Look Out the Bugs are Coming!

By Scott Sims, DVM

Of the roughly 3.5 million species of animals on earth all but a hundred thousand or so are insects. To give you an idea of how dominant the bugs are-… according to the book “Ants” if you were to weigh all the animals on earth roughly 20% of the total weight would be comprised of just the ants … and it takes one heck of a lot of ants to equal the weight of just one elephant. It’s no wonder that when spring comes and the warmer temperatures really get the bugs reproducing faster, our animal friends start having more problems with bug related issues.

There are of course the allergies that we and our pets have to biting arthropods. Antigens are often foreign proteins that react. This is a normal activity and it protects us and our animals from most infections. In our example the saliva from the fleas is the antigen. In our example the saliva from the flea is the antigen. But when the immune system over-reacts this causes what we call an allergic reaction. For example when a flea bites a dog the normal reaction would when the immune system be for the dogs immune system of the animal over-reacts is to do very little. There might be no reaction at all or there might be a small raised lump that would go away in a day or two and that would be the end of things.

But in an allergic animal the immune system might release lots of substances (histamine, interleukins and cytokines just to name a few) and the resulting tissue reactions could cause major hair loss events, excessive itching, redness, swellings or even anaphylaxis and death.

There are lots of ways to slow or stop this process if present. The best way is to limit the exposure to the offending allergen. Flea control products (Advantage, trifexis, comfortis, frontline and a variety of insect repellents) all help reduce the number of fleas that bite your pet.

Antihistamines, anti-inflammatories and cortisones all interfere with the allergic reaction by inhibiting some portion of the allergic metabolic pathway. If your pet is scratching get him/her some relief. Think how horrible it must be to be itching all the time. This is in my opinion a real quality of life issue.

There are lots of problems caused by biting arthropeds other than the bite and the possible allergic reaction to it. Continuing on with our flea example there is tapeworm infestation. Tapeworms live in the intestine of our pet and sometimes you.) They have a life cycle that involves fleas. The way your dog or cat gets tapeworms is by inadvertently eating a flea when they are licking themselves in response to the itching caused by the flea’s bite. Heartworms are transmitted from host to host by mosquitoes. There are lots of other examples.