An entomologist and veterinarian discuss the unremitting mosquito.

While much of the Western half of the United States endures near historic drought levels, one might anticipate this year’s mosquito season to be a walk in the park.

No Rain, No Problem for Mosquitoes

“Just because we don’t have rain, doesn’t mean we don’t have mosquitoes,” explains Department Head for Entomology and Plant Pathology at Oklahoma State University, and former livestock entomologist, Justin Talley, PhD. “Some of the most significant West Nile virus outbreak years have been associated without significant rainfall. Be aware, just because you don’t see water, doesn’t mean there are no breeding areas around.”

Dr. Talley shared how the Culex mosquito, which is responsible for transmitting core equine diseases such as West Nile virus (WNV), can populate in the most unsuspecting places. Standing, puddling water is not needed. “One would think that wet years equal more equine West Nile virus cases; however, the type of mosquitoes transmitting these equine diseases can develop in muddy water or a storm drain. There’s a lot of water you don’t see.”

Even a tiny hole in a tree – with just a bit of water – is enough for the Culex mosquito to repopulate within.

“The thing about mosquitoes is they’re very diverse in the habitat they can modify to, and it’s their adaptive behaviors that allow them to be successful,” Dr. Talley said.

Read more: Mosquitoes Undeterred by Drought – 4 Tips to Protect Your Horse

I've written about soil, sulfur and Methionine deficiency often. But everything I see says it's getting worse. - Dr. Eleanor Kellon, Staff Veterinary Specialist for Uckele Health & Nutrition

Methionine is an essential amino acid, meaning horses must get it from their diet. It is critical in protein synthesis since many proteins start with methionine and without it synthesis will stop.

Methionine is the king of the sulfur-containing amino acids which give strength to hair, hoof horn, skin and tendons/ligaments. It is the precursor for SAM-e, a mood stabilizer, and the major antioxidant glutathione.

Methionine is a methyl donor required for the synthesis of L-creatine and L-carnosine. These compounds are critical to muscle function and athletic performance.

Soybean, peas and beet pulp are poor methionine sources. Historically, grains, brans and other seed meals were adequate sources. Hays easily met the 0.2% sulfur content most authorities recommend to support production of good levels of sulfur-containing amino acids. This is changing.

I am increasingly seeing hay analyses with sulfur below 0.2%, even below 0.1%. This means soil levels are low so grains will also be affected. What’s going on?

Read more: An Equine Methionine Crisis is Brewing