Newsletters - April'12

April 2012

Equine Gastric Ulcers

Ulcers are defects in the lining of the horse's esophagus, stomach or upper part of the small intestines. They are the result of an imbalance between natural protective barriers and damaging factors such as stomach acid. Gastric ulcers are a widely reported problem in racehorses and show horses. They also commonly affect sick foals. There are a variety of predisposing factors which include intense training, lack of forage, minimal turnout, illness and the use of non-steroidal anti-inflammatories (NSAIDs) such as phenylbutazone (bute).

Signs: The clinical signs of gastric ulcers include poor appetite, teeth grinding (also known as bruxism), lethargy, weight loss, mild colic signs, and poor coat. Some horses may show no signs at all.

Diagnosis: Gastric ulcers can be tentatively diagnosed based on clinical signs and response to treatment. To confirm the presence of ulcers, a horse needs to undergo gastroscopy, which involves passing an endoscope (a flexible tube with a light source and often a camera) into the stomach.

Treatment: The preferred medication used to treat ulcers is omeprazole. To treat ulcers the medication is typically administered daily for 2-4 weeks. Increasing frequency and duration of turn-out, offering free choice hay, feeding smaller concentrate rations, reducing training intensity, and reducing the use of NSAIDs all assist with the healing process.

Prevention: The methods used to help treat ulcers, such as increasing turn-out time and providing free choice forage, are also important to help prevent the development of ulcers. In addition to modifying the horse's environment and training regime, medications such as omeprazole can also be used to prevent the development of ulcers by reducing acid secretion.


Orf in Sheep & Goats

Orf, also known as contagious ecthyma, is caused by the orf virus. It is a very contagious condition most commonly affecting lambs and kids. Orf is primarily a seasonal problem with most cases occuring in the spring around lambing/kidding. Skin lesions, including pustules and scabs, develop after the virus enters through broken or damaged skin. These scabs are seen around the lips and muzzle and may also be found on the udders and teats of ewes and does with affected offspring. Lesions on udders and teats can be quite painful and as a result the ewes/does may not allow the lambs/kids to nurse. Also, a severe infection on the lips/muzzle of lambs or kids can cause pain while nursing and lead to babies that don't eat.

The condition is self-limiting, but it can take over a month for the lesions to disappear. In the meantime, no treatment is usually necessary and the scabs should not be removed. If secondary bacterial infections develop, then antibiotics (such as penicillin) may need to be used. If the lesions are severe, an anti-inflammatory such as flunixin can be used to make the animals comfortable. Lambs and kids with affected dams should be monitored for signs of neglect secondary to painful udder or teat lesions, where the dam will not allow nursing. A vaccine is available to protect against orf, however it is not widely used because it is difficult to administer and not generally cost effective as orf does not cause death or even serious disease.

Orf is a zoonotic condition, meaning it can affect humans as well. Affected humans develop similar scabby lesions on their face and hands that eventually disappear after several weeks. Care should be taken when handling affected animals to reduce the risk of contracting the condition.


Using Milk Culture to Assist in Mastitis Management

Mastitis is a costly disease for producers, accounting for losses in production, discarded milk, increased labour, and increased veterinary treatment expenses. We recommend that all cows with high somatic cell counts and/or clinical mastitis have their milk cultured. Milk culture allows the most appropriate antbiotic to be selected to eliminate the bacterial pathogen grown. Knowing what types of bacteria are most commonly cultured on your farm will also allow for the use of more targeted therapies. Intramammary treatments are only a part of treating cows with mastitis. Some cases may require oxytocin and stripping, no treatment at all, management changes, culling or vaccination for prevention depending on the bacteria grown on the culture. Your herd veterinarian can advise you about the best approach to treating your cows. Oftentimes, the results of the sample will be "no growth". This can happen because some infections are only shed into the milk intermittently, sometimes there is only a small number of bacteria in the milk and some infections are high up in the udder and do not shed very much. These are frustrating cases of mastitis to deal with but we can advise you of the next steps to take in these situations.

When submitting milk samples to be cultured for mastitis-causing organisms, the following steps need to be followed:

1) Wash and dry the cow's teats (and your hands).

2) Milk a little out of each of the quarters first then use alcohol swabs to clean the end of each quarter to be sampled.

3) If sampling more than one quarter, sample the quarter(s) furthest from you first then do the closer one(s) to avoid inadvertent contamination. Collect the milk into the vial(s) taking care to avoid getting debris in the sample or on the lid (do not put the lid in your mouth, on the floor, etc…Try to hold it in the hand that is also holding the collection vial).

4) Place the lid on the sample and label which quarter was collected or if a composite sample was taken (all 4 quarters sampled in one vial).

5) Refrigerate the sample promptly or bring it to the clinic as soon as possible. Samples can be submitted Monday to Thursday, and should ideally be brought in by noon.