Is chocolate poisonous to dogs?
When a dog eats chocolate, it is possible that the dog can get very sick and need to see the vet! Sometimes, however, depending on the type of chocolate, the amount eaten and the size of the dog, only mild symptoms are seen.  Some dogs have have vomiting and diarrhea, but some have had more serious symptoms like tremors, seizures and even coma. Chocolate contains two substances that are toxic to dogs: theobromine and caffeine. Dogs metabolize these items much slower than people do. Both theobromine and caffeine are stimulants to the central nervous system. If too much chocolate is ingested then the increased stimulus to the central nervous system can cause an increase in blood pressure and irregular heart rhythms and possibly even death!

What's in those Blood Tests
by Suzanne Stack, DVM

When your veterinarian sends your greyhound's blood to a lab he is most commonly asking the lab to run a CBC (Complete Blood Count). This common analysis covers these items:

• RBC = Red Blood Cells      • Hgb = Hemoglobin     • PCV / HCT = Packed Cell Volume/Hematocrit
• WBC = White Blood Cells    • Platelets

For a more in-depth look, usually to determine kidney/liver functions, the veterinarian may also ask for a "Chem Panel". This will give them information about:
• T.P. = Total Protein Globulin   • Creatinine     • T4 (Thyroid)

If you don't understand what your veterinarian has ordered, ask. 
        
Greyhound bloodwork has enough differences from "other dog" bloodwork to sometimes make it deceivingly "normal" or "abnormal" if one isn't familiar with these differences. The salient differences are discussed below.

Greyhounds:                        Other Breeds:
• RBC: 7.4-9.0                     • RBC: 5.5-8.5  
• Hgb: 19.0-21.5                  • Hgb: 12.0-18.0  
• PCV: 55-65                        • PCV: 37-55

Greyhounds have significantly more red blood cells than other breeds. This elevates parameters for RBC, hemoglobin, and PCV/HCT, and is the reason greyhounds are so desirable as blood donors. Most veterinarians are aware of this difference.

Never accept a diagnosis of polycythemia — a once-in-a-lifetime-rare diagnosis of pathologic red cell overproduction — in a greyhound.

Conversely, never interpret a greyhound PCV in the 30's-40's as being normal just because it is for other dogs. A greyhound with a PCV in the 30's-40's is an anemic greyhound. Here in Arizona, a greyhound PCV less than 50 is a red flag to check for Ehrlichia.

WBC
• Greyhound: 3.5-6.5         • Other dogs: 6.0-17.0

Other greyhound CBC changes are less well known. The greyhound's normally low WBC has caused more than one healthy greyhound to undergo a bone marrow biopsy in search of "cancer" or some other cause of the "low WBC."

 Platelets
• Greyhound: 80,000-200,000         • Other dogs: 150,000-400,000

Likewise, greyhound platelet numbers are lower on average than other breeds, which might be mistakenly interpreted as a problem. It is thought that greyhound WBCs, platelets, and total protein may be lower to physiologically "make room" in the bloodstream for the increased red cell load. Compounding these normally low WBC and platelet numbers is the fact that Ehrlichia, a common blood parasite of greyhounds, can lower WBC and platelet counts. So if there is any doubt as to whether the WBC / platelet counts are normal, an Ehrlichia titer is always in order. The other classic changes with Ehrlichia are lowered PCV and elevated total protein. But bear in mind that every greyhound will not have every change, and Ehrlichia greyhounds can have normal CBCs.

T.P. & Globulin
• Greyhound TP: 4.5-6.                      • Other dog TP: 5.4-7.8
• Greyhound Globulin: 2.1-3.2          • Other dog Globulin: 2.8-4.2

Greyhound total proteins tend to run on the low end of normal — T.P.s in the 5.0's and 6.0's are the norm. While the albumin fraction of T.P. is the same as other dogs, the globulin component is lower.

Creatinine
• Greyhound: .8-1.6
• Other dogs: .0-1.0

Greyhound creatinine runs higher than other breeds as a function of their large lean muscle mass. A study at the Auburn University College of Veterinary Medicine found that 80% of retired greyhounds they sampled had creatinine values above the standard reference range for "other dogs." As a lone finding, an "elevated creatinine" is not indicative of impending kidney failure. If the BUN and urinalysis are normal, so is the "elevated" creatinine.

T4
• Greyhound: .5-3.6 (mean 1.47+/- .63)
• Other dogs: 1.52-3.60

These figures are from a University of Florida study of thyroid function in 221 greyhounds — 97 racers, 99 broods, and 25 studs — so it included both racers and "retired." While greyhound thyroid levels are a whole chapter unto themselves, a good rule of thumb is that greyhound T4s run about half that of other breeds.