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Vultures 313

lungs. This is especially true of weak chicks. If the chick does not swallow readily, it is better to
continue injectable fluids and/or gavage feeding until it can safely be fed by mouth.

­ Common­Medical­Problems­and Solutions

Vulture chicks are exceptionally hardy and resilient. Given appropriate rearing conditions and
diet, illness is rare. Of 40 California Condor chicks artificially hatched and hand-reared over a
10-year period, during the first 30 days after hatch, morbidity was 10% and mortality was 5%. A
chick whose un-retracted yolk sac was amputated at hatch was given extensive supportive care and
successfully treated for star-gazing (opisthotonos). Another chick developed sour crop and was
also successfully treated. Six chicks that required hatching assistance were treated prophylactically
with antibiotics but were never clinically ill. One chick was euthanized due to congenital deformi-
ties and neurological problems and another due to a severely infected yolk sac.

Hatching Difficulties
Chicks that require hatching assistance are at higher risk of infection. They may have been unable
to self-hatch due to pre-existing infection, edema, or dehydration. Eggs of these large vulture spe-
cies that are assisted to hatch may have been opened to the air 3 or more days before hatching, with
the exposed extraembryonic membranes and open umbilical seal being ideal substrates for oppor-
tunistic microbial growth. It may be useful to treat such embryos prophylactically with antibiotics.
An antibiotic least likely to cause kidney damage, such as Rocephin (Roche), is given to the embryo
in ovo if an injection site is accessible or, if not, dripped onto the inner surface of the chorioallan-
toic membrane. The dosage for a California Condor embryo, which will weigh on average 183 g at
hatch, is 12.5 mg twice daily. If the chick is normal and vigorous, with a good umbilical seal at
hatching, antibiotics are discontinued. If the chick has an open seal, exposed yolk sac, or is other-
wise compromised, the antibiotics are continued until the condition resolves.

Yolk Sac Infection/Omphalophlebitis
Although unusual, the most common illness and potential cause of death in any chick is umbilical
and/or yolk sac infection. Symptoms may include diarrhea, GI stasis, redness/inflammation
around the seal, discoloration of the yolk sac visible through the skin, lethargy, and/or swelling of
the limb joints. When some or all of these symptoms are present, the prognosis is likely to be poor,
but some chicks may recover with antibiotic therapy and supportive care.
One California Condor chick whose yolk sac was completely unretracted and partially necrotic
at hatch required complete removal of the yolk sac as part of the assisted hatching procedure.
Immediately following the procedure, the chick weighed 99 g, 84 g lighter than the average hatch
weight of 183 g of a healthy California Condor chick. This chick was given frequent, fluid meals as
described above and treated with antibiotics. Within 8 days it was indistinguishable from other
chicks of the same age and was eventually released to the wild.

Edema
Edema due to insufficient egg weight loss may severely compromise the chick’s mobility initially,
particularly when the head is very edematous and difficult for the chick to lift. Although this