteran through it, you need to be pretty sure that he will get to enjoy the next summer.
For youngsters — weanlings to three-year-olds — winter is often the time that they are put out in the field and left to fend for themselves. They do this perfectly well provided they have adequate feed and somewhere to shelter from bad weather.
Rugging isn’t strictly necessary as horses are already surprisingly well waterproofed, but this changes if there is prolonged rain. A wet coat loses its insulating layer of air and horses have to expend more energy to keep warm. Watch out, too, for rain scald, a condition in which prolonged wetting of the skin allows a painful bacterial infection to take hold.
If horses do overwinter on grass, it is important to keep up with worm control. Worm larvae can remain on the pasture in mild autumns, because rain breaks up and spreads the droppings, and it is still warm enough for the eggs to hatch.
Single negative worm egg counts are not entirely reliable for young horses, because the greatest risk comes from the larval stages of the small redworms, not the egg-producing adult worms. In addition, young horses have much less immunity to worms. Effective control requires a combination of paddock clearing, worm egg counts and periodic worming.
Diet and dust
Too much summer grass means that for every horse that is thin going into winter there may be a dozen that are significantly overweight. Owners are often disappointed that these horses don’t shed the pounds over winter. This is usually due to a combination of less exercise and the owner’s fear that without an inexhaustible supply of hay their horse is at risk of ulcers.
No horse will lose weight unless he spends part of the day with no food. Sensible restriction with a weighed daily intake has no health risks. Remember, too, that laminitis can still occur in winter, particularly on cold but sunny days when grass sugar levels can be very high. Because of their inability to metabolise sugar properly, Cushing’s sufferers are vulnerable to laminitis all year round.
Stables can be hazardous to health, due to a combination of poor ventilation, dust from feed and bedding plus high levels of irritant ammonia from urine. Shut a horse in this environment for 18 hours a day and it is no surprise that lung problems are common.
Even if your horse does not cough or wheeze, taking steps to improve the air quality in your stable can help prevent problems in the future. The most important factor in stable ventilation is having an adequate through-flow of air, so open or remove any windows at the back of the box. If the stable is only open at the front, consider knocking a hole in the back wall.
Feeding soaked hay or haylage will reduce the dust particles a horse breathes in by two-thirds. Using a haynet, meanwhile, exposes a horse to six times more dust than feeding hay from the floor.
Mucking out is said to create up to a twentyfold increase in dust, so the obvious solution is to take the horse out first. If your horse is stabled in a barn, consider where the hay and straw are stored and also how the next-door horses are kept. Avoid allowing a build-up of urine under stable mats, as this greatly increases ammonia levels.
Diseases enjoy winter. Viral respiratory infections are much more common during the colder months, as is the bacterial infection strangles and also ringworm — which is in fact a fungus.
These problems can all occur at any time of year. While heat and sunlight kill bacteria and viruses, however, damp and dark conditions allow them to persist and spread.
When you factor in the additional time spent in the shared airspace of a barn or stable block, it is clear that attention to biosecurity becomes even more important over winter.
All new arrivals at a yard should be kept fully separate from other horses for two weeks in case they are incubating an infection. Unfortunately, the chief risk from strangles comes from silent carriers — horses or ponies that show no signs of disease. Quarantine alone is inadequate to identify these cases; what’s needed is a blood test looking for antibodies to the bacteria. If a higher than normal level of antibodies is detected, further tests are necessary.
Other practical biosecurity measures include maintaining a high standard of yard hygiene and keeping each horse’s tack and equipment separate to avoid any cross-contamination. Make sure that your horse is adequately vaccinated and keep a record of his normal temperature, so that you can check it if you are concerned about his health.
Ref Horse & Hound; 20 October 2016