2013年9月28日星期六

Leptospirosis in dogs

Leptospirosis is an acute, chronic or clinically inapparent highly infectious disease of animals and man characterized by fever, haemoglobinuria, jaundice and abortion. Leptospirosis is world wide in distribution and is of zoonotic importance. Leptospirosis is also known as Weil’s disease in man.

Leptospirosis in dog is caused by Leptospira icterohaemorrhagie, Leptospira canicola, Leptospira Grippotyphosa and Leptospira pomona. Leptospira is a spiral-shaped bacteria with long, helically coiled bodies.

Which animals are susceptible to leptospirosis?
Dogs, cattle, buffalo, sheep, goat, horse, donkey are susceptible to leptospirosis. Cases of leptospirosis in cats are rare


Which dog is most susceptible to listeriosis?
Dogs of all ages suffer from leptospirosis but young dogs between the age group of 1-4 years are more suspectible to leptospirosis than matured dogs. Large breed of dogs are more susceptible than smaller breed of dogs. It is common in German Shepherds, Retrievers, mixed breed and working dogs.


How is leptospirosis transmitted in dogs?
Transmission of leptospirosis takes place by direct contact with urine of infected animals and rat. Ingestion of contaminated food and carcass, bite wounds, abrasions of skin or mucous membrane also transmitts the disease. Dogs drink, walk and swim through contaminated water and so they are very prone to leptospirosis. Stagnant water, contaminated with urine is a common source of infection as the organism multiply more in stagnant water. Indirect transmission takes place by contaminated water source, food, bedding etc. Incidence of leptospirosis is high during flood. Ticks may transmit the disease from an infected dog to a healthy one by deposition of the organism in the exposed skin and mucous membrane. Recovered dog excrete the organism in the urine as long as three years.


What are the signs and symptoms of leptospirosis in dogs?
Incubation period is usually 2-14 days.Signs in dogs include fever, anorexia, depression, oculonasal discharge, lethargy. As the disease progresses the organism damage the blood vesels of kidney and liver. In this case vomiting, dehydration, lumbar pain can be seen in dog. Kidney failure, liver disease occurs in severe cases. The dog have foul breath (halitosis) because of ulceration of buccal mucosa and tonsillar movements. In dogs with moderate infection of leptospirosis the mucous membranes, fatty tissue and unpigmented skin show yellow tinge (indicating liver disease like icterus) and this yellow discolouration is found mainly in the abdomen, foot pads, inner sides of ear. The dog increase its daily water intake and so there is increase urination. The dog has blood tinged reddish urine and uremia. Reproductive failure also occurs in dogs. Majority of these dogs recover in two or three weeks but some lose kidney function and die slowly from accumulation of waste product (uremia).










What are the signs and symptoms of listeriosis observed in man?
In the first phase of the disease non specific flu like symptoms like headaches, eye pain with bright lights, muscle aches followed by chills and fever are seen. Eye becomes red and symptoms seem to improve by the fifth to ninth day. The second phase begins with fever and aching with stiffness of the neck. Inflammation of the nerves to the eyes, brain, spinal column or other nerves develop in some cases. Abdominal pain, diarrhoea, vomiting occurs. The symptoms in humans appear after a 4–14 day incubation period.

Diagnosis of leptospirosis:
Diagnosis is done by the following:
(a) History of the dog- Whether the dog is vaccinated or not, whether the dog came in any contact with infected animals, ingested contaminated food and carcass etc
(b) Clincal signs- Yellow discolouration of skin, increase daily water intake, increase urination, blood tinged reddish urine etc
(c) Laboratory findings like elevation of leucocytic count, raise bilirubin values, raise BUN level
(d) Demonstration of organism by dark field microscopy
(e) Culture of urine or blood or infected tissues
(f) Histopathological examination of kidney, liver and brain tissues using Silver or Giemsa



stain
(g) Animal inoculation is done by injecting suspected materials from liver, spleen or brain into

mice
(h) Serological tests like ELISA, Fluorescent antibody technique etc is done

Treatment of leptospirosis in dogs:
(a) Intravenous fluid- in case of dehydration and also to flush out the kidneys and prevent their destruction
(b) Antibiotics like sodium penicillin G eliminate leptospiremia followed by doxycycline to eliminate the the renal carrier phase .Ffluoroquinolone antibiotics such as enrofloxacin are also effective
(c) Corticosteriod – to speed up the elimination of urea
(d) Vitamins and minerals- to restore vitality


Prevention and control of leptospirosis in dogs:
Dogs should be vaccinated at 9 weeks of age. Booster should be done at 12-16 weeks of age and then anually. A killed mixed vaccine of L.icterohaemorrhagiae and L.canicola is used. A new vaccine by Fort Dodge now also protects against the serovars L. grippotyphosa and L. pomona. Antibiotics like Amoxicillin or doxycycline should be given for 7-10 days to those dogs that have been recently exposed to leptospirosis to prevent infection. Rodent populations should be controlled as rodents are the main carrier of leptospirosi. Adequate measures should be taken to prevent contamination of water. Suspected or infected dogs should be seperated from healthy ones. Recovered dogs should be separated for atleast two months following clinical recovery.



Prevent exposure of the dog with rat or any other wild animal

Prevention and control of leptospirosis in man from dog:
Leptospirosis is a zoonotic disease and can pass the infection to man through contact with infected dog and also from contaminated water. Wear gloves and wash hands thoroughly after cleaning up vomit, faeces ,urine etc of infected dog and also while handling the infected dog. Do not allow the children to handle or play with dogs infected with leptospirosis or suspected of being infected from leptospirosis. Leptospira organism are destroyed by heat and disinfectants. Urine from infected dogs and other contaminated surfaces should be cleaned with antibacterial cleaning solution or a solution of 1 part household bleach in 10 parts water. Disinfectants like sodium hypochlorate, calcium chloride and sodium hydroxide can also be used. Water should not be allowed to remain stagnant for a long period of time.



没有评论:

发表评论