The Buzzkill (Flies)

More Than a Nuisance: The Disease-Carrying Dangers of Flies

Welcome to the buzzing epicenter of summertime woes, where the uninvited guests are tiny, winged, and have a knack for turning serenity into chaos. Yes, we’re about flies—the relentless party crashers in your barns, pastures, and pet hangouts. Picture this: your dog doing an impromptu dance trying to snap at a pesky fly, or your prized cow/horse swishing her tail like she's auditioning for a spot in a rodeo, in an attempt to ward off a swarm. Flies are not just a minor inconvenience; they’re the airborne villains of the animal kingdom, bringing irritation and potential health risks wherever they go.Yes, flies in pets and livestock can be a real buzzkill.

Flies are more than just an annoying presence in barns and homes; they can pose serious health risks to pets and livestock. These pests can spread diseases, cause stress, and lead to various health issues in animals. Understanding the impact of flies and implementing effective control measures is crucial for maintaining the well-being of pets and livestock.

What are flies?

Flies are winged insects, they belong to the order Diptera a Greek word which means 2 wings. They're tagged as true flies and are parasitic either as adults or larvae. Adult flies have 2 pairs of wings (membranous fore-wings and a reduced club-loke structure called halters/balancers) and feed on blood, sweat, skin secretions, tears, saliva, urine or faeces of domestic animals.

The most important flies to pets and livestock production are the biting flies as their blood-feeding activities cause anaemia and may provoke hypersensitive reactions. they act as biological and mechanical vectors for a range of pathogenic diseases.

Flies are a nuisance as they cause fly-worry (i.e.) disturbance caused due to their presence and attempted feeding behaviour resulting in a stampeeed, reduced feed intake and weight loss, stress and discomfort.

Common Flie

Two major types of flies are

• Biting Flies 

These flies feed on blood from their infested animal hosts. E.gs. are

1. Stable Fly (Stomoxys calcitrans): Grey in colour with 4 longitudinal dark stripes on the thorax. Known for their painful bites (one of the most annoying flies in cattle, horses, sheep and goats), stable flies can reduce milk production in dairy cattle, anaemia, decreased weight gain in beef cattle and transmit Surra among horses.
2. Horse Fly (Tabanidae family): A large fly, with clear wings. Frequently brown with longitudinal stripes on the abdomen. These flies deliver painful bites and can transmit diseases like equine infectious anaemia.
3. Deer Fly (Chrysops spp.): Wings are speckled or dark-banded (a single, broad, dark-stripe and spotted eye)Similar to horse flies, deer flies bite and can transmit diseases such as tularemia.
4. Sheep Ked (Melophagus ovinus): Although not technically a fly, this wingless fly-like insect feeds on sheep blood and causes irritation and wool damage.
5. Black Fly (Simuliidae family): Dark/light-coloured flies with a hump-back appearance. Have painful bites that may cause allergic reactions and act as a vector of various diseases like onchocerciasis.
6. Mosquitoes: Small, slender flies with long legs. An important vector of malaria (Plasmodium spp), Filarial nematodes and viruses.
7. Biting midges (Culicoides spp): Small flies with thorax humped over a small head with mottled wings. An important vector of over 50 arboviruses. Causes sweet itch in horses due to its linked immediate type hypersensitive reactions.
8. Horn Fly (Haematobia irritans): Grey-black flies that tend to cluster around the horns or poll regions. Particularly troublesome for cattle, horn flies cause irritation and blood loss, leading to decreased weight gain and milk production. They transmit the skin filariod of cattle (Stephanofilaria).
9. Tsetse Fly (Glosssina spp): Narrow-bodied flies, yellow to dark brown in colour having a hatchet cell in the wing. Have painful bites and transmit animal and human trypanosomosis.

• Non-biting Flies 

feed on sweat, skin secretions, tears, saliva, urine or faeces of domestic animals.

