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Bovine TB and Mad Cow Disease: What a Washington Cattle Owner Actually Needs to Know
When a cow dies without warning, two diseases tend to come up first, because they're the two with famous names. Here's the honest picture on both — including why they're almost certainly not what happened, and why Washington's disposal law still treats your animal as though disease were the cause until someone proves otherwise.
They're Two Completely Different Diseases
People use these interchangeably and they have almost nothing in common beyond affecting cattle.
- Bovine tuberculosis is a bacterial disease caused by Mycobacterium bovis, a close relative of the bacterium behind human TB. It's contagious, it's chronic and slow, and it genuinely can infect people — a real zoonotic disease, not a theoretical one.
- BSE, or "mad cow disease," is a prion disease — a misfolded protein, like CWD in deer — that destroys the central nervous system. Critically, it isn't contagious at all. Cattle get it from eating prion-contaminated feed, not from each other.
That last distinction matters for how you think about a death in your herd. A contagious bacterial disease raises an obvious question about the rest of your animals. A feed-borne prion disease doesn't spread cow to cow the way people assume it does.
Washington's Actual Bovine TB Status: Accredited Free
This is the number that should settle most of the worry. Washington holds USDA accredited-free status for bovine tuberculosis — the highest tier a state can hold under the federal eradication program. That designation isn't a participation trophy. Under federal rule, an accredited-free state must have zero percent prevalence of affected cattle and bison herds and no findings of tuberculosis in any cattle or bison herd in the state for the previous five years, and it has to re-certify annually with APHIS to keep it.
So if you're standing in a pasture wondering whether your cow had TB: statistically, in this state, almost certainly not. Washington still maintains real testing requirements for cattle movement under WAC 16-54-085 and the broader cattle and bison disease rules in chapter 16-86 WAC — the status is maintained by that surveillance, not in spite of it.
And Mad Cow? Rarer Still
BSE is vanishingly rare in the United States, and the human connection people remember — variant Creutzfeldt-Jakob disease, first identified in the UK in 1995 and linked to eating products from BSE-infected cattle — came out of a British epidemic driven by feed practices that have since been prohibited. The feed ban is the reason the disease collapsed. It is not a realistic explanation for a single unexplained death on a Washington small holding.
So Why Is the Disposal Law So Strict?
Here's the part that ties this to everything else I write about, and it's the genuinely interesting answer. Washington law (RCW 16.36.102) presumes that any livestock found dead of an unknown cause died of disease, unless proven otherwise. Not "may have." Presumes.
That presumption is why WAC 16-25-025's burial requirements are as demanding as they are — five acres minimum, 300 feet from wells, water, and neighboring homes, three feet of cover, an annual cap on how much of your land you can use. The rule is written around a worst-case animal, not an average one, and it applies identically to cattle, llamas, goats, and sheep, not just horses.
Both things are true at once, and I think that's worth saying plainly: the realistic odds that your specific cow had a famous reportable disease are very low, and the law will still treat the carcass as though it might have. Those aren't in conflict. The strictness exists precisely because nobody can tell by looking — which is also the honest case for a necropsy if a death is genuinely unexplained and you want a real answer rather than a guess.
What Actually Kills Cattle More Often
I'm a removal service, not a veterinarian, and I'm not going to pretend to diagnose from a photo. But the pattern I see is ordinary rather than exotic: bloat, hardware disease, calving complications, poisonous plants, a lightning strike, or simple age. For a bovine-specific disease that genuinely does circulate here, the more relevant one is bluetongue — the same Culicoides-gnat-borne virus behind the EHD outbreaks in Washington deer, and unlike EHD it affects livestock too. Your vet is the right call for a cause of death; I'm the right call for what happens next.
Frequently Asked Questions
What is bovine tuberculosis? A chronic, contagious bacterial disease caused by Mycobacterium bovis, closely related to human TB. It can infect people, which is why eradication programs exist.
Is there bovine TB in Washington state? Washington holds USDA accredited-free status, meaning zero prevalence of affected cattle and bison herds and no findings in any herd in the state for the previous five years, re-certified annually.
Is mad cow disease the same as bovine TB? No. BSE is a non-contagious prion disease acquired through contaminated feed; bovine TB is a contagious bacterial infection. Different causes, different transmission, different risks.
Is mad cow disease a virus? No — it's caused by a prion, a misfolded protein, which is why it isn't killed by the methods that destroy bacteria and viruses.
If disease is unlikely, why are the burial rules so strict? Because RCW 16.36.102 presumes any livestock found dead of unknown cause died of disease until proven otherwise. The rules are built around the worst case, not the likely one.
Lost an animal and need it handled properly, whatever the cause? Call or text (253) 905-2220 or request a quote — I handle cattle, horses, llamas, goats, and sheep, and I coordinate with your vet's timing when a necropsy is part of the picture.
Sources: USDA APHIS (Bovine Tuberculosis Eradication Uniform Methods and Rules; accredited-free state criteria under 9 CFR Part 77), FDA (BSE questions and answers), Washington Administrative Code 16-54-085 and chapter 16-86 WAC, Revised Code of Washington 16.36.102, Washington Administrative Code 16-25-025, Washington Department of Fish and Wildlife (bluetongue in livestock).