Dogs were the first animal to become domesticated by humans, and they represent a classic model system for unraveling the processes of domestication. We compare Australian dingo eye contact and ...socialization with Basenji and German Shepherd dog (GSD) breeds. Australian dingoes arrived in Australia 5,000-8,000 B P, and there is debate whether they were domesticated before their arrival. The Basenji represents a primitive breed that diverged from the remaining breeds early in the domestication process, while GSDs are a breed dog selected from existing domestic dogs in the late 1800s. We conducted a 4-phase study with unfamiliar and familiar investigators either sitting passively or actively calling each canid. We found 75% of dingoes made eye contact in each phase. In contrast, 86% of Basenjis and 96% of GSDs made eye contact. Dingoes also exhibited shorter eye-gaze duration than breed dogs and did not respond to their name being called actively. Sociability, quantified as a canid coming within 1 m of the experimenter, was lowest for dingoes and highest for GSDs. For sociability duration, dingoes spent less time within 1 m of the experimenter than either breed dog. When compared with previous studies, these data show that the dingo is behaviorally intermediate between wild wolves and Basenji dogs and suggest that it was not domesticated before it arrived in Australia. However, it remains possible that the accumulation of mutations since colonization has obscured historical behaviors, and dingoes now exist in a feralized retamed cycle. Additional morphological and genetic data are required to resolve this conundrum.
A 4-year-old Basenji with glycosuria was brought to our hospital. Blood glucose was normal, but aciduria and metabolic acidosis were found; we diagnosed the dog as suffering from a specific ...hereditary disease, Fanconi syndrome, which was established later by genetic tests. Bicarbonate treatment was started and continued according to Gonto's management protocol of Fanconi disease. The dog's physical condition has been good since then, although mild metabolic acidosis and hypophosphatemia are still present.
Despite its popularity among pet owners and professional trainers, we are not aware of any studies that have investigated the efficacy of clicker training in canines. To this end, we taught 35 ...basenjis to nose-touch an orange traffic cone. Upon meeting pre-determined criteria, dogs progressed through: (1) training trials, wherein correct responses were followed immediately with a click plus food (clicker group) or food alone (control group); (2) strengthening trials, wherein dogs received the same reinforcement protocol as in training trials, except nose-touching behaviour was variably reinforced; and (3) extinction trials, wherein food was withheld from both groups, but dogs in the clicker group received a click alone for nose-touches. We found that the clicker and control groups did not differ with regard to the number of trials or the time required to meet training or strengthening criteria (
P
>
0.05 for all). However, the clicker group required significantly more trials (log
10 transformed means
±
S.E.
=
1.6
±
0.03 trials versus 1.4
±
0.03 trials,
P
<
0.001) and more time (log
10 transformed means
±
S.E.
=
2.85
±
0.03
s versus 2.73
±
0.03
s,
P
=
0.008) to reach extinction criterion. Additionally, younger dogs required fewer training (
η
p
2
=
0.304
,
P
=
0.001) and strengthening (
η
p
2
=
0.140
,
P
=
0.029) trials and less training (
η
p
2
=
0.221
,
P
=
0.005) and strengthening (
η
p
2
=
0.180
,
P
=
0.013) time to meet criteria than did older dogs. However, no age effect was found on extinction for either the number or duration of trials (
P
>
0.05 for both), implying that persistence in previously reinforced behaviour did not influence the age sensitivity found in task acquisition. Overall, these results suggest that, whereas the clicker may prolong behaviour without primary reinforcement, it does not reduce the training time of a simple operant task in dogs when primary reinforcement is briefly delayed. We speculate that the clicker may be most useful in maintaining established behaviours when primary reinforcement is unavailable or when its delivery is impractical. Additionally, we found that basenji dogs may become progressively impaired with age in the acquisition of stimulus-reward contingencies.
Objective To determine the thyroid status of Basenji dogs in Australia.
Methods Jugular or cephalic venipuncture blood samples were taken from 113 Basenji, comprising 47 males, 5 castrates, 48 ...entire and 13 spayed bitches, and sent on ice in plain and EDTA tubes to a single laboratory to determine haematocrit and serum concentrations of total thyroid hormone (thyroxine, TT4), thyroid‐stimulating hormone (TSH) and cholesterol. In a subgroup of 8 dogs with abnormal elevated TSH concentrations and subnormal TT4 concentrations, 5 were further examined by dynamic endocrine testing using recombinant human (rh) TSH (54 µg).
Results Ages ranged from 1 to 14 years and weight range was 6.5 to 14.0 kg. TT4 concentrations (nmol/L) ranged from 2 to 27, with a median of 13 and a mean ± SD of 13.0 ± 5.7. Importantly, 85/113 (75%) of TT4 values were lower than the normal laboratory reference range (17–37). TSH concentrations (ng/mL) ranged from 0.05 to 5.37, with a median of 0.16 and a mean ± SD of 0.3 ± 0.6.
Conclusions Basenji have a similar reference range for serum TSH, but a considerably lower reference range for TT4 (2–27 nmol/L) than most breeds and crossbreds, resembling the sight hounds in this respect. Given the difficulty of accurately measuring TT4 concentrations that are so low, concomitant serial TSH determinations are essential to properly asses thyroid function. Taken alone, TT4 determinations are only of use when the value is within the reference range, in which case a diagnosis of hypothyroidism is likely excluded.
C. W. Emala, J. Clancy and C. A. Hirshman
Department of Anesthesiology, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205, USA.
Corticosteroids upregulate the beta-adrenergic pathway, but ...little is known
about corticosteroid regulation of muscarinic pathways. Basenji-greyhound
(BG) dogs treated for 3 days with methylprednisolone (MPS) but not
deoxycorticosterone (DOC) had decreased numbers of muscarinic receptors in
airway smooth muscle homogenates as determined by radioligand binding with
1-3Hquinuclidinyl benzilate (vehicle control, 578 +/- 53 fmol/mg protein;
MPS, 290 +/- 22 fmol/mg protein; DOC, 565 +/- 141 fmol/mg protein).
Competition radioligand binding with the M2-selective antagonist
tripitramine showed a decrease in both the M2 and M3 muscarinic receptors
with no changes in receptor affinities (M2: vehicle control, 478 +/- 41
fmol/mg protein; MPS, 265 +/- 20 fmol/mg protein, M3: vehicle control, 89
+/- 13 fmol/mg protein; MPS, 25 +/- 16 fmol/mg protein). In vitro treatment
of airway smooth muscle from control BG dogs with MPS had no effect on
muscarinic receptor number, despite increased expression of beta-adrenergic
receptors. Thus glucocorticoids indirectly decrease the expression of M2
and M3 muscarinic receptors in airway smooth muscle, which, in part, may
account for their beneficial effects in the treatment of asthma.
Mononuclear leukocytes (MNLs) have been used as a model of β-adrenergic responsiveness of airway smooth muscle, but the relevance of this model remains controversial. The basenji greyhound (BG) dog ...model of airway hyperresponsiveness shares some features with human asthma, and airway smooth muscle shows a selective impairment in isoproterenol-stimulated adenylyl cyclase activity. In this study, MNL membranes were obtained from these same dogs, and the β-adrenergic receptor–adenylyl cyclase cascade function was compared with that in airway smooth muscle. β-Adrenergic receptor numbers and affinities for iodine 125–cyanopindolol were similar in the two dog groups (receptor numbers B
max = 441 ± 101 and 447 ± 61 fmol/mg protein and dissociation constant K
d = 269 ± 44 and 312 ± 60 pmol/L for mongrel and BG MNLs, respectively). Quantities of the G
sα protein were not different in the membranes as determined by immunoblotting. Stimulation of adenylyl cyclase by isoproterenol (100 μmol/L) was impaired in MNL membranes of BG membranes (22% ± 4% increase over guanosine triphosphate 10 μmol/L) compared with mongrel membranes (47% ± 8.6% increase over guanosine triphosphate 10 μmol/L,
p < 0.05). Stimulation of adenylyl cyclase by prostaglandin E
1 (10 μmol/L), NaF (10 mmol/L), or forskolin (10 μmol/L) did not differ in membranes from the two groups. No difference was found in the lymphocyte subsets in the two groups as determined by flow cytometry. These findings are qualitatively similar to studies of trachealis muscle membranes from these same dogs. We have found a selective impairment of isoproterenol stimulation of adenylyl cyclase in membranes prepared from MNLs of the BG dog, which was previously found in airway smooth muscle membranes despite no decrease in numbers of β-adrenergic receptors. (J A
LLERGY C
LIN I
MMUNOL 1995;95:860-7.)
The electrophoretic mobility and the immunologic specificity of erythrocyte pyruvate kinase (PK) of the homozygous Basenji dog with PK deficiency were identical to those of normal M2-type PK isozyme ...seen in the white cell but not to those of the erythrocyte PK isozyme. Kinetic properties and stability were also consistent with the M2-type PK isozyme. Defective PK in the homozygous red cell was due to the absence of the erythrocyte PK isozyme and the compensatory presence of M2-type PK isozyme, as seen in the severe classical type PK deficiency in man.
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