Ducks may become very ill with few symptoms, so it is important to watch closely for everything from listlessness and ruffled feathers to diarrhea and lack of coordination. If you think your duck may be ill, separate her from other birds immediately and consult your veterinarian; many duck illnesses may be fatal within 24 hours.
Recognizing Healthy Ducks
Getting to know your duck's usual appearance and behavior will help you recognize the subtle signs of illness. Healthy ducks should have bright eyes, smooth and glossy feathers, no discharge from the eyes or nose, and a clear vent or cloaca.
Behaviorally, your duck should have a strong appetite and should spend time preening, bathing, foraging, drinking and sleeping each day. Ducks have individual personalities, so watching to see if each duck is typically friendly, active, vocal, shy or hesitant will allow you to know right away if something changes. Young ducklings are particularly susceptible to illness, so it is important to watch them very closely.
Various viral and bacterial infections can affect domestic ducks. Discharge from the eyes, nose or mouth, sneezing, sluggishness, diarrhea, weight loss, ruffled or dull feathers, loss of appetite, a drop in egg production, tremors, shaking of the head, drooping of the neck or wings, and presence of blood are indicators that a duck has an illness. Some of the most common diseases in ducks include duck virus hepatitis, duck plague, avian cholera and avian influenza.
Duck virus hepatitis causes spasms in the legs, can quickly lead to death, and typically affects ducklings under 3 weeks old.
Duck plague, also known as duck viral enteritis, causes lethargy, sudden drop in egg production, greenish-yellow diarrhea and blood in the nostrils. This condition is most common in mature ducks, but it can affect ducklings.
Avian cholera causes discharge from the mouth, loss of appetite and diarrhea. In larger ducks it may also lead to difficulty breathing.
Avian influenza may be carried without symptoms and spread to other birds. When symptoms do occur, they can include coughing, sneezing, discoloration of the legs, swelling of the head, drop in egg production, diarrhea or sudden death with no other symptoms.
Pasty vent is a symptom common to newly hatched ducklings that can be caused by a number of illnesses. A frothy, sticky diarrhea will cover the cloaca, effectively pasting it closed. This is a symptom of a serious infection passed on from the mother; it requires immediate veterinary care.
Catching Fungal Infections
When duck bedding or feed stays moist, it's a breeding ground for fungi. Ducks who inhale the spores of Aspergillus genus fungi species may develop aspergillosis, a condition that may cause lethargy, trouble breathing, gasping or dehydration. Ducklings are at a higher risk for developing aspergillosis, but you can help prevent it by regularly changing your duck's feed and bedding, especially if it becomes damp.
Noticing Physical Problems
Injury and other physical problems can significant threaten a domestic duck's health. Watch for signs of blood, limping, closed eyes or drooping wings to catch some of the most common of these conditions.
Leg injuries are relatively common in ducks. Predators and people may grab a duck's leg and cause serious damage. Niacin deficiencies in ducklings and excessive calcium in maturing birds can make them particularly susceptible to this type of injury.
Bumblefoot is a condition where the bottoms of a duck's feet become cracked and possibly infected. It is clearly identifiable by the ulcers on the duck's feet and can be reversed by covering hard surfaces with soft litter and ensuring the bedding is kept dry and clean.
Egg binding, a condition where the egg becomes trapped in the oviduct, can be dangerous to a duck. Symptoms include straining to lay, bobbing her tail and frequently sitting down. Sometimes the egg can be felt through the abdomen.
Finding Parasitic Infections
Parasites may be external, living in the skin and feathers, or internal, living in the blood or internal organs.
External parasites may cause symptoms such as itching, weight loss, slowed growth, dull feathers and in severe cases, anemia. You may be able to see certain types of external parasites on the skin.
Internal parasites, such as roundworm, grapeworm, tapeworm, coccida and capillary worm may cause symptoms including weight loss, diarrhea, weakness, head shaking, pale gums, ruffled feathers and reduced egg production. You may also see blood or worms in an affected duck's stool.