PARASITES


Animal Parasites

  • Cause health problems in our pets.
  • Not only cause local damage but also can transmit infectious diseases can be serious in many cases. 
  • They are dangerous for animals as for humans. 
  • A disease that can be transmitted from vertebrate animals to humans or vice- versa is called ZOONOSIS.
  • Zoonosis is considered any disease transmitted by insects and animals (vectors) to humans.
Animal parasites can affect their host organism in a number of ways. 
  • Fist and foremost, parasites are likely to cause some type of physical trauma to the animal due to their migration within the body. 
  • Tissue destruction, tissue displacement, ulceration of the liver, and intestinal wall damage are all possible results of animal parasitic infection. 
  • Once in the body, animal parasites generally leach nutrients such as vitamins and essential minerals. 
  • This nutrient loss can result in severe vitamin deficiencies, anemia, and weight loss.
Finally, animal parasites excrete toxins in the body that may lead to a number of symptoms such as swelling, heart problems, digestive disorders, blurred vision, joint pain, and sleep problems.
  • Parasites can move from one animal or human to the next via several pathways. 
  • The most common method of infection is the consumption of contaminated food or water. 
  • Parasites can be transmitted via insect bites, through direct contact with the skin, other animal feces, or water where these organisms are present.
The parasites can be classified as :


  • ECTOPARASITES - EXTERNAL PARASITE
An ectoparasite lives and feeds on the surface of its host. Ticks, fleas, and lice are examples of animal parasites in this category.
    • ENDOPARASITES - INTERNAL PARASITE 
    An endoparasite lives and feeds inside the body of its host. Roundworms that live in the digestive system, or blood parasites that live in the lymphatic system are two common examples of internal animal parasites.
      • HYPERPARASITE    
      A hyperparasite is the term used to describe a parasite that resides within another parasite. For example, the larvae of tapeworm can be found in fleas before they are transmitted to animals or humans.
        ECTOPARASITES - EXTERNAL PARASITE
        FLEA


        Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood. Fleas are external parasites, living by hematophagy off the blood of mammals (including bats and humans) and birds.




        LICE
        Lice are insects that can be seen with the naked eye. They are flattened and possess no wings. They are very host-specific and do not tend to leave their preferred animal, in this case dogs and puppies. Lice spend their entire life cycle on the pet. There are several kinds of lice. Blood-sucking lice belong to the group Anoplura. Those that do not suck blood, but rather chew skin, are grouped as Mallophaga.
        Transmission of lice is by direct contact with an infested pet. Unlike fleas and ticks, lice do not persist or travel in the environment. Grooming instruments may, however, serve as a source of transmission.
         The most noted sign of a louse infestation is a scruffy, dry hair coat. Hair loss may occur and the animal may itch, at times severely. In very heavy infestations of blood-sucking lice (biting), one may detect anemia, especially in puppies.



        MITES
        Mites are generally microscopic parasites that excavate their ways to your dog's body through the hair follicles or various oil glands in the epidermal layer of the skin. Your downy pet may be reduced to a patchwork of damaged skin and shabby hair, if it gets infested with mites. Also known as 'Mange'; mites on dogs may lead to conditions like acute hair loss, severe skin infections (accompanied with inflammation and itching), and sometimes to various terminal diseases also. Normally, all dogs have a certain population of mites thriving on their body. The condition gets exacerbated only when the immune system of the animal fails to retaliate the multiplying mites, thus leading to severe outbreak and unchecked reproduction of mites on the dog's body.
         Type of Mites
              Generally there are two types of mites that may infest your dog. 
              Demodex Mites 
              Demodex Mites are responsible for the severe skin disease called 'Canine Demodicosis' in dogs. These miniscule vermin are generally white and oblong. They spend their entire lifecycle in the hair follicles and sebaceous glands of the host and feed on various skin debris, cells and sebum. Mite-infested nursing bitches generally transfer these mites to their offspring.
              Sarcoptic Mites 
              These mites are also known as 'Scabies' and are more troublesome than the Demodex Mites. They thrive on the hair follicles of dogs and lead to intense skin-itching (also known as 'pruritus') and a variety of other skin infections. Sometimes, dry skin lesions and severe hair loss in your dog may be the result of Sarcoptic Mites. They might even invade the skin of healthy dogs and puppies. 
              Symptoms of Dog Mites 
              -Alopecia or unexplained hair loss
              -Bleeding from various skin abrasions and fissures
              -Cracking and scabs in the skin
              -Reddish or swollen skin
              -Severe skin itching or 'pruritus'
                TICKS

                Ticks are ectoparasites (external parasites), living by hematophagy on the blood of mammals, birds, and occasionally reptiles and amphibians. Ticks are vectors of a number of diseases, including Lyme disease, Q fever (rare; more commonly transmitted by infected excreta), Colorado tick fever, tularemia, tick-borne relapsing fever, babesiosis, ehrlichiosis and tick-borne meningoencephalitis, as well as bovine anaplasmosis.


