Anaplasmosis


The dreaded tick, the ectoparasite (external parasites) that we deal with from spring to the first frost, can expose us to many diseases.  Ticks are hematophagic, or blood feeders, western black legged tickand feed on the blood of mostly mammals and birds. Because of this they are also a vector, or carrier of diseases.  Most of us are familiar with the most common of these, Lyme Disease.

In horses we are most concerned about another tick-borne disease which can be found throughout the year, Anaplasmosis, formerly known as Ehrlichia.  Anaplasmosis is caused by the bacterium Anaplasma phagoytophilum.  Anaplasmosis is spread by the Ixodes tick (deer tick & Western black-legged tick).  Twenty percent of Ixodes ticks found in areas with horses are found to be infected with Anaplasma phagocytophilum.

Clinical signs for Anaplasmosis do not appear right away in the horse.  It can take up to three weeks after exposure from the tick bite to start showing clinical signs.  The most common indicator is a fever of 102-106°F.  Besides the fever other clinical signs are depression, loss of appetite, limb swelling, and occasionally muscle stiffness.  The severity of symptoms is dependent on the age of your horse and duration of the infection.  If you suspect that your horse has Anaplasmosis, call your local veterinarian.

morulaThere are a several things that your veterinarian will do to confirm that your horse has Anaplasmosis.  The first thing is to collect a blood sample to run a CBC (complete blood count).  In the CBC, the veterinarian will be looking for a low number of red blood cells, low platelets, and low number of white blood cells.   Secondly, they will create a blood smear with the sample, and look for an inclusion body called Morula that will be present in Neutrophils, a type of white blood cell.   However, the presence of the inclusion body usually will not occur until three days after the onset of the fever.  Due to this delay, even with a negative blood smear many veterinarians will start treatment for Anaplasmosis if the horse is exhibiting clinical signs.  Your veterinarian might also advise performing a Chemistry profile, specifically looking at kidney values for your horse.  Due to many horses affected by Anaplasmosis being dehydrated as well as the drug of choice to treat Anaplasmosis being metabolized by the kidneys, the veterinarian will want to make sure that the kidneys are functioning properly.

The course of treatment for Anaplasmosis is most commonly Oxytetracycline and Banamine to treat the fever.  Oxytetracycline is generally given for five days with horses usually responding well.   There is currently not a vaccine for Anaplasmosis.  Checking daily for ticks is the best preventative measure against your horses contracting Anaplasmosis. Anoka Equine also advises using a topical product called UltraBoss which we have found to be an effective method of tick prevention on horses.  Please call us at 763-441-3797 for more information.

Difference from Potomac Horse Fever

Many of the clinical signs for Anaplasmosis are similar to that of Potomac Horse Fever.  This may cause confusion as to which your horse may have.  Like Anaplasmosis, horses with Potomac Horse Fever show clinical signs of fever, depression and loss of appetite.  However, horses with Potomac Horse Fever can develop laminitis, colic and severe diarrhea.  Potomac Horse Fever is caused by horses being infected by the bacterium Neorickettsia risticii.  Horses are exposed to this bacterium by ingesting infected insects like Mayflies and Caddisflies.

Unlike Anaplasmosis, there is a vaccine available for Potomac Horse Fever commonly given in the fall.  If you are in an area that has had Potomac Horse Fever in the past or have low-lying areas of water (swamps or stagnant water) that attract Mayflies or aquatic insects, you should consider adding the Potomac Horse Fever vaccine to your fall vet visit.

If you would like more information on Potomac Horse Fever click here.

By: Katie Jones, CVT (revised 5/16 by PHM)

If your horse is experiencing any of the above clinical signs, please be sure to call your veterinarian and schedule an appointment.

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Biosecurity At Events

With the State Fair coming up next week it is important to keep in mind biosecurity, even when there is not a current outbreak of a disease.  Just with any large equine event, the chance of your horse becoming exposed to a disease is present.  The State Fair is a great event for the whole family and should be enjoyed.  So I am sharing a blog from a fellow veterinarian about good biosecurity measures that you can do not only for the State Fair, but all large equine events that you attend.

 

In the face of the outbreak, can I still attend Midwest Horse Fari?

Toria Waldron, DVM   Badger Veterinary Hospital

Keep clean!  Practice good biosecurity

For spectators:

  • 1) Keep the petting of horses down to a minimum.  If you are touching horses, wash hands or use hand sanitizer in between horses.
  • 2) Change clothes and shower before coming in contact with your own horses.
  • 3) Disinfect boots, tack, or other equipment prior to bring them back to your own horses.

 

For exhibitors:

  • 1) Horses should comply with the health regulation guidelines for the event.
  • 2) Avoid nose to nose contact of horses.
  • 3) Use your own water and feed buckets.
  • 4) Do not share tack or other equipment including hoses, rakes, shovels, etc.
  • 5) If you have concerns about your horse while participating in the event, take a rectal temperature and notify a veterinarian if the temperature exceeds 102.0 F.

What is the best way to disinfect equipment?

  • 1) Since disinfectants do not work as well in the face of organic material (manure, bedding, food, etc..) it is important to remove all this material prior to disinfecting.
  • 2) Then wash the equipment with soap and water and allow adequate time for the equipment to dry.
  • 3) Apply a disinfectant and comply with the label recommendations regarding application, contact times, and safety information.  Useful disinfectants include: diluted bleach water (1:10 dilution), Phenolic disinfectants (1-Stroke, Syn-Phenol), or Accelerated hydrogen peroxide products (Virkon).

