The rainy season is perfectly compatible with an increase in relative humidity and a reduction in temperature; rainfall affects both feeding quality and quantity while wind speed affects disease outbreaks

Seasonal climatic or weather changes generally affect the poultry birds and poultry production. For e.g., chickens eat more feed in the wet or cold season, drink less water and huddle together to produce heat to keep themselves warm. In the other side, in the hot season or heat, chickens and other livestock birds ingest less feed and drink more water to cool their bodies. These improvements impact bird production, most specifically laying birds, as egg production is decreased in excessively cold or hot weather conditions. This decrease in egg production occurs because these birds are stressed when there are extreme cold or hot conditions, and their ability to withstand disease or immune system is seriously affected. Some such diseases of the poultry are prevalent in the warm, humid or cold seasons, i.e
the advent of rain facilitates the proliferation and dissemination of these diseases and parasites' causative cells
Thus, during this time most poultry farmers suffer high morbidity and mortality rates
Below we will discuss some of the diseases prevalent during the rainy season

1. Fowl Pox

Fowl pox is an exceedingly infectious disease affecting poultry birds of any age. It is caused by pox virus which is often spread by mosquitoes and other blood-sucking insects. Because of the prevalence of stagnant water, the reason why fowl pox is widespread during the wet season is because mosquitoes, being the host, propagate well throughout this season. Often, where poultry houses are not sufficiently protected from rain the occurrence of wet litter becomes evident. This leads to wet liter production which then predisposes to fly problems in the pen

How to Diagnose Fowl Pox in Chickens 

You will find certain obvious signs which are evidence that your chickens or turkeys have come down with fowl pox disease. Fowl pox is responsible for the production of circular lesions with scabby centers on the birds' skin. Most skin lesions occur on the wattle, forehead, comb and others are also on the legs. Even this condition affects the lining of the mouth and windpipe. The lesions developed in the throat can grow to the point of blocking the throat, and as a result of suffocation, it may ultimately lead to death. Lesions on the face can spread to the eyes, causing the affected bird to become temporarily or permanently blind

How Chickens Eliminate Fowl pox 

Mechanical fowl pox carriers are mosquitoes. So, reducing the mosquitoes in your farm or ecosystem is advisable. Ordinary sanitation and maintenance practices are not going to eliminate this outbreak; hence prevention is always the answer. Chickens and turkeys such as breeders, egg layers and any especially susceptible to fowl pox should be vaccinated. Between age 6 and 10 weeks, live fowl pox vaccine is given in bird wing web. If violent pecking among birds is managed, the damage to the skin caused by the fowl pox is minimized

How to Treat Fowl pox in Chickens 

Unfortunately, fowl pox is untreated after a bird has been infected by the fowl pox virus. But as long as a diseased bird feeds and drinks, it can recover from the disease with low mortality rate in around two weeks or more. When a bird successfully recovers from the fowl pox it is completely resistant to the disease

2. Fowl Cholera

Fowl cholera is a bacterial disease that affects 6-week-old birds and above. Pasteurella multocida is the bacterium which is responsible for this. It is extremely infectious and, in acute cases, mortality is high. During the rainy season the causative organism is readily dispersed because the wet liter acts as a habitat for various microorganisms

How to Recognize Fowl Cholera in Chickens 

In acute cases, birds who seem healthy unexpectedly die while the infected birds display the following in chronic cases

• Diarrhea: Yellow, green or grey
• An appetite reduction
• Respiration labored
• Wings and tail feathers drooped
• Feathers Ruffled
• Swelling of leg joints, sinuses, wattle and foot pad
• Twisting of the neck (torticollis)
• Discharge from the nostril or beak

How to Treat, Prevent, and Control Fowl Cholera in Chickens 

Fowl cholera can be treated with medications such as sulfa, tetracycline, and erythromycin. Poultry birds will be vaccinated against fowl cholera by taking a cholera vaccine for fowls. Maintain good sanitation and hygiene. Follow a high biosecurity level, and avoid rodents, wild birds, and other wildlife

3. Salmonellosis, Escherichia coli, Pullorum Disease (Bacillary White Diarrhea)

These bacterial illnesses affect birds of any age. They are prevalent, as is seen when wet liters are permitted to persist for a long time, in farms or pens with poor sanitation. They affect the infected birds' digestive system

How to Recognize Salmonellosis, Escherichia coli, Pullorum in Chickens 

• Severe diarrhea
• Loss of appetite
• Depression and emaciation
• Chicks suffer omphalitis
• White pasty diarrhea in pullorum disease
• Huddling together and labored breathing

How to Treat and Eliminate Salmonella, Escherichia coli, Pullorum

Salmonellosis, E. Coli and Pullorum diseases can be treated by the application of a wide variety of antibiotics to the flock. It is important to sustain high-level farm / pen hygiene and sanitation. There should be Bio security mechanisms in operation. Stop feeding birds with feed that is dirty

4. Aspergillosis

Aspergillosis is an infection in poultry caused by Aspergillus fumigatus. Owing to the high humidity during the cold season, the feed or litter dampens, providing a suitable atmosphere for the growth and development of fungi. Aspergillus spores are often inhaled by birds and these spores evolve into lesions covering the lungs that cause breathing symptoms or discomfort. If the stocking density is high and ventilation is insufficient or low, birds under intensive management systems can exhibit elevated disease transmission

