Ask an Expert    Health Problems Anthrax & Equines       Unsightly Sarcoid       Winter Itch       Failed Foaling Q. An article about anthrax causing the death of some horses in Texas appeared in a recent issue of a U.S. horse magazine. It said that drought conditions can lead to an outbreak. Should we be concerned about this disease in Canada and if so, what precautions should we be taking to protect our horses? A. Dr. Mike Scott of Calgary, Alberta's Moore and Company Veterinary Clinic provided information about anthrax and the threat it poses to Canadian horses. Anthrax is a federally reportable disease; if a veterinarian suspects it, the Canadian Food Inspection Agency is contacted immediately. If the disease is proven to be present, the premises are quarantined and all livestock in residence are destroyed, burned, and buried. Massive disinfection procedures are undertaken and movement of vehicles and livestock on the property can be restricted for an extended period. As devastating as anthrax is, the disease is so rarely encountered in Canada that most veterinarians do not ever run into a case during the course of their careers. For that reason, the vaccines that can be used to guard against anthrax infection are not routinely used - or even readily available - in this country. In the U.S., there are districts where the disease occurs seasonally, but in Canada, outbreaks are isolated. Anthrax is an acute, usually lethal disease that can infect any warm-blooded animal, including man. It is not commonly considered an equine ailment; horses are not as susceptible as deer, cattle, sheep and goats, but they do occasionally contract the disease. The anthrax agent is a bacterium called Bacillus anthracis. It is very resistant, forming spores that protect it from heat, cold, and prolonged drying. It can remain dormant in the soil, in water and on hides for decades. It is usually contracted when animals pick up spores while grazing contaminated ground or eating feed grown on contaminated ground. Infected carcasses also pose a threat and insect bites can transmit the disease. An outbreak in cattle in Alberta this past summer was suspected to have been caused by spores in remnants of buffalo bone found in the area, which was near a buffalo jump. Certain environmental conditions can cause dormant anthrax bacteria to become active. The reference to drought conditions leading to an outbreak may be due to the need for livestock to forage closer to the ground when grass is scant, thereby ingesting spores. Periods of wet weather followed by extreme heat, water standing after a flood, certain soil pH, and disturbed soil conditions can also trigger outbreaks, causing dormant bacteria to revert to a live, reproductive state. Once an animal has ingested anthrax bacteria, they rapidly multiply, in some cases causing the animal to die so suddenly that a lightening strike or stroke may be suspected as being the cause. Anthrax in horses is acute and can last up to 96 hours. A horse that is infected is likely to exhibit colic, extreme depression, septicemia (blood poisoning), high fever, and enteritis (small intestine inflammation). Hot, painful swellings may spread about the neck, lower abdomen, and other parts of the body. Affected horses may experience dyspnea (difficult or labored breathing) due to swelling of the throat. Death is the usual outcome. Despite the dramatic symptoms and dire consequences of the disease, you shouldn't spend time worrying about it; I personally have not heard of a case of anthrax in a horse in Canada. Back to Top Q. My mule has a grayish-black scaly lump at the base of her ear. If she rubs it on something, it bleeds but it doesn't really seem to hurt her. She doesn't care if I touch it. A friend told me that it is a sarcoid. What does that mean and how can I get rid of it? A. Dr. Alexander Tolmach of Corrigan and Associates Veterinary Services in Spokane, Washington responds: An equine sarcoid is a tumour involving connective tissue that begins as a small wart-like growth, but may progress through stages of rapid growth to the size of a tennis ball. The key difference between sarcoids and similar appearing tumours such as lymphomas is that sarcoids are benign while lymphomas are malignant. Both these tumours are distinct from epithelial tumours (carcinomas & melanomas). Sarcoids can appear anywhere on an equine. Some are smooth and small, some are scaly, lumpy masses that ulcerate and bleed if bumped or rubbed. Because they are not life threatening, the main problems with a true sarcoid are those of secondary infection, physical interference with tack, and unsightliness. Sometimes sarcoids will disappear on their own but usually they are tricky to treat. In fact, treatment has been known to stimulate their growth and make them spread. Options for treatment include surgical removal, freezing, laser surgery, radiation therapy, chemotherapy and stimulation of the immune system. A complementary therapy that some people