1. House Fly (Musca domestica): Vary in colour from light to dark grey with the abdomen having a yellowish-brown background with a black median longitudinal stripe. Common around stables and homes, they can spread bacteria and viruses.
2. Face Fly (Musca autumnalis): Common around the eyes and nose of cattle, face flies can spread pinkeye (infectious bovine keratoconjunctivitis).
3. Bot Fly (Oestridae family): Grey flies, have small black spots on the abdomen covered with short brown hairs. Bot flies lay eggs on the skin of animals, and the larvae burrow into the skin or body cavities, causing irritation and potentially serious health issues.
4. Sand Fly (Phlebotominae subfamily): Have a hairy body appearance, large black eyes and long slit-like legs. Known for transmitting Leishmaniasis, these tiny flies can be a significant health concern in certain regions.

Health Implications

Flies can cause a range of health issues in pets and livestock, including:

• Disease Transmission: Flies can spread bacterial, viral, and parasitic diseases. For example, house flies can transmit Salmonella and E. coli, while horse flies can spread equine infectious anaemia.
• Stress and Discomfort: Persistent fly bites cause stress and discomfort, leading to reduced feed intake and growth rates in livestock.
• Allergic Reactions: Some animals may have allergic reactions to fly bites, resulting in severe itching, swelling, and skin lesions.
• Secondary Infections: Open wounds from fly bites can become infected, leading to further health complications.

Zoonotic importance

Flies play a significant role in the transmission of zoonotic diseases, which can affect both pets and livestock, posing a threat to human health. These insects act as vectors, carrying and spreading various pathogens that can cause serious illnesses. For instance, house flies and stable flies can transmit diseases such as Salmonella, E. coli, and parasitic worms, which are harmful to humans when they come into contact with contaminated food or surfaces. Additionally, face flies are known to spread pinkeye (infectious bovine keratoconjunctivitis) in cattle, which, although primarily an animal health issue, can have indirect zoonotic implications through reduced productivity and increased use of antibiotics, potentially contributing to antibiotic resistance.

In the context of pets, flies contribute to the spread of zoonotic diseases by facilitating the transmission of pathogens through their bites and by contaminating surfaces that pets come into contact with. Pets that are constantly harassed by flies may develop open sores and skin infections, which can become breeding grounds for bacteria and parasites transmissible to humans. Effective fly control measures are essential to mitigate these risks, protect animal health, and ensure the safety of humans interacting with both livestock and pets. Implementing integrated pest management strategies can help reduce the incidence of zoonotic diseases and promote overall public health.

Prevention and Control Strategies

Effective fly control requires a multi-faceted approach. Here are some strategies to keep flies at bay:

Environmental Management:

• Sanitation: Regularly clean and dispose of manure, bedding, and other organic waste to eliminate breeding grounds for flies.
• Proper Waste Management: Use covered bins and compost piles to reduce fly attraction.
• Drainage: Ensure proper drainage to prevent standing water, which serves as a breeding site for many fly species.

Physical Barriers:

• Fly Screens: Install screens on windows and doors to keep flies out of barns and homes.
• Fly Traps: Use sticky traps and baited traps to reduce fly populations.

Biological Control:

• Predatory Insects: Introduce natural predators, such as parasitic wasps, which lay eggs in fly pupae, reducing fly numbers.
• Beneficial Nematodes: These microscopic worms can be applied to soil to kill fly larvae.

Chemical Control:

• Insecticides: Use fly sprays, pour-ons, and insecticidal ear tags for livestock, following veterinary guidance to ensure safety and effectiveness.
• Larvicides: Apply larvicides to manure and other breeding sites to kill fly larvae before they mature.

Animal Hygiene:

• Regular Grooming: Keep pets clean and groomed to reduce fly attraction and detect any issues early.
• Protective Gear: Use fly masks and blankets for horses and other livestock to protect sensitive areas from bites.

Summary

Flies are more than just a nuisance for pets and livestock; they can pose significant health risks and impact animal well-being and productivity. These pests, including stable flies, house flies, and blowflies, often thrive in environments where animals are kept, feeding on waste and organic matter. Flies can cause direct harm through painful bites, irritation, and the transmission of various pathogens leading to diseases such as pinkeye in cattle and flystrike in sheep. Effective fly control involves maintaining clean living conditions, using fly repellents, and implementing biological control methods to minimize their presence and protect the health of pets and livestock.

Check out previous post - A Lousy Situation (Lice)