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Tick troubles – All you wanted to know about canine babesiosis

Come summers and all responsible pet parents are wary of ticks, which can become a major health hazard for our loving pooches. Here’s some info about babesiosis, a common tick-borne disease. Watch out for this disease and protect your four-legged friend from misery.

Canine babesiosis is a tick borne haemoprotozoan disease of domestic dogs widely prevalent in tropical and Dog Healthsubtropical regions of the world including India. The disease is characterized by erratic fever, malaise, anorexia, weight loss, unthriftiness and severe anaemia of haemolytic nature. Because of haemolysis, babesiosis can be a life threatening disease.

How babesiosis is caused?

The disease is caused by several species of Babesia mainly B. canis, B. gibsoni and B. vogeli. Babesia sp. are generally found inside the red blood cells (RBC) and individual RBC may contain single or multiple organisms. As many as seventeen species have been identified to infect the canines, of which B. canis and B. vogeli are of similar size, and are larger than B. gibsoni. In India, B. canis is more prevalent in southern regions of the country, whereas B. gibsoni is more prevalent in northern regions and in and around Delhi. However, several species and sub-species of Babesia i.e. B. canis rossi, B. odocoileis, B. microti, B. equi etc. have also been identified in different countries of the world which differ in their pathogenecity, leading to various grades of symptoms.

How babesiosis is transmitted?

Canine babesiosis is transmitted between dogs mainly by the brown dog ticks, Rhipicephalus sanguineus. The life-cycle of brown dog ticks is shown in the picture above. However, the disease is also transmitted through Haemophysalis or Dermacentor spp. Besides, it can also be transmitted from the infected mother to the puppy or through blood transfusion.

Which season babesia infection occurs?

The disease is occurring in tropical and subtropical regions of the world and is more common during summer and rainy seasons due to enhanced activity of the vectors (ticks) owing to favourable climate. But, the chronic cases can be encountered any time of the year. Stress can flare up the disease further. This disease is not breed-specific.

What are the symptoms of babesiosis?

The naturally occurring cases of babesiosis are manifested by a wide variety of clinical signs such as partial appetite/inappetance/anorexia, dehydration, fever/no fever/erratic fever, dullness/depression, diarrhoea/constipation, pale mucosa, ticks on body, hepatolmegaly, vomiting/nausea, splenomegaly, rapid thready pulse, nasal discharge, ataxia/CNS signs, distended abdomen/ascites, dysponea/labored breathing, yellow coloured urine/coffee coloured urine, emaciation/weight loss, occular discharge, oedema and death.

The disease occurs in per acute (severe), acute (moderate) or chronic (mild) forms. Dogs usually suffering from per acute form, are characterized by shock due to low blood pressure, deficiency of oxygen, extensive tissue damage, shock, coma or death following one day of complete loss of appetite and lethargy. Acute phase is characterized by anaemia due to destruction of RBC, enlargement of spleen and increased number of platelets. It may also be fatal in pups. Chronic phase is characterized by intermittent fever, partial loss of appetite, lethargy, depression and loss of weight. Sometimes a typical signs such as distension of abdomen due to fluid accumulation, ulcer, epileptic fits, pneumonia and cutanious manifestations are also seen.

How babesiosis can be cured?

The treatment of canine babesiosis is complicated by the wide variety of host factors and Babesia spp. with differing degrees of drug tolerance and susceptibility. Small Babesia species i.e. B. gibsoni is more refractory to treatment than B. canis. Severely anaemic dogs should receive oxygen therapy and whole blood transfusions in addition to specific antibabesial drug. Supportive therapy with poly-ionic isotonic fluids, blood transfusion, and hepatotropic tonics helps in recovery. Both diminazine aceturate and imidocarb are toxic drugs; therefore treatment of dog should be undertaken under the strict supervision of the competent veterinarians.

Why treatment failures occur?

  • Improper diagnosis at early stages of infection.
  • The small Babesia (B. gibsoni) is difficult to treat than B. canis. The same dose rate and schedule, which are effective against B. canis infection, is not enough to cure B. gibsoni infection due to its different morphological nature.
  • Different organ failures, which remain undiagnosed.
  • Drugs became unresponsive due to severe anaemia.
  • Concurrent infection of Ehrlichia canis, Trypanosoma evansi or Dirofileria immitis etc.

Although, the antibabesial drugs are easily available in market but the treatment of ailing dogs requires professional skill because of many complications and should therefore be undertaken under the advice and care of the competent veterinarian.

How babesiosis can be controlled?

  • Control of canine babesiosis is possible only with the control of tick population by spraying kennels and dipping/ spraying or bathing dogs at regular intervals.
  • Although, treated dogs clear infection, but remain sub-clinically infected and may be re-infected and serve as source for further spread of disease. Such dogs should never be used for blood transfusions because it can produce infection in recipient animals.
  • At present there is no effective vaccine available against B. gibsoni to prevent or control the infection, but B. canis infection can be controlled by using cell culture vaccines derived from exoantigens of B. canis.
  • Common acaricides such as amitraz (2 to 3 ml/litre), fiproil and pyrethrins can be used to control the vectors or ticks.

(Dr. Shubhamitra Chaudhuri has recently completed his M.V.Sc. Veterinary Medicine under the guidance of Dr. J. P. Varshney (B.V.Sc. & A.H.; M.V.Sc. (Medicine) and Ph.D. (Vet. Med.), retired principal scientist (veterinary medicine) and a renowned canine expert. Dr. Chaudhuri can be contacted at 09411222306 or email at drshubhamitra@rediffmail.comdrshubhamitra@gmail.com while Dr. Vashney can be contacted at 9897224580 or email : at dr_jpvarshney@rediffmail.com or drvarshneyjp@yahoo.co.in)