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REPRODUCTIVE DISORDERS
OF THE HEN PARROT

by Dr Brett Gartrell B.V.Sc (Hons)

Reproductive problems hit breeders where it hurts most, right in the breeding hen. There is nothing more frustrating than losing a good bird when it's breeding. The following article describes some of the more common problems and some things you can do to help.

EGG BINDING

The failure of an egg to pass through the oviduct at a normal rate.

Causes of egg binding include:-

  • oviduct muscle dysfunction due to nutritional deficiencies, especially calcium, vtamin E and selenium
  • malformed eggs
  • excessive egg production which can exhaust the birds reserves of calcium, vitamins and energy
  • previous reproductive tract damage or infection which may lead to scarring and adhesions to other organs
  • obesity which is unfortunately a very common problem
  • lack of exercise, which leads to poor muscle strength
  • senility. Older birds are more likely to become egg bound
  • other stress factors, including severe temperature changes, disease or overcrowding

Signs a bird can show include:-

  • depression
  • reluctance to fly or perch
  • persistent tail wagging or straining
  • a wide based stance ("penguin stance")
  • a hard swollen abdomen
  • and if severe a leg weakness or paralysis.

Many of the complications of egg binding can lead to the death of the bird.

Treatment involves first and foremost stabilising the patient. Make no attempts at delivering the egg until the bird is stable.

If only minimal depression is present then provide supplemental heat (28-31C) with easy access to food and water. Cropping the bird with oral calcium, vitamin D and energy supplements can be useful. Lubricate the vent (KY jelly or Vaseline are useful). Wait at least 20 minutes for the bird to pass her egg on her own before intervening.

If the hen stays stable but does not pass the egg then a short attempt at gentle manipulation of the egg can be attempted. Don't press directly down onto the egg. This will push the hard shell against the fragile kidneys, adrenal glands and ovary, which can cause death or bruising of the kidneys resulting in a leg paralysis.

Pressure can be applied to each side of the egg downwards, towards the vent. If there is not immediate success, stop. Put the bird back into the heat and wait another 15 to 20 minutes.

This process can be repeated a number of times while the bird is not severely depressed. If still no success consider veterinary help, either by phone or preferably bring the bird to us before she is too unstable.

If the hen shows signs of severe depression then immediate veterinary treatment is recommended. We can provide the hen with antibiotics, intravenous fluids, hormones (oxytocin) which promote uterine contractions, steroids and injectable calcium and energy supplements. If necessary we can collapse the egg after draining its contents (ovocentesis) or open the uterus under a general anaesthetic and remove the egg.

Complications - these are the things that can go wrong when you finally get the egg out and think you're in the clear. Murphy's Law !!

  • more eggs produced. - this can cause repeated egg binding (always more serious than the first)
  • egg impaction
  • peritonitis (infection in the abdominal cavity)
  • oviduct and uterine infection
  • ruptured oviduct, permanent damage to oviduct
  • abdominal hernia which is a rupture of the abdominal muscles making egg laying almost impossible - can be surgically repaired with varying degrees of success
  • prolapses of the oviduct and cloaca
  • hypocalcaemia - drainage of the bird's calcium reserves can lead to a problem of muscle weakness and inability to fly or even stand. Oral calcium supplements over a week to ten days can pull many of these birds through
  • paralysis and weakness can also be due to kidney damage or infection - the sciatic nerve in birds runs through the middle of the kidneys and any swelling here can cause weakness or paralysis
  • secondary infection. The stressed bird's immune system is compromised and secondary bacterial infections or resurgent chlamydiosis can occur
  • any, some or all of these can lead to DEATH.

PROLAPSE OF THE OVIDUCT AND UTERUS

An extrusion of the interior cloaca and uterus to the exterior and has the appearance of a red inflamed mass of soft tissue at the vent.

It can occur following normal egg laying but is especially common after an episode of egg binding. It is more likely to occur in birds that are in poor physical condition (eg muscle weakness, obesity or malnutrition). More likely with malformed, soft or shell-less eggs.

