Hi Donna,
Sorry not to have responded to your posting before now. I've been away for a couple of days.
The first thing we can do is almost certainly rule out any copyright infringement. From what you have told us, it is fairly unlikely that collars for dogs would qualify as 'works of artistic craftsmanship'. I say this with some confidence following a case from a few years ago (known as
Lucasfilm v Ainsworth) which established that articles whose purpose is largely practical in nature would need a good deal of artistic merit beyond just the skill of a half decent leather worker, to qualify.
So that's the good news.
Unfortunately if the other design has been registered, any design such as yours which does not produce a
different overall impression on an informed user, may well infringe the registered design, if it is made (other than for purely private purposes), offered for sale, marketed or exported without permission of the registered owner of the original design. Design right is a monopoly right so it doesn't matter if you produced your design independently.
However there are some caveats. Firstly if the purpose for which the article is made can only be met by designing a product in
a particular way, then the validity of the original design may be challenged. It could also be challenged on the grounds that the registered design
lacked novelty at the time of registration, that is to say products of a similar design were already on the market. By way of an example,
here's a pdf of a Hearing Officer's decision concerning a claim of invalidity for the registration of a design for a dog lead, to give you an insight into how these decisions are reached.
And finally, registered design right only lasts for a relatively short period (compared to copyright). There are two types of registered design: ones made under the UK's
Registered Designs Act 1949 (RDA), and those made under the auspices of European Union regulations which are known as
Registered Community Design (RCD). In both cases the maximum period of protection is 25 years but registration must be renewed every 5 years or the protection lapses. If this French person used the European version, RCD, then this will also show up on the IPO website, with an EU reference number. There are a couple of differences, the main one being that under the UK system 'innocent' infringement (ie where you were completely unaware that the other design was registered) whilst infringement may be proved, the remedies available the registered owner do not include an entitlement to damages, and the only action he can ask the court to take is an order to prevent you from selling your design (an injunction) and an order for the seizure/destruction of any existing stock. Unfortunately this provision does not apply in the case of a RCD. The second difference is that, if the UK registration has lapsed because it was not renewed on time, under the UK law any threat to sue you may itself be actionable under
section 26(1) of the RDA. This would not apply to a RCD which had lapsed.
So the first thing to do is go back the the IPO website and check what type of registered design is involved, and secondly whether the original registration has been correctly renewed. Depending on the answers to these two questions, you will probably know if you face any risk of being sued and thus whether you may need to come to a settlement with the complainant, assuming that they are the actual owner of the registered design. If they merely have a licence from the design owner, they are unlikely to have the right to bring a claim against you (there could have been some assignment of rights, so don't take this as being an invariable rule!).