Work With Your Vet To Spot Chicken Diseases

By performing routine exams of your flock and individual chickens, you can help spot health problems in the flock and communicate those abnormalities to an avian vet.

by Michelle G. Hawkins
PHOTO: David Goehring

Avian veterinarians are increasingly asked to care for backyard poultry, and backyard poultry owners are more likely today to seek treatments for individual birds. Disease spreads quickly through flocks, so it’s important for you notice abnormalities in your chickens. By observing your chicken’s behavior, as well as performing routine physical examinations on individual birds, you can potentially prevent the spread of disease and help your veterinarian target the appropriate diagnosis and care for the problem.

Get Into The Exam Routine

Routine physical exams of your chickens can help you understand their normal behaviors and identify problems more easily. First, look at your chicken’s appearance and behavior from a distance. A healthy bird is bright, alert, responsive to the environment and interacting with the flock. It will have a healthy appetite and be producing eggs consistently if still within its production period. Abnormal behaviors you might look for include voluntary separation from other birds, reluctance to move, lameness, or decreased water or food intake. Fluffed or ruffled plumage, depression, loss of appetite, and a hunched appearance can also be causes for concern. If you observe any of these signs, it’s worth taking your chicken to see an avian vet.

Next, examine your chicken’s droppings or the litter from the flock, as this can also help you identify signs of illness. Diarrhea is a common problem caused by many infectious diseases, including bacterial and viral infections and parasites. Any trace of blood is also problematic.

As you move onto examining the individual birds, take care to perform the exam the same way every time to ensure you don’t miss subtle changes. For example, I always start at the head and work my way down.

  • The bird should hold its head high and symmetrically; “wry neck” can be caused by trauma and local infections involving the middle ear.
  • The comb should be red, upright and free of scabs.
  • The head should be free of swelling; asymmetric swelling around the eyes can occur from sinus infections and trauma.
  • The eyes should not be cloudy and should be free of discharge. Blue-to-gray discoloration of the iris in birds younger than 14 weeks of age is associated with Marek’s disease virus.
  • The nostrils should be clear and free of any discharge, crust and scratches.
  • The beak should be smooth and free of cracks, and the tips should come to a point. Suspicion of trauma should be raised if there are scratches or cracks in the beak.

Evaluate the oral cavity for discharge, masses and plaques. Common diseases associated with oral plaques include yeast, poxvirus, trichomoniasis and vitamin-A deficiency. A pendulous crop is generally due to loss of muscle tone and delayed crop emptying, often following an impacted crop or after gorging following a period of starvation.

By looking at the feathers you may see signs of parasites, molt or feather-picking. The feathers should lay flat against the body and be well-preened. Lift up the feathers and check the base of the feather shafts, which should be clear and free from parasites. Lice may lay their eggs at the base of the feather shaft, appearing as white clumps. The feathers in the tail and vent region should also be clean and free from any fecal material as white build-up or pasty vents may be indicative of intestinal disease. Inspect the preen gland (at the base of the tail feathers) for masses, abscesses or impactions.

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Body Condition Scoring

A chicken’s body condition score is determined using the pectoral muscles. If the breastbone is easily palpated, it is indicative of chronic weight loss. Feel around the keel, a bone in the sternum area, for any wave abnormality. Ulcerations or scabs on the breast can mean the chicken has been down for a period of time.

Extend the wings gently and look for swelling or lacerations, and feel around for fractures and other possible injuries. The chicken shouldn’t show signs of pain when you do this.

Examine the legs, feeling for bony deformities. The scales on the feet and legs should be smooth and closely adhered to each other. Upturned scales may be the result of a scaly leg mite infestation.

The bottoms of the feet should also be free from scratches, swelling, scabs or ulcerations. Bumblefoot, or pododermatitis, is a very common problem in backyard poultry, most commonly caused by Staphylococccus aureus, which can also cause arthritis. Both conditions are common in poultry raised on wet litter or rough wire surfaces. Infection can involve the footpads, joints and tendons if severe. Systemic infections can cause acute joint swellings.

Reproductive problems are very common in backyard poultry, and reductions in egg laying are the most common reason to take your chicken to see a veterinarian. Sometimes other problems are not recognized in the flock until egg production is influenced. Conditions frequently seen include infections or cancer of the oviduct (uterus), impaction, internal laying and egg binding.

Important causes of drops in egg production include dietary and infectious diseases. Birds on commercially prepared feeds are less likely to succumb to nutrition-related diseases. Some birds may be “false layers,” showing the characteristics of egg production, but lay no actual eggs. “False layers” or abnormal egg production can result from prior infection with infectious bronchitis virus. Oviduct infections can also occur from prior respiratory disease, such as with E. coli.

A full neurological evaluation is warranted when any neurologic signs are evident: Wobbly or stilted gait and paralysis are commonly seen with Marek’s disease virus and trauma. Important causes of central neurological signs include many bacterial, fungal, viral and parasitic diseases as well as nutritional deficiencies (thiamine, vitamin E) and intoxications (botulism, lead or other heavy metal toxicosis and mycotoxicosis).

What To Expect At The Vet

When you take a chicken to a vet, it’s helpful for your veterinarian to have a thorough history of its care. Also be prepared to answer specific questions, such as:

  • What is the vaccination status of the flock, especially for Marek’s disease virus?
  • Is the chicken considered a pet, a source of food or both?
  • If the chicken is a source of eggs, has there been a drop in egg production? Any change in external or internal quality of the eggs?
  • Is the flock open or closed (e.g., exposed to other poultry from bird shows, etc.)?
  • Do caretakers have outside contact with other poultry that could serve as a source of disease?
  • What is the type of food and water source?
  • What is the type of housing? Coop size, cage materials, perches, location of the coop on the property?
  • What are the sanitation protocols?
  • Have there been any other vet evaluations?
  • Have there been any treatments administered for the problem?

I use a detailed history sheet for owners to complete to help get a complete picture of the chicken’s care. Often the answers to these questions help us target the exact problem the chicken is experiencing.

Breed, age, gender and reproductive status information also help focus the physical examination. For example, the age of the hen that has recently stopped laying may help your veterinarian assess whether whether she’s “spent” or has an underlying reproductive disease.

Your veterinarian will evaluate the respiratory rate before handling the chicken. Is the bird open-beak breathing? What is the color of the comb before and after handling? Important causes of respiratory disease in backyard fowl include fowl cholera, mycoplasmosis and infectious laryngo-tracheitis, but many infectious diseases can cause respiratory signs.

We use a good-quality scale to obtain a body weight immediately after restraining the chicken. In the clinic, if the bird is critically ill, having the body weight allows for early fluid and medication calculations that might be administered immediately after the physical examination. Hydration can be subjectively assessed by tenting the upper eyelid and rolling the skin over the keel. If the chicken is dehydrated, the eyelid might not fall back quickly into place, and the skin over the keel may stick.

After Your Vet Visit

Once the bird is released from the examination, evaluate the length and character of recovery. Birds should race back into the flock within one to two minutes after release from restraint.

Routine examinations of the individuals and the flock can help pinpoint early issues and help your veterinarian target specific problems. Once you have performed these examinations a few times, you’ll be able to pick out subtle differences in your flock that may help you make early decisions as to whether you need to seek out the advice of your avian veterinarian.

This article first ran in the November/December 2015 issue of Chickens magazine.

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