Treatment:-

  • keep exposed tissues moist and clean with copious amounts of saline solution or a very dilute iodine (Betadine / PVP-Iodine) or chlorhexidine solution (Aviclens or Hibiclens)
  • if no egg is present and tissue is not badly damaged then gently replace the prolapsed tissue by pushing it back in place with a moistened swab or cotton bud
  • can and often does recur, however if treated early have a good chance at complete repair
  • attempt to switch off the birds breeding cycle (see under Chronic Egg Laying)
  • veterinary assistance is recommended if; its a valuable bird, an egg is caught in prolapsed tissue, keeps on prolapsing or if there is significant tissue damage. There are surgeries which can assist even the most longstanding prolapses
  • also seek help if the bird shows signs of moderate to severe depression. Uterine infections are common following prolapses

INFECTIONS OF THE OVIDUCT AND UTERUS

Can be associated with general systemic infections or can occur on their own. Infectious agents include bacteria, chlamydia, mycoplasmas and fungi.

Factors which make infections more likely include:

  • egg impaction in the uterus
  • egg related peritonitis
  • excess abdominal fat
  • more common in older hens

Signs of these infections are very general and non-specific. They include; depression, anorexia, weight loss and abdominal enlargement. Occasionally a cloacal discharge will seen (smelly ooze from the vent).

Birds can produce eggs through an infection but quite commonly these eggs will be misshapen with a rough sludgy appearance to the egg shell. Normally as the shell forms the egg is rolled smoothly in the shell gland. Where there is infection the motion will be jerky and the shell rough.

Dead in shell can be as a result of uterine infections in the hen, as can the weakness and deaths of chicks after hatching.

Treatment of uterine infections is based around antibiotics. Identifying the bacteria and the correct antibiotic by cultures is worthwhile in valuable birds.

In severe cases uterine flushing can be helpful and to salvage the bird, a hysterectomy can be performed. This puts an end to a bird's breeding career but can save its life.

Complications include:-

  • egg binding
  • egg impaction
  • uterine rupture
  • peritonitis
  • septicaemia (systemic infection which can be rapidly fatal. In as little as 1-2 hours infection can spread to all body organs)

OVIDUCT IMPACTION

The binding up in the uterus of successive eggs, egg yolk material and where infection occurs also pus material.

This problem usually occurs secondary to egg binding or uterine infection.

Signs include;

  • a stop in egg production
  • progressive loss of condition
  • alternations between diarrhoea and constipation
  • abdominal enlargement
  • a reluctance to fly or walk

Treatment is limited to surgery. Attempts can be made to salvage the uterus, but most cases have severe scarring and adhesions. The birds may be saved by a hysterectomy but have no breeding future.

OOPHORITIS

Inflammation or infection of the ovary which is usually secondary to systemic disease.

Signs are difficult to distinguish from any other systemic disease including:-

  • depression
  • anorexia
  • wasting and death (most cases are diagnosed by post mortem)

Treatment is the same for any severe systemic disease and involves supportive care with warmth, fluids and nutrition. Antibiotics are useful in cases of bacterial infection.

CLOACAL PROBLEMS

Any problem in the cloaca can cause obstructions to egg laying (eg. infections, scarring, faecal stones or chronic prolapses) or to mating (e.g. dense vent feathering, abdominal fat, papillomas or warts especially those due to vitamin A deficiency).

ECTOPIC EGGS (NON-SEPTIC EGG PERITONITIS)

Eggs not taken up by the oviduct and instead are deposited into the abdomen. Can also be caused by rupture of the oviduct and is more likely to occur if hens are restrained or stressed during ovulation.

Results in yolk material spreading through the air sacs and over the abdominal organs which causes a mild inflammatory reaction. If no bacteria is present, all yolk material will be reabsorbed.

Signs are:-

  • abdominal swelling
  • wide based stance
  • weight loss

Treatment is mainly supportive, but antibiotics are used in case of septic peritonitis.

If the signs are severe then surgery to remove yolk material.

Attempt to switch off laying cycle. Manipulating the amount of light the bird gets can be successful. We recommend the hen be removed from its cage and sight and sound of its mate, then covered except for four hours of light for four days. If this is not successful hormonal injections can be used but there is a risk of significant side effects including depression, increased urine production, weight gain, liver damage, suppression of the immune system and diabetes.

SEPTIC EGG RELATED PERITONITIS

Yolk peritonitis that is contaminated with bacteria and causes a severe inflammatory reaction throughout the abdomen. It is more common than non-septic peritonitis.