feel works is the application of Tea Tree oil, which acts as an irritant and may help trigger the horse's immune system. Often more than one method of treatment will be used simultaneously. Unfortunately treatment is not always successful and even when it is tumours may reappear. If your mule's sarcoid is not a nuisance and remains the same size, you might take a wait-and-see approach: it may clear up on its own. If there is sign that it's growing or if it is continually being irritated, consult your veterinarian to develop a treatment plan. Back to Top Q. Two of my horses have become insatiable scratchers - they rub themselves on every available surface to the point of damaging their coats. They seem to be itchy all over. What is the problem and how can I help them? A. Our consultant for this question is Brian J. Taylor, DVM CVA, who works out of the Nanton Veterinary Clinic in Nanton, Alberta: Horses that are insatiable scratchers can be a real challenge and be difficult to resolve. The first thing is to try to get a diagnosis as to why they are itchy. You may need your own veterinarian to examine these horses. There are a number of reasons why they may be like this. Pruritis (itching) can be caused by external and internal parasites, bacterial infections, fungal infections, nutritional factors and boredom. Lice and mange are common external parasites especially in winter when the hair coat is long. The lice tend to be near the skin so you have to part the hair coat and look deep at the skin level. Mange usually appears as bare areas that often drain serum or appear moist. These areas commonly are found on the hocks and tail head area. Internal parasites such as pin worms often cause horses to rub their tails as the eggs are usually deposited around the rectum area. Some bacterial skin infections like rain scald (dermatophilosis) caused by Dermatophilus congolensis affect the top line of horses especially if the hair becomes matted and dirty. This traps bacteria and causes skin lesions. Ringworm is sometimes a cause of pruritis and usually shows up as white powdery bare spots found commonly on the head and neck but can be anywhere on the body. Itching may be caused by poor feed, which leads to dry skin and a dull hair coat. Attention to proper nutrition with vitamin A, D and E added usually solves this problem. Boredom is a rare cause of pruritis but occasionally a horse will scratch out of boredom. This then causes skin lesions that also become itchy which perpetuates the condition. In summary I would advise you to have your horses examined by a veterinarian so that a proper diagnosis can be made and the proper treatment can be implemented. Back to Top Q. A friend of mine just lost a foal; it was still born and had a palate deformity. Her veterinarian asked her if the mare had been turned out on green feed in the fall. Why would she have asked that question? I am interested because my own horses are turned onto barley fields after harvest. A. Mike Scott, a veterinarian with Moore and Company, Calgary Alberta, provided his insights on this subject: Your question doesn't have an easy answer. Your friend's veterinarian was likely curious about the mare's exposure to green feed because of an ongoing study being conducted by the Western College of Veterinary Medicine into something called Congenital Hypothyroidism and Dysmaturity Syndrome. I happened to be one of the researchers involved in looking into this Syndrome in 1994-95. The Syndrome, which is specific to western Canada, has been recognized since the late '70s. It is characterized by foals being born weak or dead with contracted tendons and a deformed jaw (elongated lower or shortened upper) - both signs of skeletal immaturity that are a result of malformation of the thyroid gland or lack of thyroid function. An extensive survey conducted by the WCVM of western Canadian horse breeders into the management of broodmares and breeding herds led researchers to conclude that the common denominator in the occurrence of CHDS was the feeding of green feed to mares during pregnancy. Green feed, if cut during a period when the crop is stressed by frost or drought, can have a high nitrate content. Consumption of water with high nitrate content in third world countries has been shown to result in thyroid diseases in people; it seemed likely that high nitrate in green feed could cause similar thyroid problems in horses. However, further testing involving feeding pregnant mares green feed with high nitrate content failed to prove the theory. Still, it is possible that a relationship exists between a mare eating green feed and the type of foaling problem experienced by your friend. Research into CHDS is still being done at the WCVM, spearheaded by Andy Allen. So, while there is no definite conclusion that can be drawn about why your friend lost her foal, her vet's interest in a green feed connection probably relates to this study. 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