                FLIES (CUTEREBRA)
                A Cuterebra parasite is an opportunistic parasite found under the skin of small mammals. This parasite is the larval stage of the Cuterebra fly, who uses animal hosts to complete its life cycle.
                Cuterebra fly species are also known as botflies, and they are opportunistic in that they use the small mammals (dogs, cats, rabbits, squirrels, etc.) to complete their life cycle.
                The adult files are large and do not feed on or bite animals. Eggs are deposited around animal burrows and on plants, rocks and other objects. The eggs stick on the animal host as the host passes by, and then the eggs hatch in response to the body heat of the animal. The hatched larvae enter the body through the mouth or nose during grooming, or less commonly, through an open wound in the animal.
                The larvae then migrate to specific areas on the body under the skin. The larvae make a small hole in the skin to breathe. This is when the parasite is usually discovered; a noticeable lump in the skin with a small hole. The tip of the larve will often be visible deep in the hole. Roughly 30 days later, the parasite exits the animal host, pupates on the ground, and becomes an adult fly.
                It is very important to NOT squeeze the skin in hopes of getting the larva out. This can cause the larva to break apart, and cause the host animal to have a chronic infection or perhaps an anaphylactic reaction.
                PHLEBOTOMUS
                Canine Leishmaniasis
                 Serious zoonotic protozoal infection of man and animals.
                Cause : intracellular protozoan parasites of the genus Leishmania .
                Transmission is predominantly by sand-fly bites .
                Signs : the visceral form is more common in the dog and 90% of dogs have cutaneous or mucocutaneous involvement.Specific signs include chronic weight loss, lymphadenopathy, alopecia and exfoliative dermatitis, nodular skin lesions, chronic renal failure   and epistaxis.
                                                     
                                                                 Presenting signs
                • Cutaneous lesions - periocular alopecia extends to nasal skin and ears. Exfoliative dermatitis, nodular dermatitis, ulcerative dermatitis generalized particularly involving extremities .
                • Claw abnormalities.
                • Progressive weight loss.
                • Anemia .
                • Hyperkeratosis .
                • Polyarthritis .
                • Lethargy.
                • Polydipsia /polyuria (renal failure).
                • Ulcerative and nodular dermatitis.
                • Diarrhea .
                • Abdominal distension.
                TROMBICULA AUTUMNALIS
                Harvest Mite  Infestations
                • The harvest mite (Trombicula autumnalis) is a mite the larval stage of which causes considerable discomfort to cats and dogs during the late summer and autumn. The mite is particularly abundant in chalky areas and gardens where soft fruit is grown.
                The six legged larval stage is the only stage which attacks warm blooded animals. All other stages live in the environment and are not parasitic. The larvae congregate on small clods of earth or on vegetation. They are active during the day and particularly in dry sunny weather. When a warm blooded animal comes into contact with the larvae they swarm onto it and attach onto skin particularly in sparsely haired thin skinned areas. The larvae feed for 2 to 3 days and they drop off onto the ground to complete the life cycle. The larval mite is orange and only just visible to the naked eye.
                What effect do harvest mites have on cats?
                The six legged larval mite attaches to the skin of cats to feed. It fixes onto the skin by small hooked fangs and then injects fluid into the skin which liquefies cells. The resulting liquefied food is sucked back by the mite. The fluid injected by the mite is very irritant. Irritation causes the cat to scratch, bite and lick which may result in extensive self-inflicted injury. The resulting skin lesions vary from crusted spots to areas of hair loss to raw moist bleeding areas.
                In cats mites are most commonly found on the ear flaps, on the sparsely haired area in front of the ears and between the toes but they can be found almost anywhere on the body.
                Individual cats vary greatly in their sensitivity to mites. Extreme sensitivity probably reflects the development of an allergy to the mite or its products and affected cats will cause severe self-inflicted damage to themselves.
                How are harvest mite infestations diagnosed?
                Sudden onset of intense irritation in July or August would make one suspicious that harvest mites might be involved although other ectoparasites and some forms of allergic skin disease can cause similar symptoms.
                Your veterinarian can make the diagnosis by identifying the mite. Congregations of mites may be seen as intensely orange spots on the skin. If fewer mites are present they may be seen on microscopic examination of a superficial skin scraping.
                Diagnosis can be difficult if cats are presented some time after the problem started as by then the cat may have licked or scratched off all the mites.
                How can I get rid of harvest mites from my cat?
                Your veterinarian will give you appropriate treatment. Insecticides licensed for on-animal flea control will effectively kill harvest mites provided that they reach the skin and not just the fur. This is more readily achieved with a foam or pump-on liquid than with an aerosol spray or powder. The problem is that unless the product has excellent residual action as soon as the cat returns to the infested environment it will collect more mites. To avoid this the cat can be restricted to indoors during the mite season. Fortunately there are now flea control products available with good residual action which may be able to prevent or considerably reduce reinfestation. Such products should be applied to the cat during the harvest mite season (July to October) at the highest frequency suggested in the instructions.
                What can be done to stop my cat itching?
                In most cases treatment for the mites will rapidly make the cat feel more comfortable. In cats which are very sensitive to mites additional treatment with anti-inflammatory therapy and occasionally physical restraints such as Elizabethan collars may be necessary to prevent further self-trauma.
                Do harvest mites affect people?
                People can be affected by harvest mites. These are not caught from cats or dogs but from infested outdoor environments. People's ankles become affected by walking through infested vegetation but more generalized lesions can follow sitting or lying in infested areas. A typical human skin reaction consist of an intensely irritant rash. Specific treatment is usually unnecessary. Avoidance of infested environments is the best way of preventing the problem.