Corrected on all counts first bassert are more social that the average dog and need social contact It is one reson most basset owner do not have a single dog they generally do better with a companion when no humans are around. That said simply addding another dog, cat etc is not always the answer some time it makes the problem twice as bad.
There is no clear definining line when this needyness becomes an anxiety but if the behavior it troublesome then it is likely reach the anxiety stage
some thing that help
1. down play greeting and departures. Make sure the dog is calm an quite before axknowledging it when coming home
2. thin about thge triggers most dogs start to get anxious before you even leave like pick up the keys etc
3. practice departure very short seconds at the most slowly increasing the time.
4. Medicate in the more sever case it is virtually impossible to modify the behavior without antianxiety medication
5. seek professional help you will need a vet for a perscription and a certified applied animal behaviorist to work on the behavior the other option is a number of vets are board certified behaviors ie veterinary behaviorist and can do both.
eperation Anxiety
Separation anxiety is often triggered by either a high contrast situation – months of the owner home all day followed by sudden eight-hour absences – or some sort of life change – rehoming, a stay at a boarding kennel, a death of a key family member or major change in routine.
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In severe cases, the informal interventions above will usually not help. What’s needed is a formal program of
systematic desensitization to change the dog’s deeply ingrained emotional reaction to departure. The track record of systematic desensitization is excellent for resolving separation anxiety, however it is a huge amount of work for the dog’s caregiver!
The key is to observe the dog for the first signs of anxiety during the owner’s usual ritual prior to leaving the house. Most dogs with severe separation anxiety start becoming anxious before the owner leaves. They have learned the "picture" associated with imminent departure and begin panting, pacing, salivating, whining or hiding.
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Once the kick-off point of the pre-departure anxiety is found, treatment begins by repeatedly commencing the ritual at this point but not adding the subsequent steps or leaving, to teach the dog to relax in the presence of the cues that formerly triggered anxiety. Once the dog is relaxed, subsequent steps in the ritual leading up to departure and, finally, real absences are gradually introduced, always contingent on the dog’s continued relaxation. The dog is then, over time, worked back up to normal length absences. The hard part for the owner is that, for the duration of this treatment, the dog cannot experience absences in day to day life that are longer than the point he has reached in treatment exercises. This means essentially that, early on in treatment, the dog cannot be left alone