Several differences were noted between GHs and other breeds of dogs, to include:

1. GHs have a higher PCV (packed-cell volume) -- a PCV of 50 to  65% is not unusual.
2. GHs have a lower serum total protein concentration.
3. GHs have a lower serum albumin concentration.
4. GHs have higher RBC (red blood cell) indices.
5. A low WBC (white blood cell) count is reported to be normal in  GHs.
6. GHs are more susceptible to hyperthermia.
7. GHs may have a larger heart and slower pulse rate.

The danger in using barbiturates as sedatives or anesthesia with GHs is  manifested as a "delayed drug metabolism, with prolonged anesthesia  and a prolonged excitement phase of recovery." Although I had heard it  said that the GH's extra lean body mass (meaning less fatty tissue) was  the reason they were less tolerant of these drugs, this article stated that  the problem is more a lack in the GH's liver of the oxidative enzymes  that are needed to metabolize the drugs.

Several vets provided details on their preferred use of anesthetic agents --  I decided to provide more detail here with direct quotes for clarity and  accuracy. Might be useful information to print out and give to your vet:

Dr. Robert A. Taylor, director of Alameda East Veterinary Hospital and the  Canine Sportsmedicine Clinic in Denver, Colorado:

His preference is to use "glycopyrrolate as preanesthetic medication,  inducing anesthesia with ketamine and diazepam, and maintaining  dogs on isoflurane."

Dr. Frank R. Jordan, co-owner of Abilene Animal Hospital in Abilene, Kan.:

"We use xylazine at a dosage of 0.5 mg/lb, ketamine at 2.5 mg/lb,  and atropine at 0.01 mg/lb, IV, for short procedures or for induction  prior to maintenance with gas anesthesia. When indicated, I will  substitute diazepam for the xylazine. I prefer to use halothane rather than isoflurane anesthesia for orthopedic procedures because I prefer  the slower recovery time."

Dr. Larry G. Dee (the one Paul Byther refers everyone to), co-owner of  Hollywood Animal Hospital in Hollywood, Fla.:

"We induce anesthesia by using 50 mg of ketamine HCl, 0.5 mg of  atropine, and 10 mg of xylazine, followed by 6 to 10 ml of 2%  thiamylal or thiopental sodium for the average 30-kg racing GH.  Alternatively, we may use oxymorphone and a small amount of  acepromazine as a preanesthetic agent. We then administer gas  with a mask or administer just enough thiopental or pentothal so  the dog can be intubated."

A related discussion was on the post-operative problems of hyperthermia  and postanesthetic excitement. Treatment protocols consisted of:

1. Careful monitoring of vital signs -- may include use of an  esophageal temperature probe and esophageal stethoscope  or monitoring with a capnograph (measures end-tidal CO2)  and/or pulse oximeter to check oxygen saturation.
2. Administration of IV fluids (e.g., lactated Ringer's solution).
3. Feeding the dog as soon as possible after recovery from  anesthesia.
4. Occasionally, the use of mild postoperative sedatives (such as  diazepam, oxymorphone, or acepromazine) is needed.

I found it interesting that Dr. Bradley W. Fenwick, a pathologist and  immunologist at Kansas State University [See Haemorrhagic Diarrhea, Dogs - USA (2)] , was quoted as saying, "Greyhounds may be difficult to assess clinically when hospitalized.  Unlike most pet dogs, Greyhounds are comfortable being kenneled, and  they tend to go to sleep. Unless you are used to seeing that, you might  think the dog was depressed."

Dr. Fenwick also contends that research at KSU indicates there is no  support for the theory that GHs have a greater tendency toward immune  deficiencies. However, several vets noted that they do come from a  high-stress environment, which leads to an increase in cortisol  production. Chronically higher levels of cortisol have been implicated  in a suppression of the immune system.

The tick-borne diseases, Babesia and Ehrlichia, were mentioned as  being a common problem in some areas. Additionally, internal parasites,  such as worms, appear to be more resistant in GHs than other breeds.  KSU is reportedly looking into this issue. Cancer in elderly GHs is  sometimes diagnosed, with osteosarcoma in the proximal portion of the  humerus the most frequent variety. Cryptorchidism (failure of one or both  testicles to descend) is also not unusual in GHs and the examining vet  should be aware that what they are seeing is not necessarily a neutered  male, but a bilateral cryptorchid.

Regarding the ever-controversial hypothyroidism -- several vets advised  that hair loss alone does not mean the dog is hypothyroid and that "a  muted response to thyroid function tests may be normal."

Common injuries seen on physical examination of the retired racer  include:

1. Central tarsal bone fractures.
2. Accessory carpal bone ("stopper bone") fractures.
3. Metacarpal or metatarsal ("quarter bones") fractures.
4. Toe injuries.
5. Tears of the gracilis muscle and long head of the triceps  ("monkey muscle").

Dr. Dee noted that it is worthwhile to try and find out why the GH was  retired -- whether the problem was lack of speed or a career-ending  injury. Degenerative joint disease and chronic hock arthritis may be  latent problems associated with such injuries.

Finally, the vets commented that GHs are amazingly healthy, very  friendly, gentle, intelligent dogs who don't need require nearly as  much exercise as one might expect. But then, they aren't telling us  something we don't already know!