Objective—To determine prevalence of resistance to
all anthelmintics that are commonly used to treat gastrointestinal
nematodes (GINs) in goats.
Procedure—On each farm, goats were assigned to 1
of 5 treatment groups: untreated controls, albendazole
(20 mg/kg [9.0 mg/lb], PO, once), ivermectin (0.4
mg/kg [0.18 mg/lb], PO, once), levamisole (12 mg/kg
[5.4 mg/lb], PO, once), or moxidectin (0.4 mg/kg, PO,
once), except on 3 farms where albendazole was
omitted. Fecal samples were collected 2 weeks after
treatment for determination of fecal egg counts
(FECs), and percentage reductions were calculated
by comparing data from anthelmintic-treated and
control groups. Nematode populations were categorized
as susceptible, suspected resistant, or resistant
by use of guidelines published by the World
Association for the Advancement of Veterinary
Results—Resistance to albendazole was found on 14
of 15 farms, and resistance to ivermectin, levamisole,
and moxidectin was found on 17, 6, and 1 of 18 farms,
respectively. Suspected resistance to levamisole and
moxidectin was found on 4 and 3 farms, respectively.
Resistance to multiple anthelmintics (albendazole and
ivermectin) was found on 14 of 15 farms and to albendazole,
ivermectin, and levamisole on 5 of 15 farms.
Mean overall FEC reduction percentages for albendazole,
ivermectin, levamisole, and moxidectin were 67,
54, 94, and 99%, respectively.
Conclusions and Clinical Relevance—Anthelmintic
resistance in GINs of goats is highly prevalent in the
southern United States. The high prevalence of resistance
to multiple anthelmintics emphasizes the need
for reexamination of nematode control practices.
(J Am Vet Med Assoc 2003;223:495–500)
Objective—To characterize clinical features of avian
vacuolar myelinopathy (AVM) in American coots.
Animals—26 AVM-affected American coots and 12
Procedures—Complete physical, neurologic, hematologic,
and plasma biochemical evaluations were
performed. Affected coots received supportive care.
All coots died or were euthanatized, and AVM status
was confirmed via histopathologic findings.
Results—3 severely affected coots were euthanatized
immediately after examination. Seventeen
affected coots were found dead within 7 days of
admission, but 5 affected coots survived > 21 days
and had signs of clinical recovery. Abnormal physical
examination findings appeared to be related to general
debilitation. Ataxia (88%), decreased withdrawal
reflexes (88%), proprioceptive deficits (81%),
decreased vent responses (69%), beak or tongue
weakness (42%), and head tremors (31%), as well as
absent pupillary light responses (46%), anisocoria
(15%), apparent blindness (4%), nystagmus (4%),
and strabismus (4%) were detected. Few gross
abnormalities were detected at necropsy, but histologically,
all AVM-affected coots had severe vacuolation
of white matter of the brain. None of the control
coots had vacuolation.
Conclusions and Clinical Relevance—Although
there was considerable variability in form and severity
of clinical neurologic abnormalities, clinical signs
common in AVM-affected birds were identified.
Clinical recovery of some AVM-affected coots can
occur when supportive care is administered. Until the
etiology is identified, caution should be exercised
when rehabilitating and releasing coots thought to be
affected by AVM. (J Am Vet Med Assoc 2002;221: