Vetinary Pharamacy - Ecto and Endoparasites Flashcards
What is a Definitive host?
the host that holds the adult (reproducing) stage of the parasite
What is a Intermediate host?
the host that holds the larval stages of the parasite and is necessary for the parasite’s development
What is a Paratenic host?
: a host that can maintain stages of the lifecycle but is not necessary for the parasite’s development
what is the Prepatent period?
time from infection of the definitive host until reproduction starts and eggs/larvae are released from the host
What is a zoonotic infection?
infection which affects people and animals
Describe the life cycle of a flea
Adult fleas stay on host until they die
Female flea lays eggs after 24 hours and can lay around 25 to 50 eggs a day
1. Flea dirt and eggs
2. Larvae L1
3. Larvae L2 - Flea larvae move away from light deep into carpets and cracks in flooring where they feed on flea dirt and moult from L1 to L2 to L3
4. Larvae L3
5. Pupae - larvae spin a protective cocoon and become a pupa developing into an adult flee
Stimulated by temp, vibration and CO2, young adults emerge and acquire the host
6. First blood meal within minutes
What is the diagnosis of fleas?
Diagnosis
- Fast-moving and often difficult to find: look for ‘flea dirt’ (small black specks in the pet’s coat), which consist of digested blood excreted by the fleas
- Use fine-toothed comb over a wet piece of white paper, flea dirt which falls onto the wet surface dissolves into red/brown patches
- Some flea allergic pets are so sensitive they quickly groom off and swallow the fleas, so just because no fleas are found on the pet, does not necessarily mean no fleas are present
How do you control fleas?
Methods of control:
1) Kill the adult (adulticides, kill within 24 hours) and/or prevent the development of eggs and larvae (insect growth regulators)
2) On-animal and/or environmental treatments
Range of formulations, containing different active ingredients or combinations of active ingredients:
1) For the pet: spot-on for long persistent efficacy (e.g. fipronil, imidacloprid), oral (e.g. nitenpyram), spray, collar/powder/shampoo (e.g. permethrin compounds), injectable
2) 2) For the environment: sprays (e.g. permethrin +/- (S)-methroprene), foggers
Integrated flea control = use of multiple different approaches to attack problem from several angles
- Effective and long-lasting adulticide to kill fleas on the pet
- An IGR to prevent development of eggs, larvae and pupae in the home
- Mechanical control (regular vacuuming, hot washing pet bedding )
What are Insecticidal molecules effective against fleas?
- Pyrethroids: permethrin (toxic to cats)
- Neonicotinoids: imidacloprid, nitenpyram
- Phenylpyrazoles: fipronil, pyriprole
- Oxadiazines: only POM-V
- Macrocyclic lactones (spinosyn group): only POM-V
- Macrocyclic lactones (avermectins/milbemycins group): only POM-V
- Isoxazolines: only POM-V
- Organophosphates & carbamates: not widely used anymore
- IGRs: – Analogues of the insect juvenile hormone (prevents flea eggs from developing into fleas): (S)-methroprene, pyriproxyfen – Inhibitor of the synthesis of chitin: lufenuron
How does Fipronil work (fleas)?
Different flea products work in different ways. Fipronil causes hyperexcitation, making the dying fleas more visible as they bounce through the coat and rise to the tip of the hair, so it is a sign the product is working
What is used to treat fleas in ferrets?
Fipronil (S)-methoprene
What is used to treat fleas in rabbits?
Imidacloprid
How can you get rid of a flea infestation?
Need to treat for at least 3 months to resolve the issue (pupal window)
Must treat all pets in the household with an appropriate product even if fleas only seen on one animal
Must treat environment as well as the pet with a house spray such as Frontline HomeGard Main reason for lack of resolution is poor compliance
What are the most common reason to see fleas after treatment?
1. Compliance • Product incorrectly applied • Product not applied frequently enough • Gaps in treatment • Dog bathed too frequently (product washed off) • Wrong dose used (underdose) 2. “Hitchhiker” fleas • New fleas picked up from an outdoor reservoir 3. Pupal window Household infestation
What are the ways that chewing lice and sucking lice are transmissioned?
• direct or indirect contact (bedding, brush)
What are the clinial signs of chewing lice and sucking lice?
Clinical signs: poorly groomed coat, presence of eggs (nits) or adults, excessive itching and rubbing resulting in self-inflicted skin damage, pet can be restless and bad tempered Diagnosis: close inspection and detection of adults or eggs (nits) within the hair coat
How can you control chewing lice and sucking lice?
Control: insecticide (fipronil, imidacloprid (dog only)), regular washing of bedding and grooming equipment
Describe the life cycle of chewing lice.
Lice feed on epidermal scales and sabaceous secretions, also feed on blood
Adults attach themselves to the hair and develop a complete life cycle
- Females lay eggs which attach to host hairs
- Eggs hatch and release nymphs which look like adults but are much smaller
- Nymphs moult and gradullay grow until reaching the adult stage
Describe the life cycle of sucking lice.
Adults and nymphs can move to new hosts or remain on same host to maintain their life cycle. most transfers occur during direct contact of hosts
Adults have peircing/sucking mouthparts and they feed on blood
- Females attach eggs to host hairs
- Eggs hatched and release nypmhs
- Nymphs moult and gradullay grow until reaching the adult stage
What is the most common specie of ticks in the uk?
Ixodes spp. Ixodes ricinus
Describe Lyme disease: Infectious agent Vector Affects Clinical signs Symptoms
• Infectious agent: Borrelia burgdorferi (bacteria)
• Vector: Ixodes spp. Ticks
• Affects: humans (zoonosis ) as well as dogs (cats rarely)
• Clinical signs in dogs: fever, lethargy, arthritis (stiffness and swelling)
• A dog vaccine against Lyme disease is licensed in the UK
• Symptoms in humans:
o – Early stage : tiredness, flu-like symptoms, muscle and joint pain, bull’s eye rash
o – Mid stage: numbness, localised paralysis
o – Late stage symptoms: chronic joint pain
Describe Babesiosis: Infectious agent Vector Affects Clinical signs Symptoms
- Infectious agent: Babesia (protozoa)
- Many species of Babesia, with different hosts, vectors, distribution and symptoms. Most common in western Europe is Babesia canis
- Vector: Dermacentor reticulatus (in UK), Rhipicephalus sanguineus
- Affects: dogs
- Clinical signs: fever, anaemia (pale gums, lethargy, loss of appetite), jaundice, red/brown urine
How can you control ticks?
Key steps in successful tick control:
1) Check pets for ticks after a walk and remove safely using a tick remover (do not apply butter, oil, burn or freeze as this encourages disease transmission). It’s important all parts of the tick (incl. mouthparts) are removed, so refer to their the pet’s vet if needed.
2) Use acaricide to kill and/or repel ticks regularly all year round. Products kill ticks within 48 hours (repellent products POM-V only).
3) Disease prevention through vaccination of dogs against Lyme disease in endemic areas
What are the tick treatments for dogs and cats?
Fipronil
Fipronil (S)-methoprene
Dog
Pyripole
Delatamethrin
