At your child’s or grandchild’s school, a pupil has head lice. Would you be happy with advice that all children be treated monthly with a preventative chemical that kills head lice? If you were happy to do that, would you continue this monthly prevention if you knew the chemical in the shampoo is banned in the EU because it’s harmful to wildlife such as honey bees and amphibia?
Another child at the school has pinworms. Are you content, without checking whether or not your child also has pinworms, to preventatively give your child a monthly tablet that kills pinworms, and most other parasites that might live in human intestines throughout the world?
If you have concerns with either of these situations, shouldn’t we also question the monthly use of parasite prevention in cats and dogs? Parasite numbers are lowest during the depths of winter but are now increasing so let’s discuss risk and prevention.
Many vet clinics have Health Care Plans that include monthly treatment for internal and external parasites. We never have because risk varies according to the time of year but also by how a pet lives. An indoor cat has a very low risk of fleas while a free ranging outdoor one has a high risk now that the weather makes roaming and feline demarcation disputes more likely. A small dog buddy with a satisfying life visiting Caffè Neros in Central London has a low risk of parasites while the same small dog chasing wildlife in a Sussex woods has a high risk.
It is seven years since the vet Rosemary Perkins at the University of Sussex found that chemicals (called fipronil and imidacloprid) used in many topical flea treatments, are widespread in our waterways. Rosemary observed that these chemicals are at their highest level downstream from sewage works. We wash our dogs and unwittingly put frogs at risk! Recently she published another report revealing that dogs leave these chemicals where they go swimming.
When we see you with your cat or dog for his or her annual health check our approach is “Do no harm.” both to your buddy and to the environment. We don’t use spot-ons for dogs (unless they are going abroad and foreign regulations demand it). The spot-on drug we use for outdoor cats (Bravecto) has passed an environmental impact assessment as it is used to prevent mites in poultry.
For dogs with a low risk of external parasites we don’t recommend monthly treatment but when we do treat for external parasites we use a tablet, usually Bravecto or Nexgard. For internal parasites we suggest milbemycin as infrequently as is needed. Dogs that go abroad are given praziquantel before returning to the UK, to eliminate the risk of their introducing certain types of tapeworms into the UK environment.
If you are worried about even once yearly treatment for internal parasites, we do faecal exams then treat as needed. Last comment. At York Street we set aside time for ‘clinical reviews’ where for an hour all of us discuss a single subject. At one clinical review we asked, “How many pets do you see that are sick due to the parasites they carry?” Other than dogs with imported parasites from outside the UK, we were not surprised to learn that clinical illnesses caused by UK parasites is very rare.