Causes congestion, scarring and adhesions of all abdominal organs.

Signs:-

  • can simply be sudden death
  • see abdominal swelling
  • respiratory distress
  • depression
  • anorexia
  • cessation of egg laying

Can be complicated by diabetes, strokes, intestinal obstruction and hepatitis.

Treatment initially involves supportive care to stabilise the bird. Heat, fluids and antibiotics should be given as well as the provision of high protein foods.

Surgery is helpful in valuable birds to remove pus and infected yolk material. In pet birds we generally perform a hysterectomy at the same time which prevents the disease recurring.

Any episode of this puts the birds breeding future in doubt as there is always scarring and adhesions and there can be severe uterine damage.

CHRONIC EGG LAYING

Laying beyond the normal clutch size or repeated clutches in the absence of a mate or breeding season.

Especially common in hand raised hens which have imprinted onto humans.

Signs other than the number of eggs are limited to loss of condition.

Eventually malnutrition from pouring all her resources into egg production will result in abnormal eggs or egg binding due to uterine muscle dysfunction and general muscle weakness.

Treatment revolves around trying to switch off the laying cycle. Involves:-

  • light manipulation (see under Ectopic Eggs)
  • removing any objects the bird considers as potential mates
  • removing nest boxes and nesting materials
  • and change of cage
  • If the bird is sexually oriented to humans then decreasing the amount of time spent with the bird can be helpful

In some particularly determined hens all this will fail and it may be necessary to use hormonal injections. (See under Ectopic Eggs for side effects that can occur with hormonal injections.) Injections will work for a period that can vary from as little as two weeks to up to six months.

In some hens the only solution is hysterectomy.

OVER PRODUCTION

The maximum safe levels for production have not been determined in parrots. In the wild greater than two clutches per year is abnormal but this is quite often limited by feed availability. Can breed some parrots in captivity (eg Macaws, Cockatoos, and Eclectus) up to four clutches a year with no apparent side effects.

Prolonged laying, hatching and rearing puts stresses on a bird. If birds are kept in optimal conditions they seem to be able to keep on breeding. These birds are however on a knife edge. If anything is wrong with management or diet then the birds will not be able to cope. Diseases which are usually secondary problems can become major concerns, eg Chlamydia and Megabacteria (Otherwise known as Birdkeeper’s Bogeymen).

While no absolute recommendations can be made, it is best for the bird owners not to become greedy and push them for large numbers of clutches. Allow the birds a rest period each year.

ABNORMAL EGGS

An odd abnormal egg is not a concern and it is quite common for hens to throw different shaped eggs with no problems.

However a run of soft-shelled, rough shelled or infertile eggs indicates a potential problem.

Causes :-

  • dietary insufficiency (esp. vitamins A, D3 & calcium)
  • uterine infections - suspect if eggs are rough shelled or sludgy in appearance
  • organochlorines (DDT) produce thin-shelled, fragile eggs - this is a continuing problem with birds of prey in the wild but be careful what you use around your birds
  • ovary disease - will produce yolkless, small yolked or infertile eggs
  • environmental toxins. There are many toxins that can affect the hen resulting in lowered egg production, early embryo death or weak chicks. Some common examples include: crude oil, exhaust fumes, NICOTINE, organochlorines and antibiotics containing furazolidone

KEEPING HENS IN GOOD CONDITION FOR BREEDING

  1. ENSURE THE DIET IS ADEQUATE OR EXCELLENT (refer to Dr. Adrian Gallagher's excellent and award winning notes on avian nutrition.)
  2. KEEP BIRDS LEAN. (This doesn't mean malnourished !!) Obesity is a common predisposing cause to many of these reproductive problems. Don't feed protein supplements in the off season. Allow the birds access to flight cages in off season.
  3. FLUSHING increase protein levels as breeding season commences. This simulates flush of feed in wild which is usually tied in to breeding season. Can improve fertility of male and female, increase sexual activity and ovulation rates.
  4. MINIMAL HANDLING BUT CLOSE ATTENTION for early detection of problems.

IF YOU'RE UNSURE WHETHER OR NOT YOU HAVE A PROBLEM - assume you do and ring us for advice. 

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