Resources:

Rabies

By: Katie Jones, CVT

For many, when they think of rabies affecting their animals dogs and cats are at the very top of that list. Rabies cases in horses are rare, and can be preventable. Horses exposed to the virus are more sensitive and susceptible to the disease.

Rabies is caused by a virus of the rhabdovirus family. Rabies is a zoonotic disease that is spread through the saliva of an infected animal and is easily spread from one animal to another; including humans. It is believed that any warm blooded mammal is susceptible to this awful disease.

With any suddenly rapid progressing neurological signs, rabies should be considered. At onset additional signs infected horses can begin exhibiting are depression, anorexia, and ataxia. As the disease progresses, other signs that may show include:

  • Repetitive twitching

sick horse

  • Hypersensitivity to touch and sound
  • Hypermetria (a condition in which voluntary muscular movement overreaches the intended goal)
  • Proprioceptive deficits (lack of physical awareness of limbs and their placement)
  • Superlibido
  • Regional pruritus (itchiness)
  • Belligerousness
  • Periods of violence interspersed with periods of normalcy or depression
  • Normal, increased, decreased, or absent spinal reflexes

Rabies is a fatal disease with death typically occurring 3-5 days after onset. There are no treatments or tests for live animals. A postmortem test is currently the only definitive diagnosis for rabies. There are vaccinations available through a veterinarian as a preventative for contracting rabies. Horses can be vaccinated as young as three months of age, but must be boostered yearly to continue the coverage. Although the rabies vaccine is not a required in horse, the American Association of Equine Practitioners (AAEP) lists it as part of the core group of annual vaccines. Increased chances of exposure can be linked to:Rabies2

  • Pasturing
  • Presence of wild animals in area
  • Presence of known rabid animals in the area
  • Horse traveling to areas with frequent rabies cases

The number of horses infected with rabies each year in Minnesota is extremely low.  With statistics like this, it is extremely easy to choose not to vaccinate your animals, but with the virus being lethal yet preventable, is it not worth the risk.

Below is a map of Minnesota showing the positive Rabies cases for 2014.

rabies-map-2014

Video:

http://www.thehorse.com/Video.aspx?vID=264

Additional Information:

http://www.thehorse.com/ViewArticle.aspx?ID=17185&src=topic

http://cvm.msu.edu/alumni-friends/information-for-animal-owners/rabies-in-horses/

http://www.thehorse.com/Free-Reports/View.aspx?n=equine-rabies&id=15&src=topic

http://www.thehorse.com/ViewArticle.aspx?ID=20456&src=topic

 

 

 

Laminitis

By: Katie Jones, CVT

LaminitisLaminitis can be career ending or even life-threatening, causing deep seated fears in many horse owners. With continued research and the development of new treatment techniques, many cases have been resolved before life altering decisions had to be made. What is this condition? What can be done as horse owners to prevent the development of a laminitic episode?

Laminitis is inflammation of the laminae. The bones in the hoof are suspended within the hoof capsule by modified skin cells known as laminae (lamellae). The relationship between the laminae, bone, and hoof capsule is very similar to Velcro when fastened together. One end of the laminae is attached to the bone while the other is attached to the hoof wall. When working correctly, this relationship forms a shock absorber during a horse’s movements. When inflammation occurs in this delicate support system, it damages the integrity of this crucial bond. This leads to bone and soft tissue damage within the hoof and cuts off the laminae blood supply. Laminitis most commonly occurs in the front feet, but can also affect the hinds.

Laminitis can be triggered by numerous causes ranging from environmental factors to Laminitis1metabolic or systemic diseases. The predominant causes of laminitis are: metabolic or systemic in origin from excessive intake of lush green grass, Cushing’s disease, insulin resistance, secondary to infection, or excessive administration of specific drugs (corticosteroids); environmental factors such as grain engorgement; or mechanical factors such as excessive weight bearing on one limb due to a severe injury on the opposite leg. Lush pastures trigger laminitic episodes when the amount of sugar builds up in the blades on warm days with cool nights during optimal growing conditions. The sugar then triggers a metabolic event, stressing body and may result in laminitis.

There are vast inconsistencies in the progression and outcomes between horses in laminitic cases. Some will progress from barely lame to the hoof bone (coffin bone) rotating through the hoof sole rather quickly. Part of the variation lies in the individual animal as well as eating habits and metabolic issues. It is difficult to know which horses, when looking at them clinically, will progress to be more severely affected.

If your horse is exhibiting signs of laminitis, it needs to be treated as an emergency. Early intervention is critical and can dramatically reduce the likelihood of the laminitis progressing. A veterinarian will create a specific treatment plan for each individual case and it will be dictated by the progression of the disease. Treatment options may include: applying cushioned frog support, changing their diet, pain management practices, anti-inflammatories of various mechanisms, and limiting their exercise to stall rest.

If a joint effort between a veterinarian and a farrier is established with early treatment, laminitis will not always be a devastating disease. With early detection and good management practices laminitic episodes can resolve, returning the horse to normal daily functions.