Last week, I was invited at the annual Breeder Convention held by Royal Canin Mexico. It was my third time in Mexico City. As usual, it was great! I had the opportunity to speak in front of 200+ passionate canine breeders about one of our current favorite topic: gastro-intestinal parasites in breeding kennels. Always a good way to remind everybody that, unfortunately, parasite-free dogs –especially in breeding kennels- might always be a myth.
Do you think you have GI parasites in your kennel? This is a question I like to ask to our canine breeder partners. And I am always surprised about the variety of answers we can get! I think everything comes back to this initial assumption: “I don’t see any of them, so that’s evidence there are no parasites in my kennel.” Unfortunately, this is far from being true… A recent study highlighted the fact that while GI parasitic infestation was only visible in very rare occasions (0.6% of the puppies), in fact more in-depth analyses detected parasites in 94.3% of them (study performed on 316 puppies in France). They are definitely among us: for canine breeders, it means they definitely need to be prepared!
“A host-parasite relationship is only successful in evolution if both produce progeny. A dead host is a poor host”. This citation from Darwin gives us a better understanding on why these parasites are so well-established in our breeding kennels. Over time they indeed developed effective strategies in order to survive despite of their hosts’ (=our dogs) immune system:
– They can hide from the immune system (what we call “hypobiosis”) of immunocompetent adults and wait for a more favorable moment to reactivate themselves and start over their reproductive cycle. While they’re in such a hiding, they cannot be destroyed by any medical treatment. Reactivation typically occurs during heats/pregnancy/lactation in the bitch (because of a decrease of the efficiency of the immune system related to sex hormones).
– Their eggs are extremely resistant in the outside environment (eggs of Trichuris vulpis can survive up to 5 years!)
– They have several ways to pass from infected adults onto puppies, including transplacental and through milk during lactation.
Fig 1: How Toxocara canis (aka ascaris) can be transmitted from adult to puppies
Therefore when you breed dogs, somehow you also inevitably breed parasites at the same time.The three most common parasites found in breeding kennels are Toxocara sp (aka ascaris), Giardia spand Isospora sp (aka coccidia). On the following graph, you can have an idea of the percentage of dogs that usually host these parasites. When it comes to a breeding kennel however, these numbers nearly reach 100% anytime!
Fig 2: Prevalence of most common gastro-intestinal parasites found in individual dogs.