Ehrlichiosis

Posted on August 26, 2016

Ehrlichiosis is the medical term for diseases caused by various species of Ehrlichia which are disease-inducing agents transmitted by ticks. Two other genera, known as Anaplasma and Neorickettsia, are also included in the same family of organisms as Ehrlichia, thus they are included under the diseases known as Ehrlichiosis.

Ehrlichiosis can occur in cats and dogs of all ages. Chronic forms of the diseases caused by Ehrlichia canis are observed to be more predominant in Doberman pinschers and German Shepherd dogs than other breeds of dogs. Duration of onset of clinical signs between initial acute illness and presentation to a veterinarian is usually greater than 2 months.

Clinical signs can include common lethargy, inappetance, depression and weight loss. However, Ehrlichiosis can garner signs inclusive of:

  • Fever
  • Haemorrhage from nose or nasal passages
  • Breathing distress
  • Wobbly, uncoordinated or drunken-like gait (also known as ataxia)
  • Tilted head
  • Eye pain (inflammation of the iris and other surface areas of the eye)

Signs of acute Ehrlichiosis include:

  • Bleeding disorders, characterized by pinpoint areas of bleeding in the gums, as a result of a low platelet count
  • Fever, depression, lack of appetite, weight loss
  • Generalized enlarged lymph nodes
  • Ticks – found in 40% of the cases
  • Difficulty breathing and possible bluish discolouration of the skin and mucous membranes of the body caused by inadequate oxygen levels in the red blood cells, also known as cyanosis, increased lung sounds may be noted when listening to the chest with a stethoscope
  • Widespread central nervous system disease
  • Wobbly, uncoordinated or drunken-like gait (also known as ataxia)
  • Altered sense of balance
  • Generalized or localized areas where the pet is overly sensitive to pain or touch
  • Most dogs recover without treatment and enter a subclinical state in which the animal is infected but has no signs of the disease

Signs of Chronic Ehrlichiosis

  • Spontaneous bleeding
  • Low red blood cell count
  • Generalized enlarged lymph nodes
  • Fluid accumulation in the scrotum and legs
  • Enlarged spleen
  • Enlarged liver
  • Inflammation of the iris and the other surface areas of the eye; some animals may have the inflammation in both eyes and some can have this inflammation as the only showing clinical sign
  • Accumulation of blood in the anterior chamber of the eye (front of the eye, between cornea and iris)
  • Bleeding in the back of the eye and separation of the back part of the eye from the underlying, vascular part of the eyeball with blindness
  • Fluid accumulation in the clear part of the eye
  • Inflammation of the joints also known as arthritis
  • Seizures

Dogs can be infected with a number of species of Ehrlichia; Ehrlichia canis, Anaplasma platys, Anaplasma phagocytophila, Ehrlichia ewingii, and Ehrlichia chaffeensis produce main disease entities. Cats can be infected by Neorickettsia risticii and Anaplasma phagocytophila.

Concurrent infection with other blood parasites such as Babesia, Haemobartonella, Anaplasma platys, and Hepatozoon canis can worsen the clinical signs.

The most effective way to avoid Ehrlichiosis is to control tick infestation by starting your dog on routine tick preventions such as advantix, advocate and bravecto as per recommended by your veterinarian. Tick-infested areas such as grasses and bushes should also be avoided. Though there is always a possibility of accidently bringing a tick home from outdoors, as long as your dog is on proper tick prevention, it would have maximum possible protection from tick issues. In the event of finding a tick on your dog, remove it using gloved hands. Ensure that all the mouth parts are removed to avoid a foreign-body reaction.

Dogs infected with acute ehrlichiosis usually recover well under appropriate treatment. However, dogs suffering from chronic ehrlichiosis infection may require up to 4 weeks to respond to the treatment. They may not recover from this infection and the ability of the bone marrow could decrease, affecting the production of blood cells. Progression from acute to chronic ehrlichiosis can be prevented easily by early and effective treatment. Many dogs nonetheless remain positive on serologic tests and may have a relapse.