Littermate Syndrome: understanding and preventing dog sibling issues

Littermate Syndrome is a complex behavioural problem that occurs when an owner adopts two or more dogs from the same litter. It's a dependency issue where one or both dogs become overly dependent on each other, leading to a loss of confidence, behaviour challenges and stress. As an owner, Littermate Syndrome can put a lot of emotional and mental strain on you; it's hard to deal with, so please reach out for help if you need it. But it isn't an untreatable condition. Here, we discuss what Littermate Syndrome is, how to manage it and when you should seek professional help. What's Littermate Syndrome? Littermate Syndrome is a term for when two dogs raised together begin to encounter behavioural problems. Other names for it include "dog sibling syndrome" or "litter syndrome in dogs". It typically occurs when two puppies raised together from the same litter begin to encounter behavioural issues at the same time. It happens because they become dependent on each other. It isn't a formal veterinary diagnosis; it's more a term to explain a recognised pattern of behaviour. Raising multiple puppies from the same litter doesn't guarantee this condition will happen, but there is a great chance. Symptoms of Littermate Syndrome Littermate Syndrome usually results in behavioural problems. It's important to know that the condition and symptoms exist as a spectrum - some symptoms will be mild, while others can get severe. Examples include: Aggression Puppies may become more aggressive, especially towards humans and other dogs that aren't their littermates. Difficulty forming bonds They may find it hard to form bonds with humans and other dogs, but instead prefer to spend time with their littermates. Excessive dependence Littermate Syndrome puppies become extremely dependent on each other and their owners. Excessive fear Dogs may struggle with confidence, meeting other pets or humans and typically meet new experiences with fear. Leash problems Leash training a littermate dog is more difficult than normal as these dogs tend to be more reactive. Separation anxiety This is a key symptom of Littermate Syndrome. Read our separation anxiety guide to learn more about this complex condition. Training difficulties Training a littermate dog, even with positive reinforcement, is hard. These dogs may be slow to respond to training or struggle to learn new things. What causes Littermate Syndrome? Littermate Syndrome is a difficult condition that comes from an oddly heart-warming place: puppies forming close bonds. But these bonds are too close; it isn't just about liking each other, both puppies are unable to function independently. When they're alone, they lose all sense of confidence and calm. It's formed due to early experiences in their litter. Puppies become too reliant on each other or lack individual training and attention, leading to a lack of confidence and a fearful nature. Puppies who experience too much resource guarding (puppies competing for attention or food) can develop aggressive behaviour, too. So, it's a mix of being dependent on a sibling and stress due to competition. It's why socialising puppies separately is essential. Some breeds and temperaments are more prone to Littermate Syndrome, too. Breeds prone to Littermate Syndrome But remember that any breed can suffer from Littermate Syndrome under the right conditions. Temperament plays a part, but it's only a small factor. At what age is Littermate Syndrome most common? Littermate Syndrome is likely to happen at around 10-weeks-old, but can happen slightly before or after. It typically starts when a puppy is brought to a new home and is away from their litter. Puppies who have been properly socialised won't normally experience this, but with large litters, it's easy for breeders to miss one or two pups. How to prevent Littermate Syndrome in dogs Preventing Littermate Syndrome primarily comes down to proper training, socialisation, lots of walks and plenty of playtime. Generally, it's best not to raise two puppies of the same litter together. But we understand that, sometimes, this isn't possible. Some key strategies include: How to socialise Littermate dogs Both socialising and training need to follow structured separation - keeping both dogs apart but in a sensible way. There needs to be a plan behind the separation, with socialisation and training. To socialise them, separate both dogs when possible and, when separated, follow socialisation training , which is gently introducing them to new people and dogs while positively reinforcing good behaviour. Never punish or negatively reinforce either dog if things don't go according to plan; this will just make their symptoms worse. Generally, you should: Feed them separately This is to prevent food-related aggression and resource guarding. But it also allows you to perform food-based training and form good habits around mealtime. Introduce them to new people and dogs separately Take them to dog parks, out for walks and with any friend's dogs for socialisation. Do this slowly and with care, and follow good socialisation training principles, like stopping training if your puppy becomes too stressed. Teaching them basic training separately Follow basic training separately; training them together isn't possible and can cause problems. Forming positive, fun experiences separately Take them on separate walks, play separately and form strong bonds with them separately. Over time, this can improve their mental health and independence. Independent time Allow them to have time alone. Follow separation anxiety training for this. How to train Littermate dogs separately Training is about first creating separate routines and then incorporating training into those routines. So, follow the socialisation steps above, but then, as part of this separate time, start training. It's helpful to have multiple people do this, as it's quite time-intensive. You can do training like: Our guide on positive reinforcement training can help. Positive training is essential to build your puppy's confidence. Remember: be patient, be consistent and reach out for help if you need. Managing Littermate Syndrome With careful management, diligent training and a lot of patience, you can manage and treat Littermate Syndrome. It's a long-term process of counter-conditioning, positively reinforcing the right behaviours and fostering independence. It's about giving both dogs an opportunity to form their own individual experiences without the other; it's why the separate socialisation and training sessions are so essential. These things take time, and consistency is the key. There's a potential your dogs may face lifelong challenges and may always be slightly dependent on each other. But ongoing management and attention can keep symptoms mild and infrequent. Eventually, your dogs will become less dependent on one another and will become confident, individual dogs instead of co-dependent siblings. But if you can't manage to decouple their dependence, don't panic - Littermate Syndrome is hard to manage and treat on your own. If you're struggling, be sure to ask your vet or a qualified behaviourist for help. When to see a vet or behaviourist You should see your vet if one or both dogs experience: Early intervention for these symptoms and Littermate Syndrome generally is important. But there is a difference between behaviourists and vets. While your vet can rule out medical issues and could refer you to a behaviourist, they provide different types of help. Our dog insurance can help provide behaviour cover as long as your vet refers it (terms apply).

Littermate Syndrome: understanding and preventing dog sibling issues

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