Abstract
T he evaluation and monitoring ~ of avian chicks are of utmost ': importance to the success of i any psittacine breeding program. This ~ article is intended to provide some ~ basic guidelines.Evaluating Newly Hatched Chicks State of Hydration
New chicks may appear shriveled, hut should hecome well hydrated within the first day. Having a source of humidity in the incuhator will aid in the normal hydration of the chick. As the chick ages, other signs of dehydration would include dark colored, leathery skin, small dark intestinal loops seen in the ahdominal window, and increased urates around the cloaca. If hydration is a prohlem, the environment as well as the chick should he evaluated further. Suhcutaneous fluids may he necessary.
Umbilical Seal
Should the yolk sac not he completely absorbed into the body and sealed over with skin, it is possible to suture this area closed. Great care should he taken not to rupture the yolk sac heneath the skin.
If the umbilicus does not have yolk or excess flesh protruding from it, hut does not appear to be adequately sealed, skin glue such as Nexiband can be used to seal it. Be careful that the glue does not drip down over the cloaca. As the chick progresses, the size of the umbilical scab should decrease in size and eventually fall off between one to two weeks of age. Abdominal Window
One should he able to clearly delineate the margins of the yolk sac. It can vary in color from pale green to brilliant yellow. Not heing able to see this may alert the observer to a possible ruptured yolk sac.
The margins of the liver should he evaluated for any signs of subcapsular hemorrhages due to hatching trauma. If it is not thought to he due to hatching trauma, screening for bacterial pathogens and supplements of vitamin K may he beneficial, As the chick ages the liver should grow in proportion to the chick. A disproportionately large liver could he indicative of a bacterial infection.
If the enlargement is accompanied by paling in color it could indicate early liver malfunction. This condition is referred to as fatty liver. Possible causes of this are thought to be dietary and hacterial. Early detection and appropriate therapy with antibiotics and a reduction of fat in the diet can be successful. Older chicks with liver enlargement tend to present with respiratory distress and ascites attributed to the enlarged liver compromising the function of the air sacs.
Yolk Sac Digestion
In the normal chick the yolk sac should decrease in size over the first three to five days. To encourage utilization of the yolk, the chicks should he fed dilute formula for the first three days. If the yolk is still large after five days, it is important to culture the chick's cloaca to screen for bacteria and continue on the dilute formula for a few more days.
General Body Conformation Examine the chick for a straight spine, no limh deformities, and patency of ears.
Specific Problems of Pediatric Avian Patients
Bacterial Infections
One of the earliest indications of a hacterial infection in chicks is erratic digestion. Other common signs are enlarged livers and signs of dehydration. If the chick is examined daily, it is much easier to detect suhtle changes that would lead one to suspect a bacterial infection. If a hacterial infection is suspected, the chick's crop and cloaca hath should be cultured. The crop culture gives a good indication of the cleanliness of the formula, syringes and utensils. The cloaca! culture is more indicative of the gastrointestinal tract of the patient.
Chicks that are sick and dehydrated usually are given subcutaneous fluids with the antibiotic for the first two to three days, and then switched to oral antibiotics when hydration and digestion have improved. An antifungal agent such as Nystatin or Itraconazole is often used in conjunction with antibiotic therapy. This is done to hopefully prevent fungal (mainly yeast) overgrowth as the crop's flora is affected by the antibiotic.