ectoparasites sheep

What are ectoparasites in relation to dermatological diseases?

Ectoparasites are external parasites that affect the skin, such as mites, lice, ticks, and flies.

What are the impacts of sheep scab/scabies?

Itching, scratching, biting at flanks, loss of wool, exudative pruritic skin lesions, scabs, skin excoriations, secondary infections, pain, and weight loss.

What species causes sheep scab?

Psoroptes ovis.

How is sheep scab diagnosed?

Diagnosis involves a skin scrape to find oval-shaped mites with funnel suckers and blood tests to identify antigens in subclinical carriers.

What is the treatment for sheep scab?

Treatment can include OP dip or ML injections such as moxidectin or doramectin.

What control issues are associated with treating mites?

Concerns include safety of chemical treatments, resistance of mites to MLs, sub-clinical infestations, and biosecurity issues.

What are effective prevention methods for ectoparasites in sheep?

Quarantine new animals and use serology tests for high sensitivity and specificity.

What are the two types of lice that affect sheep?

Sucking lice: Linognathus vituli and Pedalis; Biting lice: Bovicula ovis.

What is the lifecycle of lice?

Lice have a simple and direct lifecycle, all occurring on the host.

What are the clinical signs of lice infestation in sheep?

Itching, rubbing, licking, with a high burden of sucking leading to anemia, decreased body condition score, and damaged skin or fleeces.

How can lice be diagnosed in sheep?

Lice can be seen with the naked eye during examination.

What is a common treatment for lice in sheep?

Pour-on synthetic pyrethroid, such as deltamethrin, or OP dips with required PPE.

What is the most common tick species affecting sheep?

Ixodes ricinus.

What is the lifecycle of Ixodes ricinus?

Ixodes ricinus has a 3-host lifecycle.

What disease is transmitted by ticks that affects weaned lambs?

Louping ill.

What are the clinical signs of tickborne fever in sheep?

Pyrexia, anorexia, depression, and abortion.

What is Tick pyaemia?

A staphylococcal infection following immunosuppression resulting in lameness, paralysis, and death in lambs.

Which fly species is the most common affecting sheep?

Lucilla sericata.

What are the clinical signs of myiasis in sheep?

Separation from the flock, restlessness, pruritus, and discolored wool with an unpleasant smell.

What is a common treatment for myiasis?

Synthetic pyrethroids and cleaning affected areas with shearing.

What preventative measures can be taken for flies in sheep management?

Reducing susceptibility through mechanical and chemical control measures, monitoring wounds, and reducing fly abundance.

What does OP stand for in the context of ectoparasite control?

Organophosphate.

What is one challenge with moxidectin treatment for mites?

Resistance development in the mite populations.

What are exemples of mechanical control measures for reducing fly susceptibility?

Dagging and shearing.

Why are secondary skin infections a concern in sheep with mite infestations?

They can lead to more severe pain and other health complications.

What might indicate a subclinical mite infestation in sheep?

Animals that spread disease without showing clinical signs.

What does the term 'pruritic' mean?

Causing itching.

What does it indicate if a sheep exhibits restlessness and pruritus?

Possible ectoparasite infestation.

Why might some lice treatments require PPE?

To protect the handler from harmful chemicals and ensure safe application.

How can biosecurity issues impact ectoparasite management on a farm?

They can facilitate the spread of infestations between animals or herds.

What is the significance of serologic testing in sheep health management?

It helps in identifying subclinical carriers that can spread diseases.

What is the role of the immune system in tickborne diseases?

Ticks can immunosuppress the sheep, leading to increased susceptibility to diseases.

What is the common treatment approach for ticks in sheep?

Use of acaricides or insecticides to reduce tick populations.

What effect does a high burden of sucking lice have on sheep?

It can lead to anemia.

What is the primary impact of ectoparasite infestations on sheep production?

Decreased body condition and potential weight loss.

What are 'funnel suckers' in the context of skin scraping diagnosis?

Structures found on some mites that help them attach to the host's skin.

What is a potential animal welfare issue related to ectoparasites?

Severe itching and pain caused by infestations can lead to distress.

Why is it important to monitor for open wounds in sheep?

Open wounds can attract flies and increase the risk of myiasis.

What is one challenge associated with chemical control measures for ectoparasites?

The risk of resistance developing among pest populations.

What is a symptom of pruritic skin lesions in sheep?

Itching and discomfort leading to behavioral changes like scratching.

Why is it important to shear and clean affected areas in sheep?

To remove parasites and reduce the risk of further infestation or infection.

What are insect growth regulators (IGRs) used for?

To prevent the development of ectoparasites and control their populations.