July 2017

What's New at the Clinic?

We don't have too much in the way of news to report this time around! Over the past few months we have been busy with all of the fun that spring brings. As things wind down a bit, the veterinarians and staff will be taking turns enjoying some holidays.

We would like to say good-bye and thank you to two of our wonderful part-time staff members, Lauren and Brooke, who will be attending university in the fall. We wish them both all of the best!

We are excited to announce that we recently purchased a new ultrasound machine. This machine will primarily be used for equine reproductive and musculoskeletal ultrasounds.

An Indepth Look at Lice

Lice are wingless flattened insects that are usually 2-4mm in length. They tend to be fairly species specific meaning the lice found on horses will not affect humans, and vice versa. There are two general types of lice, chewing/biting lice and sucking lice. Chewing lice have mouthparts that are designed to feed on skin cells, secretions, etc...and sucking lice have mouthparts that allow them to feed on an animal's blood.

Infection with lice is called pediculosis and it can cause skin issues, production loss, and in severe cases can cause anemia secondary to blood loss. Transmission of lice occurs when affected animals make direct contact with other animals. Lice themselves do not live long off of the host but the eggs (nits) can still hatch if they fall off of the host animal and can ultimately develop into adult lice. We tend to see more cases in the fall and winter when animals are more densely housed. Oftentimes there are other reasons contributing to pediculosis, such as concurrent illness, poor quality of feed or inadequate housing conditions.

Diagnosis is based on clinical signs and the presence of lice which can be seen with the naked eye. Affected animals can be seen scratching, rubbing or biting themselves and can have areas of hair loss or poor, rough coats. Infested animals can also experience poor weight gain and reduced milk production. Some of the most common sites to find lice are on the head, neck, topline and tail head and they can usually be seen when the coat is parted.

Treatment of pediculosis involves treating all affected animals and those of the same species that are in contact with them. Determining whether the animals are infected with chewing vs. sucking lice will guide which type of treatment is used as certain formulations are only effective for a particular type of lice. There are a number of treatment options available including pour-ons, dusting powders, insecticide sprays, shampoos, etc...It is best to seek veterinary advice to determine the best treatment for your animals since the use of some of these products may be considered off-label. There are also meat and milk withdrawal guidelines that need to be observed. Animals should be retreated at least once more approximately 2 weeks after their first treatment since most of the treatments are ineffective against the eggs. Depending on the level of infestation at a particular farm, more than 2 treatments may be warranted. It is also important to clean the animal's environment including bedding and any equipment that comes in contact with the affected animals. Finally, if there are any other contributing health or husbandry issues, they should be addressed also.

Equine Infectious Anemia

Most horse owners have, at one time or another, had a "Coggins test" done on their horse, but what exactly are they being tested for?

The "Coggins test" tests for the Equine Infectious Anemia (EIA) virus. Although the type of test performed has changed since the original one developed by Dr. Leroy Coggins, we still tend to call it a Coggins test. With a few recent positive tests across the country, including in Manitoba and Quebec, it is important to understand why we continue to test most horses that move around and come into close contact with animals that may have spent time in the areas where positive tests have occurred. Proof of a negative EIA test is required for export to the USA as well as many horse shows.

EIA is a contagious disease, caused by a virus that is transmitted between horses mainly by biting insects. Insects with painful bites (such as deer flies and horse flies) are most likely to spread the virus as they are often interrupted during feeding by the swish of a tail, or stomp of a leg, and move on to another food source. There are a wide variety of clinical signs associated with the disease, including loss of appetite, fever, stocking up, edema along the ventral abdomen, weight loss and weakness. Some horses are carriers that show no clinical signs themselves but act as reservoirs for the virus, capable of spreading the disease to other horses. It is these silent carriers that make testing of apparently healthy animals so important.

Once a horse in Canada has been confirmed positive, the Canadian Food Inspection Agency (CFIA) requires that all other horses on that premise obtain negative test results before moving from that location. All horses that have come in contact with the positive animal within 30days of the sampling date must also get tested. If an animal with a positive test is also showing clinical signs, they must be euthanized. If the test positive horse is not showing any signs, the owner must decide between euthanasia or lifelong isolation from other equids. These control measures are in place as there is no treatment for EIA or preventative vaccine available.

Although yearly or more frequent Coggins tests may seem like a hassle, it's important to know that they are a valuable tool in keeping a potentially devastating diagnosis from affecting you and your horse(s).

Skin Lesions in 4-H Calves

One of the most common questions we get at this time of year is what is acceptable as far as skin lesions go for a calf to enter a 4-H show. Here are some answers and a bit about the most common skin diseases.
  1. Ringworm - Ringworm (Trichophyton verrucosum) is a fungus that affects the skin and hair of calves. It is highly contagious and zoonotic (meaning it can affect people also). There are lots of old remedy ideas floating around on how to make it go away faster, but none of them have been proven to work. You can reduce the time a lesion takes to heal (it can take up to 4 months) by keeping the calf in a well-ventilatedsunny area, but ultimately it will still have to run its course. Acceptable healing for the show ring has occurred when the lesions are completely covered in hair. Another requirement is that the lesions all be less than 2.5 cm in diameter.

  2. Warts - Warts are caused by a viral disease (Bovine Papillomavirus) of cattle that is highly contagious from animal to animal but not to people. They are unsightly in the show ring. There is also no cure for this, however proper removal of the warts at least 3 weeks prior to a show will have the area cleared up and normal looking by show time.

  3. Lice - Lice are a parasite of the skin in cattle that is contagious from animal to animal but not to people. There are two types, Linognathus (blood sucking) and Damalinia (chewing). They cause extreme itching and thus bald spots develop. It is a good management practice to apply a topical anthelmentic to 4-H calves.
Good management practices of 4-H calves include vaccination and deworming to ensure you have the healthiest calf possible on show day. Keeping your calf free from other diseases like pneumonia and diarrhea will also decrease the severity of the above diseases as they tend to be worse in more immune compromised calves. A good herd health program is very important to the well-being of any calf heading to the show ring. Also keep in mind good biosecurity procedures so as not to spread disease to your calf from another one. Things like halters, brushes, buckets and people can transmit many diseases from calf to calf, so make sure you have your own supplies and wash your hands after touching other calves.

Best of luck to all of you showing 4-H calves this year!!