How to Recognize Aspergillosis in Chickens 

If the stocking density is high and ventilation is insufficient or low, birds under intensive management systems can exhibit elevated disease transmission

Aspergillosis may be acute or chronic in nature

• Acute form: This normally happens in young chicks and causes high morbidity and mortality. The progression is very rapid and typically occurs within a week. The majority of the birds affected will die without emergency veterinary treatment within a few days. Lethargy, nausea, lack of appetite, trouble breathing, and cyanosis (bluish / purple comb) are among the most frequent symptoms
• Chronic form: Initially, this is typically very gradual, and it can take several weeks or months to evolve. It is most prevalent in older birds, with many having a history of malnutrition, stress, concurrent disease or excessive use of antibiotics / corticosteroids. The whole phase of the disease varies in length from under 1 week to over 6 weeks

Typically, a presumptive aspergillosis diagnosis can be made based on flock history, clinical symptoms and physical examination. To have a definitive diagnosis of aspergillosis, the veterinarian would need to take several samples and send them to a testing laboratory, to validate the presence of Aspergillus in the bird

How to Prevent Aspergillosis in Chickens 

In the prevention of aspergillosis, dry, high quality litter and feeding and grooming can help. It is possible to use antimicrobials such as Thiabendazole or Nystatin in the feed

How to Treat Aspergillosis in Chickens 

Normally zero. Environmental spraying will help reduce the risk with successful antifungal antiseptic. In high-value birds, Amphotericin B and Nystatin have been used

5. Coccidiosis

Coccidiosis is caused in poultry by the protozoan Eimeria spp, the majority of species invade different intestinal locations. The infectious process is fast (4-7 days) and is characterized by replication of parasites in host cells with extensive intestinal mucosal injury. Coccidia of poultry is usually host-specific, and the multiple organisms parasitize specific areas of the intestine. Coccidia, however, can parasitize the entire intestinal tract in game birds, including quail. Coccidia is spread to chickens, game birds raised in captivity, and wild birds worldwide

Commonly found in the rainy season, the moist litter and the hot pen temperature favor the sporulation of the coccidian oocyst and hence the outbreak of coccidiosis

How to Recognize Coccidiosis in Chickens 

Bloody urine, ruffled feathers, anemia, and sleepiness are scientifically observed. Other symptoms of coccidiosis range from a lowered rate of development to a high proportion of noticeably ill birds, extreme diarrhea, and high mortality. The intake of feed and water is depressed

Outbreaks may be followed by weight loss, the growth of culls, reduced egg production, and increased mortality. Mild intestinal infections, otherwise classified as sub clinical, may cause depigmentation and potentially lead to secondary infection, particularly Clostridium spp. Extreme infection survivors heal within 10–14 days but can never recover lost results

The lesions are often always in the intestinal tract and also have a characteristic location and appearance that is helpful in diagnosis

How to Prevent Coccidiosis in Chickens 

Your first step in protection is simple grooming. It's good to usually ensure the poultry house is clean and dry

• Ensure water is clean and fresh. Keep feeding areas clean and dry
• Ensure the birds have enough space i.e. overcrowding should be prevented as it is a predisposing factor for coccidiosis. Chickens need an average of a square meter for 3-5 birds
• Provide medicated starter feed for your chicks if they have not been vaccinated against coccidiosis. The chicks should be given anticoccidial treatment at about 12 days of age (this may vary based on the vaccine schedule being followed)
• An all-in all-out approach can be used at the farm to avoid a horizontal infection shift. If this approach is not possible, for the safety of the existing stock, keep the fresh batch quarantined for a minimum of two weeks

How to Treat Coccidiosis in Chickens 

When a flock is diagnosed with coccidiosis all birds need to be treated. The litter also has to be altered so that birds do not suck up the sporulated oocyst from affected bird droppings. Popular medications are: amprolium, toltrazuril, sulfa quinoxaline, etc

How to Manage Poultry Birds Optimally in the Cold or Rainy Season

Poultry farmers have to do the following to manage poultry such as ducks, turkeys, quails, duck and pheasants during cold or rainy periods

• Add oil or fat to a bird 's diet or decrease the amount of nutrients not needed by birds to produce heat. Since birds use more feed to produce heat, this is important to minimize wastage and reduce feed production costs
• Place electric bulbs or heaters in the pen to support the birds as a secondary heat source. This will help the birds drink more water to remain warm without the reserved resources being taken up in the process
• Although very rare in an intensive system but common in a free-range system, birds drink from the contaminated water surrounding it, thus collecting eggs from parasitic species such as intestinal worms. That is why the bi-monthly deworming of poultry birds with effective dewormers such as piperazine is significant. Every month a wide spectrum antibiotic such as oxytetracycline should be given to the birds.
• Install a generous overhanging roof over the entry and sides of the pens to prevent rainwater from flooding the pen as it rains. Build a foot dip at the pen's openings, and a good disinfectant solution should always be in the foot dip
• Vaccinate birds at the right time
  
  References 

https://www.afrimash.com/common-poultry-diseases-rainy-season-signs-preventiontreatment/