Update 30 September 2020 for a similar judgment at the Belgian Constitutional Court, see here. This judgment engaged with A1P1 ECHR, as well as alleged discrimination, particularly viz dog therapists where use may be continued; and viz electric cattle prods. Re e-collars for dogs the point is made that the danger to the animal’s welfare lies with its inappropriate use by the owner, something which the drafters of the statute is not the case with farmers; I do not think that is a correct assumption). The legality of the device in other Member States was not discussed.
I tweeted the judgment the day it was issued, apologies for late succinct review. I wrote a few years back on the legality of use restrictions on goods lawfully marketed in other Member States, and see also my brief review of Amsterdam’s booze bikes here. In  EWHC 2813 (Admin) The Electronic Collar Manufacturers Association v Secretary of State for Environment, Food and Rural Affairs, Morris J upheld the UK Government’s ban on e-collars (a hand-held remote-controlled (not automated: a distinction that matters as Rosalind English points out) e-collar device for cats and dogs, used particularly in dogs for training purposes).
His analysis engages all the right issues in discussing the lawfulness of a ban at 204 ff under Article 34 TFEU (including consultation and commissioned research issues and of course proportionality), less focused than I would have expected perhaps on the fact that these items are lawfully marketed elsewhere in the EU, and indeed A1P1 (Article 1, first Protocol) ECHR. The remainder of the judgment discusses internal UK judicial review. An excellent primer on trade and animal welfare under EU and ECHR law.